1 //===--- ASTWriter.cpp - AST File Writer ------------------------*- C++ -*-===//
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 "ASTReaderInternals.h"
17 #include "MultiOnDiskHashTable.h"
18 #include "clang/AST/ASTContext.h"
19 #include "clang/AST/ASTUnresolvedSet.h"
20 #include "clang/AST/Decl.h"
21 #include "clang/AST/DeclContextInternals.h"
22 #include "clang/AST/DeclCXX.h"
23 #include "clang/AST/DeclFriend.h"
24 #include "clang/AST/DeclTemplate.h"
25 #include "clang/AST/Expr.h"
26 #include "clang/AST/ExprCXX.h"
27 #include "clang/AST/LambdaCapture.h"
28 #include "clang/AST/NestedNameSpecifier.h"
29 #include "clang/AST/RawCommentList.h"
30 #include "clang/AST/TemplateName.h"
31 #include "clang/AST/Type.h"
32 #include "clang/AST/TypeLocVisitor.h"
33 #include "clang/Basic/DiagnosticOptions.h"
34 #include "clang/Basic/FileManager.h"
35 #include "clang/Basic/FileSystemOptions.h"
36 #include "clang/Basic/LangOptions.h"
37 #include "clang/Basic/LLVM.h"
38 #include "clang/Basic/Module.h"
39 #include "clang/Basic/ObjCRuntime.h"
40 #include "clang/Basic/SourceManager.h"
41 #include "clang/Basic/SourceManagerInternals.h"
42 #include "clang/Basic/TargetInfo.h"
43 #include "clang/Basic/TargetOptions.h"
44 #include "clang/Basic/Version.h"
45 #include "clang/Basic/VersionTuple.h"
46 #include "clang/Lex/HeaderSearch.h"
47 #include "clang/Lex/HeaderSearchOptions.h"
48 #include "clang/Lex/MacroInfo.h"
49 #include "clang/Lex/ModuleMap.h"
50 #include "clang/Lex/PreprocessingRecord.h"
51 #include "clang/Lex/Preprocessor.h"
52 #include "clang/Lex/PreprocessorOptions.h"
53 #include "clang/Lex/Token.h"
54 #include "clang/Sema/IdentifierResolver.h"
55 #include "clang/Sema/ObjCMethodList.h"
56 #include "clang/Sema/Sema.h"
57 #include "clang/Sema/Weak.h"
58 #include "clang/Serialization/ASTReader.h"
59 #include "clang/Serialization/Module.h"
60 #include "clang/Serialization/ModuleFileExtension.h"
61 #include "clang/Serialization/SerializationDiagnostic.h"
62 #include "llvm/ADT/APFloat.h"
63 #include "llvm/ADT/APInt.h"
64 #include "llvm/ADT/Hashing.h"
65 #include "llvm/ADT/IntrusiveRefCntPtr.h"
66 #include "llvm/ADT/Optional.h"
67 #include "llvm/ADT/SmallSet.h"
68 #include "llvm/ADT/SmallString.h"
69 #include "llvm/ADT/STLExtras.h"
70 #include "llvm/ADT/StringExtras.h"
71 #include "llvm/Bitcode/BitCodes.h"
72 #include "llvm/Bitcode/BitstreamWriter.h"
73 #include "llvm/Support/Casting.h"
74 #include "llvm/Support/Compression.h"
75 #include "llvm/Support/EndianStream.h"
76 #include "llvm/Support/ErrorHandling.h"
77 #include "llvm/Support/MemoryBuffer.h"
78 #include "llvm/Support/OnDiskHashTable.h"
79 #include "llvm/Support/Path.h"
80 #include "llvm/Support/Process.h"
81 #include "llvm/Support/raw_ostream.h"
82 #include <algorithm>
83 #include <cassert>
84 #include <cstdint>
85 #include <cstdlib>
86 #include <cstring>
87 #include <deque>
88 #include <limits>
89 #include <new>
90 #include <tuple>
91 #include <utility>
92 
93 using namespace clang;
94 using namespace clang::serialization;
95 
96 template <typename T, typename Allocator>
97 static StringRef bytes(const std::vector<T, Allocator> &v) {
98   if (v.empty()) return StringRef();
99   return StringRef(reinterpret_cast<const char*>(&v[0]),
100                          sizeof(T) * v.size());
101 }
102 
103 template <typename T>
104 static StringRef bytes(const SmallVectorImpl<T> &v) {
105   return StringRef(reinterpret_cast<const char*>(v.data()),
106                          sizeof(T) * v.size());
107 }
108 
109 //===----------------------------------------------------------------------===//
110 // Type serialization
111 //===----------------------------------------------------------------------===//
112 
113 namespace clang {
114 
115   class ASTTypeWriter {
116     ASTWriter &Writer;
117     ASTRecordWriter Record;
118 
119     /// \brief Type code that corresponds to the record generated.
120     TypeCode Code;
121     /// \brief Abbreviation to use for the record, if any.
122     unsigned AbbrevToUse;
123 
124   public:
125     ASTTypeWriter(ASTWriter &Writer, ASTWriter::RecordDataImpl &Record)
126       : Writer(Writer), Record(Writer, Record), Code((TypeCode)0), AbbrevToUse(0) { }
127 
128     uint64_t Emit() {
129       return Record.Emit(Code, AbbrevToUse);
130     }
131 
132     void Visit(QualType T) {
133       if (T.hasLocalNonFastQualifiers()) {
134         Qualifiers Qs = T.getLocalQualifiers();
135         Record.AddTypeRef(T.getLocalUnqualifiedType());
136         Record.push_back(Qs.getAsOpaqueValue());
137         Code = TYPE_EXT_QUAL;
138         AbbrevToUse = Writer.TypeExtQualAbbrev;
139       } else {
140         switch (T->getTypeClass()) {
141           // For all of the concrete, non-dependent types, call the
142           // appropriate visitor function.
143 #define TYPE(Class, Base) \
144         case Type::Class: Visit##Class##Type(cast<Class##Type>(T)); break;
145 #define ABSTRACT_TYPE(Class, Base)
146 #include "clang/AST/TypeNodes.def"
147         }
148       }
149     }
150 
151     void VisitArrayType(const ArrayType *T);
152     void VisitFunctionType(const FunctionType *T);
153     void VisitTagType(const TagType *T);
154 
155 #define TYPE(Class, Base) void Visit##Class##Type(const Class##Type *T);
156 #define ABSTRACT_TYPE(Class, Base)
157 #include "clang/AST/TypeNodes.def"
158   };
159 
160 } // end namespace clang
161 
162 void ASTTypeWriter::VisitBuiltinType(const BuiltinType *T) {
163   llvm_unreachable("Built-in types are never serialized");
164 }
165 
166 void ASTTypeWriter::VisitComplexType(const ComplexType *T) {
167   Record.AddTypeRef(T->getElementType());
168   Code = TYPE_COMPLEX;
169 }
170 
171 void ASTTypeWriter::VisitPointerType(const PointerType *T) {
172   Record.AddTypeRef(T->getPointeeType());
173   Code = TYPE_POINTER;
174 }
175 
176 void ASTTypeWriter::VisitDecayedType(const DecayedType *T) {
177   Record.AddTypeRef(T->getOriginalType());
178   Code = TYPE_DECAYED;
179 }
180 
181 void ASTTypeWriter::VisitAdjustedType(const AdjustedType *T) {
182   Record.AddTypeRef(T->getOriginalType());
183   Record.AddTypeRef(T->getAdjustedType());
184   Code = TYPE_ADJUSTED;
185 }
186 
187 void ASTTypeWriter::VisitBlockPointerType(const BlockPointerType *T) {
188   Record.AddTypeRef(T->getPointeeType());
189   Code = TYPE_BLOCK_POINTER;
190 }
191 
192 void ASTTypeWriter::VisitLValueReferenceType(const LValueReferenceType *T) {
193   Record.AddTypeRef(T->getPointeeTypeAsWritten());
194   Record.push_back(T->isSpelledAsLValue());
195   Code = TYPE_LVALUE_REFERENCE;
196 }
197 
198 void ASTTypeWriter::VisitRValueReferenceType(const RValueReferenceType *T) {
199   Record.AddTypeRef(T->getPointeeTypeAsWritten());
200   Code = TYPE_RVALUE_REFERENCE;
201 }
202 
203 void ASTTypeWriter::VisitMemberPointerType(const MemberPointerType *T) {
204   Record.AddTypeRef(T->getPointeeType());
205   Record.AddTypeRef(QualType(T->getClass(), 0));
206   Code = TYPE_MEMBER_POINTER;
207 }
208 
209 void ASTTypeWriter::VisitArrayType(const ArrayType *T) {
210   Record.AddTypeRef(T->getElementType());
211   Record.push_back(T->getSizeModifier()); // FIXME: stable values
212   Record.push_back(T->getIndexTypeCVRQualifiers()); // FIXME: stable values
213 }
214 
215 void ASTTypeWriter::VisitConstantArrayType(const ConstantArrayType *T) {
216   VisitArrayType(T);
217   Record.AddAPInt(T->getSize());
218   Code = TYPE_CONSTANT_ARRAY;
219 }
220 
221 void ASTTypeWriter::VisitIncompleteArrayType(const IncompleteArrayType *T) {
222   VisitArrayType(T);
223   Code = TYPE_INCOMPLETE_ARRAY;
224 }
225 
226 void ASTTypeWriter::VisitVariableArrayType(const VariableArrayType *T) {
227   VisitArrayType(T);
228   Record.AddSourceLocation(T->getLBracketLoc());
229   Record.AddSourceLocation(T->getRBracketLoc());
230   Record.AddStmt(T->getSizeExpr());
231   Code = TYPE_VARIABLE_ARRAY;
232 }
233 
234 void ASTTypeWriter::VisitVectorType(const VectorType *T) {
235   Record.AddTypeRef(T->getElementType());
236   Record.push_back(T->getNumElements());
237   Record.push_back(T->getVectorKind());
238   Code = TYPE_VECTOR;
239 }
240 
241 void ASTTypeWriter::VisitExtVectorType(const ExtVectorType *T) {
242   VisitVectorType(T);
243   Code = TYPE_EXT_VECTOR;
244 }
245 
246 void ASTTypeWriter::VisitFunctionType(const FunctionType *T) {
247   Record.AddTypeRef(T->getReturnType());
248   FunctionType::ExtInfo C = T->getExtInfo();
249   Record.push_back(C.getNoReturn());
250   Record.push_back(C.getHasRegParm());
251   Record.push_back(C.getRegParm());
252   // FIXME: need to stabilize encoding of calling convention...
253   Record.push_back(C.getCC());
254   Record.push_back(C.getProducesResult());
255 
256   if (C.getHasRegParm() || C.getRegParm() || C.getProducesResult())
257     AbbrevToUse = 0;
258 }
259 
260 void ASTTypeWriter::VisitFunctionNoProtoType(const FunctionNoProtoType *T) {
261   VisitFunctionType(T);
262   Code = TYPE_FUNCTION_NO_PROTO;
263 }
264 
265 static void addExceptionSpec(const FunctionProtoType *T,
266                              ASTRecordWriter &Record) {
267   Record.push_back(T->getExceptionSpecType());
268   if (T->getExceptionSpecType() == EST_Dynamic) {
269     Record.push_back(T->getNumExceptions());
270     for (unsigned I = 0, N = T->getNumExceptions(); I != N; ++I)
271       Record.AddTypeRef(T->getExceptionType(I));
272   } else if (T->getExceptionSpecType() == EST_ComputedNoexcept) {
273     Record.AddStmt(T->getNoexceptExpr());
274   } else if (T->getExceptionSpecType() == EST_Uninstantiated) {
275     Record.AddDeclRef(T->getExceptionSpecDecl());
276     Record.AddDeclRef(T->getExceptionSpecTemplate());
277   } else if (T->getExceptionSpecType() == EST_Unevaluated) {
278     Record.AddDeclRef(T->getExceptionSpecDecl());
279   }
280 }
281 
282 void ASTTypeWriter::VisitFunctionProtoType(const FunctionProtoType *T) {
283   VisitFunctionType(T);
284 
285   Record.push_back(T->isVariadic());
286   Record.push_back(T->hasTrailingReturn());
287   Record.push_back(T->getTypeQuals());
288   Record.push_back(static_cast<unsigned>(T->getRefQualifier()));
289   addExceptionSpec(T, Record);
290 
291   Record.push_back(T->getNumParams());
292   for (unsigned I = 0, N = T->getNumParams(); I != N; ++I)
293     Record.AddTypeRef(T->getParamType(I));
294 
295   if (T->hasExtParameterInfos()) {
296     for (unsigned I = 0, N = T->getNumParams(); I != N; ++I)
297       Record.push_back(T->getExtParameterInfo(I).getOpaqueValue());
298   }
299 
300   if (T->isVariadic() || T->hasTrailingReturn() || T->getTypeQuals() ||
301       T->getRefQualifier() || T->getExceptionSpecType() != EST_None ||
302       T->hasExtParameterInfos())
303     AbbrevToUse = 0;
304 
305   Code = TYPE_FUNCTION_PROTO;
306 }
307 
308 void ASTTypeWriter::VisitUnresolvedUsingType(const UnresolvedUsingType *T) {
309   Record.AddDeclRef(T->getDecl());
310   Code = TYPE_UNRESOLVED_USING;
311 }
312 
313 void ASTTypeWriter::VisitTypedefType(const TypedefType *T) {
314   Record.AddDeclRef(T->getDecl());
315   assert(!T->isCanonicalUnqualified() && "Invalid typedef ?");
316   Record.AddTypeRef(T->getCanonicalTypeInternal());
317   Code = TYPE_TYPEDEF;
318 }
319 
320 void ASTTypeWriter::VisitTypeOfExprType(const TypeOfExprType *T) {
321   Record.AddStmt(T->getUnderlyingExpr());
322   Code = TYPE_TYPEOF_EXPR;
323 }
324 
325 void ASTTypeWriter::VisitTypeOfType(const TypeOfType *T) {
326   Record.AddTypeRef(T->getUnderlyingType());
327   Code = TYPE_TYPEOF;
328 }
329 
330 void ASTTypeWriter::VisitDecltypeType(const DecltypeType *T) {
331   Record.AddTypeRef(T->getUnderlyingType());
332   Record.AddStmt(T->getUnderlyingExpr());
333   Code = TYPE_DECLTYPE;
334 }
335 
336 void ASTTypeWriter::VisitUnaryTransformType(const UnaryTransformType *T) {
337   Record.AddTypeRef(T->getBaseType());
338   Record.AddTypeRef(T->getUnderlyingType());
339   Record.push_back(T->getUTTKind());
340   Code = TYPE_UNARY_TRANSFORM;
341 }
342 
343 void ASTTypeWriter::VisitAutoType(const AutoType *T) {
344   Record.AddTypeRef(T->getDeducedType());
345   Record.push_back((unsigned)T->getKeyword());
346   if (T->getDeducedType().isNull())
347     Record.push_back(T->isDependentType());
348   Code = TYPE_AUTO;
349 }
350 
351 void ASTTypeWriter::VisitTagType(const TagType *T) {
352   Record.push_back(T->isDependentType());
353   Record.AddDeclRef(T->getDecl()->getCanonicalDecl());
354   assert(!T->isBeingDefined() &&
355          "Cannot serialize in the middle of a type definition");
356 }
357 
358 void ASTTypeWriter::VisitRecordType(const RecordType *T) {
359   VisitTagType(T);
360   Code = TYPE_RECORD;
361 }
362 
363 void ASTTypeWriter::VisitEnumType(const EnumType *T) {
364   VisitTagType(T);
365   Code = TYPE_ENUM;
366 }
367 
368 void ASTTypeWriter::VisitAttributedType(const AttributedType *T) {
369   Record.AddTypeRef(T->getModifiedType());
370   Record.AddTypeRef(T->getEquivalentType());
371   Record.push_back(T->getAttrKind());
372   Code = TYPE_ATTRIBUTED;
373 }
374 
375 void
376 ASTTypeWriter::VisitSubstTemplateTypeParmType(
377                                         const SubstTemplateTypeParmType *T) {
378   Record.AddTypeRef(QualType(T->getReplacedParameter(), 0));
379   Record.AddTypeRef(T->getReplacementType());
380   Code = TYPE_SUBST_TEMPLATE_TYPE_PARM;
381 }
382 
383 void
384 ASTTypeWriter::VisitSubstTemplateTypeParmPackType(
385                                       const SubstTemplateTypeParmPackType *T) {
386   Record.AddTypeRef(QualType(T->getReplacedParameter(), 0));
387   Record.AddTemplateArgument(T->getArgumentPack());
388   Code = TYPE_SUBST_TEMPLATE_TYPE_PARM_PACK;
389 }
390 
391 void
392 ASTTypeWriter::VisitTemplateSpecializationType(
393                                        const TemplateSpecializationType *T) {
394   Record.push_back(T->isDependentType());
395   Record.AddTemplateName(T->getTemplateName());
396   Record.push_back(T->getNumArgs());
397   for (const auto &ArgI : *T)
398     Record.AddTemplateArgument(ArgI);
399   Record.AddTypeRef(T->isTypeAlias() ? T->getAliasedType()
400                                      : T->isCanonicalUnqualified()
401                                            ? QualType()
402                                            : T->getCanonicalTypeInternal());
403   Code = TYPE_TEMPLATE_SPECIALIZATION;
404 }
405 
406 void
407 ASTTypeWriter::VisitDependentSizedArrayType(const DependentSizedArrayType *T) {
408   VisitArrayType(T);
409   Record.AddStmt(T->getSizeExpr());
410   Record.AddSourceRange(T->getBracketsRange());
411   Code = TYPE_DEPENDENT_SIZED_ARRAY;
412 }
413 
414 void
415 ASTTypeWriter::VisitDependentSizedExtVectorType(
416                                         const DependentSizedExtVectorType *T) {
417   // FIXME: Serialize this type (C++ only)
418   llvm_unreachable("Cannot serialize dependent sized extended vector types");
419 }
420 
421 void
422 ASTTypeWriter::VisitTemplateTypeParmType(const TemplateTypeParmType *T) {
423   Record.push_back(T->getDepth());
424   Record.push_back(T->getIndex());
425   Record.push_back(T->isParameterPack());
426   Record.AddDeclRef(T->getDecl());
427   Code = TYPE_TEMPLATE_TYPE_PARM;
428 }
429 
430 void
431 ASTTypeWriter::VisitDependentNameType(const DependentNameType *T) {
432   Record.push_back(T->getKeyword());
433   Record.AddNestedNameSpecifier(T->getQualifier());
434   Record.AddIdentifierRef(T->getIdentifier());
435   Record.AddTypeRef(
436       T->isCanonicalUnqualified() ? QualType() : T->getCanonicalTypeInternal());
437   Code = TYPE_DEPENDENT_NAME;
438 }
439 
440 void
441 ASTTypeWriter::VisitDependentTemplateSpecializationType(
442                                 const DependentTemplateSpecializationType *T) {
443   Record.push_back(T->getKeyword());
444   Record.AddNestedNameSpecifier(T->getQualifier());
445   Record.AddIdentifierRef(T->getIdentifier());
446   Record.push_back(T->getNumArgs());
447   for (const auto &I : *T)
448     Record.AddTemplateArgument(I);
449   Code = TYPE_DEPENDENT_TEMPLATE_SPECIALIZATION;
450 }
451 
452 void ASTTypeWriter::VisitPackExpansionType(const PackExpansionType *T) {
453   Record.AddTypeRef(T->getPattern());
454   if (Optional<unsigned> NumExpansions = T->getNumExpansions())
455     Record.push_back(*NumExpansions + 1);
456   else
457     Record.push_back(0);
458   Code = TYPE_PACK_EXPANSION;
459 }
460 
461 void ASTTypeWriter::VisitParenType(const ParenType *T) {
462   Record.AddTypeRef(T->getInnerType());
463   Code = TYPE_PAREN;
464 }
465 
466 void ASTTypeWriter::VisitElaboratedType(const ElaboratedType *T) {
467   Record.push_back(T->getKeyword());
468   Record.AddNestedNameSpecifier(T->getQualifier());
469   Record.AddTypeRef(T->getNamedType());
470   Code = TYPE_ELABORATED;
471 }
472 
473 void ASTTypeWriter::VisitInjectedClassNameType(const InjectedClassNameType *T) {
474   Record.AddDeclRef(T->getDecl()->getCanonicalDecl());
475   Record.AddTypeRef(T->getInjectedSpecializationType());
476   Code = TYPE_INJECTED_CLASS_NAME;
477 }
478 
479 void ASTTypeWriter::VisitObjCInterfaceType(const ObjCInterfaceType *T) {
480   Record.AddDeclRef(T->getDecl()->getCanonicalDecl());
481   Code = TYPE_OBJC_INTERFACE;
482 }
483 
484 void ASTTypeWriter::VisitObjCObjectType(const ObjCObjectType *T) {
485   Record.AddTypeRef(T->getBaseType());
486   Record.push_back(T->getTypeArgsAsWritten().size());
487   for (auto TypeArg : T->getTypeArgsAsWritten())
488     Record.AddTypeRef(TypeArg);
489   Record.push_back(T->getNumProtocols());
490   for (const auto *I : T->quals())
491     Record.AddDeclRef(I);
492   Record.push_back(T->isKindOfTypeAsWritten());
493   Code = TYPE_OBJC_OBJECT;
494 }
495 
496 void
497 ASTTypeWriter::VisitObjCObjectPointerType(const ObjCObjectPointerType *T) {
498   Record.AddTypeRef(T->getPointeeType());
499   Code = TYPE_OBJC_OBJECT_POINTER;
500 }
501 
502 void
503 ASTTypeWriter::VisitAtomicType(const AtomicType *T) {
504   Record.AddTypeRef(T->getValueType());
505   Code = TYPE_ATOMIC;
506 }
507 
508 void
509 ASTTypeWriter::VisitPipeType(const PipeType *T) {
510   Record.AddTypeRef(T->getElementType());
511   Code = TYPE_PIPE;
512 }
513 
514 namespace {
515 
516 class TypeLocWriter : public TypeLocVisitor<TypeLocWriter> {
517   ASTRecordWriter &Record;
518 
519 public:
520   TypeLocWriter(ASTRecordWriter &Record)
521     : Record(Record) { }
522 
523 #define ABSTRACT_TYPELOC(CLASS, PARENT)
524 #define TYPELOC(CLASS, PARENT) \
525     void Visit##CLASS##TypeLoc(CLASS##TypeLoc TyLoc);
526 #include "clang/AST/TypeLocNodes.def"
527 
528   void VisitArrayTypeLoc(ArrayTypeLoc TyLoc);
529   void VisitFunctionTypeLoc(FunctionTypeLoc TyLoc);
530 };
531 
532 } // end anonymous namespace
533 
534 void TypeLocWriter::VisitQualifiedTypeLoc(QualifiedTypeLoc TL) {
535   // nothing to do
536 }
537 
538 void TypeLocWriter::VisitBuiltinTypeLoc(BuiltinTypeLoc TL) {
539   Record.AddSourceLocation(TL.getBuiltinLoc());
540   if (TL.needsExtraLocalData()) {
541     Record.push_back(TL.getWrittenTypeSpec());
542     Record.push_back(TL.getWrittenSignSpec());
543     Record.push_back(TL.getWrittenWidthSpec());
544     Record.push_back(TL.hasModeAttr());
545   }
546 }
547 
548 void TypeLocWriter::VisitComplexTypeLoc(ComplexTypeLoc TL) {
549   Record.AddSourceLocation(TL.getNameLoc());
550 }
551 
552 void TypeLocWriter::VisitPointerTypeLoc(PointerTypeLoc TL) {
553   Record.AddSourceLocation(TL.getStarLoc());
554 }
555 
556 void TypeLocWriter::VisitDecayedTypeLoc(DecayedTypeLoc TL) {
557   // nothing to do
558 }
559 
560 void TypeLocWriter::VisitAdjustedTypeLoc(AdjustedTypeLoc TL) {
561   // nothing to do
562 }
563 
564 void TypeLocWriter::VisitBlockPointerTypeLoc(BlockPointerTypeLoc TL) {
565   Record.AddSourceLocation(TL.getCaretLoc());
566 }
567 
568 void TypeLocWriter::VisitLValueReferenceTypeLoc(LValueReferenceTypeLoc TL) {
569   Record.AddSourceLocation(TL.getAmpLoc());
570 }
571 
572 void TypeLocWriter::VisitRValueReferenceTypeLoc(RValueReferenceTypeLoc TL) {
573   Record.AddSourceLocation(TL.getAmpAmpLoc());
574 }
575 
576 void TypeLocWriter::VisitMemberPointerTypeLoc(MemberPointerTypeLoc TL) {
577   Record.AddSourceLocation(TL.getStarLoc());
578   Record.AddTypeSourceInfo(TL.getClassTInfo());
579 }
580 
581 void TypeLocWriter::VisitArrayTypeLoc(ArrayTypeLoc TL) {
582   Record.AddSourceLocation(TL.getLBracketLoc());
583   Record.AddSourceLocation(TL.getRBracketLoc());
584   Record.push_back(TL.getSizeExpr() ? 1 : 0);
585   if (TL.getSizeExpr())
586     Record.AddStmt(TL.getSizeExpr());
587 }
588 
589 void TypeLocWriter::VisitConstantArrayTypeLoc(ConstantArrayTypeLoc TL) {
590   VisitArrayTypeLoc(TL);
591 }
592 
593 void TypeLocWriter::VisitIncompleteArrayTypeLoc(IncompleteArrayTypeLoc TL) {
594   VisitArrayTypeLoc(TL);
595 }
596 
597 void TypeLocWriter::VisitVariableArrayTypeLoc(VariableArrayTypeLoc TL) {
598   VisitArrayTypeLoc(TL);
599 }
600 
601 void TypeLocWriter::VisitDependentSizedArrayTypeLoc(
602                                             DependentSizedArrayTypeLoc TL) {
603   VisitArrayTypeLoc(TL);
604 }
605 
606 void TypeLocWriter::VisitDependentSizedExtVectorTypeLoc(
607                                         DependentSizedExtVectorTypeLoc TL) {
608   Record.AddSourceLocation(TL.getNameLoc());
609 }
610 
611 void TypeLocWriter::VisitVectorTypeLoc(VectorTypeLoc TL) {
612   Record.AddSourceLocation(TL.getNameLoc());
613 }
614 
615 void TypeLocWriter::VisitExtVectorTypeLoc(ExtVectorTypeLoc TL) {
616   Record.AddSourceLocation(TL.getNameLoc());
617 }
618 
619 void TypeLocWriter::VisitFunctionTypeLoc(FunctionTypeLoc TL) {
620   Record.AddSourceLocation(TL.getLocalRangeBegin());
621   Record.AddSourceLocation(TL.getLParenLoc());
622   Record.AddSourceLocation(TL.getRParenLoc());
623   Record.AddSourceLocation(TL.getLocalRangeEnd());
624   for (unsigned i = 0, e = TL.getNumParams(); i != e; ++i)
625     Record.AddDeclRef(TL.getParam(i));
626 }
627 void TypeLocWriter::VisitFunctionProtoTypeLoc(FunctionProtoTypeLoc TL) {
628   VisitFunctionTypeLoc(TL);
629 }
630 void TypeLocWriter::VisitFunctionNoProtoTypeLoc(FunctionNoProtoTypeLoc TL) {
631   VisitFunctionTypeLoc(TL);
632 }
633 void TypeLocWriter::VisitUnresolvedUsingTypeLoc(UnresolvedUsingTypeLoc TL) {
634   Record.AddSourceLocation(TL.getNameLoc());
635 }
636 void TypeLocWriter::VisitTypedefTypeLoc(TypedefTypeLoc TL) {
637   Record.AddSourceLocation(TL.getNameLoc());
638 }
639 void TypeLocWriter::VisitTypeOfExprTypeLoc(TypeOfExprTypeLoc TL) {
640   Record.AddSourceLocation(TL.getTypeofLoc());
641   Record.AddSourceLocation(TL.getLParenLoc());
642   Record.AddSourceLocation(TL.getRParenLoc());
643 }
644 
645 void TypeLocWriter::VisitTypeOfTypeLoc(TypeOfTypeLoc TL) {
646   Record.AddSourceLocation(TL.getTypeofLoc());
647   Record.AddSourceLocation(TL.getLParenLoc());
648   Record.AddSourceLocation(TL.getRParenLoc());
649   Record.AddTypeSourceInfo(TL.getUnderlyingTInfo());
650 }
651 
652 void TypeLocWriter::VisitDecltypeTypeLoc(DecltypeTypeLoc TL) {
653   Record.AddSourceLocation(TL.getNameLoc());
654 }
655 
656 void TypeLocWriter::VisitUnaryTransformTypeLoc(UnaryTransformTypeLoc TL) {
657   Record.AddSourceLocation(TL.getKWLoc());
658   Record.AddSourceLocation(TL.getLParenLoc());
659   Record.AddSourceLocation(TL.getRParenLoc());
660   Record.AddTypeSourceInfo(TL.getUnderlyingTInfo());
661 }
662 
663 void TypeLocWriter::VisitAutoTypeLoc(AutoTypeLoc TL) {
664   Record.AddSourceLocation(TL.getNameLoc());
665 }
666 
667 void TypeLocWriter::VisitRecordTypeLoc(RecordTypeLoc TL) {
668   Record.AddSourceLocation(TL.getNameLoc());
669 }
670 
671 void TypeLocWriter::VisitEnumTypeLoc(EnumTypeLoc TL) {
672   Record.AddSourceLocation(TL.getNameLoc());
673 }
674 
675 void TypeLocWriter::VisitAttributedTypeLoc(AttributedTypeLoc TL) {
676   Record.AddSourceLocation(TL.getAttrNameLoc());
677   if (TL.hasAttrOperand()) {
678     SourceRange range = TL.getAttrOperandParensRange();
679     Record.AddSourceLocation(range.getBegin());
680     Record.AddSourceLocation(range.getEnd());
681   }
682   if (TL.hasAttrExprOperand()) {
683     Expr *operand = TL.getAttrExprOperand();
684     Record.push_back(operand ? 1 : 0);
685     if (operand) Record.AddStmt(operand);
686   } else if (TL.hasAttrEnumOperand()) {
687     Record.AddSourceLocation(TL.getAttrEnumOperandLoc());
688   }
689 }
690 
691 void TypeLocWriter::VisitTemplateTypeParmTypeLoc(TemplateTypeParmTypeLoc TL) {
692   Record.AddSourceLocation(TL.getNameLoc());
693 }
694 
695 void TypeLocWriter::VisitSubstTemplateTypeParmTypeLoc(
696                                             SubstTemplateTypeParmTypeLoc TL) {
697   Record.AddSourceLocation(TL.getNameLoc());
698 }
699 
700 void TypeLocWriter::VisitSubstTemplateTypeParmPackTypeLoc(
701                                           SubstTemplateTypeParmPackTypeLoc TL) {
702   Record.AddSourceLocation(TL.getNameLoc());
703 }
704 
705 void TypeLocWriter::VisitTemplateSpecializationTypeLoc(
706                                            TemplateSpecializationTypeLoc TL) {
707   Record.AddSourceLocation(TL.getTemplateKeywordLoc());
708   Record.AddSourceLocation(TL.getTemplateNameLoc());
709   Record.AddSourceLocation(TL.getLAngleLoc());
710   Record.AddSourceLocation(TL.getRAngleLoc());
711   for (unsigned i = 0, e = TL.getNumArgs(); i != e; ++i)
712     Record.AddTemplateArgumentLocInfo(TL.getArgLoc(i).getArgument().getKind(),
713                                       TL.getArgLoc(i).getLocInfo());
714 }
715 
716 void TypeLocWriter::VisitParenTypeLoc(ParenTypeLoc TL) {
717   Record.AddSourceLocation(TL.getLParenLoc());
718   Record.AddSourceLocation(TL.getRParenLoc());
719 }
720 
721 void TypeLocWriter::VisitElaboratedTypeLoc(ElaboratedTypeLoc TL) {
722   Record.AddSourceLocation(TL.getElaboratedKeywordLoc());
723   Record.AddNestedNameSpecifierLoc(TL.getQualifierLoc());
724 }
725 
726 void TypeLocWriter::VisitInjectedClassNameTypeLoc(InjectedClassNameTypeLoc TL) {
727   Record.AddSourceLocation(TL.getNameLoc());
728 }
729 
730 void TypeLocWriter::VisitDependentNameTypeLoc(DependentNameTypeLoc TL) {
731   Record.AddSourceLocation(TL.getElaboratedKeywordLoc());
732   Record.AddNestedNameSpecifierLoc(TL.getQualifierLoc());
733   Record.AddSourceLocation(TL.getNameLoc());
734 }
735 
736 void TypeLocWriter::VisitDependentTemplateSpecializationTypeLoc(
737        DependentTemplateSpecializationTypeLoc TL) {
738   Record.AddSourceLocation(TL.getElaboratedKeywordLoc());
739   Record.AddNestedNameSpecifierLoc(TL.getQualifierLoc());
740   Record.AddSourceLocation(TL.getTemplateKeywordLoc());
741   Record.AddSourceLocation(TL.getTemplateNameLoc());
742   Record.AddSourceLocation(TL.getLAngleLoc());
743   Record.AddSourceLocation(TL.getRAngleLoc());
744   for (unsigned I = 0, E = TL.getNumArgs(); I != E; ++I)
745     Record.AddTemplateArgumentLocInfo(TL.getArgLoc(I).getArgument().getKind(),
746                                       TL.getArgLoc(I).getLocInfo());
747 }
748 
749 void TypeLocWriter::VisitPackExpansionTypeLoc(PackExpansionTypeLoc TL) {
750   Record.AddSourceLocation(TL.getEllipsisLoc());
751 }
752 
753 void TypeLocWriter::VisitObjCInterfaceTypeLoc(ObjCInterfaceTypeLoc TL) {
754   Record.AddSourceLocation(TL.getNameLoc());
755 }
756 
757 void TypeLocWriter::VisitObjCObjectTypeLoc(ObjCObjectTypeLoc TL) {
758   Record.push_back(TL.hasBaseTypeAsWritten());
759   Record.AddSourceLocation(TL.getTypeArgsLAngleLoc());
760   Record.AddSourceLocation(TL.getTypeArgsRAngleLoc());
761   for (unsigned i = 0, e = TL.getNumTypeArgs(); i != e; ++i)
762     Record.AddTypeSourceInfo(TL.getTypeArgTInfo(i));
763   Record.AddSourceLocation(TL.getProtocolLAngleLoc());
764   Record.AddSourceLocation(TL.getProtocolRAngleLoc());
765   for (unsigned i = 0, e = TL.getNumProtocols(); i != e; ++i)
766     Record.AddSourceLocation(TL.getProtocolLoc(i));
767 }
768 
769 void TypeLocWriter::VisitObjCObjectPointerTypeLoc(ObjCObjectPointerTypeLoc TL) {
770   Record.AddSourceLocation(TL.getStarLoc());
771 }
772 
773 void TypeLocWriter::VisitAtomicTypeLoc(AtomicTypeLoc TL) {
774   Record.AddSourceLocation(TL.getKWLoc());
775   Record.AddSourceLocation(TL.getLParenLoc());
776   Record.AddSourceLocation(TL.getRParenLoc());
777 }
778 
779 void TypeLocWriter::VisitPipeTypeLoc(PipeTypeLoc TL) {
780   Record.AddSourceLocation(TL.getKWLoc());
781 }
782 
783 void ASTWriter::WriteTypeAbbrevs() {
784   using namespace llvm;
785 
786   BitCodeAbbrev *Abv;
787 
788   // Abbreviation for TYPE_EXT_QUAL
789   Abv = new BitCodeAbbrev();
790   Abv->Add(BitCodeAbbrevOp(serialization::TYPE_EXT_QUAL));
791   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // Type
792   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 3));   // Quals
793   TypeExtQualAbbrev = Stream.EmitAbbrev(Abv);
794 
795   // Abbreviation for TYPE_FUNCTION_PROTO
796   Abv = new BitCodeAbbrev();
797   Abv->Add(BitCodeAbbrevOp(serialization::TYPE_FUNCTION_PROTO));
798   // FunctionType
799   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // ReturnType
800   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // NoReturn
801   Abv->Add(BitCodeAbbrevOp(0));                         // HasRegParm
802   Abv->Add(BitCodeAbbrevOp(0));                         // RegParm
803   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // CC
804   Abv->Add(BitCodeAbbrevOp(0));                         // ProducesResult
805   // FunctionProtoType
806   Abv->Add(BitCodeAbbrevOp(0));                         // IsVariadic
807   Abv->Add(BitCodeAbbrevOp(0));                         // HasTrailingReturn
808   Abv->Add(BitCodeAbbrevOp(0));                         // TypeQuals
809   Abv->Add(BitCodeAbbrevOp(0));                         // RefQualifier
810   Abv->Add(BitCodeAbbrevOp(EST_None));                  // ExceptionSpec
811   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // NumParams
812   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
813   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // Params
814   TypeFunctionProtoAbbrev = Stream.EmitAbbrev(Abv);
815 }
816 
817 //===----------------------------------------------------------------------===//
818 // ASTWriter Implementation
819 //===----------------------------------------------------------------------===//
820 
821 static void EmitBlockID(unsigned ID, const char *Name,
822                         llvm::BitstreamWriter &Stream,
823                         ASTWriter::RecordDataImpl &Record) {
824   Record.clear();
825   Record.push_back(ID);
826   Stream.EmitRecord(llvm::bitc::BLOCKINFO_CODE_SETBID, Record);
827 
828   // Emit the block name if present.
829   if (!Name || Name[0] == 0)
830     return;
831   Record.clear();
832   while (*Name)
833     Record.push_back(*Name++);
834   Stream.EmitRecord(llvm::bitc::BLOCKINFO_CODE_BLOCKNAME, Record);
835 }
836 
837 static void EmitRecordID(unsigned ID, const char *Name,
838                          llvm::BitstreamWriter &Stream,
839                          ASTWriter::RecordDataImpl &Record) {
840   Record.clear();
841   Record.push_back(ID);
842   while (*Name)
843     Record.push_back(*Name++);
844   Stream.EmitRecord(llvm::bitc::BLOCKINFO_CODE_SETRECORDNAME, Record);
845 }
846 
847 static void AddStmtsExprs(llvm::BitstreamWriter &Stream,
848                           ASTWriter::RecordDataImpl &Record) {
849 #define RECORD(X) EmitRecordID(X, #X, Stream, Record)
850   RECORD(STMT_STOP);
851   RECORD(STMT_NULL_PTR);
852   RECORD(STMT_REF_PTR);
853   RECORD(STMT_NULL);
854   RECORD(STMT_COMPOUND);
855   RECORD(STMT_CASE);
856   RECORD(STMT_DEFAULT);
857   RECORD(STMT_LABEL);
858   RECORD(STMT_ATTRIBUTED);
859   RECORD(STMT_IF);
860   RECORD(STMT_SWITCH);
861   RECORD(STMT_WHILE);
862   RECORD(STMT_DO);
863   RECORD(STMT_FOR);
864   RECORD(STMT_GOTO);
865   RECORD(STMT_INDIRECT_GOTO);
866   RECORD(STMT_CONTINUE);
867   RECORD(STMT_BREAK);
868   RECORD(STMT_RETURN);
869   RECORD(STMT_DECL);
870   RECORD(STMT_GCCASM);
871   RECORD(STMT_MSASM);
872   RECORD(EXPR_PREDEFINED);
873   RECORD(EXPR_DECL_REF);
874   RECORD(EXPR_INTEGER_LITERAL);
875   RECORD(EXPR_FLOATING_LITERAL);
876   RECORD(EXPR_IMAGINARY_LITERAL);
877   RECORD(EXPR_STRING_LITERAL);
878   RECORD(EXPR_CHARACTER_LITERAL);
879   RECORD(EXPR_PAREN);
880   RECORD(EXPR_PAREN_LIST);
881   RECORD(EXPR_UNARY_OPERATOR);
882   RECORD(EXPR_SIZEOF_ALIGN_OF);
883   RECORD(EXPR_ARRAY_SUBSCRIPT);
884   RECORD(EXPR_CALL);
885   RECORD(EXPR_MEMBER);
886   RECORD(EXPR_BINARY_OPERATOR);
887   RECORD(EXPR_COMPOUND_ASSIGN_OPERATOR);
888   RECORD(EXPR_CONDITIONAL_OPERATOR);
889   RECORD(EXPR_IMPLICIT_CAST);
890   RECORD(EXPR_CSTYLE_CAST);
891   RECORD(EXPR_COMPOUND_LITERAL);
892   RECORD(EXPR_EXT_VECTOR_ELEMENT);
893   RECORD(EXPR_INIT_LIST);
894   RECORD(EXPR_DESIGNATED_INIT);
895   RECORD(EXPR_DESIGNATED_INIT_UPDATE);
896   RECORD(EXPR_IMPLICIT_VALUE_INIT);
897   RECORD(EXPR_NO_INIT);
898   RECORD(EXPR_VA_ARG);
899   RECORD(EXPR_ADDR_LABEL);
900   RECORD(EXPR_STMT);
901   RECORD(EXPR_CHOOSE);
902   RECORD(EXPR_GNU_NULL);
903   RECORD(EXPR_SHUFFLE_VECTOR);
904   RECORD(EXPR_BLOCK);
905   RECORD(EXPR_GENERIC_SELECTION);
906   RECORD(EXPR_OBJC_STRING_LITERAL);
907   RECORD(EXPR_OBJC_BOXED_EXPRESSION);
908   RECORD(EXPR_OBJC_ARRAY_LITERAL);
909   RECORD(EXPR_OBJC_DICTIONARY_LITERAL);
910   RECORD(EXPR_OBJC_ENCODE);
911   RECORD(EXPR_OBJC_SELECTOR_EXPR);
912   RECORD(EXPR_OBJC_PROTOCOL_EXPR);
913   RECORD(EXPR_OBJC_IVAR_REF_EXPR);
914   RECORD(EXPR_OBJC_PROPERTY_REF_EXPR);
915   RECORD(EXPR_OBJC_KVC_REF_EXPR);
916   RECORD(EXPR_OBJC_MESSAGE_EXPR);
917   RECORD(STMT_OBJC_FOR_COLLECTION);
918   RECORD(STMT_OBJC_CATCH);
919   RECORD(STMT_OBJC_FINALLY);
920   RECORD(STMT_OBJC_AT_TRY);
921   RECORD(STMT_OBJC_AT_SYNCHRONIZED);
922   RECORD(STMT_OBJC_AT_THROW);
923   RECORD(EXPR_OBJC_BOOL_LITERAL);
924   RECORD(STMT_CXX_CATCH);
925   RECORD(STMT_CXX_TRY);
926   RECORD(STMT_CXX_FOR_RANGE);
927   RECORD(EXPR_CXX_OPERATOR_CALL);
928   RECORD(EXPR_CXX_MEMBER_CALL);
929   RECORD(EXPR_CXX_CONSTRUCT);
930   RECORD(EXPR_CXX_TEMPORARY_OBJECT);
931   RECORD(EXPR_CXX_STATIC_CAST);
932   RECORD(EXPR_CXX_DYNAMIC_CAST);
933   RECORD(EXPR_CXX_REINTERPRET_CAST);
934   RECORD(EXPR_CXX_CONST_CAST);
935   RECORD(EXPR_CXX_FUNCTIONAL_CAST);
936   RECORD(EXPR_USER_DEFINED_LITERAL);
937   RECORD(EXPR_CXX_STD_INITIALIZER_LIST);
938   RECORD(EXPR_CXX_BOOL_LITERAL);
939   RECORD(EXPR_CXX_NULL_PTR_LITERAL);
940   RECORD(EXPR_CXX_TYPEID_EXPR);
941   RECORD(EXPR_CXX_TYPEID_TYPE);
942   RECORD(EXPR_CXX_THIS);
943   RECORD(EXPR_CXX_THROW);
944   RECORD(EXPR_CXX_DEFAULT_ARG);
945   RECORD(EXPR_CXX_DEFAULT_INIT);
946   RECORD(EXPR_CXX_BIND_TEMPORARY);
947   RECORD(EXPR_CXX_SCALAR_VALUE_INIT);
948   RECORD(EXPR_CXX_NEW);
949   RECORD(EXPR_CXX_DELETE);
950   RECORD(EXPR_CXX_PSEUDO_DESTRUCTOR);
951   RECORD(EXPR_EXPR_WITH_CLEANUPS);
952   RECORD(EXPR_CXX_DEPENDENT_SCOPE_MEMBER);
953   RECORD(EXPR_CXX_DEPENDENT_SCOPE_DECL_REF);
954   RECORD(EXPR_CXX_UNRESOLVED_CONSTRUCT);
955   RECORD(EXPR_CXX_UNRESOLVED_MEMBER);
956   RECORD(EXPR_CXX_UNRESOLVED_LOOKUP);
957   RECORD(EXPR_CXX_EXPRESSION_TRAIT);
958   RECORD(EXPR_CXX_NOEXCEPT);
959   RECORD(EXPR_OPAQUE_VALUE);
960   RECORD(EXPR_BINARY_CONDITIONAL_OPERATOR);
961   RECORD(EXPR_TYPE_TRAIT);
962   RECORD(EXPR_ARRAY_TYPE_TRAIT);
963   RECORD(EXPR_PACK_EXPANSION);
964   RECORD(EXPR_SIZEOF_PACK);
965   RECORD(EXPR_SUBST_NON_TYPE_TEMPLATE_PARM);
966   RECORD(EXPR_SUBST_NON_TYPE_TEMPLATE_PARM_PACK);
967   RECORD(EXPR_FUNCTION_PARM_PACK);
968   RECORD(EXPR_MATERIALIZE_TEMPORARY);
969   RECORD(EXPR_CUDA_KERNEL_CALL);
970   RECORD(EXPR_CXX_UUIDOF_EXPR);
971   RECORD(EXPR_CXX_UUIDOF_TYPE);
972   RECORD(EXPR_LAMBDA);
973 #undef RECORD
974 }
975 
976 void ASTWriter::WriteBlockInfoBlock() {
977   RecordData Record;
978   Stream.EnterSubblock(llvm::bitc::BLOCKINFO_BLOCK_ID, 3);
979 
980 #define BLOCK(X) EmitBlockID(X ## _ID, #X, Stream, Record)
981 #define RECORD(X) EmitRecordID(X, #X, Stream, Record)
982 
983   // Control Block.
984   BLOCK(CONTROL_BLOCK);
985   RECORD(METADATA);
986   RECORD(SIGNATURE);
987   RECORD(MODULE_NAME);
988   RECORD(MODULE_DIRECTORY);
989   RECORD(MODULE_MAP_FILE);
990   RECORD(IMPORTS);
991   RECORD(ORIGINAL_FILE);
992   RECORD(ORIGINAL_PCH_DIR);
993   RECORD(ORIGINAL_FILE_ID);
994   RECORD(INPUT_FILE_OFFSETS);
995 
996   BLOCK(OPTIONS_BLOCK);
997   RECORD(LANGUAGE_OPTIONS);
998   RECORD(TARGET_OPTIONS);
999   RECORD(DIAGNOSTIC_OPTIONS);
1000   RECORD(FILE_SYSTEM_OPTIONS);
1001   RECORD(HEADER_SEARCH_OPTIONS);
1002   RECORD(PREPROCESSOR_OPTIONS);
1003 
1004   BLOCK(INPUT_FILES_BLOCK);
1005   RECORD(INPUT_FILE);
1006 
1007   // AST Top-Level Block.
1008   BLOCK(AST_BLOCK);
1009   RECORD(TYPE_OFFSET);
1010   RECORD(DECL_OFFSET);
1011   RECORD(IDENTIFIER_OFFSET);
1012   RECORD(IDENTIFIER_TABLE);
1013   RECORD(EAGERLY_DESERIALIZED_DECLS);
1014   RECORD(SPECIAL_TYPES);
1015   RECORD(STATISTICS);
1016   RECORD(TENTATIVE_DEFINITIONS);
1017   RECORD(SELECTOR_OFFSETS);
1018   RECORD(METHOD_POOL);
1019   RECORD(PP_COUNTER_VALUE);
1020   RECORD(SOURCE_LOCATION_OFFSETS);
1021   RECORD(SOURCE_LOCATION_PRELOADS);
1022   RECORD(EXT_VECTOR_DECLS);
1023   RECORD(UNUSED_FILESCOPED_DECLS);
1024   RECORD(PPD_ENTITIES_OFFSETS);
1025   RECORD(VTABLE_USES);
1026   RECORD(REFERENCED_SELECTOR_POOL);
1027   RECORD(TU_UPDATE_LEXICAL);
1028   RECORD(SEMA_DECL_REFS);
1029   RECORD(WEAK_UNDECLARED_IDENTIFIERS);
1030   RECORD(PENDING_IMPLICIT_INSTANTIATIONS);
1031   RECORD(UPDATE_VISIBLE);
1032   RECORD(DECL_UPDATE_OFFSETS);
1033   RECORD(DECL_UPDATES);
1034   RECORD(DIAG_PRAGMA_MAPPINGS);
1035   RECORD(CUDA_SPECIAL_DECL_REFS);
1036   RECORD(HEADER_SEARCH_TABLE);
1037   RECORD(FP_PRAGMA_OPTIONS);
1038   RECORD(OPENCL_EXTENSIONS);
1039   RECORD(DELEGATING_CTORS);
1040   RECORD(KNOWN_NAMESPACES);
1041   RECORD(MODULE_OFFSET_MAP);
1042   RECORD(SOURCE_MANAGER_LINE_TABLE);
1043   RECORD(OBJC_CATEGORIES_MAP);
1044   RECORD(FILE_SORTED_DECLS);
1045   RECORD(IMPORTED_MODULES);
1046   RECORD(OBJC_CATEGORIES);
1047   RECORD(MACRO_OFFSET);
1048   RECORD(INTERESTING_IDENTIFIERS);
1049   RECORD(UNDEFINED_BUT_USED);
1050   RECORD(LATE_PARSED_TEMPLATE);
1051   RECORD(OPTIMIZE_PRAGMA_OPTIONS);
1052   RECORD(MSSTRUCT_PRAGMA_OPTIONS);
1053   RECORD(POINTERS_TO_MEMBERS_PRAGMA_OPTIONS);
1054   RECORD(UNUSED_LOCAL_TYPEDEF_NAME_CANDIDATES);
1055   RECORD(DELETE_EXPRS_TO_ANALYZE);
1056 
1057   // SourceManager Block.
1058   BLOCK(SOURCE_MANAGER_BLOCK);
1059   RECORD(SM_SLOC_FILE_ENTRY);
1060   RECORD(SM_SLOC_BUFFER_ENTRY);
1061   RECORD(SM_SLOC_BUFFER_BLOB);
1062   RECORD(SM_SLOC_BUFFER_BLOB_COMPRESSED);
1063   RECORD(SM_SLOC_EXPANSION_ENTRY);
1064 
1065   // Preprocessor Block.
1066   BLOCK(PREPROCESSOR_BLOCK);
1067   RECORD(PP_MACRO_DIRECTIVE_HISTORY);
1068   RECORD(PP_MACRO_FUNCTION_LIKE);
1069   RECORD(PP_MACRO_OBJECT_LIKE);
1070   RECORD(PP_MODULE_MACRO);
1071   RECORD(PP_TOKEN);
1072 
1073   // Submodule Block.
1074   BLOCK(SUBMODULE_BLOCK);
1075   RECORD(SUBMODULE_METADATA);
1076   RECORD(SUBMODULE_DEFINITION);
1077   RECORD(SUBMODULE_UMBRELLA_HEADER);
1078   RECORD(SUBMODULE_HEADER);
1079   RECORD(SUBMODULE_TOPHEADER);
1080   RECORD(SUBMODULE_UMBRELLA_DIR);
1081   RECORD(SUBMODULE_IMPORTS);
1082   RECORD(SUBMODULE_EXPORTS);
1083   RECORD(SUBMODULE_REQUIRES);
1084   RECORD(SUBMODULE_EXCLUDED_HEADER);
1085   RECORD(SUBMODULE_LINK_LIBRARY);
1086   RECORD(SUBMODULE_CONFIG_MACRO);
1087   RECORD(SUBMODULE_CONFLICT);
1088   RECORD(SUBMODULE_PRIVATE_HEADER);
1089   RECORD(SUBMODULE_TEXTUAL_HEADER);
1090   RECORD(SUBMODULE_PRIVATE_TEXTUAL_HEADER);
1091   RECORD(SUBMODULE_INITIALIZERS);
1092 
1093   // Comments Block.
1094   BLOCK(COMMENTS_BLOCK);
1095   RECORD(COMMENTS_RAW_COMMENT);
1096 
1097   // Decls and Types block.
1098   BLOCK(DECLTYPES_BLOCK);
1099   RECORD(TYPE_EXT_QUAL);
1100   RECORD(TYPE_COMPLEX);
1101   RECORD(TYPE_POINTER);
1102   RECORD(TYPE_BLOCK_POINTER);
1103   RECORD(TYPE_LVALUE_REFERENCE);
1104   RECORD(TYPE_RVALUE_REFERENCE);
1105   RECORD(TYPE_MEMBER_POINTER);
1106   RECORD(TYPE_CONSTANT_ARRAY);
1107   RECORD(TYPE_INCOMPLETE_ARRAY);
1108   RECORD(TYPE_VARIABLE_ARRAY);
1109   RECORD(TYPE_VECTOR);
1110   RECORD(TYPE_EXT_VECTOR);
1111   RECORD(TYPE_FUNCTION_NO_PROTO);
1112   RECORD(TYPE_FUNCTION_PROTO);
1113   RECORD(TYPE_TYPEDEF);
1114   RECORD(TYPE_TYPEOF_EXPR);
1115   RECORD(TYPE_TYPEOF);
1116   RECORD(TYPE_RECORD);
1117   RECORD(TYPE_ENUM);
1118   RECORD(TYPE_OBJC_INTERFACE);
1119   RECORD(TYPE_OBJC_OBJECT_POINTER);
1120   RECORD(TYPE_DECLTYPE);
1121   RECORD(TYPE_ELABORATED);
1122   RECORD(TYPE_SUBST_TEMPLATE_TYPE_PARM);
1123   RECORD(TYPE_UNRESOLVED_USING);
1124   RECORD(TYPE_INJECTED_CLASS_NAME);
1125   RECORD(TYPE_OBJC_OBJECT);
1126   RECORD(TYPE_TEMPLATE_TYPE_PARM);
1127   RECORD(TYPE_TEMPLATE_SPECIALIZATION);
1128   RECORD(TYPE_DEPENDENT_NAME);
1129   RECORD(TYPE_DEPENDENT_TEMPLATE_SPECIALIZATION);
1130   RECORD(TYPE_DEPENDENT_SIZED_ARRAY);
1131   RECORD(TYPE_PAREN);
1132   RECORD(TYPE_PACK_EXPANSION);
1133   RECORD(TYPE_ATTRIBUTED);
1134   RECORD(TYPE_SUBST_TEMPLATE_TYPE_PARM_PACK);
1135   RECORD(TYPE_AUTO);
1136   RECORD(TYPE_UNARY_TRANSFORM);
1137   RECORD(TYPE_ATOMIC);
1138   RECORD(TYPE_DECAYED);
1139   RECORD(TYPE_ADJUSTED);
1140   RECORD(LOCAL_REDECLARATIONS);
1141   RECORD(DECL_TYPEDEF);
1142   RECORD(DECL_TYPEALIAS);
1143   RECORD(DECL_ENUM);
1144   RECORD(DECL_RECORD);
1145   RECORD(DECL_ENUM_CONSTANT);
1146   RECORD(DECL_FUNCTION);
1147   RECORD(DECL_OBJC_METHOD);
1148   RECORD(DECL_OBJC_INTERFACE);
1149   RECORD(DECL_OBJC_PROTOCOL);
1150   RECORD(DECL_OBJC_IVAR);
1151   RECORD(DECL_OBJC_AT_DEFS_FIELD);
1152   RECORD(DECL_OBJC_CATEGORY);
1153   RECORD(DECL_OBJC_CATEGORY_IMPL);
1154   RECORD(DECL_OBJC_IMPLEMENTATION);
1155   RECORD(DECL_OBJC_COMPATIBLE_ALIAS);
1156   RECORD(DECL_OBJC_PROPERTY);
1157   RECORD(DECL_OBJC_PROPERTY_IMPL);
1158   RECORD(DECL_FIELD);
1159   RECORD(DECL_MS_PROPERTY);
1160   RECORD(DECL_VAR);
1161   RECORD(DECL_IMPLICIT_PARAM);
1162   RECORD(DECL_PARM_VAR);
1163   RECORD(DECL_FILE_SCOPE_ASM);
1164   RECORD(DECL_BLOCK);
1165   RECORD(DECL_CONTEXT_LEXICAL);
1166   RECORD(DECL_CONTEXT_VISIBLE);
1167   RECORD(DECL_NAMESPACE);
1168   RECORD(DECL_NAMESPACE_ALIAS);
1169   RECORD(DECL_USING);
1170   RECORD(DECL_USING_SHADOW);
1171   RECORD(DECL_USING_DIRECTIVE);
1172   RECORD(DECL_UNRESOLVED_USING_VALUE);
1173   RECORD(DECL_UNRESOLVED_USING_TYPENAME);
1174   RECORD(DECL_LINKAGE_SPEC);
1175   RECORD(DECL_CXX_RECORD);
1176   RECORD(DECL_CXX_METHOD);
1177   RECORD(DECL_CXX_CONSTRUCTOR);
1178   RECORD(DECL_CXX_INHERITED_CONSTRUCTOR);
1179   RECORD(DECL_CXX_DESTRUCTOR);
1180   RECORD(DECL_CXX_CONVERSION);
1181   RECORD(DECL_ACCESS_SPEC);
1182   RECORD(DECL_FRIEND);
1183   RECORD(DECL_FRIEND_TEMPLATE);
1184   RECORD(DECL_CLASS_TEMPLATE);
1185   RECORD(DECL_CLASS_TEMPLATE_SPECIALIZATION);
1186   RECORD(DECL_CLASS_TEMPLATE_PARTIAL_SPECIALIZATION);
1187   RECORD(DECL_VAR_TEMPLATE);
1188   RECORD(DECL_VAR_TEMPLATE_SPECIALIZATION);
1189   RECORD(DECL_VAR_TEMPLATE_PARTIAL_SPECIALIZATION);
1190   RECORD(DECL_FUNCTION_TEMPLATE);
1191   RECORD(DECL_TEMPLATE_TYPE_PARM);
1192   RECORD(DECL_NON_TYPE_TEMPLATE_PARM);
1193   RECORD(DECL_TEMPLATE_TEMPLATE_PARM);
1194   RECORD(DECL_TYPE_ALIAS_TEMPLATE);
1195   RECORD(DECL_STATIC_ASSERT);
1196   RECORD(DECL_CXX_BASE_SPECIFIERS);
1197   RECORD(DECL_CXX_CTOR_INITIALIZERS);
1198   RECORD(DECL_INDIRECTFIELD);
1199   RECORD(DECL_EXPANDED_NON_TYPE_TEMPLATE_PARM_PACK);
1200   RECORD(DECL_EXPANDED_TEMPLATE_TEMPLATE_PARM_PACK);
1201   RECORD(DECL_CLASS_SCOPE_FUNCTION_SPECIALIZATION);
1202   RECORD(DECL_IMPORT);
1203   RECORD(DECL_OMP_THREADPRIVATE);
1204   RECORD(DECL_EMPTY);
1205   RECORD(DECL_OBJC_TYPE_PARAM);
1206   RECORD(DECL_OMP_CAPTUREDEXPR);
1207   RECORD(DECL_PRAGMA_COMMENT);
1208   RECORD(DECL_PRAGMA_DETECT_MISMATCH);
1209   RECORD(DECL_OMP_DECLARE_REDUCTION);
1210 
1211   // Statements and Exprs can occur in the Decls and Types block.
1212   AddStmtsExprs(Stream, Record);
1213 
1214   BLOCK(PREPROCESSOR_DETAIL_BLOCK);
1215   RECORD(PPD_MACRO_EXPANSION);
1216   RECORD(PPD_MACRO_DEFINITION);
1217   RECORD(PPD_INCLUSION_DIRECTIVE);
1218 
1219   // Decls and Types block.
1220   BLOCK(EXTENSION_BLOCK);
1221   RECORD(EXTENSION_METADATA);
1222 
1223 #undef RECORD
1224 #undef BLOCK
1225   Stream.ExitBlock();
1226 }
1227 
1228 /// \brief Prepares a path for being written to an AST file by converting it
1229 /// to an absolute path and removing nested './'s.
1230 ///
1231 /// \return \c true if the path was changed.
1232 static bool cleanPathForOutput(FileManager &FileMgr,
1233                                SmallVectorImpl<char> &Path) {
1234   bool Changed = FileMgr.makeAbsolutePath(Path);
1235   return Changed | llvm::sys::path::remove_dots(Path);
1236 }
1237 
1238 /// \brief Adjusts the given filename to only write out the portion of the
1239 /// filename that is not part of the system root directory.
1240 ///
1241 /// \param Filename the file name to adjust.
1242 ///
1243 /// \param BaseDir When non-NULL, the PCH file is a relocatable AST file and
1244 /// the returned filename will be adjusted by this root directory.
1245 ///
1246 /// \returns either the original filename (if it needs no adjustment) or the
1247 /// adjusted filename (which points into the @p Filename parameter).
1248 static const char *
1249 adjustFilenameForRelocatableAST(const char *Filename, StringRef BaseDir) {
1250   assert(Filename && "No file name to adjust?");
1251 
1252   if (BaseDir.empty())
1253     return Filename;
1254 
1255   // Verify that the filename and the system root have the same prefix.
1256   unsigned Pos = 0;
1257   for (; Filename[Pos] && Pos < BaseDir.size(); ++Pos)
1258     if (Filename[Pos] != BaseDir[Pos])
1259       return Filename; // Prefixes don't match.
1260 
1261   // We hit the end of the filename before we hit the end of the system root.
1262   if (!Filename[Pos])
1263     return Filename;
1264 
1265   // If there's not a path separator at the end of the base directory nor
1266   // immediately after it, then this isn't within the base directory.
1267   if (!llvm::sys::path::is_separator(Filename[Pos])) {
1268     if (!llvm::sys::path::is_separator(BaseDir.back()))
1269       return Filename;
1270   } else {
1271     // If the file name has a '/' at the current position, skip over the '/'.
1272     // We distinguish relative paths from absolute paths by the
1273     // absence of '/' at the beginning of relative paths.
1274     //
1275     // FIXME: This is wrong. We distinguish them by asking if the path is
1276     // absolute, which isn't the same thing. And there might be multiple '/'s
1277     // in a row. Use a better mechanism to indicate whether we have emitted an
1278     // absolute or relative path.
1279     ++Pos;
1280   }
1281 
1282   return Filename + Pos;
1283 }
1284 
1285 static ASTFileSignature getSignature() {
1286   while (true) {
1287     if (ASTFileSignature S = llvm::sys::Process::GetRandomNumber())
1288       return S;
1289     // Rely on GetRandomNumber to eventually return non-zero...
1290   }
1291 }
1292 
1293 /// \brief Write the control block.
1294 uint64_t ASTWriter::WriteControlBlock(Preprocessor &PP,
1295                                       ASTContext &Context,
1296                                       StringRef isysroot,
1297                                       const std::string &OutputFile) {
1298   ASTFileSignature Signature = 0;
1299 
1300   using namespace llvm;
1301   Stream.EnterSubblock(CONTROL_BLOCK_ID, 5);
1302   RecordData Record;
1303 
1304   // Metadata
1305   auto *MetadataAbbrev = new BitCodeAbbrev();
1306   MetadataAbbrev->Add(BitCodeAbbrevOp(METADATA));
1307   MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 16)); // Major
1308   MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 16)); // Minor
1309   MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 16)); // Clang maj.
1310   MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 16)); // Clang min.
1311   MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Relocatable
1312   MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Timestamps
1313   MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Errors
1314   MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // SVN branch/tag
1315   unsigned MetadataAbbrevCode = Stream.EmitAbbrev(MetadataAbbrev);
1316   assert((!WritingModule || isysroot.empty()) &&
1317          "writing module as a relocatable PCH?");
1318   {
1319     RecordData::value_type Record[] = {METADATA, VERSION_MAJOR, VERSION_MINOR,
1320                                        CLANG_VERSION_MAJOR, CLANG_VERSION_MINOR,
1321                                        !isysroot.empty(), IncludeTimestamps,
1322                                        ASTHasCompilerErrors};
1323     Stream.EmitRecordWithBlob(MetadataAbbrevCode, Record,
1324                               getClangFullRepositoryVersion());
1325   }
1326   if (WritingModule) {
1327     // For implicit modules we output a signature that we can use to ensure
1328     // duplicate module builds don't collide in the cache as their output order
1329     // is non-deterministic.
1330     // FIXME: Remove this when output is deterministic.
1331     if (Context.getLangOpts().ImplicitModules) {
1332       Signature = getSignature();
1333       RecordData::value_type Record[] = {Signature};
1334       Stream.EmitRecord(SIGNATURE, Record);
1335     }
1336 
1337     // Module name
1338     auto *Abbrev = new BitCodeAbbrev();
1339     Abbrev->Add(BitCodeAbbrevOp(MODULE_NAME));
1340     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
1341     unsigned AbbrevCode = Stream.EmitAbbrev(Abbrev);
1342     RecordData::value_type Record[] = {MODULE_NAME};
1343     Stream.EmitRecordWithBlob(AbbrevCode, Record, WritingModule->Name);
1344   }
1345 
1346   if (WritingModule && WritingModule->Directory) {
1347     SmallString<128> BaseDir(WritingModule->Directory->getName());
1348     cleanPathForOutput(Context.getSourceManager().getFileManager(), BaseDir);
1349 
1350     // If the home of the module is the current working directory, then we
1351     // want to pick up the cwd of the build process loading the module, not
1352     // our cwd, when we load this module.
1353     if (!PP.getHeaderSearchInfo()
1354              .getHeaderSearchOpts()
1355              .ModuleMapFileHomeIsCwd ||
1356         WritingModule->Directory->getName() != StringRef(".")) {
1357       // Module directory.
1358       auto *Abbrev = new BitCodeAbbrev();
1359       Abbrev->Add(BitCodeAbbrevOp(MODULE_DIRECTORY));
1360       Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Directory
1361       unsigned AbbrevCode = Stream.EmitAbbrev(Abbrev);
1362 
1363       RecordData::value_type Record[] = {MODULE_DIRECTORY};
1364       Stream.EmitRecordWithBlob(AbbrevCode, Record, BaseDir);
1365     }
1366 
1367     // Write out all other paths relative to the base directory if possible.
1368     BaseDirectory.assign(BaseDir.begin(), BaseDir.end());
1369   } else if (!isysroot.empty()) {
1370     // Write out paths relative to the sysroot if possible.
1371     BaseDirectory = isysroot;
1372   }
1373 
1374   // Module map file
1375   if (WritingModule) {
1376     Record.clear();
1377 
1378     auto &Map = PP.getHeaderSearchInfo().getModuleMap();
1379 
1380     // Primary module map file.
1381     AddPath(Map.getModuleMapFileForUniquing(WritingModule)->getName(), Record);
1382 
1383     // Additional module map files.
1384     if (auto *AdditionalModMaps =
1385             Map.getAdditionalModuleMapFiles(WritingModule)) {
1386       Record.push_back(AdditionalModMaps->size());
1387       for (const FileEntry *F : *AdditionalModMaps)
1388         AddPath(F->getName(), Record);
1389     } else {
1390       Record.push_back(0);
1391     }
1392 
1393     Stream.EmitRecord(MODULE_MAP_FILE, Record);
1394   }
1395 
1396   // Imports
1397   if (Chain) {
1398     serialization::ModuleManager &Mgr = Chain->getModuleManager();
1399     Record.clear();
1400 
1401     for (auto *M : Mgr) {
1402       // Skip modules that weren't directly imported.
1403       if (!M->isDirectlyImported())
1404         continue;
1405 
1406       Record.push_back((unsigned)M->Kind); // FIXME: Stable encoding
1407       AddSourceLocation(M->ImportLoc, Record);
1408       Record.push_back(M->File->getSize());
1409       Record.push_back(getTimestampForOutput(M->File));
1410       Record.push_back(M->Signature);
1411       AddPath(M->FileName, Record);
1412     }
1413     Stream.EmitRecord(IMPORTS, Record);
1414   }
1415 
1416   // Write the options block.
1417   Stream.EnterSubblock(OPTIONS_BLOCK_ID, 4);
1418 
1419   // Language options.
1420   Record.clear();
1421   const LangOptions &LangOpts = Context.getLangOpts();
1422 #define LANGOPT(Name, Bits, Default, Description) \
1423   Record.push_back(LangOpts.Name);
1424 #define ENUM_LANGOPT(Name, Type, Bits, Default, Description) \
1425   Record.push_back(static_cast<unsigned>(LangOpts.get##Name()));
1426 #include "clang/Basic/LangOptions.def"
1427 #define SANITIZER(NAME, ID)                                                    \
1428   Record.push_back(LangOpts.Sanitize.has(SanitizerKind::ID));
1429 #include "clang/Basic/Sanitizers.def"
1430 
1431   Record.push_back(LangOpts.ModuleFeatures.size());
1432   for (StringRef Feature : LangOpts.ModuleFeatures)
1433     AddString(Feature, Record);
1434 
1435   Record.push_back((unsigned) LangOpts.ObjCRuntime.getKind());
1436   AddVersionTuple(LangOpts.ObjCRuntime.getVersion(), Record);
1437 
1438   AddString(LangOpts.CurrentModule, Record);
1439 
1440   // Comment options.
1441   Record.push_back(LangOpts.CommentOpts.BlockCommandNames.size());
1442   for (const auto &I : LangOpts.CommentOpts.BlockCommandNames) {
1443     AddString(I, Record);
1444   }
1445   Record.push_back(LangOpts.CommentOpts.ParseAllComments);
1446 
1447   // OpenMP offloading options.
1448   Record.push_back(LangOpts.OMPTargetTriples.size());
1449   for (auto &T : LangOpts.OMPTargetTriples)
1450     AddString(T.getTriple(), Record);
1451 
1452   AddString(LangOpts.OMPHostIRFile, Record);
1453 
1454   Stream.EmitRecord(LANGUAGE_OPTIONS, Record);
1455 
1456   // Target options.
1457   Record.clear();
1458   const TargetInfo &Target = Context.getTargetInfo();
1459   const TargetOptions &TargetOpts = Target.getTargetOpts();
1460   AddString(TargetOpts.Triple, Record);
1461   AddString(TargetOpts.CPU, Record);
1462   AddString(TargetOpts.ABI, Record);
1463   Record.push_back(TargetOpts.FeaturesAsWritten.size());
1464   for (unsigned I = 0, N = TargetOpts.FeaturesAsWritten.size(); I != N; ++I) {
1465     AddString(TargetOpts.FeaturesAsWritten[I], Record);
1466   }
1467   Record.push_back(TargetOpts.Features.size());
1468   for (unsigned I = 0, N = TargetOpts.Features.size(); I != N; ++I) {
1469     AddString(TargetOpts.Features[I], Record);
1470   }
1471   Stream.EmitRecord(TARGET_OPTIONS, Record);
1472 
1473   // Diagnostic options.
1474   Record.clear();
1475   const DiagnosticOptions &DiagOpts
1476     = Context.getDiagnostics().getDiagnosticOptions();
1477 #define DIAGOPT(Name, Bits, Default) Record.push_back(DiagOpts.Name);
1478 #define ENUM_DIAGOPT(Name, Type, Bits, Default) \
1479   Record.push_back(static_cast<unsigned>(DiagOpts.get##Name()));
1480 #include "clang/Basic/DiagnosticOptions.def"
1481   Record.push_back(DiagOpts.Warnings.size());
1482   for (unsigned I = 0, N = DiagOpts.Warnings.size(); I != N; ++I)
1483     AddString(DiagOpts.Warnings[I], Record);
1484   Record.push_back(DiagOpts.Remarks.size());
1485   for (unsigned I = 0, N = DiagOpts.Remarks.size(); I != N; ++I)
1486     AddString(DiagOpts.Remarks[I], Record);
1487   // Note: we don't serialize the log or serialization file names, because they
1488   // are generally transient files and will almost always be overridden.
1489   Stream.EmitRecord(DIAGNOSTIC_OPTIONS, Record);
1490 
1491   // File system options.
1492   Record.clear();
1493   const FileSystemOptions &FSOpts =
1494       Context.getSourceManager().getFileManager().getFileSystemOpts();
1495   AddString(FSOpts.WorkingDir, Record);
1496   Stream.EmitRecord(FILE_SYSTEM_OPTIONS, Record);
1497 
1498   // Header search options.
1499   Record.clear();
1500   const HeaderSearchOptions &HSOpts
1501     = PP.getHeaderSearchInfo().getHeaderSearchOpts();
1502   AddString(HSOpts.Sysroot, Record);
1503 
1504   // Include entries.
1505   Record.push_back(HSOpts.UserEntries.size());
1506   for (unsigned I = 0, N = HSOpts.UserEntries.size(); I != N; ++I) {
1507     const HeaderSearchOptions::Entry &Entry = HSOpts.UserEntries[I];
1508     AddString(Entry.Path, Record);
1509     Record.push_back(static_cast<unsigned>(Entry.Group));
1510     Record.push_back(Entry.IsFramework);
1511     Record.push_back(Entry.IgnoreSysRoot);
1512   }
1513 
1514   // System header prefixes.
1515   Record.push_back(HSOpts.SystemHeaderPrefixes.size());
1516   for (unsigned I = 0, N = HSOpts.SystemHeaderPrefixes.size(); I != N; ++I) {
1517     AddString(HSOpts.SystemHeaderPrefixes[I].Prefix, Record);
1518     Record.push_back(HSOpts.SystemHeaderPrefixes[I].IsSystemHeader);
1519   }
1520 
1521   AddString(HSOpts.ResourceDir, Record);
1522   AddString(HSOpts.ModuleCachePath, Record);
1523   AddString(HSOpts.ModuleUserBuildPath, Record);
1524   Record.push_back(HSOpts.DisableModuleHash);
1525   Record.push_back(HSOpts.UseBuiltinIncludes);
1526   Record.push_back(HSOpts.UseStandardSystemIncludes);
1527   Record.push_back(HSOpts.UseStandardCXXIncludes);
1528   Record.push_back(HSOpts.UseLibcxx);
1529   // Write out the specific module cache path that contains the module files.
1530   AddString(PP.getHeaderSearchInfo().getModuleCachePath(), Record);
1531   Stream.EmitRecord(HEADER_SEARCH_OPTIONS, Record);
1532 
1533   // Preprocessor options.
1534   Record.clear();
1535   const PreprocessorOptions &PPOpts = PP.getPreprocessorOpts();
1536 
1537   // Macro definitions.
1538   Record.push_back(PPOpts.Macros.size());
1539   for (unsigned I = 0, N = PPOpts.Macros.size(); I != N; ++I) {
1540     AddString(PPOpts.Macros[I].first, Record);
1541     Record.push_back(PPOpts.Macros[I].second);
1542   }
1543 
1544   // Includes
1545   Record.push_back(PPOpts.Includes.size());
1546   for (unsigned I = 0, N = PPOpts.Includes.size(); I != N; ++I)
1547     AddString(PPOpts.Includes[I], Record);
1548 
1549   // Macro includes
1550   Record.push_back(PPOpts.MacroIncludes.size());
1551   for (unsigned I = 0, N = PPOpts.MacroIncludes.size(); I != N; ++I)
1552     AddString(PPOpts.MacroIncludes[I], Record);
1553 
1554   Record.push_back(PPOpts.UsePredefines);
1555   // Detailed record is important since it is used for the module cache hash.
1556   Record.push_back(PPOpts.DetailedRecord);
1557   AddString(PPOpts.ImplicitPCHInclude, Record);
1558   AddString(PPOpts.ImplicitPTHInclude, Record);
1559   Record.push_back(static_cast<unsigned>(PPOpts.ObjCXXARCStandardLibrary));
1560   Stream.EmitRecord(PREPROCESSOR_OPTIONS, Record);
1561 
1562   // Leave the options block.
1563   Stream.ExitBlock();
1564 
1565   // Original file name and file ID
1566   SourceManager &SM = Context.getSourceManager();
1567   if (const FileEntry *MainFile = SM.getFileEntryForID(SM.getMainFileID())) {
1568     auto *FileAbbrev = new BitCodeAbbrev();
1569     FileAbbrev->Add(BitCodeAbbrevOp(ORIGINAL_FILE));
1570     FileAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // File ID
1571     FileAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // File name
1572     unsigned FileAbbrevCode = Stream.EmitAbbrev(FileAbbrev);
1573 
1574     Record.clear();
1575     Record.push_back(ORIGINAL_FILE);
1576     Record.push_back(SM.getMainFileID().getOpaqueValue());
1577     EmitRecordWithPath(FileAbbrevCode, Record, MainFile->getName());
1578   }
1579 
1580   Record.clear();
1581   Record.push_back(SM.getMainFileID().getOpaqueValue());
1582   Stream.EmitRecord(ORIGINAL_FILE_ID, Record);
1583 
1584   // Original PCH directory
1585   if (!OutputFile.empty() && OutputFile != "-") {
1586     auto *Abbrev = new BitCodeAbbrev();
1587     Abbrev->Add(BitCodeAbbrevOp(ORIGINAL_PCH_DIR));
1588     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // File name
1589     unsigned AbbrevCode = Stream.EmitAbbrev(Abbrev);
1590 
1591     SmallString<128> OutputPath(OutputFile);
1592 
1593     SM.getFileManager().makeAbsolutePath(OutputPath);
1594     StringRef origDir = llvm::sys::path::parent_path(OutputPath);
1595 
1596     RecordData::value_type Record[] = {ORIGINAL_PCH_DIR};
1597     Stream.EmitRecordWithBlob(AbbrevCode, Record, origDir);
1598   }
1599 
1600   WriteInputFiles(Context.SourceMgr,
1601                   PP.getHeaderSearchInfo().getHeaderSearchOpts(),
1602                   PP.getLangOpts().Modules);
1603   Stream.ExitBlock();
1604   return Signature;
1605 }
1606 
1607 namespace  {
1608 
1609   /// \brief An input file.
1610   struct InputFileEntry {
1611     const FileEntry *File;
1612     bool IsSystemFile;
1613     bool IsTransient;
1614     bool BufferOverridden;
1615   };
1616 
1617 } // end anonymous namespace
1618 
1619 void ASTWriter::WriteInputFiles(SourceManager &SourceMgr,
1620                                 HeaderSearchOptions &HSOpts,
1621                                 bool Modules) {
1622   using namespace llvm;
1623   Stream.EnterSubblock(INPUT_FILES_BLOCK_ID, 4);
1624 
1625   // Create input-file abbreviation.
1626   auto *IFAbbrev = new BitCodeAbbrev();
1627   IFAbbrev->Add(BitCodeAbbrevOp(INPUT_FILE));
1628   IFAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ID
1629   IFAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 12)); // Size
1630   IFAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 32)); // Modification time
1631   IFAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Overridden
1632   IFAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Transient
1633   IFAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // File name
1634   unsigned IFAbbrevCode = Stream.EmitAbbrev(IFAbbrev);
1635 
1636   // Get all ContentCache objects for files, sorted by whether the file is a
1637   // system one or not. System files go at the back, users files at the front.
1638   std::deque<InputFileEntry> SortedFiles;
1639   for (unsigned I = 1, N = SourceMgr.local_sloc_entry_size(); I != N; ++I) {
1640     // Get this source location entry.
1641     const SrcMgr::SLocEntry *SLoc = &SourceMgr.getLocalSLocEntry(I);
1642     assert(&SourceMgr.getSLocEntry(FileID::get(I)) == SLoc);
1643 
1644     // We only care about file entries that were not overridden.
1645     if (!SLoc->isFile())
1646       continue;
1647     const SrcMgr::ContentCache *Cache = SLoc->getFile().getContentCache();
1648     if (!Cache->OrigEntry)
1649       continue;
1650 
1651     InputFileEntry Entry;
1652     Entry.File = Cache->OrigEntry;
1653     Entry.IsSystemFile = Cache->IsSystemFile;
1654     Entry.IsTransient = Cache->IsTransient;
1655     Entry.BufferOverridden = Cache->BufferOverridden;
1656     if (Cache->IsSystemFile)
1657       SortedFiles.push_back(Entry);
1658     else
1659       SortedFiles.push_front(Entry);
1660   }
1661 
1662   unsigned UserFilesNum = 0;
1663   // Write out all of the input files.
1664   std::vector<uint64_t> InputFileOffsets;
1665   for (const auto &Entry : SortedFiles) {
1666     uint32_t &InputFileID = InputFileIDs[Entry.File];
1667     if (InputFileID != 0)
1668       continue; // already recorded this file.
1669 
1670     // Record this entry's offset.
1671     InputFileOffsets.push_back(Stream.GetCurrentBitNo());
1672 
1673     InputFileID = InputFileOffsets.size();
1674 
1675     if (!Entry.IsSystemFile)
1676       ++UserFilesNum;
1677 
1678     // Emit size/modification time for this file.
1679     // And whether this file was overridden.
1680     RecordData::value_type Record[] = {
1681         INPUT_FILE,
1682         InputFileOffsets.size(),
1683         (uint64_t)Entry.File->getSize(),
1684         (uint64_t)getTimestampForOutput(Entry.File),
1685         Entry.BufferOverridden,
1686         Entry.IsTransient};
1687 
1688     EmitRecordWithPath(IFAbbrevCode, Record, Entry.File->getName());
1689   }
1690 
1691   Stream.ExitBlock();
1692 
1693   // Create input file offsets abbreviation.
1694   auto *OffsetsAbbrev = new BitCodeAbbrev();
1695   OffsetsAbbrev->Add(BitCodeAbbrevOp(INPUT_FILE_OFFSETS));
1696   OffsetsAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // # input files
1697   OffsetsAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // # non-system
1698                                                                 //   input files
1699   OffsetsAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));   // Array
1700   unsigned OffsetsAbbrevCode = Stream.EmitAbbrev(OffsetsAbbrev);
1701 
1702   // Write input file offsets.
1703   RecordData::value_type Record[] = {INPUT_FILE_OFFSETS,
1704                                      InputFileOffsets.size(), UserFilesNum};
1705   Stream.EmitRecordWithBlob(OffsetsAbbrevCode, Record, bytes(InputFileOffsets));
1706 }
1707 
1708 //===----------------------------------------------------------------------===//
1709 // Source Manager Serialization
1710 //===----------------------------------------------------------------------===//
1711 
1712 /// \brief Create an abbreviation for the SLocEntry that refers to a
1713 /// file.
1714 static unsigned CreateSLocFileAbbrev(llvm::BitstreamWriter &Stream) {
1715   using namespace llvm;
1716 
1717   auto *Abbrev = new BitCodeAbbrev();
1718   Abbrev->Add(BitCodeAbbrevOp(SM_SLOC_FILE_ENTRY));
1719   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Offset
1720   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Include location
1721   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // Characteristic
1722   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Line directives
1723   // FileEntry fields.
1724   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Input File ID
1725   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // NumCreatedFIDs
1726   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 24)); // FirstDeclIndex
1727   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // NumDecls
1728   return Stream.EmitAbbrev(Abbrev);
1729 }
1730 
1731 /// \brief Create an abbreviation for the SLocEntry that refers to a
1732 /// buffer.
1733 static unsigned CreateSLocBufferAbbrev(llvm::BitstreamWriter &Stream) {
1734   using namespace llvm;
1735 
1736   auto *Abbrev = new BitCodeAbbrev();
1737   Abbrev->Add(BitCodeAbbrevOp(SM_SLOC_BUFFER_ENTRY));
1738   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Offset
1739   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Include location
1740   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // Characteristic
1741   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Line directives
1742   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Buffer name blob
1743   return Stream.EmitAbbrev(Abbrev);
1744 }
1745 
1746 /// \brief Create an abbreviation for the SLocEntry that refers to a
1747 /// buffer's blob.
1748 static unsigned CreateSLocBufferBlobAbbrev(llvm::BitstreamWriter &Stream,
1749                                            bool Compressed) {
1750   using namespace llvm;
1751 
1752   auto *Abbrev = new BitCodeAbbrev();
1753   Abbrev->Add(BitCodeAbbrevOp(Compressed ? SM_SLOC_BUFFER_BLOB_COMPRESSED
1754                                          : SM_SLOC_BUFFER_BLOB));
1755   if (Compressed)
1756     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Uncompressed size
1757   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Blob
1758   return Stream.EmitAbbrev(Abbrev);
1759 }
1760 
1761 /// \brief Create an abbreviation for the SLocEntry that refers to a macro
1762 /// expansion.
1763 static unsigned CreateSLocExpansionAbbrev(llvm::BitstreamWriter &Stream) {
1764   using namespace llvm;
1765 
1766   auto *Abbrev = new BitCodeAbbrev();
1767   Abbrev->Add(BitCodeAbbrevOp(SM_SLOC_EXPANSION_ENTRY));
1768   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Offset
1769   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Spelling location
1770   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Start location
1771   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // End location
1772   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Token length
1773   return Stream.EmitAbbrev(Abbrev);
1774 }
1775 
1776 namespace {
1777 
1778   // Trait used for the on-disk hash table of header search information.
1779   class HeaderFileInfoTrait {
1780     ASTWriter &Writer;
1781     const HeaderSearch &HS;
1782 
1783     // Keep track of the framework names we've used during serialization.
1784     SmallVector<char, 128> FrameworkStringData;
1785     llvm::StringMap<unsigned> FrameworkNameOffset;
1786 
1787   public:
1788     HeaderFileInfoTrait(ASTWriter &Writer, const HeaderSearch &HS)
1789       : Writer(Writer), HS(HS) { }
1790 
1791     struct key_type {
1792       const FileEntry *FE;
1793       const char *Filename;
1794     };
1795     typedef const key_type &key_type_ref;
1796 
1797     typedef HeaderFileInfo data_type;
1798     typedef const data_type &data_type_ref;
1799     typedef unsigned hash_value_type;
1800     typedef unsigned offset_type;
1801 
1802     hash_value_type ComputeHash(key_type_ref key) {
1803       // The hash is based only on size/time of the file, so that the reader can
1804       // match even when symlinking or excess path elements ("foo/../", "../")
1805       // change the form of the name. However, complete path is still the key.
1806       return llvm::hash_combine(key.FE->getSize(),
1807                                 Writer.getTimestampForOutput(key.FE));
1808     }
1809 
1810     std::pair<unsigned,unsigned>
1811     EmitKeyDataLength(raw_ostream& Out, key_type_ref key, data_type_ref Data) {
1812       using namespace llvm::support;
1813       endian::Writer<little> LE(Out);
1814       unsigned KeyLen = strlen(key.Filename) + 1 + 8 + 8;
1815       LE.write<uint16_t>(KeyLen);
1816       unsigned DataLen = 1 + 2 + 4 + 4;
1817       for (auto ModInfo : HS.getModuleMap().findAllModulesForHeader(key.FE))
1818         if (Writer.getLocalOrImportedSubmoduleID(ModInfo.getModule()))
1819           DataLen += 4;
1820       LE.write<uint8_t>(DataLen);
1821       return std::make_pair(KeyLen, DataLen);
1822     }
1823 
1824     void EmitKey(raw_ostream& Out, key_type_ref key, unsigned KeyLen) {
1825       using namespace llvm::support;
1826       endian::Writer<little> LE(Out);
1827       LE.write<uint64_t>(key.FE->getSize());
1828       KeyLen -= 8;
1829       LE.write<uint64_t>(Writer.getTimestampForOutput(key.FE));
1830       KeyLen -= 8;
1831       Out.write(key.Filename, KeyLen);
1832     }
1833 
1834     void EmitData(raw_ostream &Out, key_type_ref key,
1835                   data_type_ref Data, unsigned DataLen) {
1836       using namespace llvm::support;
1837       endian::Writer<little> LE(Out);
1838       uint64_t Start = Out.tell(); (void)Start;
1839 
1840       unsigned char Flags = (Data.isImport << 4)
1841                           | (Data.isPragmaOnce << 3)
1842                           | (Data.DirInfo << 1)
1843                           | Data.IndexHeaderMapHeader;
1844       LE.write<uint8_t>(Flags);
1845       LE.write<uint16_t>(Data.NumIncludes);
1846 
1847       if (!Data.ControllingMacro)
1848         LE.write<uint32_t>(Data.ControllingMacroID);
1849       else
1850         LE.write<uint32_t>(Writer.getIdentifierRef(Data.ControllingMacro));
1851 
1852       unsigned Offset = 0;
1853       if (!Data.Framework.empty()) {
1854         // If this header refers into a framework, save the framework name.
1855         llvm::StringMap<unsigned>::iterator Pos
1856           = FrameworkNameOffset.find(Data.Framework);
1857         if (Pos == FrameworkNameOffset.end()) {
1858           Offset = FrameworkStringData.size() + 1;
1859           FrameworkStringData.append(Data.Framework.begin(),
1860                                      Data.Framework.end());
1861           FrameworkStringData.push_back(0);
1862 
1863           FrameworkNameOffset[Data.Framework] = Offset;
1864         } else
1865           Offset = Pos->second;
1866       }
1867       LE.write<uint32_t>(Offset);
1868 
1869       // FIXME: If the header is excluded, we should write out some
1870       // record of that fact.
1871       for (auto ModInfo : HS.getModuleMap().findAllModulesForHeader(key.FE)) {
1872         if (uint32_t ModID =
1873                 Writer.getLocalOrImportedSubmoduleID(ModInfo.getModule())) {
1874           uint32_t Value = (ModID << 2) | (unsigned)ModInfo.getRole();
1875           assert((Value >> 2) == ModID && "overflow in header module info");
1876           LE.write<uint32_t>(Value);
1877         }
1878       }
1879 
1880       assert(Out.tell() - Start == DataLen && "Wrong data length");
1881     }
1882 
1883     const char *strings_begin() const { return FrameworkStringData.begin(); }
1884     const char *strings_end() const { return FrameworkStringData.end(); }
1885   };
1886 
1887 } // end anonymous namespace
1888 
1889 /// \brief Write the header search block for the list of files that
1890 ///
1891 /// \param HS The header search structure to save.
1892 void ASTWriter::WriteHeaderSearch(const HeaderSearch &HS) {
1893   SmallVector<const FileEntry *, 16> FilesByUID;
1894   HS.getFileMgr().GetUniqueIDMapping(FilesByUID);
1895 
1896   if (FilesByUID.size() > HS.header_file_size())
1897     FilesByUID.resize(HS.header_file_size());
1898 
1899   HeaderFileInfoTrait GeneratorTrait(*this, HS);
1900   llvm::OnDiskChainedHashTableGenerator<HeaderFileInfoTrait> Generator;
1901   SmallVector<const char *, 4> SavedStrings;
1902   unsigned NumHeaderSearchEntries = 0;
1903   for (unsigned UID = 0, LastUID = FilesByUID.size(); UID != LastUID; ++UID) {
1904     const FileEntry *File = FilesByUID[UID];
1905     if (!File)
1906       continue;
1907 
1908     // Get the file info. This will load info from the external source if
1909     // necessary. Skip emitting this file if we have no information on it
1910     // as a header file (in which case HFI will be null) or if it hasn't
1911     // changed since it was loaded. Also skip it if it's for a modular header
1912     // from a different module; in that case, we rely on the module(s)
1913     // containing the header to provide this information.
1914     const HeaderFileInfo *HFI =
1915         HS.getExistingFileInfo(File, /*WantExternal*/!Chain);
1916     if (!HFI || (HFI->isModuleHeader && !HFI->isCompilingModuleHeader))
1917       continue;
1918 
1919     // Massage the file path into an appropriate form.
1920     const char *Filename = File->getName();
1921     SmallString<128> FilenameTmp(Filename);
1922     if (PreparePathForOutput(FilenameTmp)) {
1923       // If we performed any translation on the file name at all, we need to
1924       // save this string, since the generator will refer to it later.
1925       Filename = strdup(FilenameTmp.c_str());
1926       SavedStrings.push_back(Filename);
1927     }
1928 
1929     HeaderFileInfoTrait::key_type key = { File, Filename };
1930     Generator.insert(key, *HFI, GeneratorTrait);
1931     ++NumHeaderSearchEntries;
1932   }
1933 
1934   // Create the on-disk hash table in a buffer.
1935   SmallString<4096> TableData;
1936   uint32_t BucketOffset;
1937   {
1938     using namespace llvm::support;
1939     llvm::raw_svector_ostream Out(TableData);
1940     // Make sure that no bucket is at offset 0
1941     endian::Writer<little>(Out).write<uint32_t>(0);
1942     BucketOffset = Generator.Emit(Out, GeneratorTrait);
1943   }
1944 
1945   // Create a blob abbreviation
1946   using namespace llvm;
1947 
1948   auto *Abbrev = new BitCodeAbbrev();
1949   Abbrev->Add(BitCodeAbbrevOp(HEADER_SEARCH_TABLE));
1950   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
1951   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
1952   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
1953   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
1954   unsigned TableAbbrev = Stream.EmitAbbrev(Abbrev);
1955 
1956   // Write the header search table
1957   RecordData::value_type Record[] = {HEADER_SEARCH_TABLE, BucketOffset,
1958                                      NumHeaderSearchEntries, TableData.size()};
1959   TableData.append(GeneratorTrait.strings_begin(),GeneratorTrait.strings_end());
1960   Stream.EmitRecordWithBlob(TableAbbrev, Record, TableData);
1961 
1962   // Free all of the strings we had to duplicate.
1963   for (unsigned I = 0, N = SavedStrings.size(); I != N; ++I)
1964     free(const_cast<char *>(SavedStrings[I]));
1965 }
1966 
1967 /// \brief Writes the block containing the serialized form of the
1968 /// source manager.
1969 ///
1970 /// TODO: We should probably use an on-disk hash table (stored in a
1971 /// blob), indexed based on the file name, so that we only create
1972 /// entries for files that we actually need. In the common case (no
1973 /// errors), we probably won't have to create file entries for any of
1974 /// the files in the AST.
1975 void ASTWriter::WriteSourceManagerBlock(SourceManager &SourceMgr,
1976                                         const Preprocessor &PP) {
1977   RecordData Record;
1978 
1979   // Enter the source manager block.
1980   Stream.EnterSubblock(SOURCE_MANAGER_BLOCK_ID, 4);
1981 
1982   // Abbreviations for the various kinds of source-location entries.
1983   unsigned SLocFileAbbrv = CreateSLocFileAbbrev(Stream);
1984   unsigned SLocBufferAbbrv = CreateSLocBufferAbbrev(Stream);
1985   unsigned SLocBufferBlobAbbrv = CreateSLocBufferBlobAbbrev(Stream, false);
1986   unsigned SLocBufferBlobCompressedAbbrv =
1987       CreateSLocBufferBlobAbbrev(Stream, true);
1988   unsigned SLocExpansionAbbrv = CreateSLocExpansionAbbrev(Stream);
1989 
1990   // Write out the source location entry table. We skip the first
1991   // entry, which is always the same dummy entry.
1992   std::vector<uint32_t> SLocEntryOffsets;
1993   RecordData PreloadSLocs;
1994   SLocEntryOffsets.reserve(SourceMgr.local_sloc_entry_size() - 1);
1995   for (unsigned I = 1, N = SourceMgr.local_sloc_entry_size();
1996        I != N; ++I) {
1997     // Get this source location entry.
1998     const SrcMgr::SLocEntry *SLoc = &SourceMgr.getLocalSLocEntry(I);
1999     FileID FID = FileID::get(I);
2000     assert(&SourceMgr.getSLocEntry(FID) == SLoc);
2001 
2002     // Record the offset of this source-location entry.
2003     SLocEntryOffsets.push_back(Stream.GetCurrentBitNo());
2004 
2005     // Figure out which record code to use.
2006     unsigned Code;
2007     if (SLoc->isFile()) {
2008       const SrcMgr::ContentCache *Cache = SLoc->getFile().getContentCache();
2009       if (Cache->OrigEntry) {
2010         Code = SM_SLOC_FILE_ENTRY;
2011       } else
2012         Code = SM_SLOC_BUFFER_ENTRY;
2013     } else
2014       Code = SM_SLOC_EXPANSION_ENTRY;
2015     Record.clear();
2016     Record.push_back(Code);
2017 
2018     // Starting offset of this entry within this module, so skip the dummy.
2019     Record.push_back(SLoc->getOffset() - 2);
2020     if (SLoc->isFile()) {
2021       const SrcMgr::FileInfo &File = SLoc->getFile();
2022       AddSourceLocation(File.getIncludeLoc(), Record);
2023       Record.push_back(File.getFileCharacteristic()); // FIXME: stable encoding
2024       Record.push_back(File.hasLineDirectives());
2025 
2026       const SrcMgr::ContentCache *Content = File.getContentCache();
2027       bool EmitBlob = false;
2028       if (Content->OrigEntry) {
2029         assert(Content->OrigEntry == Content->ContentsEntry &&
2030                "Writing to AST an overridden file is not supported");
2031 
2032         // The source location entry is a file. Emit input file ID.
2033         assert(InputFileIDs[Content->OrigEntry] != 0 && "Missed file entry");
2034         Record.push_back(InputFileIDs[Content->OrigEntry]);
2035 
2036         Record.push_back(File.NumCreatedFIDs);
2037 
2038         FileDeclIDsTy::iterator FDI = FileDeclIDs.find(FID);
2039         if (FDI != FileDeclIDs.end()) {
2040           Record.push_back(FDI->second->FirstDeclIndex);
2041           Record.push_back(FDI->second->DeclIDs.size());
2042         } else {
2043           Record.push_back(0);
2044           Record.push_back(0);
2045         }
2046 
2047         Stream.EmitRecordWithAbbrev(SLocFileAbbrv, Record);
2048 
2049         if (Content->BufferOverridden || Content->IsTransient)
2050           EmitBlob = true;
2051       } else {
2052         // The source location entry is a buffer. The blob associated
2053         // with this entry contains the contents of the buffer.
2054 
2055         // We add one to the size so that we capture the trailing NULL
2056         // that is required by llvm::MemoryBuffer::getMemBuffer (on
2057         // the reader side).
2058         const llvm::MemoryBuffer *Buffer
2059           = Content->getBuffer(PP.getDiagnostics(), PP.getSourceManager());
2060         const char *Name = Buffer->getBufferIdentifier();
2061         Stream.EmitRecordWithBlob(SLocBufferAbbrv, Record,
2062                                   StringRef(Name, strlen(Name) + 1));
2063         EmitBlob = true;
2064 
2065         if (strcmp(Name, "<built-in>") == 0) {
2066           PreloadSLocs.push_back(SLocEntryOffsets.size());
2067         }
2068       }
2069 
2070       if (EmitBlob) {
2071         // Include the implicit terminating null character in the on-disk buffer
2072         // if we're writing it uncompressed.
2073         const llvm::MemoryBuffer *Buffer =
2074             Content->getBuffer(PP.getDiagnostics(), PP.getSourceManager());
2075         StringRef Blob(Buffer->getBufferStart(), Buffer->getBufferSize() + 1);
2076 
2077         // Compress the buffer if possible. We expect that almost all PCM
2078         // consumers will not want its contents.
2079         SmallString<0> CompressedBuffer;
2080         if (llvm::zlib::compress(Blob.drop_back(1), CompressedBuffer) ==
2081             llvm::zlib::StatusOK) {
2082           RecordData::value_type Record[] = {SM_SLOC_BUFFER_BLOB_COMPRESSED,
2083                                              Blob.size() - 1};
2084           Stream.EmitRecordWithBlob(SLocBufferBlobCompressedAbbrv, Record,
2085                                     CompressedBuffer);
2086         } else {
2087           RecordData::value_type Record[] = {SM_SLOC_BUFFER_BLOB};
2088           Stream.EmitRecordWithBlob(SLocBufferBlobAbbrv, Record, Blob);
2089         }
2090       }
2091     } else {
2092       // The source location entry is a macro expansion.
2093       const SrcMgr::ExpansionInfo &Expansion = SLoc->getExpansion();
2094       AddSourceLocation(Expansion.getSpellingLoc(), Record);
2095       AddSourceLocation(Expansion.getExpansionLocStart(), Record);
2096       AddSourceLocation(Expansion.isMacroArgExpansion()
2097                             ? SourceLocation()
2098                             : Expansion.getExpansionLocEnd(),
2099                         Record);
2100 
2101       // Compute the token length for this macro expansion.
2102       unsigned NextOffset = SourceMgr.getNextLocalOffset();
2103       if (I + 1 != N)
2104         NextOffset = SourceMgr.getLocalSLocEntry(I + 1).getOffset();
2105       Record.push_back(NextOffset - SLoc->getOffset() - 1);
2106       Stream.EmitRecordWithAbbrev(SLocExpansionAbbrv, Record);
2107     }
2108   }
2109 
2110   Stream.ExitBlock();
2111 
2112   if (SLocEntryOffsets.empty())
2113     return;
2114 
2115   // Write the source-location offsets table into the AST block. This
2116   // table is used for lazily loading source-location information.
2117   using namespace llvm;
2118 
2119   auto *Abbrev = new BitCodeAbbrev();
2120   Abbrev->Add(BitCodeAbbrevOp(SOURCE_LOCATION_OFFSETS));
2121   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 16)); // # of slocs
2122   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 16)); // total size
2123   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // offsets
2124   unsigned SLocOffsetsAbbrev = Stream.EmitAbbrev(Abbrev);
2125   {
2126     RecordData::value_type Record[] = {
2127         SOURCE_LOCATION_OFFSETS, SLocEntryOffsets.size(),
2128         SourceMgr.getNextLocalOffset() - 1 /* skip dummy */};
2129     Stream.EmitRecordWithBlob(SLocOffsetsAbbrev, Record,
2130                               bytes(SLocEntryOffsets));
2131   }
2132   // Write the source location entry preloads array, telling the AST
2133   // reader which source locations entries it should load eagerly.
2134   Stream.EmitRecord(SOURCE_LOCATION_PRELOADS, PreloadSLocs);
2135 
2136   // Write the line table. It depends on remapping working, so it must come
2137   // after the source location offsets.
2138   if (SourceMgr.hasLineTable()) {
2139     LineTableInfo &LineTable = SourceMgr.getLineTable();
2140 
2141     Record.clear();
2142 
2143     // Emit the needed file names.
2144     llvm::DenseMap<int, int> FilenameMap;
2145     for (const auto &L : LineTable) {
2146       if (L.first.ID < 0)
2147         continue;
2148       for (auto &LE : L.second) {
2149         if (FilenameMap.insert(std::make_pair(LE.FilenameID,
2150                                               FilenameMap.size())).second)
2151           AddPath(LineTable.getFilename(LE.FilenameID), Record);
2152       }
2153     }
2154     Record.push_back(0);
2155 
2156     // Emit the line entries
2157     for (const auto &L : LineTable) {
2158       // Only emit entries for local files.
2159       if (L.first.ID < 0)
2160         continue;
2161 
2162       // Emit the file ID
2163       Record.push_back(L.first.ID);
2164 
2165       // Emit the line entries
2166       Record.push_back(L.second.size());
2167       for (const auto &LE : L.second) {
2168         Record.push_back(LE.FileOffset);
2169         Record.push_back(LE.LineNo);
2170         Record.push_back(FilenameMap[LE.FilenameID]);
2171         Record.push_back((unsigned)LE.FileKind);
2172         Record.push_back(LE.IncludeOffset);
2173       }
2174     }
2175 
2176     Stream.EmitRecord(SOURCE_MANAGER_LINE_TABLE, Record);
2177   }
2178 }
2179 
2180 //===----------------------------------------------------------------------===//
2181 // Preprocessor Serialization
2182 //===----------------------------------------------------------------------===//
2183 
2184 static bool shouldIgnoreMacro(MacroDirective *MD, bool IsModule,
2185                               const Preprocessor &PP) {
2186   if (MacroInfo *MI = MD->getMacroInfo())
2187     if (MI->isBuiltinMacro())
2188       return true;
2189 
2190   if (IsModule) {
2191     SourceLocation Loc = MD->getLocation();
2192     if (Loc.isInvalid())
2193       return true;
2194     if (PP.getSourceManager().getFileID(Loc) == PP.getPredefinesFileID())
2195       return true;
2196   }
2197 
2198   return false;
2199 }
2200 
2201 /// \brief Writes the block containing the serialized form of the
2202 /// preprocessor.
2203 ///
2204 void ASTWriter::WritePreprocessor(const Preprocessor &PP, bool IsModule) {
2205   PreprocessingRecord *PPRec = PP.getPreprocessingRecord();
2206   if (PPRec)
2207     WritePreprocessorDetail(*PPRec);
2208 
2209   RecordData Record;
2210   RecordData ModuleMacroRecord;
2211 
2212   // If the preprocessor __COUNTER__ value has been bumped, remember it.
2213   if (PP.getCounterValue() != 0) {
2214     RecordData::value_type Record[] = {PP.getCounterValue()};
2215     Stream.EmitRecord(PP_COUNTER_VALUE, Record);
2216   }
2217 
2218   // Enter the preprocessor block.
2219   Stream.EnterSubblock(PREPROCESSOR_BLOCK_ID, 3);
2220 
2221   // If the AST file contains __DATE__ or __TIME__ emit a warning about this.
2222   // FIXME: Include a location for the use, and say which one was used.
2223   if (PP.SawDateOrTime())
2224     PP.Diag(SourceLocation(), diag::warn_module_uses_date_time) << IsModule;
2225 
2226   // Loop over all the macro directives that are live at the end of the file,
2227   // emitting each to the PP section.
2228 
2229   // Construct the list of identifiers with macro directives that need to be
2230   // serialized.
2231   SmallVector<const IdentifierInfo *, 128> MacroIdentifiers;
2232   for (auto &Id : PP.getIdentifierTable())
2233     if (Id.second->hadMacroDefinition() &&
2234         (!Id.second->isFromAST() ||
2235          Id.second->hasChangedSinceDeserialization()))
2236       MacroIdentifiers.push_back(Id.second);
2237   // Sort the set of macro definitions that need to be serialized by the
2238   // name of the macro, to provide a stable ordering.
2239   std::sort(MacroIdentifiers.begin(), MacroIdentifiers.end(),
2240             llvm::less_ptr<IdentifierInfo>());
2241 
2242   // Emit the macro directives as a list and associate the offset with the
2243   // identifier they belong to.
2244   for (const IdentifierInfo *Name : MacroIdentifiers) {
2245     MacroDirective *MD = PP.getLocalMacroDirectiveHistory(Name);
2246     auto StartOffset = Stream.GetCurrentBitNo();
2247 
2248     // Emit the macro directives in reverse source order.
2249     for (; MD; MD = MD->getPrevious()) {
2250       // Once we hit an ignored macro, we're done: the rest of the chain
2251       // will all be ignored macros.
2252       if (shouldIgnoreMacro(MD, IsModule, PP))
2253         break;
2254 
2255       AddSourceLocation(MD->getLocation(), Record);
2256       Record.push_back(MD->getKind());
2257       if (auto *DefMD = dyn_cast<DefMacroDirective>(MD)) {
2258         Record.push_back(getMacroRef(DefMD->getInfo(), Name));
2259       } else if (auto *VisMD = dyn_cast<VisibilityMacroDirective>(MD)) {
2260         Record.push_back(VisMD->isPublic());
2261       }
2262     }
2263 
2264     // Write out any exported module macros.
2265     bool EmittedModuleMacros = false;
2266     // We write out exported module macros for PCH as well.
2267     auto Leafs = PP.getLeafModuleMacros(Name);
2268     SmallVector<ModuleMacro*, 8> Worklist(Leafs.begin(), Leafs.end());
2269     llvm::DenseMap<ModuleMacro*, unsigned> Visits;
2270     while (!Worklist.empty()) {
2271       auto *Macro = Worklist.pop_back_val();
2272 
2273       // Emit a record indicating this submodule exports this macro.
2274       ModuleMacroRecord.push_back(
2275           getSubmoduleID(Macro->getOwningModule()));
2276       ModuleMacroRecord.push_back(getMacroRef(Macro->getMacroInfo(), Name));
2277       for (auto *M : Macro->overrides())
2278         ModuleMacroRecord.push_back(getSubmoduleID(M->getOwningModule()));
2279 
2280       Stream.EmitRecord(PP_MODULE_MACRO, ModuleMacroRecord);
2281       ModuleMacroRecord.clear();
2282 
2283       // Enqueue overridden macros once we've visited all their ancestors.
2284       for (auto *M : Macro->overrides())
2285         if (++Visits[M] == M->getNumOverridingMacros())
2286           Worklist.push_back(M);
2287 
2288       EmittedModuleMacros = true;
2289     }
2290 
2291     if (Record.empty() && !EmittedModuleMacros)
2292       continue;
2293 
2294     IdentMacroDirectivesOffsetMap[Name] = StartOffset;
2295     Stream.EmitRecord(PP_MACRO_DIRECTIVE_HISTORY, Record);
2296     Record.clear();
2297   }
2298 
2299   /// \brief Offsets of each of the macros into the bitstream, indexed by
2300   /// the local macro ID
2301   ///
2302   /// For each identifier that is associated with a macro, this map
2303   /// provides the offset into the bitstream where that macro is
2304   /// defined.
2305   std::vector<uint32_t> MacroOffsets;
2306 
2307   for (unsigned I = 0, N = MacroInfosToEmit.size(); I != N; ++I) {
2308     const IdentifierInfo *Name = MacroInfosToEmit[I].Name;
2309     MacroInfo *MI = MacroInfosToEmit[I].MI;
2310     MacroID ID = MacroInfosToEmit[I].ID;
2311 
2312     if (ID < FirstMacroID) {
2313       assert(0 && "Loaded MacroInfo entered MacroInfosToEmit ?");
2314       continue;
2315     }
2316 
2317     // Record the local offset of this macro.
2318     unsigned Index = ID - FirstMacroID;
2319     if (Index == MacroOffsets.size())
2320       MacroOffsets.push_back(Stream.GetCurrentBitNo());
2321     else {
2322       if (Index > MacroOffsets.size())
2323         MacroOffsets.resize(Index + 1);
2324 
2325       MacroOffsets[Index] = Stream.GetCurrentBitNo();
2326     }
2327 
2328     AddIdentifierRef(Name, Record);
2329     Record.push_back(inferSubmoduleIDFromLocation(MI->getDefinitionLoc()));
2330     AddSourceLocation(MI->getDefinitionLoc(), Record);
2331     AddSourceLocation(MI->getDefinitionEndLoc(), Record);
2332     Record.push_back(MI->isUsed());
2333     Record.push_back(MI->isUsedForHeaderGuard());
2334     unsigned Code;
2335     if (MI->isObjectLike()) {
2336       Code = PP_MACRO_OBJECT_LIKE;
2337     } else {
2338       Code = PP_MACRO_FUNCTION_LIKE;
2339 
2340       Record.push_back(MI->isC99Varargs());
2341       Record.push_back(MI->isGNUVarargs());
2342       Record.push_back(MI->hasCommaPasting());
2343       Record.push_back(MI->getNumArgs());
2344       for (const IdentifierInfo *Arg : MI->args())
2345         AddIdentifierRef(Arg, Record);
2346     }
2347 
2348     // If we have a detailed preprocessing record, record the macro definition
2349     // ID that corresponds to this macro.
2350     if (PPRec)
2351       Record.push_back(MacroDefinitions[PPRec->findMacroDefinition(MI)]);
2352 
2353     Stream.EmitRecord(Code, Record);
2354     Record.clear();
2355 
2356     // Emit the tokens array.
2357     for (unsigned TokNo = 0, e = MI->getNumTokens(); TokNo != e; ++TokNo) {
2358       // Note that we know that the preprocessor does not have any annotation
2359       // tokens in it because they are created by the parser, and thus can't
2360       // be in a macro definition.
2361       const Token &Tok = MI->getReplacementToken(TokNo);
2362       AddToken(Tok, Record);
2363       Stream.EmitRecord(PP_TOKEN, Record);
2364       Record.clear();
2365     }
2366     ++NumMacros;
2367   }
2368 
2369   Stream.ExitBlock();
2370 
2371   // Write the offsets table for macro IDs.
2372   using namespace llvm;
2373 
2374   auto *Abbrev = new BitCodeAbbrev();
2375   Abbrev->Add(BitCodeAbbrevOp(MACRO_OFFSET));
2376   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // # of macros
2377   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // first ID
2378   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2379 
2380   unsigned MacroOffsetAbbrev = Stream.EmitAbbrev(Abbrev);
2381   {
2382     RecordData::value_type Record[] = {MACRO_OFFSET, MacroOffsets.size(),
2383                                        FirstMacroID - NUM_PREDEF_MACRO_IDS};
2384     Stream.EmitRecordWithBlob(MacroOffsetAbbrev, Record, bytes(MacroOffsets));
2385   }
2386 }
2387 
2388 void ASTWriter::WritePreprocessorDetail(PreprocessingRecord &PPRec) {
2389   if (PPRec.local_begin() == PPRec.local_end())
2390     return;
2391 
2392   SmallVector<PPEntityOffset, 64> PreprocessedEntityOffsets;
2393 
2394   // Enter the preprocessor block.
2395   Stream.EnterSubblock(PREPROCESSOR_DETAIL_BLOCK_ID, 3);
2396 
2397   // If the preprocessor has a preprocessing record, emit it.
2398   unsigned NumPreprocessingRecords = 0;
2399   using namespace llvm;
2400 
2401   // Set up the abbreviation for
2402   unsigned InclusionAbbrev = 0;
2403   {
2404     auto *Abbrev = new BitCodeAbbrev();
2405     Abbrev->Add(BitCodeAbbrevOp(PPD_INCLUSION_DIRECTIVE));
2406     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // filename length
2407     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // in quotes
2408     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // kind
2409     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // imported module
2410     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2411     InclusionAbbrev = Stream.EmitAbbrev(Abbrev);
2412   }
2413 
2414   unsigned FirstPreprocessorEntityID
2415     = (Chain ? PPRec.getNumLoadedPreprocessedEntities() : 0)
2416     + NUM_PREDEF_PP_ENTITY_IDS;
2417   unsigned NextPreprocessorEntityID = FirstPreprocessorEntityID;
2418   RecordData Record;
2419   for (PreprocessingRecord::iterator E = PPRec.local_begin(),
2420                                   EEnd = PPRec.local_end();
2421        E != EEnd;
2422        (void)++E, ++NumPreprocessingRecords, ++NextPreprocessorEntityID) {
2423     Record.clear();
2424 
2425     PreprocessedEntityOffsets.push_back(
2426         PPEntityOffset((*E)->getSourceRange(), Stream.GetCurrentBitNo()));
2427 
2428     if (auto *MD = dyn_cast<MacroDefinitionRecord>(*E)) {
2429       // Record this macro definition's ID.
2430       MacroDefinitions[MD] = NextPreprocessorEntityID;
2431 
2432       AddIdentifierRef(MD->getName(), Record);
2433       Stream.EmitRecord(PPD_MACRO_DEFINITION, Record);
2434       continue;
2435     }
2436 
2437     if (auto *ME = dyn_cast<MacroExpansion>(*E)) {
2438       Record.push_back(ME->isBuiltinMacro());
2439       if (ME->isBuiltinMacro())
2440         AddIdentifierRef(ME->getName(), Record);
2441       else
2442         Record.push_back(MacroDefinitions[ME->getDefinition()]);
2443       Stream.EmitRecord(PPD_MACRO_EXPANSION, Record);
2444       continue;
2445     }
2446 
2447     if (auto *ID = dyn_cast<InclusionDirective>(*E)) {
2448       Record.push_back(PPD_INCLUSION_DIRECTIVE);
2449       Record.push_back(ID->getFileName().size());
2450       Record.push_back(ID->wasInQuotes());
2451       Record.push_back(static_cast<unsigned>(ID->getKind()));
2452       Record.push_back(ID->importedModule());
2453       SmallString<64> Buffer;
2454       Buffer += ID->getFileName();
2455       // Check that the FileEntry is not null because it was not resolved and
2456       // we create a PCH even with compiler errors.
2457       if (ID->getFile())
2458         Buffer += ID->getFile()->getName();
2459       Stream.EmitRecordWithBlob(InclusionAbbrev, Record, Buffer);
2460       continue;
2461     }
2462 
2463     llvm_unreachable("Unhandled PreprocessedEntity in ASTWriter");
2464   }
2465   Stream.ExitBlock();
2466 
2467   // Write the offsets table for the preprocessing record.
2468   if (NumPreprocessingRecords > 0) {
2469     assert(PreprocessedEntityOffsets.size() == NumPreprocessingRecords);
2470 
2471     // Write the offsets table for identifier IDs.
2472     using namespace llvm;
2473 
2474     auto *Abbrev = new BitCodeAbbrev();
2475     Abbrev->Add(BitCodeAbbrevOp(PPD_ENTITIES_OFFSETS));
2476     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // first pp entity
2477     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2478     unsigned PPEOffsetAbbrev = Stream.EmitAbbrev(Abbrev);
2479 
2480     RecordData::value_type Record[] = {PPD_ENTITIES_OFFSETS,
2481                                        FirstPreprocessorEntityID -
2482                                            NUM_PREDEF_PP_ENTITY_IDS};
2483     Stream.EmitRecordWithBlob(PPEOffsetAbbrev, Record,
2484                               bytes(PreprocessedEntityOffsets));
2485   }
2486 }
2487 
2488 unsigned ASTWriter::getLocalOrImportedSubmoduleID(Module *Mod) {
2489   if (!Mod)
2490     return 0;
2491 
2492   llvm::DenseMap<Module *, unsigned>::iterator Known = SubmoduleIDs.find(Mod);
2493   if (Known != SubmoduleIDs.end())
2494     return Known->second;
2495 
2496   auto *Top = Mod->getTopLevelModule();
2497   if (Top != WritingModule &&
2498       !Top->fullModuleNameIs(StringRef(getLangOpts().CurrentModule)))
2499     return 0;
2500 
2501   return SubmoduleIDs[Mod] = NextSubmoduleID++;
2502 }
2503 
2504 unsigned ASTWriter::getSubmoduleID(Module *Mod) {
2505   // FIXME: This can easily happen, if we have a reference to a submodule that
2506   // did not result in us loading a module file for that submodule. For
2507   // instance, a cross-top-level-module 'conflict' declaration will hit this.
2508   unsigned ID = getLocalOrImportedSubmoduleID(Mod);
2509   assert((ID || !Mod) &&
2510          "asked for module ID for non-local, non-imported module");
2511   return ID;
2512 }
2513 
2514 /// \brief Compute the number of modules within the given tree (including the
2515 /// given module).
2516 static unsigned getNumberOfModules(Module *Mod) {
2517   unsigned ChildModules = 0;
2518   for (auto Sub = Mod->submodule_begin(), SubEnd = Mod->submodule_end();
2519        Sub != SubEnd; ++Sub)
2520     ChildModules += getNumberOfModules(*Sub);
2521 
2522   return ChildModules + 1;
2523 }
2524 
2525 void ASTWriter::WriteSubmodules(Module *WritingModule) {
2526   // Enter the submodule description block.
2527   Stream.EnterSubblock(SUBMODULE_BLOCK_ID, /*bits for abbreviations*/5);
2528 
2529   // Write the abbreviations needed for the submodules block.
2530   using namespace llvm;
2531 
2532   auto *Abbrev = new BitCodeAbbrev();
2533   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_DEFINITION));
2534   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ID
2535   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Parent
2536   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsFramework
2537   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsExplicit
2538   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsSystem
2539   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsExternC
2540   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // InferSubmodules...
2541   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // InferExplicit...
2542   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // InferExportWild...
2543   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // ConfigMacrosExh...
2544   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2545   unsigned DefinitionAbbrev = Stream.EmitAbbrev(Abbrev);
2546 
2547   Abbrev = new BitCodeAbbrev();
2548   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_UMBRELLA_HEADER));
2549   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2550   unsigned UmbrellaAbbrev = Stream.EmitAbbrev(Abbrev);
2551 
2552   Abbrev = new BitCodeAbbrev();
2553   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_HEADER));
2554   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2555   unsigned HeaderAbbrev = Stream.EmitAbbrev(Abbrev);
2556 
2557   Abbrev = new BitCodeAbbrev();
2558   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_TOPHEADER));
2559   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2560   unsigned TopHeaderAbbrev = Stream.EmitAbbrev(Abbrev);
2561 
2562   Abbrev = new BitCodeAbbrev();
2563   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_UMBRELLA_DIR));
2564   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2565   unsigned UmbrellaDirAbbrev = Stream.EmitAbbrev(Abbrev);
2566 
2567   Abbrev = new BitCodeAbbrev();
2568   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_REQUIRES));
2569   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // State
2570   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));     // Feature
2571   unsigned RequiresAbbrev = Stream.EmitAbbrev(Abbrev);
2572 
2573   Abbrev = new BitCodeAbbrev();
2574   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_EXCLUDED_HEADER));
2575   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2576   unsigned ExcludedHeaderAbbrev = Stream.EmitAbbrev(Abbrev);
2577 
2578   Abbrev = new BitCodeAbbrev();
2579   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_TEXTUAL_HEADER));
2580   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2581   unsigned TextualHeaderAbbrev = Stream.EmitAbbrev(Abbrev);
2582 
2583   Abbrev = new BitCodeAbbrev();
2584   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_PRIVATE_HEADER));
2585   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2586   unsigned PrivateHeaderAbbrev = Stream.EmitAbbrev(Abbrev);
2587 
2588   Abbrev = new BitCodeAbbrev();
2589   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_PRIVATE_TEXTUAL_HEADER));
2590   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2591   unsigned PrivateTextualHeaderAbbrev = Stream.EmitAbbrev(Abbrev);
2592 
2593   Abbrev = new BitCodeAbbrev();
2594   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_LINK_LIBRARY));
2595   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsFramework
2596   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));     // Name
2597   unsigned LinkLibraryAbbrev = Stream.EmitAbbrev(Abbrev);
2598 
2599   Abbrev = new BitCodeAbbrev();
2600   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_CONFIG_MACRO));
2601   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));    // Macro name
2602   unsigned ConfigMacroAbbrev = Stream.EmitAbbrev(Abbrev);
2603 
2604   Abbrev = new BitCodeAbbrev();
2605   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_CONFLICT));
2606   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));  // Other module
2607   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));    // Message
2608   unsigned ConflictAbbrev = Stream.EmitAbbrev(Abbrev);
2609 
2610   // Write the submodule metadata block.
2611   RecordData::value_type Record[] = {getNumberOfModules(WritingModule),
2612                                      FirstSubmoduleID -
2613                                          NUM_PREDEF_SUBMODULE_IDS};
2614   Stream.EmitRecord(SUBMODULE_METADATA, Record);
2615 
2616   // Write all of the submodules.
2617   std::queue<Module *> Q;
2618   Q.push(WritingModule);
2619   while (!Q.empty()) {
2620     Module *Mod = Q.front();
2621     Q.pop();
2622     unsigned ID = getSubmoduleID(Mod);
2623 
2624     uint64_t ParentID = 0;
2625     if (Mod->Parent) {
2626       assert(SubmoduleIDs[Mod->Parent] && "Submodule parent not written?");
2627       ParentID = SubmoduleIDs[Mod->Parent];
2628     }
2629 
2630     // Emit the definition of the block.
2631     {
2632       RecordData::value_type Record[] = {
2633           SUBMODULE_DEFINITION, ID, ParentID, Mod->IsFramework, Mod->IsExplicit,
2634           Mod->IsSystem, Mod->IsExternC, Mod->InferSubmodules,
2635           Mod->InferExplicitSubmodules, Mod->InferExportWildcard,
2636           Mod->ConfigMacrosExhaustive};
2637       Stream.EmitRecordWithBlob(DefinitionAbbrev, Record, Mod->Name);
2638     }
2639 
2640     // Emit the requirements.
2641     for (const auto &R : Mod->Requirements) {
2642       RecordData::value_type Record[] = {SUBMODULE_REQUIRES, R.second};
2643       Stream.EmitRecordWithBlob(RequiresAbbrev, Record, R.first);
2644     }
2645 
2646     // Emit the umbrella header, if there is one.
2647     if (auto UmbrellaHeader = Mod->getUmbrellaHeader()) {
2648       RecordData::value_type Record[] = {SUBMODULE_UMBRELLA_HEADER};
2649       Stream.EmitRecordWithBlob(UmbrellaAbbrev, Record,
2650                                 UmbrellaHeader.NameAsWritten);
2651     } else if (auto UmbrellaDir = Mod->getUmbrellaDir()) {
2652       RecordData::value_type Record[] = {SUBMODULE_UMBRELLA_DIR};
2653       Stream.EmitRecordWithBlob(UmbrellaDirAbbrev, Record,
2654                                 UmbrellaDir.NameAsWritten);
2655     }
2656 
2657     // Emit the headers.
2658     struct {
2659       unsigned RecordKind;
2660       unsigned Abbrev;
2661       Module::HeaderKind HeaderKind;
2662     } HeaderLists[] = {
2663       {SUBMODULE_HEADER, HeaderAbbrev, Module::HK_Normal},
2664       {SUBMODULE_TEXTUAL_HEADER, TextualHeaderAbbrev, Module::HK_Textual},
2665       {SUBMODULE_PRIVATE_HEADER, PrivateHeaderAbbrev, Module::HK_Private},
2666       {SUBMODULE_PRIVATE_TEXTUAL_HEADER, PrivateTextualHeaderAbbrev,
2667         Module::HK_PrivateTextual},
2668       {SUBMODULE_EXCLUDED_HEADER, ExcludedHeaderAbbrev, Module::HK_Excluded}
2669     };
2670     for (auto &HL : HeaderLists) {
2671       RecordData::value_type Record[] = {HL.RecordKind};
2672       for (auto &H : Mod->Headers[HL.HeaderKind])
2673         Stream.EmitRecordWithBlob(HL.Abbrev, Record, H.NameAsWritten);
2674     }
2675 
2676     // Emit the top headers.
2677     {
2678       auto TopHeaders = Mod->getTopHeaders(PP->getFileManager());
2679       RecordData::value_type Record[] = {SUBMODULE_TOPHEADER};
2680       for (auto *H : TopHeaders)
2681         Stream.EmitRecordWithBlob(TopHeaderAbbrev, Record, H->getName());
2682     }
2683 
2684     // Emit the imports.
2685     if (!Mod->Imports.empty()) {
2686       RecordData Record;
2687       for (auto *I : Mod->Imports)
2688         Record.push_back(getSubmoduleID(I));
2689       Stream.EmitRecord(SUBMODULE_IMPORTS, Record);
2690     }
2691 
2692     // Emit the exports.
2693     if (!Mod->Exports.empty()) {
2694       RecordData Record;
2695       for (const auto &E : Mod->Exports) {
2696         // FIXME: This may fail; we don't require that all exported modules
2697         // are local or imported.
2698         Record.push_back(getSubmoduleID(E.getPointer()));
2699         Record.push_back(E.getInt());
2700       }
2701       Stream.EmitRecord(SUBMODULE_EXPORTS, Record);
2702     }
2703 
2704     //FIXME: How do we emit the 'use'd modules?  They may not be submodules.
2705     // Might be unnecessary as use declarations are only used to build the
2706     // module itself.
2707 
2708     // Emit the link libraries.
2709     for (const auto &LL : Mod->LinkLibraries) {
2710       RecordData::value_type Record[] = {SUBMODULE_LINK_LIBRARY,
2711                                          LL.IsFramework};
2712       Stream.EmitRecordWithBlob(LinkLibraryAbbrev, Record, LL.Library);
2713     }
2714 
2715     // Emit the conflicts.
2716     for (const auto &C : Mod->Conflicts) {
2717       // FIXME: This may fail; we don't require that all conflicting modules
2718       // are local or imported.
2719       RecordData::value_type Record[] = {SUBMODULE_CONFLICT,
2720                                          getSubmoduleID(C.Other)};
2721       Stream.EmitRecordWithBlob(ConflictAbbrev, Record, C.Message);
2722     }
2723 
2724     // Emit the configuration macros.
2725     for (const auto &CM : Mod->ConfigMacros) {
2726       RecordData::value_type Record[] = {SUBMODULE_CONFIG_MACRO};
2727       Stream.EmitRecordWithBlob(ConfigMacroAbbrev, Record, CM);
2728     }
2729 
2730     // Emit the initializers, if any.
2731     RecordData Inits;
2732     for (Decl *D : Context->getModuleInitializers(Mod))
2733       Inits.push_back(GetDeclRef(D));
2734     if (!Inits.empty())
2735       Stream.EmitRecord(SUBMODULE_INITIALIZERS, Inits);
2736 
2737     // Queue up the submodules of this module.
2738     for (auto *M : Mod->submodules())
2739       Q.push(M);
2740   }
2741 
2742   Stream.ExitBlock();
2743 
2744   assert((NextSubmoduleID - FirstSubmoduleID ==
2745           getNumberOfModules(WritingModule)) &&
2746          "Wrong # of submodules; found a reference to a non-local, "
2747          "non-imported submodule?");
2748 }
2749 
2750 serialization::SubmoduleID
2751 ASTWriter::inferSubmoduleIDFromLocation(SourceLocation Loc) {
2752   if (Loc.isInvalid() || !WritingModule)
2753     return 0; // No submodule
2754 
2755   // Find the module that owns this location.
2756   ModuleMap &ModMap = PP->getHeaderSearchInfo().getModuleMap();
2757   Module *OwningMod
2758     = ModMap.inferModuleFromLocation(FullSourceLoc(Loc,PP->getSourceManager()));
2759   if (!OwningMod)
2760     return 0;
2761 
2762   // Check whether this submodule is part of our own module.
2763   if (WritingModule != OwningMod && !OwningMod->isSubModuleOf(WritingModule))
2764     return 0;
2765 
2766   return getSubmoduleID(OwningMod);
2767 }
2768 
2769 void ASTWriter::WritePragmaDiagnosticMappings(const DiagnosticsEngine &Diag,
2770                                               bool isModule) {
2771   // Make sure set diagnostic pragmas don't affect the translation unit that
2772   // imports the module.
2773   // FIXME: Make diagnostic pragma sections work properly with modules.
2774   if (isModule)
2775     return;
2776 
2777   llvm::SmallDenseMap<const DiagnosticsEngine::DiagState *, unsigned, 64>
2778       DiagStateIDMap;
2779   unsigned CurrID = 0;
2780   DiagStateIDMap[&Diag.DiagStates.front()] = ++CurrID; // the command-line one.
2781   RecordData Record;
2782   for (DiagnosticsEngine::DiagStatePointsTy::const_iterator
2783          I = Diag.DiagStatePoints.begin(), E = Diag.DiagStatePoints.end();
2784          I != E; ++I) {
2785     const DiagnosticsEngine::DiagStatePoint &point = *I;
2786     if (point.Loc.isInvalid())
2787       continue;
2788 
2789     AddSourceLocation(point.Loc, Record);
2790     unsigned &DiagStateID = DiagStateIDMap[point.State];
2791     Record.push_back(DiagStateID);
2792 
2793     if (DiagStateID == 0) {
2794       DiagStateID = ++CurrID;
2795       for (const auto &I : *(point.State)) {
2796         if (I.second.isPragma()) {
2797           Record.push_back(I.first);
2798           Record.push_back((unsigned)I.second.getSeverity());
2799         }
2800       }
2801       Record.push_back(-1); // mark the end of the diag/map pairs for this
2802                             // location.
2803     }
2804   }
2805 
2806   if (!Record.empty())
2807     Stream.EmitRecord(DIAG_PRAGMA_MAPPINGS, Record);
2808 }
2809 
2810 //===----------------------------------------------------------------------===//
2811 // Type Serialization
2812 //===----------------------------------------------------------------------===//
2813 
2814 /// \brief Write the representation of a type to the AST stream.
2815 void ASTWriter::WriteType(QualType T) {
2816   TypeIdx &IdxRef = TypeIdxs[T];
2817   if (IdxRef.getIndex() == 0) // we haven't seen this type before.
2818     IdxRef = TypeIdx(NextTypeID++);
2819   TypeIdx Idx = IdxRef;
2820 
2821   assert(Idx.getIndex() >= FirstTypeID && "Re-writing a type from a prior AST");
2822 
2823   RecordData Record;
2824 
2825   // Emit the type's representation.
2826   ASTTypeWriter W(*this, Record);
2827   W.Visit(T);
2828   uint64_t Offset = W.Emit();
2829 
2830   // Record the offset for this type.
2831   unsigned Index = Idx.getIndex() - FirstTypeID;
2832   if (TypeOffsets.size() == Index)
2833     TypeOffsets.push_back(Offset);
2834   else if (TypeOffsets.size() < Index) {
2835     TypeOffsets.resize(Index + 1);
2836     TypeOffsets[Index] = Offset;
2837   } else {
2838     llvm_unreachable("Types emitted in wrong order");
2839   }
2840 }
2841 
2842 //===----------------------------------------------------------------------===//
2843 // Declaration Serialization
2844 //===----------------------------------------------------------------------===//
2845 
2846 /// \brief Write the block containing all of the declaration IDs
2847 /// lexically declared within the given DeclContext.
2848 ///
2849 /// \returns the offset of the DECL_CONTEXT_LEXICAL block within the
2850 /// bistream, or 0 if no block was written.
2851 uint64_t ASTWriter::WriteDeclContextLexicalBlock(ASTContext &Context,
2852                                                  DeclContext *DC) {
2853   if (DC->decls_empty())
2854     return 0;
2855 
2856   uint64_t Offset = Stream.GetCurrentBitNo();
2857   SmallVector<uint32_t, 128> KindDeclPairs;
2858   for (const auto *D : DC->decls()) {
2859     KindDeclPairs.push_back(D->getKind());
2860     KindDeclPairs.push_back(GetDeclRef(D));
2861   }
2862 
2863   ++NumLexicalDeclContexts;
2864   RecordData::value_type Record[] = {DECL_CONTEXT_LEXICAL};
2865   Stream.EmitRecordWithBlob(DeclContextLexicalAbbrev, Record,
2866                             bytes(KindDeclPairs));
2867   return Offset;
2868 }
2869 
2870 void ASTWriter::WriteTypeDeclOffsets() {
2871   using namespace llvm;
2872 
2873   // Write the type offsets array
2874   auto *Abbrev = new BitCodeAbbrev();
2875   Abbrev->Add(BitCodeAbbrevOp(TYPE_OFFSET));
2876   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // # of types
2877   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // base type index
2878   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // types block
2879   unsigned TypeOffsetAbbrev = Stream.EmitAbbrev(Abbrev);
2880   {
2881     RecordData::value_type Record[] = {TYPE_OFFSET, TypeOffsets.size(),
2882                                        FirstTypeID - NUM_PREDEF_TYPE_IDS};
2883     Stream.EmitRecordWithBlob(TypeOffsetAbbrev, Record, bytes(TypeOffsets));
2884   }
2885 
2886   // Write the declaration offsets array
2887   Abbrev = new BitCodeAbbrev();
2888   Abbrev->Add(BitCodeAbbrevOp(DECL_OFFSET));
2889   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // # of declarations
2890   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // base decl ID
2891   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // declarations block
2892   unsigned DeclOffsetAbbrev = Stream.EmitAbbrev(Abbrev);
2893   {
2894     RecordData::value_type Record[] = {DECL_OFFSET, DeclOffsets.size(),
2895                                        FirstDeclID - NUM_PREDEF_DECL_IDS};
2896     Stream.EmitRecordWithBlob(DeclOffsetAbbrev, Record, bytes(DeclOffsets));
2897   }
2898 }
2899 
2900 void ASTWriter::WriteFileDeclIDsMap() {
2901   using namespace llvm;
2902 
2903   SmallVector<std::pair<FileID, DeclIDInFileInfo *>, 64> SortedFileDeclIDs(
2904       FileDeclIDs.begin(), FileDeclIDs.end());
2905   std::sort(SortedFileDeclIDs.begin(), SortedFileDeclIDs.end(),
2906             llvm::less_first());
2907 
2908   // Join the vectors of DeclIDs from all files.
2909   SmallVector<DeclID, 256> FileGroupedDeclIDs;
2910   for (auto &FileDeclEntry : SortedFileDeclIDs) {
2911     DeclIDInFileInfo &Info = *FileDeclEntry.second;
2912     Info.FirstDeclIndex = FileGroupedDeclIDs.size();
2913     for (auto &LocDeclEntry : Info.DeclIDs)
2914       FileGroupedDeclIDs.push_back(LocDeclEntry.second);
2915   }
2916 
2917   auto *Abbrev = new BitCodeAbbrev();
2918   Abbrev->Add(BitCodeAbbrevOp(FILE_SORTED_DECLS));
2919   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
2920   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2921   unsigned AbbrevCode = Stream.EmitAbbrev(Abbrev);
2922   RecordData::value_type Record[] = {FILE_SORTED_DECLS,
2923                                      FileGroupedDeclIDs.size()};
2924   Stream.EmitRecordWithBlob(AbbrevCode, Record, bytes(FileGroupedDeclIDs));
2925 }
2926 
2927 void ASTWriter::WriteComments() {
2928   Stream.EnterSubblock(COMMENTS_BLOCK_ID, 3);
2929   ArrayRef<RawComment *> RawComments = Context->Comments.getComments();
2930   RecordData Record;
2931   for (const auto *I : RawComments) {
2932     Record.clear();
2933     AddSourceRange(I->getSourceRange(), Record);
2934     Record.push_back(I->getKind());
2935     Record.push_back(I->isTrailingComment());
2936     Record.push_back(I->isAlmostTrailingComment());
2937     Stream.EmitRecord(COMMENTS_RAW_COMMENT, Record);
2938   }
2939   Stream.ExitBlock();
2940 }
2941 
2942 //===----------------------------------------------------------------------===//
2943 // Global Method Pool and Selector Serialization
2944 //===----------------------------------------------------------------------===//
2945 
2946 namespace {
2947 
2948 // Trait used for the on-disk hash table used in the method pool.
2949 class ASTMethodPoolTrait {
2950   ASTWriter &Writer;
2951 
2952 public:
2953   typedef Selector key_type;
2954   typedef key_type key_type_ref;
2955 
2956   struct data_type {
2957     SelectorID ID;
2958     ObjCMethodList Instance, Factory;
2959   };
2960   typedef const data_type& data_type_ref;
2961 
2962   typedef unsigned hash_value_type;
2963   typedef unsigned offset_type;
2964 
2965   explicit ASTMethodPoolTrait(ASTWriter &Writer) : Writer(Writer) { }
2966 
2967   static hash_value_type ComputeHash(Selector Sel) {
2968     return serialization::ComputeHash(Sel);
2969   }
2970 
2971   std::pair<unsigned,unsigned>
2972     EmitKeyDataLength(raw_ostream& Out, Selector Sel,
2973                       data_type_ref Methods) {
2974     using namespace llvm::support;
2975     endian::Writer<little> LE(Out);
2976     unsigned KeyLen = 2 + (Sel.getNumArgs()? Sel.getNumArgs() * 4 : 4);
2977     LE.write<uint16_t>(KeyLen);
2978     unsigned DataLen = 4 + 2 + 2; // 2 bytes for each of the method counts
2979     for (const ObjCMethodList *Method = &Methods.Instance; Method;
2980          Method = Method->getNext())
2981       if (Method->getMethod())
2982         DataLen += 4;
2983     for (const ObjCMethodList *Method = &Methods.Factory; Method;
2984          Method = Method->getNext())
2985       if (Method->getMethod())
2986         DataLen += 4;
2987     LE.write<uint16_t>(DataLen);
2988     return std::make_pair(KeyLen, DataLen);
2989   }
2990 
2991   void EmitKey(raw_ostream& Out, Selector Sel, unsigned) {
2992     using namespace llvm::support;
2993     endian::Writer<little> LE(Out);
2994     uint64_t Start = Out.tell();
2995     assert((Start >> 32) == 0 && "Selector key offset too large");
2996     Writer.SetSelectorOffset(Sel, Start);
2997     unsigned N = Sel.getNumArgs();
2998     LE.write<uint16_t>(N);
2999     if (N == 0)
3000       N = 1;
3001     for (unsigned I = 0; I != N; ++I)
3002       LE.write<uint32_t>(
3003           Writer.getIdentifierRef(Sel.getIdentifierInfoForSlot(I)));
3004   }
3005 
3006   void EmitData(raw_ostream& Out, key_type_ref,
3007                 data_type_ref Methods, unsigned DataLen) {
3008     using namespace llvm::support;
3009     endian::Writer<little> LE(Out);
3010     uint64_t Start = Out.tell(); (void)Start;
3011     LE.write<uint32_t>(Methods.ID);
3012     unsigned NumInstanceMethods = 0;
3013     for (const ObjCMethodList *Method = &Methods.Instance; Method;
3014          Method = Method->getNext())
3015       if (Method->getMethod())
3016         ++NumInstanceMethods;
3017 
3018     unsigned NumFactoryMethods = 0;
3019     for (const ObjCMethodList *Method = &Methods.Factory; Method;
3020          Method = Method->getNext())
3021       if (Method->getMethod())
3022         ++NumFactoryMethods;
3023 
3024     unsigned InstanceBits = Methods.Instance.getBits();
3025     assert(InstanceBits < 4);
3026     unsigned InstanceHasMoreThanOneDeclBit =
3027         Methods.Instance.hasMoreThanOneDecl();
3028     unsigned FullInstanceBits = (NumInstanceMethods << 3) |
3029                                 (InstanceHasMoreThanOneDeclBit << 2) |
3030                                 InstanceBits;
3031     unsigned FactoryBits = Methods.Factory.getBits();
3032     assert(FactoryBits < 4);
3033     unsigned FactoryHasMoreThanOneDeclBit =
3034         Methods.Factory.hasMoreThanOneDecl();
3035     unsigned FullFactoryBits = (NumFactoryMethods << 3) |
3036                                (FactoryHasMoreThanOneDeclBit << 2) |
3037                                FactoryBits;
3038     LE.write<uint16_t>(FullInstanceBits);
3039     LE.write<uint16_t>(FullFactoryBits);
3040     for (const ObjCMethodList *Method = &Methods.Instance; Method;
3041          Method = Method->getNext())
3042       if (Method->getMethod())
3043         LE.write<uint32_t>(Writer.getDeclID(Method->getMethod()));
3044     for (const ObjCMethodList *Method = &Methods.Factory; Method;
3045          Method = Method->getNext())
3046       if (Method->getMethod())
3047         LE.write<uint32_t>(Writer.getDeclID(Method->getMethod()));
3048 
3049     assert(Out.tell() - Start == DataLen && "Data length is wrong");
3050   }
3051 };
3052 
3053 } // end anonymous namespace
3054 
3055 /// \brief Write ObjC data: selectors and the method pool.
3056 ///
3057 /// The method pool contains both instance and factory methods, stored
3058 /// in an on-disk hash table indexed by the selector. The hash table also
3059 /// contains an empty entry for every other selector known to Sema.
3060 void ASTWriter::WriteSelectors(Sema &SemaRef) {
3061   using namespace llvm;
3062 
3063   // Do we have to do anything at all?
3064   if (SemaRef.MethodPool.empty() && SelectorIDs.empty())
3065     return;
3066   unsigned NumTableEntries = 0;
3067   // Create and write out the blob that contains selectors and the method pool.
3068   {
3069     llvm::OnDiskChainedHashTableGenerator<ASTMethodPoolTrait> Generator;
3070     ASTMethodPoolTrait Trait(*this);
3071 
3072     // Create the on-disk hash table representation. We walk through every
3073     // selector we've seen and look it up in the method pool.
3074     SelectorOffsets.resize(NextSelectorID - FirstSelectorID);
3075     for (auto &SelectorAndID : SelectorIDs) {
3076       Selector S = SelectorAndID.first;
3077       SelectorID ID = SelectorAndID.second;
3078       Sema::GlobalMethodPool::iterator F = SemaRef.MethodPool.find(S);
3079       ASTMethodPoolTrait::data_type Data = {
3080         ID,
3081         ObjCMethodList(),
3082         ObjCMethodList()
3083       };
3084       if (F != SemaRef.MethodPool.end()) {
3085         Data.Instance = F->second.first;
3086         Data.Factory = F->second.second;
3087       }
3088       // Only write this selector if it's not in an existing AST or something
3089       // changed.
3090       if (Chain && ID < FirstSelectorID) {
3091         // Selector already exists. Did it change?
3092         bool changed = false;
3093         for (ObjCMethodList *M = &Data.Instance;
3094              !changed && M && M->getMethod(); M = M->getNext()) {
3095           if (!M->getMethod()->isFromASTFile())
3096             changed = true;
3097         }
3098         for (ObjCMethodList *M = &Data.Factory; !changed && M && M->getMethod();
3099              M = M->getNext()) {
3100           if (!M->getMethod()->isFromASTFile())
3101             changed = true;
3102         }
3103         if (!changed)
3104           continue;
3105       } else if (Data.Instance.getMethod() || Data.Factory.getMethod()) {
3106         // A new method pool entry.
3107         ++NumTableEntries;
3108       }
3109       Generator.insert(S, Data, Trait);
3110     }
3111 
3112     // Create the on-disk hash table in a buffer.
3113     SmallString<4096> MethodPool;
3114     uint32_t BucketOffset;
3115     {
3116       using namespace llvm::support;
3117       ASTMethodPoolTrait Trait(*this);
3118       llvm::raw_svector_ostream Out(MethodPool);
3119       // Make sure that no bucket is at offset 0
3120       endian::Writer<little>(Out).write<uint32_t>(0);
3121       BucketOffset = Generator.Emit(Out, Trait);
3122     }
3123 
3124     // Create a blob abbreviation
3125     auto *Abbrev = new BitCodeAbbrev();
3126     Abbrev->Add(BitCodeAbbrevOp(METHOD_POOL));
3127     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
3128     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
3129     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
3130     unsigned MethodPoolAbbrev = Stream.EmitAbbrev(Abbrev);
3131 
3132     // Write the method pool
3133     {
3134       RecordData::value_type Record[] = {METHOD_POOL, BucketOffset,
3135                                          NumTableEntries};
3136       Stream.EmitRecordWithBlob(MethodPoolAbbrev, Record, MethodPool);
3137     }
3138 
3139     // Create a blob abbreviation for the selector table offsets.
3140     Abbrev = new BitCodeAbbrev();
3141     Abbrev->Add(BitCodeAbbrevOp(SELECTOR_OFFSETS));
3142     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // size
3143     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // first ID
3144     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
3145     unsigned SelectorOffsetAbbrev = Stream.EmitAbbrev(Abbrev);
3146 
3147     // Write the selector offsets table.
3148     {
3149       RecordData::value_type Record[] = {
3150           SELECTOR_OFFSETS, SelectorOffsets.size(),
3151           FirstSelectorID - NUM_PREDEF_SELECTOR_IDS};
3152       Stream.EmitRecordWithBlob(SelectorOffsetAbbrev, Record,
3153                                 bytes(SelectorOffsets));
3154     }
3155   }
3156 }
3157 
3158 /// \brief Write the selectors referenced in @selector expression into AST file.
3159 void ASTWriter::WriteReferencedSelectorsPool(Sema &SemaRef) {
3160   using namespace llvm;
3161   if (SemaRef.ReferencedSelectors.empty())
3162     return;
3163 
3164   RecordData Record;
3165   ASTRecordWriter Writer(*this, Record);
3166 
3167   // Note: this writes out all references even for a dependent AST. But it is
3168   // very tricky to fix, and given that @selector shouldn't really appear in
3169   // headers, probably not worth it. It's not a correctness issue.
3170   for (auto &SelectorAndLocation : SemaRef.ReferencedSelectors) {
3171     Selector Sel = SelectorAndLocation.first;
3172     SourceLocation Loc = SelectorAndLocation.second;
3173     Writer.AddSelectorRef(Sel);
3174     Writer.AddSourceLocation(Loc);
3175   }
3176   Writer.Emit(REFERENCED_SELECTOR_POOL);
3177 }
3178 
3179 //===----------------------------------------------------------------------===//
3180 // Identifier Table Serialization
3181 //===----------------------------------------------------------------------===//
3182 
3183 /// Determine the declaration that should be put into the name lookup table to
3184 /// represent the given declaration in this module. This is usually D itself,
3185 /// but if D was imported and merged into a local declaration, we want the most
3186 /// recent local declaration instead. The chosen declaration will be the most
3187 /// recent declaration in any module that imports this one.
3188 static NamedDecl *getDeclForLocalLookup(const LangOptions &LangOpts,
3189                                         NamedDecl *D) {
3190   if (!LangOpts.Modules || !D->isFromASTFile())
3191     return D;
3192 
3193   if (Decl *Redecl = D->getPreviousDecl()) {
3194     // For Redeclarable decls, a prior declaration might be local.
3195     for (; Redecl; Redecl = Redecl->getPreviousDecl()) {
3196       // If we find a local decl, we're done.
3197       if (!Redecl->isFromASTFile()) {
3198         // Exception: in very rare cases (for injected-class-names), not all
3199         // redeclarations are in the same semantic context. Skip ones in a
3200         // different context. They don't go in this lookup table at all.
3201         if (!Redecl->getDeclContext()->getRedeclContext()->Equals(
3202                 D->getDeclContext()->getRedeclContext()))
3203           continue;
3204         return cast<NamedDecl>(Redecl);
3205       }
3206 
3207       // If we find a decl from a (chained-)PCH stop since we won't find a
3208       // local one.
3209       if (Redecl->getOwningModuleID() == 0)
3210         break;
3211     }
3212   } else if (Decl *First = D->getCanonicalDecl()) {
3213     // For Mergeable decls, the first decl might be local.
3214     if (!First->isFromASTFile())
3215       return cast<NamedDecl>(First);
3216   }
3217 
3218   // All declarations are imported. Our most recent declaration will also be
3219   // the most recent one in anyone who imports us.
3220   return D;
3221 }
3222 
3223 namespace {
3224 
3225 class ASTIdentifierTableTrait {
3226   ASTWriter &Writer;
3227   Preprocessor &PP;
3228   IdentifierResolver &IdResolver;
3229   bool IsModule;
3230   bool NeedDecls;
3231   ASTWriter::RecordData *InterestingIdentifierOffsets;
3232 
3233   /// \brief Determines whether this is an "interesting" identifier that needs a
3234   /// full IdentifierInfo structure written into the hash table. Notably, this
3235   /// doesn't check whether the name has macros defined; use PublicMacroIterator
3236   /// to check that.
3237   bool isInterestingIdentifier(const IdentifierInfo *II, uint64_t MacroOffset) {
3238     if (MacroOffset ||
3239         II->isPoisoned() ||
3240         (IsModule ? II->hasRevertedBuiltin() : II->getObjCOrBuiltinID()) ||
3241         II->hasRevertedTokenIDToIdentifier() ||
3242         (NeedDecls && II->getFETokenInfo<void>()))
3243       return true;
3244 
3245     return false;
3246   }
3247 
3248 public:
3249   typedef IdentifierInfo* key_type;
3250   typedef key_type  key_type_ref;
3251 
3252   typedef IdentID data_type;
3253   typedef data_type data_type_ref;
3254 
3255   typedef unsigned hash_value_type;
3256   typedef unsigned offset_type;
3257 
3258   ASTIdentifierTableTrait(ASTWriter &Writer, Preprocessor &PP,
3259                           IdentifierResolver &IdResolver, bool IsModule,
3260                           ASTWriter::RecordData *InterestingIdentifierOffsets)
3261       : Writer(Writer), PP(PP), IdResolver(IdResolver), IsModule(IsModule),
3262         NeedDecls(!IsModule || !Writer.getLangOpts().CPlusPlus),
3263         InterestingIdentifierOffsets(InterestingIdentifierOffsets) {}
3264 
3265   bool needDecls() const { return NeedDecls; }
3266 
3267   static hash_value_type ComputeHash(const IdentifierInfo* II) {
3268     return llvm::HashString(II->getName());
3269   }
3270 
3271   bool isInterestingIdentifier(const IdentifierInfo *II) {
3272     auto MacroOffset = Writer.getMacroDirectivesOffset(II);
3273     return isInterestingIdentifier(II, MacroOffset);
3274   }
3275 
3276   bool isInterestingNonMacroIdentifier(const IdentifierInfo *II) {
3277     return isInterestingIdentifier(II, 0);
3278   }
3279 
3280   std::pair<unsigned,unsigned>
3281   EmitKeyDataLength(raw_ostream& Out, IdentifierInfo* II, IdentID ID) {
3282     unsigned KeyLen = II->getLength() + 1;
3283     unsigned DataLen = 4; // 4 bytes for the persistent ID << 1
3284     auto MacroOffset = Writer.getMacroDirectivesOffset(II);
3285     if (isInterestingIdentifier(II, MacroOffset)) {
3286       DataLen += 2; // 2 bytes for builtin ID
3287       DataLen += 2; // 2 bytes for flags
3288       if (MacroOffset)
3289         DataLen += 4; // MacroDirectives offset.
3290 
3291       if (NeedDecls) {
3292         for (IdentifierResolver::iterator D = IdResolver.begin(II),
3293                                        DEnd = IdResolver.end();
3294              D != DEnd; ++D)
3295           DataLen += 4;
3296       }
3297     }
3298     using namespace llvm::support;
3299     endian::Writer<little> LE(Out);
3300 
3301     assert((uint16_t)DataLen == DataLen && (uint16_t)KeyLen == KeyLen);
3302     LE.write<uint16_t>(DataLen);
3303     // We emit the key length after the data length so that every
3304     // string is preceded by a 16-bit length. This matches the PTH
3305     // format for storing identifiers.
3306     LE.write<uint16_t>(KeyLen);
3307     return std::make_pair(KeyLen, DataLen);
3308   }
3309 
3310   void EmitKey(raw_ostream& Out, const IdentifierInfo* II,
3311                unsigned KeyLen) {
3312     // Record the location of the key data.  This is used when generating
3313     // the mapping from persistent IDs to strings.
3314     Writer.SetIdentifierOffset(II, Out.tell());
3315 
3316     // Emit the offset of the key/data length information to the interesting
3317     // identifiers table if necessary.
3318     if (InterestingIdentifierOffsets && isInterestingIdentifier(II))
3319       InterestingIdentifierOffsets->push_back(Out.tell() - 4);
3320 
3321     Out.write(II->getNameStart(), KeyLen);
3322   }
3323 
3324   void EmitData(raw_ostream& Out, IdentifierInfo* II,
3325                 IdentID ID, unsigned) {
3326     using namespace llvm::support;
3327     endian::Writer<little> LE(Out);
3328 
3329     auto MacroOffset = Writer.getMacroDirectivesOffset(II);
3330     if (!isInterestingIdentifier(II, MacroOffset)) {
3331       LE.write<uint32_t>(ID << 1);
3332       return;
3333     }
3334 
3335     LE.write<uint32_t>((ID << 1) | 0x01);
3336     uint32_t Bits = (uint32_t)II->getObjCOrBuiltinID();
3337     assert((Bits & 0xffff) == Bits && "ObjCOrBuiltinID too big for ASTReader.");
3338     LE.write<uint16_t>(Bits);
3339     Bits = 0;
3340     bool HadMacroDefinition = MacroOffset != 0;
3341     Bits = (Bits << 1) | unsigned(HadMacroDefinition);
3342     Bits = (Bits << 1) | unsigned(II->isExtensionToken());
3343     Bits = (Bits << 1) | unsigned(II->isPoisoned());
3344     Bits = (Bits << 1) | unsigned(II->hasRevertedBuiltin());
3345     Bits = (Bits << 1) | unsigned(II->hasRevertedTokenIDToIdentifier());
3346     Bits = (Bits << 1) | unsigned(II->isCPlusPlusOperatorKeyword());
3347     LE.write<uint16_t>(Bits);
3348 
3349     if (HadMacroDefinition)
3350       LE.write<uint32_t>(MacroOffset);
3351 
3352     if (NeedDecls) {
3353       // Emit the declaration IDs in reverse order, because the
3354       // IdentifierResolver provides the declarations as they would be
3355       // visible (e.g., the function "stat" would come before the struct
3356       // "stat"), but the ASTReader adds declarations to the end of the list
3357       // (so we need to see the struct "stat" before the function "stat").
3358       // Only emit declarations that aren't from a chained PCH, though.
3359       SmallVector<NamedDecl *, 16> Decls(IdResolver.begin(II),
3360                                          IdResolver.end());
3361       for (SmallVectorImpl<NamedDecl *>::reverse_iterator D = Decls.rbegin(),
3362                                                           DEnd = Decls.rend();
3363            D != DEnd; ++D)
3364         LE.write<uint32_t>(
3365             Writer.getDeclID(getDeclForLocalLookup(PP.getLangOpts(), *D)));
3366     }
3367   }
3368 };
3369 
3370 } // end anonymous namespace
3371 
3372 /// \brief Write the identifier table into the AST file.
3373 ///
3374 /// The identifier table consists of a blob containing string data
3375 /// (the actual identifiers themselves) and a separate "offsets" index
3376 /// that maps identifier IDs to locations within the blob.
3377 void ASTWriter::WriteIdentifierTable(Preprocessor &PP,
3378                                      IdentifierResolver &IdResolver,
3379                                      bool IsModule) {
3380   using namespace llvm;
3381 
3382   RecordData InterestingIdents;
3383 
3384   // Create and write out the blob that contains the identifier
3385   // strings.
3386   {
3387     llvm::OnDiskChainedHashTableGenerator<ASTIdentifierTableTrait> Generator;
3388     ASTIdentifierTableTrait Trait(
3389         *this, PP, IdResolver, IsModule,
3390         (getLangOpts().CPlusPlus && IsModule) ? &InterestingIdents : nullptr);
3391 
3392     // Look for any identifiers that were named while processing the
3393     // headers, but are otherwise not needed. We add these to the hash
3394     // table to enable checking of the predefines buffer in the case
3395     // where the user adds new macro definitions when building the AST
3396     // file.
3397     SmallVector<const IdentifierInfo *, 128> IIs;
3398     for (const auto &ID : PP.getIdentifierTable())
3399       IIs.push_back(ID.second);
3400     // Sort the identifiers lexicographically before getting them references so
3401     // that their order is stable.
3402     std::sort(IIs.begin(), IIs.end(), llvm::less_ptr<IdentifierInfo>());
3403     for (const IdentifierInfo *II : IIs)
3404       if (Trait.isInterestingNonMacroIdentifier(II))
3405         getIdentifierRef(II);
3406 
3407     // Create the on-disk hash table representation. We only store offsets
3408     // for identifiers that appear here for the first time.
3409     IdentifierOffsets.resize(NextIdentID - FirstIdentID);
3410     for (auto IdentIDPair : IdentifierIDs) {
3411       auto *II = const_cast<IdentifierInfo *>(IdentIDPair.first);
3412       IdentID ID = IdentIDPair.second;
3413       assert(II && "NULL identifier in identifier table");
3414       // Write out identifiers if either the ID is local or the identifier has
3415       // changed since it was loaded.
3416       if (ID >= FirstIdentID || !Chain || !II->isFromAST()
3417           || II->hasChangedSinceDeserialization() ||
3418           (Trait.needDecls() &&
3419            II->hasFETokenInfoChangedSinceDeserialization()))
3420         Generator.insert(II, ID, Trait);
3421     }
3422 
3423     // Create the on-disk hash table in a buffer.
3424     SmallString<4096> IdentifierTable;
3425     uint32_t BucketOffset;
3426     {
3427       using namespace llvm::support;
3428       llvm::raw_svector_ostream Out(IdentifierTable);
3429       // Make sure that no bucket is at offset 0
3430       endian::Writer<little>(Out).write<uint32_t>(0);
3431       BucketOffset = Generator.Emit(Out, Trait);
3432     }
3433 
3434     // Create a blob abbreviation
3435     auto *Abbrev = new BitCodeAbbrev();
3436     Abbrev->Add(BitCodeAbbrevOp(IDENTIFIER_TABLE));
3437     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
3438     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
3439     unsigned IDTableAbbrev = Stream.EmitAbbrev(Abbrev);
3440 
3441     // Write the identifier table
3442     RecordData::value_type Record[] = {IDENTIFIER_TABLE, BucketOffset};
3443     Stream.EmitRecordWithBlob(IDTableAbbrev, Record, IdentifierTable);
3444   }
3445 
3446   // Write the offsets table for identifier IDs.
3447   auto *Abbrev = new BitCodeAbbrev();
3448   Abbrev->Add(BitCodeAbbrevOp(IDENTIFIER_OFFSET));
3449   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // # of identifiers
3450   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // first ID
3451   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
3452   unsigned IdentifierOffsetAbbrev = Stream.EmitAbbrev(Abbrev);
3453 
3454 #ifndef NDEBUG
3455   for (unsigned I = 0, N = IdentifierOffsets.size(); I != N; ++I)
3456     assert(IdentifierOffsets[I] && "Missing identifier offset?");
3457 #endif
3458 
3459   RecordData::value_type Record[] = {IDENTIFIER_OFFSET,
3460                                      IdentifierOffsets.size(),
3461                                      FirstIdentID - NUM_PREDEF_IDENT_IDS};
3462   Stream.EmitRecordWithBlob(IdentifierOffsetAbbrev, Record,
3463                             bytes(IdentifierOffsets));
3464 
3465   // In C++, write the list of interesting identifiers (those that are
3466   // defined as macros, poisoned, or similar unusual things).
3467   if (!InterestingIdents.empty())
3468     Stream.EmitRecord(INTERESTING_IDENTIFIERS, InterestingIdents);
3469 }
3470 
3471 //===----------------------------------------------------------------------===//
3472 // DeclContext's Name Lookup Table Serialization
3473 //===----------------------------------------------------------------------===//
3474 
3475 namespace {
3476 
3477 // Trait used for the on-disk hash table used in the method pool.
3478 class ASTDeclContextNameLookupTrait {
3479   ASTWriter &Writer;
3480   llvm::SmallVector<DeclID, 64> DeclIDs;
3481 
3482 public:
3483   typedef DeclarationNameKey key_type;
3484   typedef key_type key_type_ref;
3485 
3486   /// A start and end index into DeclIDs, representing a sequence of decls.
3487   typedef std::pair<unsigned, unsigned> data_type;
3488   typedef const data_type& data_type_ref;
3489 
3490   typedef unsigned hash_value_type;
3491   typedef unsigned offset_type;
3492 
3493   explicit ASTDeclContextNameLookupTrait(ASTWriter &Writer) : Writer(Writer) { }
3494 
3495   template<typename Coll>
3496   data_type getData(const Coll &Decls) {
3497     unsigned Start = DeclIDs.size();
3498     for (NamedDecl *D : Decls) {
3499       DeclIDs.push_back(
3500           Writer.GetDeclRef(getDeclForLocalLookup(Writer.getLangOpts(), D)));
3501     }
3502     return std::make_pair(Start, DeclIDs.size());
3503   }
3504 
3505   data_type ImportData(const reader::ASTDeclContextNameLookupTrait::data_type &FromReader) {
3506     unsigned Start = DeclIDs.size();
3507     for (auto ID : FromReader)
3508       DeclIDs.push_back(ID);
3509     return std::make_pair(Start, DeclIDs.size());
3510   }
3511 
3512   static bool EqualKey(key_type_ref a, key_type_ref b) {
3513     return a == b;
3514   }
3515 
3516   hash_value_type ComputeHash(DeclarationNameKey Name) {
3517     return Name.getHash();
3518   }
3519 
3520   void EmitFileRef(raw_ostream &Out, ModuleFile *F) const {
3521     assert(Writer.hasChain() &&
3522            "have reference to loaded module file but no chain?");
3523 
3524     using namespace llvm::support;
3525     endian::Writer<little>(Out)
3526         .write<uint32_t>(Writer.getChain()->getModuleFileID(F));
3527   }
3528 
3529   std::pair<unsigned, unsigned> EmitKeyDataLength(raw_ostream &Out,
3530                                                   DeclarationNameKey Name,
3531                                                   data_type_ref Lookup) {
3532     using namespace llvm::support;
3533     endian::Writer<little> LE(Out);
3534     unsigned KeyLen = 1;
3535     switch (Name.getKind()) {
3536     case DeclarationName::Identifier:
3537     case DeclarationName::ObjCZeroArgSelector:
3538     case DeclarationName::ObjCOneArgSelector:
3539     case DeclarationName::ObjCMultiArgSelector:
3540     case DeclarationName::CXXLiteralOperatorName:
3541       KeyLen += 4;
3542       break;
3543     case DeclarationName::CXXOperatorName:
3544       KeyLen += 1;
3545       break;
3546     case DeclarationName::CXXConstructorName:
3547     case DeclarationName::CXXDestructorName:
3548     case DeclarationName::CXXConversionFunctionName:
3549     case DeclarationName::CXXUsingDirective:
3550       break;
3551     }
3552     LE.write<uint16_t>(KeyLen);
3553 
3554     // 4 bytes for each DeclID.
3555     unsigned DataLen = 4 * (Lookup.second - Lookup.first);
3556     assert(uint16_t(DataLen) == DataLen &&
3557            "too many decls for serialized lookup result");
3558     LE.write<uint16_t>(DataLen);
3559 
3560     return std::make_pair(KeyLen, DataLen);
3561   }
3562 
3563   void EmitKey(raw_ostream &Out, DeclarationNameKey Name, unsigned) {
3564     using namespace llvm::support;
3565     endian::Writer<little> LE(Out);
3566     LE.write<uint8_t>(Name.getKind());
3567     switch (Name.getKind()) {
3568     case DeclarationName::Identifier:
3569     case DeclarationName::CXXLiteralOperatorName:
3570       LE.write<uint32_t>(Writer.getIdentifierRef(Name.getIdentifier()));
3571       return;
3572     case DeclarationName::ObjCZeroArgSelector:
3573     case DeclarationName::ObjCOneArgSelector:
3574     case DeclarationName::ObjCMultiArgSelector:
3575       LE.write<uint32_t>(Writer.getSelectorRef(Name.getSelector()));
3576       return;
3577     case DeclarationName::CXXOperatorName:
3578       assert(Name.getOperatorKind() < NUM_OVERLOADED_OPERATORS &&
3579              "Invalid operator?");
3580       LE.write<uint8_t>(Name.getOperatorKind());
3581       return;
3582     case DeclarationName::CXXConstructorName:
3583     case DeclarationName::CXXDestructorName:
3584     case DeclarationName::CXXConversionFunctionName:
3585     case DeclarationName::CXXUsingDirective:
3586       return;
3587     }
3588 
3589     llvm_unreachable("Invalid name kind?");
3590   }
3591 
3592   void EmitData(raw_ostream &Out, key_type_ref, data_type Lookup,
3593                 unsigned DataLen) {
3594     using namespace llvm::support;
3595     endian::Writer<little> LE(Out);
3596     uint64_t Start = Out.tell(); (void)Start;
3597     for (unsigned I = Lookup.first, N = Lookup.second; I != N; ++I)
3598       LE.write<uint32_t>(DeclIDs[I]);
3599     assert(Out.tell() - Start == DataLen && "Data length is wrong");
3600   }
3601 };
3602 
3603 } // end anonymous namespace
3604 
3605 bool ASTWriter::isLookupResultExternal(StoredDeclsList &Result,
3606                                        DeclContext *DC) {
3607   return Result.hasExternalDecls() && DC->NeedToReconcileExternalVisibleStorage;
3608 }
3609 
3610 bool ASTWriter::isLookupResultEntirelyExternal(StoredDeclsList &Result,
3611                                                DeclContext *DC) {
3612   for (auto *D : Result.getLookupResult())
3613     if (!getDeclForLocalLookup(getLangOpts(), D)->isFromASTFile())
3614       return false;
3615 
3616   return true;
3617 }
3618 
3619 void
3620 ASTWriter::GenerateNameLookupTable(const DeclContext *ConstDC,
3621                                    llvm::SmallVectorImpl<char> &LookupTable) {
3622   assert(!ConstDC->HasLazyLocalLexicalLookups &&
3623          !ConstDC->HasLazyExternalLexicalLookups &&
3624          "must call buildLookups first");
3625 
3626   // FIXME: We need to build the lookups table, which is logically const.
3627   auto *DC = const_cast<DeclContext*>(ConstDC);
3628   assert(DC == DC->getPrimaryContext() && "only primary DC has lookup table");
3629 
3630   // Create the on-disk hash table representation.
3631   MultiOnDiskHashTableGenerator<reader::ASTDeclContextNameLookupTrait,
3632                                 ASTDeclContextNameLookupTrait> Generator;
3633   ASTDeclContextNameLookupTrait Trait(*this);
3634 
3635   // The first step is to collect the declaration names which we need to
3636   // serialize into the name lookup table, and to collect them in a stable
3637   // order.
3638   SmallVector<DeclarationName, 16> Names;
3639 
3640   // We also build up small sets of the constructor and conversion function
3641   // names which are visible.
3642   llvm::SmallSet<DeclarationName, 8> ConstructorNameSet, ConversionNameSet;
3643 
3644   for (auto &Lookup : *DC->buildLookup()) {
3645     auto &Name = Lookup.first;
3646     auto &Result = Lookup.second;
3647 
3648     // If there are no local declarations in our lookup result, we
3649     // don't need to write an entry for the name at all. If we can't
3650     // write out a lookup set without performing more deserialization,
3651     // just skip this entry.
3652     if (isLookupResultExternal(Result, DC) &&
3653         isLookupResultEntirelyExternal(Result, DC))
3654       continue;
3655 
3656     // We also skip empty results. If any of the results could be external and
3657     // the currently available results are empty, then all of the results are
3658     // external and we skip it above. So the only way we get here with an empty
3659     // results is when no results could have been external *and* we have
3660     // external results.
3661     //
3662     // FIXME: While we might want to start emitting on-disk entries for negative
3663     // lookups into a decl context as an optimization, today we *have* to skip
3664     // them because there are names with empty lookup results in decl contexts
3665     // which we can't emit in any stable ordering: we lookup constructors and
3666     // conversion functions in the enclosing namespace scope creating empty
3667     // results for them. This in almost certainly a bug in Clang's name lookup,
3668     // but that is likely to be hard or impossible to fix and so we tolerate it
3669     // here by omitting lookups with empty results.
3670     if (Lookup.second.getLookupResult().empty())
3671       continue;
3672 
3673     switch (Lookup.first.getNameKind()) {
3674     default:
3675       Names.push_back(Lookup.first);
3676       break;
3677 
3678     case DeclarationName::CXXConstructorName:
3679       assert(isa<CXXRecordDecl>(DC) &&
3680              "Cannot have a constructor name outside of a class!");
3681       ConstructorNameSet.insert(Name);
3682       break;
3683 
3684     case DeclarationName::CXXConversionFunctionName:
3685       assert(isa<CXXRecordDecl>(DC) &&
3686              "Cannot have a conversion function name outside of a class!");
3687       ConversionNameSet.insert(Name);
3688       break;
3689     }
3690   }
3691 
3692   // Sort the names into a stable order.
3693   std::sort(Names.begin(), Names.end());
3694 
3695   if (auto *D = dyn_cast<CXXRecordDecl>(DC)) {
3696     // We need to establish an ordering of constructor and conversion function
3697     // names, and they don't have an intrinsic ordering.
3698 
3699     // First we try the easy case by forming the current context's constructor
3700     // name and adding that name first. This is a very useful optimization to
3701     // avoid walking the lexical declarations in many cases, and it also
3702     // handles the only case where a constructor name can come from some other
3703     // lexical context -- when that name is an implicit constructor merged from
3704     // another declaration in the redecl chain. Any non-implicit constructor or
3705     // conversion function which doesn't occur in all the lexical contexts
3706     // would be an ODR violation.
3707     auto ImplicitCtorName = Context->DeclarationNames.getCXXConstructorName(
3708         Context->getCanonicalType(Context->getRecordType(D)));
3709     if (ConstructorNameSet.erase(ImplicitCtorName))
3710       Names.push_back(ImplicitCtorName);
3711 
3712     // If we still have constructors or conversion functions, we walk all the
3713     // names in the decl and add the constructors and conversion functions
3714     // which are visible in the order they lexically occur within the context.
3715     if (!ConstructorNameSet.empty() || !ConversionNameSet.empty())
3716       for (Decl *ChildD : cast<CXXRecordDecl>(DC)->decls())
3717         if (auto *ChildND = dyn_cast<NamedDecl>(ChildD)) {
3718           auto Name = ChildND->getDeclName();
3719           switch (Name.getNameKind()) {
3720           default:
3721             continue;
3722 
3723           case DeclarationName::CXXConstructorName:
3724             if (ConstructorNameSet.erase(Name))
3725               Names.push_back(Name);
3726             break;
3727 
3728           case DeclarationName::CXXConversionFunctionName:
3729             if (ConversionNameSet.erase(Name))
3730               Names.push_back(Name);
3731             break;
3732           }
3733 
3734           if (ConstructorNameSet.empty() && ConversionNameSet.empty())
3735             break;
3736         }
3737 
3738     assert(ConstructorNameSet.empty() && "Failed to find all of the visible "
3739                                          "constructors by walking all the "
3740                                          "lexical members of the context.");
3741     assert(ConversionNameSet.empty() && "Failed to find all of the visible "
3742                                         "conversion functions by walking all "
3743                                         "the lexical members of the context.");
3744   }
3745 
3746   // Next we need to do a lookup with each name into this decl context to fully
3747   // populate any results from external sources. We don't actually use the
3748   // results of these lookups because we only want to use the results after all
3749   // results have been loaded and the pointers into them will be stable.
3750   for (auto &Name : Names)
3751     DC->lookup(Name);
3752 
3753   // Now we need to insert the results for each name into the hash table. For
3754   // constructor names and conversion function names, we actually need to merge
3755   // all of the results for them into one list of results each and insert
3756   // those.
3757   SmallVector<NamedDecl *, 8> ConstructorDecls;
3758   SmallVector<NamedDecl *, 8> ConversionDecls;
3759 
3760   // Now loop over the names, either inserting them or appending for the two
3761   // special cases.
3762   for (auto &Name : Names) {
3763     DeclContext::lookup_result Result = DC->noload_lookup(Name);
3764 
3765     switch (Name.getNameKind()) {
3766     default:
3767       Generator.insert(Name, Trait.getData(Result), Trait);
3768       break;
3769 
3770     case DeclarationName::CXXConstructorName:
3771       ConstructorDecls.append(Result.begin(), Result.end());
3772       break;
3773 
3774     case DeclarationName::CXXConversionFunctionName:
3775       ConversionDecls.append(Result.begin(), Result.end());
3776       break;
3777     }
3778   }
3779 
3780   // Handle our two special cases if we ended up having any. We arbitrarily use
3781   // the first declaration's name here because the name itself isn't part of
3782   // the key, only the kind of name is used.
3783   if (!ConstructorDecls.empty())
3784     Generator.insert(ConstructorDecls.front()->getDeclName(),
3785                      Trait.getData(ConstructorDecls), Trait);
3786   if (!ConversionDecls.empty())
3787     Generator.insert(ConversionDecls.front()->getDeclName(),
3788                      Trait.getData(ConversionDecls), Trait);
3789 
3790   // Create the on-disk hash table. Also emit the existing imported and
3791   // merged table if there is one.
3792   auto *Lookups = Chain ? Chain->getLoadedLookupTables(DC) : nullptr;
3793   Generator.emit(LookupTable, Trait, Lookups ? &Lookups->Table : nullptr);
3794 }
3795 
3796 /// \brief Write the block containing all of the declaration IDs
3797 /// visible from the given DeclContext.
3798 ///
3799 /// \returns the offset of the DECL_CONTEXT_VISIBLE block within the
3800 /// bitstream, or 0 if no block was written.
3801 uint64_t ASTWriter::WriteDeclContextVisibleBlock(ASTContext &Context,
3802                                                  DeclContext *DC) {
3803   // If we imported a key declaration of this namespace, write the visible
3804   // lookup results as an update record for it rather than including them
3805   // on this declaration. We will only look at key declarations on reload.
3806   if (isa<NamespaceDecl>(DC) && Chain &&
3807       Chain->getKeyDeclaration(cast<Decl>(DC))->isFromASTFile()) {
3808     // Only do this once, for the first local declaration of the namespace.
3809     for (auto *Prev = cast<NamespaceDecl>(DC)->getPreviousDecl(); Prev;
3810          Prev = Prev->getPreviousDecl())
3811       if (!Prev->isFromASTFile())
3812         return 0;
3813 
3814     // Note that we need to emit an update record for the primary context.
3815     UpdatedDeclContexts.insert(DC->getPrimaryContext());
3816 
3817     // Make sure all visible decls are written. They will be recorded later. We
3818     // do this using a side data structure so we can sort the names into
3819     // a deterministic order.
3820     StoredDeclsMap *Map = DC->getPrimaryContext()->buildLookup();
3821     SmallVector<std::pair<DeclarationName, DeclContext::lookup_result>, 16>
3822         LookupResults;
3823     if (Map) {
3824       LookupResults.reserve(Map->size());
3825       for (auto &Entry : *Map)
3826         LookupResults.push_back(
3827             std::make_pair(Entry.first, Entry.second.getLookupResult()));
3828     }
3829 
3830     std::sort(LookupResults.begin(), LookupResults.end(), llvm::less_first());
3831     for (auto &NameAndResult : LookupResults) {
3832       DeclarationName Name = NameAndResult.first;
3833       DeclContext::lookup_result Result = NameAndResult.second;
3834       if (Name.getNameKind() == DeclarationName::CXXConstructorName ||
3835           Name.getNameKind() == DeclarationName::CXXConversionFunctionName) {
3836         // We have to work around a name lookup bug here where negative lookup
3837         // results for these names get cached in namespace lookup tables (these
3838         // names should never be looked up in a namespace).
3839         assert(Result.empty() && "Cannot have a constructor or conversion "
3840                                  "function name in a namespace!");
3841         continue;
3842       }
3843 
3844       for (NamedDecl *ND : Result)
3845         if (!ND->isFromASTFile())
3846           GetDeclRef(ND);
3847     }
3848 
3849     return 0;
3850   }
3851 
3852   if (DC->getPrimaryContext() != DC)
3853     return 0;
3854 
3855   // Skip contexts which don't support name lookup.
3856   if (!DC->isLookupContext())
3857     return 0;
3858 
3859   // If not in C++, we perform name lookup for the translation unit via the
3860   // IdentifierInfo chains, don't bother to build a visible-declarations table.
3861   if (DC->isTranslationUnit() && !Context.getLangOpts().CPlusPlus)
3862     return 0;
3863 
3864   // Serialize the contents of the mapping used for lookup. Note that,
3865   // although we have two very different code paths, the serialized
3866   // representation is the same for both cases: a declaration name,
3867   // followed by a size, followed by references to the visible
3868   // declarations that have that name.
3869   uint64_t Offset = Stream.GetCurrentBitNo();
3870   StoredDeclsMap *Map = DC->buildLookup();
3871   if (!Map || Map->empty())
3872     return 0;
3873 
3874   // Create the on-disk hash table in a buffer.
3875   SmallString<4096> LookupTable;
3876   GenerateNameLookupTable(DC, LookupTable);
3877 
3878   // Write the lookup table
3879   RecordData::value_type Record[] = {DECL_CONTEXT_VISIBLE};
3880   Stream.EmitRecordWithBlob(DeclContextVisibleLookupAbbrev, Record,
3881                             LookupTable);
3882   ++NumVisibleDeclContexts;
3883   return Offset;
3884 }
3885 
3886 /// \brief Write an UPDATE_VISIBLE block for the given context.
3887 ///
3888 /// UPDATE_VISIBLE blocks contain the declarations that are added to an existing
3889 /// DeclContext in a dependent AST file. As such, they only exist for the TU
3890 /// (in C++), for namespaces, and for classes with forward-declared unscoped
3891 /// enumeration members (in C++11).
3892 void ASTWriter::WriteDeclContextVisibleUpdate(const DeclContext *DC) {
3893   StoredDeclsMap *Map = DC->getLookupPtr();
3894   if (!Map || Map->empty())
3895     return;
3896 
3897   // Create the on-disk hash table in a buffer.
3898   SmallString<4096> LookupTable;
3899   GenerateNameLookupTable(DC, LookupTable);
3900 
3901   // If we're updating a namespace, select a key declaration as the key for the
3902   // update record; those are the only ones that will be checked on reload.
3903   if (isa<NamespaceDecl>(DC))
3904     DC = cast<DeclContext>(Chain->getKeyDeclaration(cast<Decl>(DC)));
3905 
3906   // Write the lookup table
3907   RecordData::value_type Record[] = {UPDATE_VISIBLE, getDeclID(cast<Decl>(DC))};
3908   Stream.EmitRecordWithBlob(UpdateVisibleAbbrev, Record, LookupTable);
3909 }
3910 
3911 /// \brief Write an FP_PRAGMA_OPTIONS block for the given FPOptions.
3912 void ASTWriter::WriteFPPragmaOptions(const FPOptions &Opts) {
3913   RecordData::value_type Record[] = {Opts.fp_contract};
3914   Stream.EmitRecord(FP_PRAGMA_OPTIONS, Record);
3915 }
3916 
3917 /// \brief Write an OPENCL_EXTENSIONS block for the given OpenCLOptions.
3918 void ASTWriter::WriteOpenCLExtensions(Sema &SemaRef) {
3919   if (!SemaRef.Context.getLangOpts().OpenCL)
3920     return;
3921 
3922   const OpenCLOptions &Opts = SemaRef.getOpenCLOptions();
3923   RecordData Record;
3924 #define OPENCLEXT(nm)  Record.push_back(Opts.nm);
3925 #include "clang/Basic/OpenCLExtensions.def"
3926   Stream.EmitRecord(OPENCL_EXTENSIONS, Record);
3927 }
3928 
3929 void ASTWriter::WriteObjCCategories() {
3930   SmallVector<ObjCCategoriesInfo, 2> CategoriesMap;
3931   RecordData Categories;
3932 
3933   for (unsigned I = 0, N = ObjCClassesWithCategories.size(); I != N; ++I) {
3934     unsigned Size = 0;
3935     unsigned StartIndex = Categories.size();
3936 
3937     ObjCInterfaceDecl *Class = ObjCClassesWithCategories[I];
3938 
3939     // Allocate space for the size.
3940     Categories.push_back(0);
3941 
3942     // Add the categories.
3943     for (ObjCInterfaceDecl::known_categories_iterator
3944            Cat = Class->known_categories_begin(),
3945            CatEnd = Class->known_categories_end();
3946          Cat != CatEnd; ++Cat, ++Size) {
3947       assert(getDeclID(*Cat) != 0 && "Bogus category");
3948       AddDeclRef(*Cat, Categories);
3949     }
3950 
3951     // Update the size.
3952     Categories[StartIndex] = Size;
3953 
3954     // Record this interface -> category map.
3955     ObjCCategoriesInfo CatInfo = { getDeclID(Class), StartIndex };
3956     CategoriesMap.push_back(CatInfo);
3957   }
3958 
3959   // Sort the categories map by the definition ID, since the reader will be
3960   // performing binary searches on this information.
3961   llvm::array_pod_sort(CategoriesMap.begin(), CategoriesMap.end());
3962 
3963   // Emit the categories map.
3964   using namespace llvm;
3965 
3966   auto *Abbrev = new BitCodeAbbrev();
3967   Abbrev->Add(BitCodeAbbrevOp(OBJC_CATEGORIES_MAP));
3968   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // # of entries
3969   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
3970   unsigned AbbrevID = Stream.EmitAbbrev(Abbrev);
3971 
3972   RecordData::value_type Record[] = {OBJC_CATEGORIES_MAP, CategoriesMap.size()};
3973   Stream.EmitRecordWithBlob(AbbrevID, Record,
3974                             reinterpret_cast<char *>(CategoriesMap.data()),
3975                             CategoriesMap.size() * sizeof(ObjCCategoriesInfo));
3976 
3977   // Emit the category lists.
3978   Stream.EmitRecord(OBJC_CATEGORIES, Categories);
3979 }
3980 
3981 void ASTWriter::WriteLateParsedTemplates(Sema &SemaRef) {
3982   Sema::LateParsedTemplateMapT &LPTMap = SemaRef.LateParsedTemplateMap;
3983 
3984   if (LPTMap.empty())
3985     return;
3986 
3987   RecordData Record;
3988   for (auto LPTMapEntry : LPTMap) {
3989     const FunctionDecl *FD = LPTMapEntry.first;
3990     LateParsedTemplate *LPT = LPTMapEntry.second;
3991     AddDeclRef(FD, Record);
3992     AddDeclRef(LPT->D, Record);
3993     Record.push_back(LPT->Toks.size());
3994 
3995     for (const auto &Tok : LPT->Toks) {
3996       AddToken(Tok, Record);
3997     }
3998   }
3999   Stream.EmitRecord(LATE_PARSED_TEMPLATE, Record);
4000 }
4001 
4002 /// \brief Write the state of 'pragma clang optimize' at the end of the module.
4003 void ASTWriter::WriteOptimizePragmaOptions(Sema &SemaRef) {
4004   RecordData Record;
4005   SourceLocation PragmaLoc = SemaRef.getOptimizeOffPragmaLocation();
4006   AddSourceLocation(PragmaLoc, Record);
4007   Stream.EmitRecord(OPTIMIZE_PRAGMA_OPTIONS, Record);
4008 }
4009 
4010 /// \brief Write the state of 'pragma ms_struct' at the end of the module.
4011 void ASTWriter::WriteMSStructPragmaOptions(Sema &SemaRef) {
4012   RecordData Record;
4013   Record.push_back(SemaRef.MSStructPragmaOn ? PMSST_ON : PMSST_OFF);
4014   Stream.EmitRecord(MSSTRUCT_PRAGMA_OPTIONS, Record);
4015 }
4016 
4017 /// \brief Write the state of 'pragma pointers_to_members' at the end of the
4018 //module.
4019 void ASTWriter::WriteMSPointersToMembersPragmaOptions(Sema &SemaRef) {
4020   RecordData Record;
4021   Record.push_back(SemaRef.MSPointerToMemberRepresentationMethod);
4022   AddSourceLocation(SemaRef.ImplicitMSInheritanceAttrLoc, Record);
4023   Stream.EmitRecord(POINTERS_TO_MEMBERS_PRAGMA_OPTIONS, Record);
4024 }
4025 
4026 void ASTWriter::WriteModuleFileExtension(Sema &SemaRef,
4027                                          ModuleFileExtensionWriter &Writer) {
4028   // Enter the extension block.
4029   Stream.EnterSubblock(EXTENSION_BLOCK_ID, 4);
4030 
4031   // Emit the metadata record abbreviation.
4032   auto *Abv = new llvm::BitCodeAbbrev();
4033   Abv->Add(llvm::BitCodeAbbrevOp(EXTENSION_METADATA));
4034   Abv->Add(llvm::BitCodeAbbrevOp(llvm::BitCodeAbbrevOp::VBR, 6));
4035   Abv->Add(llvm::BitCodeAbbrevOp(llvm::BitCodeAbbrevOp::VBR, 6));
4036   Abv->Add(llvm::BitCodeAbbrevOp(llvm::BitCodeAbbrevOp::VBR, 6));
4037   Abv->Add(llvm::BitCodeAbbrevOp(llvm::BitCodeAbbrevOp::VBR, 6));
4038   Abv->Add(llvm::BitCodeAbbrevOp(llvm::BitCodeAbbrevOp::Blob));
4039   unsigned Abbrev = Stream.EmitAbbrev(Abv);
4040 
4041   // Emit the metadata record.
4042   RecordData Record;
4043   auto Metadata = Writer.getExtension()->getExtensionMetadata();
4044   Record.push_back(EXTENSION_METADATA);
4045   Record.push_back(Metadata.MajorVersion);
4046   Record.push_back(Metadata.MinorVersion);
4047   Record.push_back(Metadata.BlockName.size());
4048   Record.push_back(Metadata.UserInfo.size());
4049   SmallString<64> Buffer;
4050   Buffer += Metadata.BlockName;
4051   Buffer += Metadata.UserInfo;
4052   Stream.EmitRecordWithBlob(Abbrev, Record, Buffer);
4053 
4054   // Emit the contents of the extension block.
4055   Writer.writeExtensionContents(SemaRef, Stream);
4056 
4057   // Exit the extension block.
4058   Stream.ExitBlock();
4059 }
4060 
4061 //===----------------------------------------------------------------------===//
4062 // General Serialization Routines
4063 //===----------------------------------------------------------------------===//
4064 
4065 /// \brief Emit the list of attributes to the specified record.
4066 void ASTRecordWriter::AddAttributes(ArrayRef<const Attr *> Attrs) {
4067   auto &Record = *this;
4068   Record.push_back(Attrs.size());
4069   for (const auto *A : Attrs) {
4070     Record.push_back(A->getKind()); // FIXME: stable encoding, target attrs
4071     Record.AddSourceRange(A->getRange());
4072 
4073 #include "clang/Serialization/AttrPCHWrite.inc"
4074 
4075   }
4076 }
4077 
4078 void ASTWriter::AddToken(const Token &Tok, RecordDataImpl &Record) {
4079   AddSourceLocation(Tok.getLocation(), Record);
4080   Record.push_back(Tok.getLength());
4081 
4082   // FIXME: When reading literal tokens, reconstruct the literal pointer
4083   // if it is needed.
4084   AddIdentifierRef(Tok.getIdentifierInfo(), Record);
4085   // FIXME: Should translate token kind to a stable encoding.
4086   Record.push_back(Tok.getKind());
4087   // FIXME: Should translate token flags to a stable encoding.
4088   Record.push_back(Tok.getFlags());
4089 }
4090 
4091 void ASTWriter::AddString(StringRef Str, RecordDataImpl &Record) {
4092   Record.push_back(Str.size());
4093   Record.insert(Record.end(), Str.begin(), Str.end());
4094 }
4095 
4096 bool ASTWriter::PreparePathForOutput(SmallVectorImpl<char> &Path) {
4097   assert(Context && "should have context when outputting path");
4098 
4099   bool Changed =
4100       cleanPathForOutput(Context->getSourceManager().getFileManager(), Path);
4101 
4102   // Remove a prefix to make the path relative, if relevant.
4103   const char *PathBegin = Path.data();
4104   const char *PathPtr =
4105       adjustFilenameForRelocatableAST(PathBegin, BaseDirectory);
4106   if (PathPtr != PathBegin) {
4107     Path.erase(Path.begin(), Path.begin() + (PathPtr - PathBegin));
4108     Changed = true;
4109   }
4110 
4111   return Changed;
4112 }
4113 
4114 void ASTWriter::AddPath(StringRef Path, RecordDataImpl &Record) {
4115   SmallString<128> FilePath(Path);
4116   PreparePathForOutput(FilePath);
4117   AddString(FilePath, Record);
4118 }
4119 
4120 void ASTWriter::EmitRecordWithPath(unsigned Abbrev, RecordDataRef Record,
4121                                    StringRef Path) {
4122   SmallString<128> FilePath(Path);
4123   PreparePathForOutput(FilePath);
4124   Stream.EmitRecordWithBlob(Abbrev, Record, FilePath);
4125 }
4126 
4127 void ASTWriter::AddVersionTuple(const VersionTuple &Version,
4128                                 RecordDataImpl &Record) {
4129   Record.push_back(Version.getMajor());
4130   if (Optional<unsigned> Minor = Version.getMinor())
4131     Record.push_back(*Minor + 1);
4132   else
4133     Record.push_back(0);
4134   if (Optional<unsigned> Subminor = Version.getSubminor())
4135     Record.push_back(*Subminor + 1);
4136   else
4137     Record.push_back(0);
4138 }
4139 
4140 /// \brief Note that the identifier II occurs at the given offset
4141 /// within the identifier table.
4142 void ASTWriter::SetIdentifierOffset(const IdentifierInfo *II, uint32_t Offset) {
4143   IdentID ID = IdentifierIDs[II];
4144   // Only store offsets new to this AST file. Other identifier names are looked
4145   // up earlier in the chain and thus don't need an offset.
4146   if (ID >= FirstIdentID)
4147     IdentifierOffsets[ID - FirstIdentID] = Offset;
4148 }
4149 
4150 /// \brief Note that the selector Sel occurs at the given offset
4151 /// within the method pool/selector table.
4152 void ASTWriter::SetSelectorOffset(Selector Sel, uint32_t Offset) {
4153   unsigned ID = SelectorIDs[Sel];
4154   assert(ID && "Unknown selector");
4155   // Don't record offsets for selectors that are also available in a different
4156   // file.
4157   if (ID < FirstSelectorID)
4158     return;
4159   SelectorOffsets[ID - FirstSelectorID] = Offset;
4160 }
4161 
4162 ASTWriter::ASTWriter(
4163   llvm::BitstreamWriter &Stream,
4164   ArrayRef<llvm::IntrusiveRefCntPtr<ModuleFileExtension>> Extensions,
4165   bool IncludeTimestamps)
4166     : Stream(Stream), Context(nullptr), PP(nullptr), Chain(nullptr),
4167       WritingModule(nullptr), IncludeTimestamps(IncludeTimestamps),
4168       WritingAST(false), DoneWritingDeclsAndTypes(false),
4169       ASTHasCompilerErrors(false), FirstDeclID(NUM_PREDEF_DECL_IDS),
4170       NextDeclID(FirstDeclID), FirstTypeID(NUM_PREDEF_TYPE_IDS),
4171       NextTypeID(FirstTypeID), FirstIdentID(NUM_PREDEF_IDENT_IDS),
4172       NextIdentID(FirstIdentID), FirstMacroID(NUM_PREDEF_MACRO_IDS),
4173       NextMacroID(FirstMacroID), FirstSubmoduleID(NUM_PREDEF_SUBMODULE_IDS),
4174       NextSubmoduleID(FirstSubmoduleID),
4175       FirstSelectorID(NUM_PREDEF_SELECTOR_IDS), NextSelectorID(FirstSelectorID),
4176       NumStatements(0), NumMacros(0),
4177       NumLexicalDeclContexts(0), NumVisibleDeclContexts(0),
4178       TypeExtQualAbbrev(0), TypeFunctionProtoAbbrev(0), DeclParmVarAbbrev(0),
4179       DeclContextLexicalAbbrev(0), DeclContextVisibleLookupAbbrev(0),
4180       UpdateVisibleAbbrev(0), DeclRecordAbbrev(0), DeclTypedefAbbrev(0),
4181       DeclVarAbbrev(0), DeclFieldAbbrev(0), DeclEnumAbbrev(0),
4182       DeclObjCIvarAbbrev(0), DeclCXXMethodAbbrev(0), DeclRefExprAbbrev(0),
4183       CharacterLiteralAbbrev(0), IntegerLiteralAbbrev(0),
4184       ExprImplicitCastAbbrev(0) {
4185   for (const auto &Ext : Extensions) {
4186     if (auto Writer = Ext->createExtensionWriter(*this))
4187       ModuleFileExtensionWriters.push_back(std::move(Writer));
4188   }
4189 }
4190 
4191 ASTWriter::~ASTWriter() {
4192   llvm::DeleteContainerSeconds(FileDeclIDs);
4193 }
4194 
4195 const LangOptions &ASTWriter::getLangOpts() const {
4196   assert(WritingAST && "can't determine lang opts when not writing AST");
4197   return Context->getLangOpts();
4198 }
4199 
4200 time_t ASTWriter::getTimestampForOutput(const FileEntry *E) const {
4201   return IncludeTimestamps ? E->getModificationTime() : 0;
4202 }
4203 
4204 uint64_t ASTWriter::WriteAST(Sema &SemaRef, const std::string &OutputFile,
4205                              Module *WritingModule, StringRef isysroot,
4206                              bool hasErrors) {
4207   WritingAST = true;
4208 
4209   ASTHasCompilerErrors = hasErrors;
4210 
4211   // Emit the file header.
4212   Stream.Emit((unsigned)'C', 8);
4213   Stream.Emit((unsigned)'P', 8);
4214   Stream.Emit((unsigned)'C', 8);
4215   Stream.Emit((unsigned)'H', 8);
4216 
4217   WriteBlockInfoBlock();
4218 
4219   Context = &SemaRef.Context;
4220   PP = &SemaRef.PP;
4221   this->WritingModule = WritingModule;
4222   ASTFileSignature Signature =
4223       WriteASTCore(SemaRef, isysroot, OutputFile, WritingModule);
4224   Context = nullptr;
4225   PP = nullptr;
4226   this->WritingModule = nullptr;
4227   this->BaseDirectory.clear();
4228 
4229   WritingAST = false;
4230   return Signature;
4231 }
4232 
4233 template<typename Vector>
4234 static void AddLazyVectorDecls(ASTWriter &Writer, Vector &Vec,
4235                                ASTWriter::RecordData &Record) {
4236   for (typename Vector::iterator I = Vec.begin(nullptr, true), E = Vec.end();
4237        I != E; ++I) {
4238     Writer.AddDeclRef(*I, Record);
4239   }
4240 }
4241 
4242 uint64_t ASTWriter::WriteASTCore(Sema &SemaRef, StringRef isysroot,
4243                                  const std::string &OutputFile,
4244                                  Module *WritingModule) {
4245   using namespace llvm;
4246 
4247   bool isModule = WritingModule != nullptr;
4248 
4249   // Make sure that the AST reader knows to finalize itself.
4250   if (Chain)
4251     Chain->finalizeForWriting();
4252 
4253   ASTContext &Context = SemaRef.Context;
4254   Preprocessor &PP = SemaRef.PP;
4255 
4256   // Set up predefined declaration IDs.
4257   auto RegisterPredefDecl = [&] (Decl *D, PredefinedDeclIDs ID) {
4258     if (D) {
4259       assert(D->isCanonicalDecl() && "predefined decl is not canonical");
4260       DeclIDs[D] = ID;
4261     }
4262   };
4263   RegisterPredefDecl(Context.getTranslationUnitDecl(),
4264                      PREDEF_DECL_TRANSLATION_UNIT_ID);
4265   RegisterPredefDecl(Context.ObjCIdDecl, PREDEF_DECL_OBJC_ID_ID);
4266   RegisterPredefDecl(Context.ObjCSelDecl, PREDEF_DECL_OBJC_SEL_ID);
4267   RegisterPredefDecl(Context.ObjCClassDecl, PREDEF_DECL_OBJC_CLASS_ID);
4268   RegisterPredefDecl(Context.ObjCProtocolClassDecl,
4269                      PREDEF_DECL_OBJC_PROTOCOL_ID);
4270   RegisterPredefDecl(Context.Int128Decl, PREDEF_DECL_INT_128_ID);
4271   RegisterPredefDecl(Context.UInt128Decl, PREDEF_DECL_UNSIGNED_INT_128_ID);
4272   RegisterPredefDecl(Context.ObjCInstanceTypeDecl,
4273                      PREDEF_DECL_OBJC_INSTANCETYPE_ID);
4274   RegisterPredefDecl(Context.BuiltinVaListDecl, PREDEF_DECL_BUILTIN_VA_LIST_ID);
4275   RegisterPredefDecl(Context.VaListTagDecl, PREDEF_DECL_VA_LIST_TAG);
4276   RegisterPredefDecl(Context.BuiltinMSVaListDecl,
4277                      PREDEF_DECL_BUILTIN_MS_VA_LIST_ID);
4278   RegisterPredefDecl(Context.ExternCContext, PREDEF_DECL_EXTERN_C_CONTEXT_ID);
4279   RegisterPredefDecl(Context.MakeIntegerSeqDecl,
4280                      PREDEF_DECL_MAKE_INTEGER_SEQ_ID);
4281   RegisterPredefDecl(Context.CFConstantStringTypeDecl,
4282                      PREDEF_DECL_CF_CONSTANT_STRING_ID);
4283   RegisterPredefDecl(Context.CFConstantStringTagDecl,
4284                      PREDEF_DECL_CF_CONSTANT_STRING_TAG_ID);
4285   RegisterPredefDecl(Context.TypePackElementDecl,
4286                      PREDEF_DECL_TYPE_PACK_ELEMENT_ID);
4287 
4288   // Build a record containing all of the tentative definitions in this file, in
4289   // TentativeDefinitions order.  Generally, this record will be empty for
4290   // headers.
4291   RecordData TentativeDefinitions;
4292   AddLazyVectorDecls(*this, SemaRef.TentativeDefinitions, TentativeDefinitions);
4293 
4294   // Build a record containing all of the file scoped decls in this file.
4295   RecordData UnusedFileScopedDecls;
4296   if (!isModule)
4297     AddLazyVectorDecls(*this, SemaRef.UnusedFileScopedDecls,
4298                        UnusedFileScopedDecls);
4299 
4300   // Build a record containing all of the delegating constructors we still need
4301   // to resolve.
4302   RecordData DelegatingCtorDecls;
4303   if (!isModule)
4304     AddLazyVectorDecls(*this, SemaRef.DelegatingCtorDecls, DelegatingCtorDecls);
4305 
4306   // Write the set of weak, undeclared identifiers. We always write the
4307   // entire table, since later PCH files in a PCH chain are only interested in
4308   // the results at the end of the chain.
4309   RecordData WeakUndeclaredIdentifiers;
4310   for (auto &WeakUndeclaredIdentifier : SemaRef.WeakUndeclaredIdentifiers) {
4311     IdentifierInfo *II = WeakUndeclaredIdentifier.first;
4312     WeakInfo &WI = WeakUndeclaredIdentifier.second;
4313     AddIdentifierRef(II, WeakUndeclaredIdentifiers);
4314     AddIdentifierRef(WI.getAlias(), WeakUndeclaredIdentifiers);
4315     AddSourceLocation(WI.getLocation(), WeakUndeclaredIdentifiers);
4316     WeakUndeclaredIdentifiers.push_back(WI.getUsed());
4317   }
4318 
4319   // Build a record containing all of the ext_vector declarations.
4320   RecordData ExtVectorDecls;
4321   AddLazyVectorDecls(*this, SemaRef.ExtVectorDecls, ExtVectorDecls);
4322 
4323   // Build a record containing all of the VTable uses information.
4324   RecordData VTableUses;
4325   if (!SemaRef.VTableUses.empty()) {
4326     for (unsigned I = 0, N = SemaRef.VTableUses.size(); I != N; ++I) {
4327       AddDeclRef(SemaRef.VTableUses[I].first, VTableUses);
4328       AddSourceLocation(SemaRef.VTableUses[I].second, VTableUses);
4329       VTableUses.push_back(SemaRef.VTablesUsed[SemaRef.VTableUses[I].first]);
4330     }
4331   }
4332 
4333   // Build a record containing all of the UnusedLocalTypedefNameCandidates.
4334   RecordData UnusedLocalTypedefNameCandidates;
4335   for (const TypedefNameDecl *TD : SemaRef.UnusedLocalTypedefNameCandidates)
4336     AddDeclRef(TD, UnusedLocalTypedefNameCandidates);
4337 
4338   // Build a record containing all of pending implicit instantiations.
4339   RecordData PendingInstantiations;
4340   for (const auto &I : SemaRef.PendingInstantiations) {
4341     AddDeclRef(I.first, PendingInstantiations);
4342     AddSourceLocation(I.second, PendingInstantiations);
4343   }
4344   assert(SemaRef.PendingLocalImplicitInstantiations.empty() &&
4345          "There are local ones at end of translation unit!");
4346 
4347   // Build a record containing some declaration references.
4348   RecordData SemaDeclRefs;
4349   if (SemaRef.StdNamespace || SemaRef.StdBadAlloc) {
4350     AddDeclRef(SemaRef.getStdNamespace(), SemaDeclRefs);
4351     AddDeclRef(SemaRef.getStdBadAlloc(), SemaDeclRefs);
4352   }
4353 
4354   RecordData CUDASpecialDeclRefs;
4355   if (Context.getcudaConfigureCallDecl()) {
4356     AddDeclRef(Context.getcudaConfigureCallDecl(), CUDASpecialDeclRefs);
4357   }
4358 
4359   // Build a record containing all of the known namespaces.
4360   RecordData KnownNamespaces;
4361   for (const auto &I : SemaRef.KnownNamespaces) {
4362     if (!I.second)
4363       AddDeclRef(I.first, KnownNamespaces);
4364   }
4365 
4366   // Build a record of all used, undefined objects that require definitions.
4367   RecordData UndefinedButUsed;
4368 
4369   SmallVector<std::pair<NamedDecl *, SourceLocation>, 16> Undefined;
4370   SemaRef.getUndefinedButUsed(Undefined);
4371   for (const auto &I : Undefined) {
4372     AddDeclRef(I.first, UndefinedButUsed);
4373     AddSourceLocation(I.second, UndefinedButUsed);
4374   }
4375 
4376   // Build a record containing all delete-expressions that we would like to
4377   // analyze later in AST.
4378   RecordData DeleteExprsToAnalyze;
4379 
4380   for (const auto &DeleteExprsInfo :
4381        SemaRef.getMismatchingDeleteExpressions()) {
4382     AddDeclRef(DeleteExprsInfo.first, DeleteExprsToAnalyze);
4383     DeleteExprsToAnalyze.push_back(DeleteExprsInfo.second.size());
4384     for (const auto &DeleteLoc : DeleteExprsInfo.second) {
4385       AddSourceLocation(DeleteLoc.first, DeleteExprsToAnalyze);
4386       DeleteExprsToAnalyze.push_back(DeleteLoc.second);
4387     }
4388   }
4389 
4390   // Write the control block
4391   uint64_t Signature = WriteControlBlock(PP, Context, isysroot, OutputFile);
4392 
4393   // Write the remaining AST contents.
4394   Stream.EnterSubblock(AST_BLOCK_ID, 5);
4395 
4396   // This is so that older clang versions, before the introduction
4397   // of the control block, can read and reject the newer PCH format.
4398   {
4399     RecordData Record = {VERSION_MAJOR};
4400     Stream.EmitRecord(METADATA_OLD_FORMAT, Record);
4401   }
4402 
4403   // Create a lexical update block containing all of the declarations in the
4404   // translation unit that do not come from other AST files.
4405   const TranslationUnitDecl *TU = Context.getTranslationUnitDecl();
4406   SmallVector<uint32_t, 128> NewGlobalKindDeclPairs;
4407   for (const auto *D : TU->noload_decls()) {
4408     if (!D->isFromASTFile()) {
4409       NewGlobalKindDeclPairs.push_back(D->getKind());
4410       NewGlobalKindDeclPairs.push_back(GetDeclRef(D));
4411     }
4412   }
4413 
4414   auto *Abv = new llvm::BitCodeAbbrev();
4415   Abv->Add(llvm::BitCodeAbbrevOp(TU_UPDATE_LEXICAL));
4416   Abv->Add(llvm::BitCodeAbbrevOp(llvm::BitCodeAbbrevOp::Blob));
4417   unsigned TuUpdateLexicalAbbrev = Stream.EmitAbbrev(Abv);
4418   {
4419     RecordData::value_type Record[] = {TU_UPDATE_LEXICAL};
4420     Stream.EmitRecordWithBlob(TuUpdateLexicalAbbrev, Record,
4421                               bytes(NewGlobalKindDeclPairs));
4422   }
4423 
4424   // And a visible updates block for the translation unit.
4425   Abv = new llvm::BitCodeAbbrev();
4426   Abv->Add(llvm::BitCodeAbbrevOp(UPDATE_VISIBLE));
4427   Abv->Add(llvm::BitCodeAbbrevOp(llvm::BitCodeAbbrevOp::VBR, 6));
4428   Abv->Add(llvm::BitCodeAbbrevOp(llvm::BitCodeAbbrevOp::Blob));
4429   UpdateVisibleAbbrev = Stream.EmitAbbrev(Abv);
4430   WriteDeclContextVisibleUpdate(TU);
4431 
4432   // If we have any extern "C" names, write out a visible update for them.
4433   if (Context.ExternCContext)
4434     WriteDeclContextVisibleUpdate(Context.ExternCContext);
4435 
4436   // If the translation unit has an anonymous namespace, and we don't already
4437   // have an update block for it, write it as an update block.
4438   // FIXME: Why do we not do this if there's already an update block?
4439   if (NamespaceDecl *NS = TU->getAnonymousNamespace()) {
4440     ASTWriter::UpdateRecord &Record = DeclUpdates[TU];
4441     if (Record.empty())
4442       Record.push_back(DeclUpdate(UPD_CXX_ADDED_ANONYMOUS_NAMESPACE, NS));
4443   }
4444 
4445   // Add update records for all mangling numbers and static local numbers.
4446   // These aren't really update records, but this is a convenient way of
4447   // tagging this rare extra data onto the declarations.
4448   for (const auto &Number : Context.MangleNumbers)
4449     if (!Number.first->isFromASTFile())
4450       DeclUpdates[Number.first].push_back(DeclUpdate(UPD_MANGLING_NUMBER,
4451                                                      Number.second));
4452   for (const auto &Number : Context.StaticLocalNumbers)
4453     if (!Number.first->isFromASTFile())
4454       DeclUpdates[Number.first].push_back(DeclUpdate(UPD_STATIC_LOCAL_NUMBER,
4455                                                      Number.second));
4456 
4457   // Make sure visible decls, added to DeclContexts previously loaded from
4458   // an AST file, are registered for serialization.
4459   for (const auto *I : UpdatingVisibleDecls) {
4460     GetDeclRef(I);
4461   }
4462 
4463   // Make sure all decls associated with an identifier are registered for
4464   // serialization, if we're storing decls with identifiers.
4465   if (!WritingModule || !getLangOpts().CPlusPlus) {
4466     llvm::SmallVector<const IdentifierInfo*, 256> IIs;
4467     for (const auto &ID : PP.getIdentifierTable()) {
4468       const IdentifierInfo *II = ID.second;
4469       if (!Chain || !II->isFromAST() || II->hasChangedSinceDeserialization())
4470         IIs.push_back(II);
4471     }
4472     // Sort the identifiers to visit based on their name.
4473     std::sort(IIs.begin(), IIs.end(), llvm::less_ptr<IdentifierInfo>());
4474     for (const IdentifierInfo *II : IIs) {
4475       for (IdentifierResolver::iterator D = SemaRef.IdResolver.begin(II),
4476                                      DEnd = SemaRef.IdResolver.end();
4477            D != DEnd; ++D) {
4478         GetDeclRef(*D);
4479       }
4480     }
4481   }
4482 
4483   // For method pool in the module, if it contains an entry for a selector,
4484   // the entry should be complete, containing everything introduced by that
4485   // module and all modules it imports. It's possible that the entry is out of
4486   // date, so we need to pull in the new content here.
4487 
4488   // It's possible that updateOutOfDateSelector can update SelectorIDs. To be
4489   // safe, we copy all selectors out.
4490   llvm::SmallVector<Selector, 256> AllSelectors;
4491   for (auto &SelectorAndID : SelectorIDs)
4492     AllSelectors.push_back(SelectorAndID.first);
4493   for (auto &Selector : AllSelectors)
4494     SemaRef.updateOutOfDateSelector(Selector);
4495 
4496   // Form the record of special types.
4497   RecordData SpecialTypes;
4498   AddTypeRef(Context.getRawCFConstantStringType(), SpecialTypes);
4499   AddTypeRef(Context.getFILEType(), SpecialTypes);
4500   AddTypeRef(Context.getjmp_bufType(), SpecialTypes);
4501   AddTypeRef(Context.getsigjmp_bufType(), SpecialTypes);
4502   AddTypeRef(Context.ObjCIdRedefinitionType, SpecialTypes);
4503   AddTypeRef(Context.ObjCClassRedefinitionType, SpecialTypes);
4504   AddTypeRef(Context.ObjCSelRedefinitionType, SpecialTypes);
4505   AddTypeRef(Context.getucontext_tType(), SpecialTypes);
4506 
4507   if (Chain) {
4508     // Write the mapping information describing our module dependencies and how
4509     // each of those modules were mapped into our own offset/ID space, so that
4510     // the reader can build the appropriate mapping to its own offset/ID space.
4511     // The map consists solely of a blob with the following format:
4512     // *(module-name-len:i16 module-name:len*i8
4513     //   source-location-offset:i32
4514     //   identifier-id:i32
4515     //   preprocessed-entity-id:i32
4516     //   macro-definition-id:i32
4517     //   submodule-id:i32
4518     //   selector-id:i32
4519     //   declaration-id:i32
4520     //   c++-base-specifiers-id:i32
4521     //   type-id:i32)
4522     //
4523     auto *Abbrev = new BitCodeAbbrev();
4524     Abbrev->Add(BitCodeAbbrevOp(MODULE_OFFSET_MAP));
4525     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
4526     unsigned ModuleOffsetMapAbbrev = Stream.EmitAbbrev(Abbrev);
4527     SmallString<2048> Buffer;
4528     {
4529       llvm::raw_svector_ostream Out(Buffer);
4530       for (ModuleFile *M : Chain->ModuleMgr) {
4531         using namespace llvm::support;
4532         endian::Writer<little> LE(Out);
4533         StringRef FileName = M->FileName;
4534         LE.write<uint16_t>(FileName.size());
4535         Out.write(FileName.data(), FileName.size());
4536 
4537         // Note: if a base ID was uint max, it would not be possible to load
4538         // another module after it or have more than one entity inside it.
4539         uint32_t None = std::numeric_limits<uint32_t>::max();
4540 
4541         auto writeBaseIDOrNone = [&](uint32_t BaseID, bool ShouldWrite) {
4542           assert(BaseID < std::numeric_limits<uint32_t>::max() && "base id too high");
4543           if (ShouldWrite)
4544             LE.write<uint32_t>(BaseID);
4545           else
4546             LE.write<uint32_t>(None);
4547         };
4548 
4549         // These values should be unique within a chain, since they will be read
4550         // as keys into ContinuousRangeMaps.
4551         writeBaseIDOrNone(M->SLocEntryBaseOffset, M->LocalNumSLocEntries);
4552         writeBaseIDOrNone(M->BaseIdentifierID, M->LocalNumIdentifiers);
4553         writeBaseIDOrNone(M->BaseMacroID, M->LocalNumMacros);
4554         writeBaseIDOrNone(M->BasePreprocessedEntityID,
4555                           M->NumPreprocessedEntities);
4556         writeBaseIDOrNone(M->BaseSubmoduleID, M->LocalNumSubmodules);
4557         writeBaseIDOrNone(M->BaseSelectorID, M->LocalNumSelectors);
4558         writeBaseIDOrNone(M->BaseDeclID, M->LocalNumDecls);
4559         writeBaseIDOrNone(M->BaseTypeIndex, M->LocalNumTypes);
4560       }
4561     }
4562     RecordData::value_type Record[] = {MODULE_OFFSET_MAP};
4563     Stream.EmitRecordWithBlob(ModuleOffsetMapAbbrev, Record,
4564                               Buffer.data(), Buffer.size());
4565   }
4566 
4567   RecordData DeclUpdatesOffsetsRecord;
4568 
4569   // Keep writing types, declarations, and declaration update records
4570   // until we've emitted all of them.
4571   Stream.EnterSubblock(DECLTYPES_BLOCK_ID, /*bits for abbreviations*/5);
4572   WriteTypeAbbrevs();
4573   WriteDeclAbbrevs();
4574   do {
4575     WriteDeclUpdatesBlocks(DeclUpdatesOffsetsRecord);
4576     while (!DeclTypesToEmit.empty()) {
4577       DeclOrType DOT = DeclTypesToEmit.front();
4578       DeclTypesToEmit.pop();
4579       if (DOT.isType())
4580         WriteType(DOT.getType());
4581       else
4582         WriteDecl(Context, DOT.getDecl());
4583     }
4584   } while (!DeclUpdates.empty());
4585   Stream.ExitBlock();
4586 
4587   DoneWritingDeclsAndTypes = true;
4588 
4589   // These things can only be done once we've written out decls and types.
4590   WriteTypeDeclOffsets();
4591   if (!DeclUpdatesOffsetsRecord.empty())
4592     Stream.EmitRecord(DECL_UPDATE_OFFSETS, DeclUpdatesOffsetsRecord);
4593   WriteFileDeclIDsMap();
4594   WriteSourceManagerBlock(Context.getSourceManager(), PP);
4595   WriteComments();
4596   WritePreprocessor(PP, isModule);
4597   WriteHeaderSearch(PP.getHeaderSearchInfo());
4598   WriteSelectors(SemaRef);
4599   WriteReferencedSelectorsPool(SemaRef);
4600   WriteLateParsedTemplates(SemaRef);
4601   WriteIdentifierTable(PP, SemaRef.IdResolver, isModule);
4602   WriteFPPragmaOptions(SemaRef.getFPOptions());
4603   WriteOpenCLExtensions(SemaRef);
4604   WritePragmaDiagnosticMappings(Context.getDiagnostics(), isModule);
4605 
4606   // If we're emitting a module, write out the submodule information.
4607   if (WritingModule)
4608     WriteSubmodules(WritingModule);
4609   else if (!getLangOpts().CurrentModule.empty()) {
4610     // If we're building a PCH in the implementation of a module, we may need
4611     // the description of the current module.
4612     //
4613     // FIXME: We may need other modules that we did not load from an AST file,
4614     // such as if a module declares a 'conflicts' on a different module.
4615     Module *M = PP.getHeaderSearchInfo().getModuleMap().findModule(
4616         getLangOpts().CurrentModule);
4617     if (M && !M->IsFromModuleFile)
4618       WriteSubmodules(M);
4619   }
4620 
4621   Stream.EmitRecord(SPECIAL_TYPES, SpecialTypes);
4622 
4623   // Write the record containing external, unnamed definitions.
4624   if (!EagerlyDeserializedDecls.empty())
4625     Stream.EmitRecord(EAGERLY_DESERIALIZED_DECLS, EagerlyDeserializedDecls);
4626 
4627   // Write the record containing tentative definitions.
4628   if (!TentativeDefinitions.empty())
4629     Stream.EmitRecord(TENTATIVE_DEFINITIONS, TentativeDefinitions);
4630 
4631   // Write the record containing unused file scoped decls.
4632   if (!UnusedFileScopedDecls.empty())
4633     Stream.EmitRecord(UNUSED_FILESCOPED_DECLS, UnusedFileScopedDecls);
4634 
4635   // Write the record containing weak undeclared identifiers.
4636   if (!WeakUndeclaredIdentifiers.empty())
4637     Stream.EmitRecord(WEAK_UNDECLARED_IDENTIFIERS,
4638                       WeakUndeclaredIdentifiers);
4639 
4640   // Write the record containing ext_vector type names.
4641   if (!ExtVectorDecls.empty())
4642     Stream.EmitRecord(EXT_VECTOR_DECLS, ExtVectorDecls);
4643 
4644   // Write the record containing VTable uses information.
4645   if (!VTableUses.empty())
4646     Stream.EmitRecord(VTABLE_USES, VTableUses);
4647 
4648   // Write the record containing potentially unused local typedefs.
4649   if (!UnusedLocalTypedefNameCandidates.empty())
4650     Stream.EmitRecord(UNUSED_LOCAL_TYPEDEF_NAME_CANDIDATES,
4651                       UnusedLocalTypedefNameCandidates);
4652 
4653   // Write the record containing pending implicit instantiations.
4654   if (!PendingInstantiations.empty())
4655     Stream.EmitRecord(PENDING_IMPLICIT_INSTANTIATIONS, PendingInstantiations);
4656 
4657   // Write the record containing declaration references of Sema.
4658   if (!SemaDeclRefs.empty())
4659     Stream.EmitRecord(SEMA_DECL_REFS, SemaDeclRefs);
4660 
4661   // Write the record containing CUDA-specific declaration references.
4662   if (!CUDASpecialDeclRefs.empty())
4663     Stream.EmitRecord(CUDA_SPECIAL_DECL_REFS, CUDASpecialDeclRefs);
4664 
4665   // Write the delegating constructors.
4666   if (!DelegatingCtorDecls.empty())
4667     Stream.EmitRecord(DELEGATING_CTORS, DelegatingCtorDecls);
4668 
4669   // Write the known namespaces.
4670   if (!KnownNamespaces.empty())
4671     Stream.EmitRecord(KNOWN_NAMESPACES, KnownNamespaces);
4672 
4673   // Write the undefined internal functions and variables, and inline functions.
4674   if (!UndefinedButUsed.empty())
4675     Stream.EmitRecord(UNDEFINED_BUT_USED, UndefinedButUsed);
4676 
4677   if (!DeleteExprsToAnalyze.empty())
4678     Stream.EmitRecord(DELETE_EXPRS_TO_ANALYZE, DeleteExprsToAnalyze);
4679 
4680   // Write the visible updates to DeclContexts.
4681   for (auto *DC : UpdatedDeclContexts)
4682     WriteDeclContextVisibleUpdate(DC);
4683 
4684   if (!WritingModule) {
4685     // Write the submodules that were imported, if any.
4686     struct ModuleInfo {
4687       uint64_t ID;
4688       Module *M;
4689       ModuleInfo(uint64_t ID, Module *M) : ID(ID), M(M) {}
4690     };
4691     llvm::SmallVector<ModuleInfo, 64> Imports;
4692     for (const auto *I : Context.local_imports()) {
4693       assert(SubmoduleIDs.find(I->getImportedModule()) != SubmoduleIDs.end());
4694       Imports.push_back(ModuleInfo(SubmoduleIDs[I->getImportedModule()],
4695                          I->getImportedModule()));
4696     }
4697 
4698     if (!Imports.empty()) {
4699       auto Cmp = [](const ModuleInfo &A, const ModuleInfo &B) {
4700         return A.ID < B.ID;
4701       };
4702       auto Eq = [](const ModuleInfo &A, const ModuleInfo &B) {
4703         return A.ID == B.ID;
4704       };
4705 
4706       // Sort and deduplicate module IDs.
4707       std::sort(Imports.begin(), Imports.end(), Cmp);
4708       Imports.erase(std::unique(Imports.begin(), Imports.end(), Eq),
4709                     Imports.end());
4710 
4711       RecordData ImportedModules;
4712       for (const auto &Import : Imports) {
4713         ImportedModules.push_back(Import.ID);
4714         // FIXME: If the module has macros imported then later has declarations
4715         // imported, this location won't be the right one as a location for the
4716         // declaration imports.
4717         AddSourceLocation(PP.getModuleImportLoc(Import.M), ImportedModules);
4718       }
4719 
4720       Stream.EmitRecord(IMPORTED_MODULES, ImportedModules);
4721     }
4722   }
4723 
4724   WriteObjCCategories();
4725   if(!WritingModule) {
4726     WriteOptimizePragmaOptions(SemaRef);
4727     WriteMSStructPragmaOptions(SemaRef);
4728     WriteMSPointersToMembersPragmaOptions(SemaRef);
4729   }
4730 
4731   // Some simple statistics
4732   RecordData::value_type Record[] = {
4733       NumStatements, NumMacros, NumLexicalDeclContexts, NumVisibleDeclContexts};
4734   Stream.EmitRecord(STATISTICS, Record);
4735   Stream.ExitBlock();
4736 
4737   // Write the module file extension blocks.
4738   for (const auto &ExtWriter : ModuleFileExtensionWriters)
4739     WriteModuleFileExtension(SemaRef, *ExtWriter);
4740 
4741   return Signature;
4742 }
4743 
4744 void ASTWriter::WriteDeclUpdatesBlocks(RecordDataImpl &OffsetsRecord) {
4745   if (DeclUpdates.empty())
4746     return;
4747 
4748   DeclUpdateMap LocalUpdates;
4749   LocalUpdates.swap(DeclUpdates);
4750 
4751   for (auto &DeclUpdate : LocalUpdates) {
4752     const Decl *D = DeclUpdate.first;
4753 
4754     bool HasUpdatedBody = false;
4755     RecordData RecordData;
4756     ASTRecordWriter Record(*this, RecordData);
4757     for (auto &Update : DeclUpdate.second) {
4758       DeclUpdateKind Kind = (DeclUpdateKind)Update.getKind();
4759 
4760       // An updated body is emitted last, so that the reader doesn't need
4761       // to skip over the lazy body to reach statements for other records.
4762       if (Kind == UPD_CXX_ADDED_FUNCTION_DEFINITION)
4763         HasUpdatedBody = true;
4764       else
4765         Record.push_back(Kind);
4766 
4767       switch (Kind) {
4768       case UPD_CXX_ADDED_IMPLICIT_MEMBER:
4769       case UPD_CXX_ADDED_TEMPLATE_SPECIALIZATION:
4770       case UPD_CXX_ADDED_ANONYMOUS_NAMESPACE:
4771         assert(Update.getDecl() && "no decl to add?");
4772         Record.push_back(GetDeclRef(Update.getDecl()));
4773         break;
4774 
4775       case UPD_CXX_ADDED_FUNCTION_DEFINITION:
4776         break;
4777 
4778       case UPD_CXX_INSTANTIATED_STATIC_DATA_MEMBER:
4779         Record.AddSourceLocation(Update.getLoc());
4780         break;
4781 
4782       case UPD_CXX_INSTANTIATED_DEFAULT_ARGUMENT:
4783         Record.AddStmt(const_cast<Expr *>(
4784             cast<ParmVarDecl>(Update.getDecl())->getDefaultArg()));
4785         break;
4786 
4787       case UPD_CXX_INSTANTIATED_DEFAULT_MEMBER_INITIALIZER:
4788         Record.AddStmt(
4789             cast<FieldDecl>(Update.getDecl())->getInClassInitializer());
4790         break;
4791 
4792       case UPD_CXX_INSTANTIATED_CLASS_DEFINITION: {
4793         auto *RD = cast<CXXRecordDecl>(D);
4794         UpdatedDeclContexts.insert(RD->getPrimaryContext());
4795         Record.AddCXXDefinitionData(RD);
4796         Record.AddOffset(WriteDeclContextLexicalBlock(
4797             *Context, const_cast<CXXRecordDecl *>(RD)));
4798 
4799         // This state is sometimes updated by template instantiation, when we
4800         // switch from the specialization referring to the template declaration
4801         // to it referring to the template definition.
4802         if (auto *MSInfo = RD->getMemberSpecializationInfo()) {
4803           Record.push_back(MSInfo->getTemplateSpecializationKind());
4804           Record.AddSourceLocation(MSInfo->getPointOfInstantiation());
4805         } else {
4806           auto *Spec = cast<ClassTemplateSpecializationDecl>(RD);
4807           Record.push_back(Spec->getTemplateSpecializationKind());
4808           Record.AddSourceLocation(Spec->getPointOfInstantiation());
4809 
4810           // The instantiation might have been resolved to a partial
4811           // specialization. If so, record which one.
4812           auto From = Spec->getInstantiatedFrom();
4813           if (auto PartialSpec =
4814                 From.dyn_cast<ClassTemplatePartialSpecializationDecl*>()) {
4815             Record.push_back(true);
4816             Record.AddDeclRef(PartialSpec);
4817             Record.AddTemplateArgumentList(
4818                 &Spec->getTemplateInstantiationArgs());
4819           } else {
4820             Record.push_back(false);
4821           }
4822         }
4823         Record.push_back(RD->getTagKind());
4824         Record.AddSourceLocation(RD->getLocation());
4825         Record.AddSourceLocation(RD->getLocStart());
4826         Record.AddSourceRange(RD->getBraceRange());
4827 
4828         // Instantiation may change attributes; write them all out afresh.
4829         Record.push_back(D->hasAttrs());
4830         if (D->hasAttrs())
4831           Record.AddAttributes(D->getAttrs());
4832 
4833         // FIXME: Ensure we don't get here for explicit instantiations.
4834         break;
4835       }
4836 
4837       case UPD_CXX_RESOLVED_DTOR_DELETE:
4838         Record.AddDeclRef(Update.getDecl());
4839         break;
4840 
4841       case UPD_CXX_RESOLVED_EXCEPTION_SPEC:
4842         addExceptionSpec(
4843             cast<FunctionDecl>(D)->getType()->castAs<FunctionProtoType>(),
4844             Record);
4845         break;
4846 
4847       case UPD_CXX_DEDUCED_RETURN_TYPE:
4848         Record.push_back(GetOrCreateTypeID(Update.getType()));
4849         break;
4850 
4851       case UPD_DECL_MARKED_USED:
4852         break;
4853 
4854       case UPD_MANGLING_NUMBER:
4855       case UPD_STATIC_LOCAL_NUMBER:
4856         Record.push_back(Update.getNumber());
4857         break;
4858 
4859       case UPD_DECL_MARKED_OPENMP_THREADPRIVATE:
4860         Record.AddSourceRange(
4861             D->getAttr<OMPThreadPrivateDeclAttr>()->getRange());
4862         break;
4863 
4864       case UPD_DECL_MARKED_OPENMP_DECLARETARGET:
4865         Record.AddSourceRange(
4866             D->getAttr<OMPDeclareTargetDeclAttr>()->getRange());
4867         break;
4868 
4869       case UPD_DECL_EXPORTED:
4870         Record.push_back(getSubmoduleID(Update.getModule()));
4871         break;
4872 
4873       case UPD_ADDED_ATTR_TO_RECORD:
4874         Record.AddAttributes(llvm::makeArrayRef(Update.getAttr()));
4875         break;
4876       }
4877     }
4878 
4879     if (HasUpdatedBody) {
4880       const auto *Def = cast<FunctionDecl>(D);
4881       Record.push_back(UPD_CXX_ADDED_FUNCTION_DEFINITION);
4882       Record.push_back(Def->isInlined());
4883       Record.AddSourceLocation(Def->getInnerLocStart());
4884       Record.AddFunctionDefinition(Def);
4885     }
4886 
4887     OffsetsRecord.push_back(GetDeclRef(D));
4888     OffsetsRecord.push_back(Record.Emit(DECL_UPDATES));
4889   }
4890 }
4891 
4892 void ASTWriter::AddSourceLocation(SourceLocation Loc, RecordDataImpl &Record) {
4893   uint32_t Raw = Loc.getRawEncoding();
4894   Record.push_back((Raw << 1) | (Raw >> 31));
4895 }
4896 
4897 void ASTWriter::AddSourceRange(SourceRange Range, RecordDataImpl &Record) {
4898   AddSourceLocation(Range.getBegin(), Record);
4899   AddSourceLocation(Range.getEnd(), Record);
4900 }
4901 
4902 void ASTRecordWriter::AddAPInt(const llvm::APInt &Value) {
4903   Record->push_back(Value.getBitWidth());
4904   const uint64_t *Words = Value.getRawData();
4905   Record->append(Words, Words + Value.getNumWords());
4906 }
4907 
4908 void ASTRecordWriter::AddAPSInt(const llvm::APSInt &Value) {
4909   Record->push_back(Value.isUnsigned());
4910   AddAPInt(Value);
4911 }
4912 
4913 void ASTRecordWriter::AddAPFloat(const llvm::APFloat &Value) {
4914   AddAPInt(Value.bitcastToAPInt());
4915 }
4916 
4917 void ASTWriter::AddIdentifierRef(const IdentifierInfo *II, RecordDataImpl &Record) {
4918   Record.push_back(getIdentifierRef(II));
4919 }
4920 
4921 IdentID ASTWriter::getIdentifierRef(const IdentifierInfo *II) {
4922   if (!II)
4923     return 0;
4924 
4925   IdentID &ID = IdentifierIDs[II];
4926   if (ID == 0)
4927     ID = NextIdentID++;
4928   return ID;
4929 }
4930 
4931 MacroID ASTWriter::getMacroRef(MacroInfo *MI, const IdentifierInfo *Name) {
4932   // Don't emit builtin macros like __LINE__ to the AST file unless they
4933   // have been redefined by the header (in which case they are not
4934   // isBuiltinMacro).
4935   if (!MI || MI->isBuiltinMacro())
4936     return 0;
4937 
4938   MacroID &ID = MacroIDs[MI];
4939   if (ID == 0) {
4940     ID = NextMacroID++;
4941     MacroInfoToEmitData Info = { Name, MI, ID };
4942     MacroInfosToEmit.push_back(Info);
4943   }
4944   return ID;
4945 }
4946 
4947 MacroID ASTWriter::getMacroID(MacroInfo *MI) {
4948   if (!MI || MI->isBuiltinMacro())
4949     return 0;
4950 
4951   assert(MacroIDs.find(MI) != MacroIDs.end() && "Macro not emitted!");
4952   return MacroIDs[MI];
4953 }
4954 
4955 uint64_t ASTWriter::getMacroDirectivesOffset(const IdentifierInfo *Name) {
4956   return IdentMacroDirectivesOffsetMap.lookup(Name);
4957 }
4958 
4959 void ASTRecordWriter::AddSelectorRef(const Selector SelRef) {
4960   Record->push_back(Writer->getSelectorRef(SelRef));
4961 }
4962 
4963 SelectorID ASTWriter::getSelectorRef(Selector Sel) {
4964   if (Sel.getAsOpaquePtr() == nullptr) {
4965     return 0;
4966   }
4967 
4968   SelectorID SID = SelectorIDs[Sel];
4969   if (SID == 0 && Chain) {
4970     // This might trigger a ReadSelector callback, which will set the ID for
4971     // this selector.
4972     Chain->LoadSelector(Sel);
4973     SID = SelectorIDs[Sel];
4974   }
4975   if (SID == 0) {
4976     SID = NextSelectorID++;
4977     SelectorIDs[Sel] = SID;
4978   }
4979   return SID;
4980 }
4981 
4982 void ASTRecordWriter::AddCXXTemporary(const CXXTemporary *Temp) {
4983   AddDeclRef(Temp->getDestructor());
4984 }
4985 
4986 void ASTRecordWriter::AddTemplateArgumentLocInfo(
4987     TemplateArgument::ArgKind Kind, const TemplateArgumentLocInfo &Arg) {
4988   switch (Kind) {
4989   case TemplateArgument::Expression:
4990     AddStmt(Arg.getAsExpr());
4991     break;
4992   case TemplateArgument::Type:
4993     AddTypeSourceInfo(Arg.getAsTypeSourceInfo());
4994     break;
4995   case TemplateArgument::Template:
4996     AddNestedNameSpecifierLoc(Arg.getTemplateQualifierLoc());
4997     AddSourceLocation(Arg.getTemplateNameLoc());
4998     break;
4999   case TemplateArgument::TemplateExpansion:
5000     AddNestedNameSpecifierLoc(Arg.getTemplateQualifierLoc());
5001     AddSourceLocation(Arg.getTemplateNameLoc());
5002     AddSourceLocation(Arg.getTemplateEllipsisLoc());
5003     break;
5004   case TemplateArgument::Null:
5005   case TemplateArgument::Integral:
5006   case TemplateArgument::Declaration:
5007   case TemplateArgument::NullPtr:
5008   case TemplateArgument::Pack:
5009     // FIXME: Is this right?
5010     break;
5011   }
5012 }
5013 
5014 void ASTRecordWriter::AddTemplateArgumentLoc(const TemplateArgumentLoc &Arg) {
5015   AddTemplateArgument(Arg.getArgument());
5016 
5017   if (Arg.getArgument().getKind() == TemplateArgument::Expression) {
5018     bool InfoHasSameExpr
5019       = Arg.getArgument().getAsExpr() == Arg.getLocInfo().getAsExpr();
5020     Record->push_back(InfoHasSameExpr);
5021     if (InfoHasSameExpr)
5022       return; // Avoid storing the same expr twice.
5023   }
5024   AddTemplateArgumentLocInfo(Arg.getArgument().getKind(), Arg.getLocInfo());
5025 }
5026 
5027 void ASTRecordWriter::AddTypeSourceInfo(TypeSourceInfo *TInfo) {
5028   if (!TInfo) {
5029     AddTypeRef(QualType());
5030     return;
5031   }
5032 
5033   AddTypeLoc(TInfo->getTypeLoc());
5034 }
5035 
5036 void ASTRecordWriter::AddTypeLoc(TypeLoc TL) {
5037   AddTypeRef(TL.getType());
5038 
5039   TypeLocWriter TLW(*this);
5040   for (; !TL.isNull(); TL = TL.getNextTypeLoc())
5041     TLW.Visit(TL);
5042 }
5043 
5044 void ASTWriter::AddTypeRef(QualType T, RecordDataImpl &Record) {
5045   Record.push_back(GetOrCreateTypeID(T));
5046 }
5047 
5048 TypeID ASTWriter::GetOrCreateTypeID(QualType T) {
5049   assert(Context);
5050   return MakeTypeID(*Context, T, [&](QualType T) -> TypeIdx {
5051     if (T.isNull())
5052       return TypeIdx();
5053     assert(!T.getLocalFastQualifiers());
5054 
5055     TypeIdx &Idx = TypeIdxs[T];
5056     if (Idx.getIndex() == 0) {
5057       if (DoneWritingDeclsAndTypes) {
5058         assert(0 && "New type seen after serializing all the types to emit!");
5059         return TypeIdx();
5060       }
5061 
5062       // We haven't seen this type before. Assign it a new ID and put it
5063       // into the queue of types to emit.
5064       Idx = TypeIdx(NextTypeID++);
5065       DeclTypesToEmit.push(T);
5066     }
5067     return Idx;
5068   });
5069 }
5070 
5071 TypeID ASTWriter::getTypeID(QualType T) const {
5072   assert(Context);
5073   return MakeTypeID(*Context, T, [&](QualType T) -> TypeIdx {
5074     if (T.isNull())
5075       return TypeIdx();
5076     assert(!T.getLocalFastQualifiers());
5077 
5078     TypeIdxMap::const_iterator I = TypeIdxs.find(T);
5079     assert(I != TypeIdxs.end() && "Type not emitted!");
5080     return I->second;
5081   });
5082 }
5083 
5084 void ASTWriter::AddDeclRef(const Decl *D, RecordDataImpl &Record) {
5085   Record.push_back(GetDeclRef(D));
5086 }
5087 
5088 DeclID ASTWriter::GetDeclRef(const Decl *D) {
5089   assert(WritingAST && "Cannot request a declaration ID before AST writing");
5090 
5091   if (!D) {
5092     return 0;
5093   }
5094 
5095   // If D comes from an AST file, its declaration ID is already known and
5096   // fixed.
5097   if (D->isFromASTFile())
5098     return D->getGlobalID();
5099 
5100   assert(!(reinterpret_cast<uintptr_t>(D) & 0x01) && "Invalid decl pointer");
5101   DeclID &ID = DeclIDs[D];
5102   if (ID == 0) {
5103     if (DoneWritingDeclsAndTypes) {
5104       assert(0 && "New decl seen after serializing all the decls to emit!");
5105       return 0;
5106     }
5107 
5108     // We haven't seen this declaration before. Give it a new ID and
5109     // enqueue it in the list of declarations to emit.
5110     ID = NextDeclID++;
5111     DeclTypesToEmit.push(const_cast<Decl *>(D));
5112   }
5113 
5114   return ID;
5115 }
5116 
5117 DeclID ASTWriter::getDeclID(const Decl *D) {
5118   if (!D)
5119     return 0;
5120 
5121   // If D comes from an AST file, its declaration ID is already known and
5122   // fixed.
5123   if (D->isFromASTFile())
5124     return D->getGlobalID();
5125 
5126   assert(DeclIDs.find(D) != DeclIDs.end() && "Declaration not emitted!");
5127   return DeclIDs[D];
5128 }
5129 
5130 void ASTWriter::associateDeclWithFile(const Decl *D, DeclID ID) {
5131   assert(ID);
5132   assert(D);
5133 
5134   SourceLocation Loc = D->getLocation();
5135   if (Loc.isInvalid())
5136     return;
5137 
5138   // We only keep track of the file-level declarations of each file.
5139   if (!D->getLexicalDeclContext()->isFileContext())
5140     return;
5141   // FIXME: ParmVarDecls that are part of a function type of a parameter of
5142   // a function/objc method, should not have TU as lexical context.
5143   if (isa<ParmVarDecl>(D))
5144     return;
5145 
5146   SourceManager &SM = Context->getSourceManager();
5147   SourceLocation FileLoc = SM.getFileLoc(Loc);
5148   assert(SM.isLocalSourceLocation(FileLoc));
5149   FileID FID;
5150   unsigned Offset;
5151   std::tie(FID, Offset) = SM.getDecomposedLoc(FileLoc);
5152   if (FID.isInvalid())
5153     return;
5154   assert(SM.getSLocEntry(FID).isFile());
5155 
5156   DeclIDInFileInfo *&Info = FileDeclIDs[FID];
5157   if (!Info)
5158     Info = new DeclIDInFileInfo();
5159 
5160   std::pair<unsigned, serialization::DeclID> LocDecl(Offset, ID);
5161   LocDeclIDsTy &Decls = Info->DeclIDs;
5162 
5163   if (Decls.empty() || Decls.back().first <= Offset) {
5164     Decls.push_back(LocDecl);
5165     return;
5166   }
5167 
5168   LocDeclIDsTy::iterator I =
5169       std::upper_bound(Decls.begin(), Decls.end(), LocDecl, llvm::less_first());
5170 
5171   Decls.insert(I, LocDecl);
5172 }
5173 
5174 void ASTRecordWriter::AddDeclarationName(DeclarationName Name) {
5175   // FIXME: Emit a stable enum for NameKind.  0 = Identifier etc.
5176   Record->push_back(Name.getNameKind());
5177   switch (Name.getNameKind()) {
5178   case DeclarationName::Identifier:
5179     AddIdentifierRef(Name.getAsIdentifierInfo());
5180     break;
5181 
5182   case DeclarationName::ObjCZeroArgSelector:
5183   case DeclarationName::ObjCOneArgSelector:
5184   case DeclarationName::ObjCMultiArgSelector:
5185     AddSelectorRef(Name.getObjCSelector());
5186     break;
5187 
5188   case DeclarationName::CXXConstructorName:
5189   case DeclarationName::CXXDestructorName:
5190   case DeclarationName::CXXConversionFunctionName:
5191     AddTypeRef(Name.getCXXNameType());
5192     break;
5193 
5194   case DeclarationName::CXXOperatorName:
5195     Record->push_back(Name.getCXXOverloadedOperator());
5196     break;
5197 
5198   case DeclarationName::CXXLiteralOperatorName:
5199     AddIdentifierRef(Name.getCXXLiteralIdentifier());
5200     break;
5201 
5202   case DeclarationName::CXXUsingDirective:
5203     // No extra data to emit
5204     break;
5205   }
5206 }
5207 
5208 unsigned ASTWriter::getAnonymousDeclarationNumber(const NamedDecl *D) {
5209   assert(needsAnonymousDeclarationNumber(D) &&
5210          "expected an anonymous declaration");
5211 
5212   // Number the anonymous declarations within this context, if we've not
5213   // already done so.
5214   auto It = AnonymousDeclarationNumbers.find(D);
5215   if (It == AnonymousDeclarationNumbers.end()) {
5216     auto *DC = D->getLexicalDeclContext();
5217     numberAnonymousDeclsWithin(DC, [&](const NamedDecl *ND, unsigned Number) {
5218       AnonymousDeclarationNumbers[ND] = Number;
5219     });
5220 
5221     It = AnonymousDeclarationNumbers.find(D);
5222     assert(It != AnonymousDeclarationNumbers.end() &&
5223            "declaration not found within its lexical context");
5224   }
5225 
5226   return It->second;
5227 }
5228 
5229 void ASTRecordWriter::AddDeclarationNameLoc(const DeclarationNameLoc &DNLoc,
5230                                             DeclarationName Name) {
5231   switch (Name.getNameKind()) {
5232   case DeclarationName::CXXConstructorName:
5233   case DeclarationName::CXXDestructorName:
5234   case DeclarationName::CXXConversionFunctionName:
5235     AddTypeSourceInfo(DNLoc.NamedType.TInfo);
5236     break;
5237 
5238   case DeclarationName::CXXOperatorName:
5239     AddSourceLocation(SourceLocation::getFromRawEncoding(
5240         DNLoc.CXXOperatorName.BeginOpNameLoc));
5241     AddSourceLocation(
5242         SourceLocation::getFromRawEncoding(DNLoc.CXXOperatorName.EndOpNameLoc));
5243     break;
5244 
5245   case DeclarationName::CXXLiteralOperatorName:
5246     AddSourceLocation(SourceLocation::getFromRawEncoding(
5247         DNLoc.CXXLiteralOperatorName.OpNameLoc));
5248     break;
5249 
5250   case DeclarationName::Identifier:
5251   case DeclarationName::ObjCZeroArgSelector:
5252   case DeclarationName::ObjCOneArgSelector:
5253   case DeclarationName::ObjCMultiArgSelector:
5254   case DeclarationName::CXXUsingDirective:
5255     break;
5256   }
5257 }
5258 
5259 void ASTRecordWriter::AddDeclarationNameInfo(
5260     const DeclarationNameInfo &NameInfo) {
5261   AddDeclarationName(NameInfo.getName());
5262   AddSourceLocation(NameInfo.getLoc());
5263   AddDeclarationNameLoc(NameInfo.getInfo(), NameInfo.getName());
5264 }
5265 
5266 void ASTRecordWriter::AddQualifierInfo(const QualifierInfo &Info) {
5267   AddNestedNameSpecifierLoc(Info.QualifierLoc);
5268   Record->push_back(Info.NumTemplParamLists);
5269   for (unsigned i = 0, e = Info.NumTemplParamLists; i != e; ++i)
5270     AddTemplateParameterList(Info.TemplParamLists[i]);
5271 }
5272 
5273 void ASTRecordWriter::AddNestedNameSpecifier(NestedNameSpecifier *NNS) {
5274   // Nested name specifiers usually aren't too long. I think that 8 would
5275   // typically accommodate the vast majority.
5276   SmallVector<NestedNameSpecifier *, 8> NestedNames;
5277 
5278   // Push each of the NNS's onto a stack for serialization in reverse order.
5279   while (NNS) {
5280     NestedNames.push_back(NNS);
5281     NNS = NNS->getPrefix();
5282   }
5283 
5284   Record->push_back(NestedNames.size());
5285   while(!NestedNames.empty()) {
5286     NNS = NestedNames.pop_back_val();
5287     NestedNameSpecifier::SpecifierKind Kind = NNS->getKind();
5288     Record->push_back(Kind);
5289     switch (Kind) {
5290     case NestedNameSpecifier::Identifier:
5291       AddIdentifierRef(NNS->getAsIdentifier());
5292       break;
5293 
5294     case NestedNameSpecifier::Namespace:
5295       AddDeclRef(NNS->getAsNamespace());
5296       break;
5297 
5298     case NestedNameSpecifier::NamespaceAlias:
5299       AddDeclRef(NNS->getAsNamespaceAlias());
5300       break;
5301 
5302     case NestedNameSpecifier::TypeSpec:
5303     case NestedNameSpecifier::TypeSpecWithTemplate:
5304       AddTypeRef(QualType(NNS->getAsType(), 0));
5305       Record->push_back(Kind == NestedNameSpecifier::TypeSpecWithTemplate);
5306       break;
5307 
5308     case NestedNameSpecifier::Global:
5309       // Don't need to write an associated value.
5310       break;
5311 
5312     case NestedNameSpecifier::Super:
5313       AddDeclRef(NNS->getAsRecordDecl());
5314       break;
5315     }
5316   }
5317 }
5318 
5319 void ASTRecordWriter::AddNestedNameSpecifierLoc(NestedNameSpecifierLoc NNS) {
5320   // Nested name specifiers usually aren't too long. I think that 8 would
5321   // typically accommodate the vast majority.
5322   SmallVector<NestedNameSpecifierLoc , 8> NestedNames;
5323 
5324   // Push each of the nested-name-specifiers's onto a stack for
5325   // serialization in reverse order.
5326   while (NNS) {
5327     NestedNames.push_back(NNS);
5328     NNS = NNS.getPrefix();
5329   }
5330 
5331   Record->push_back(NestedNames.size());
5332   while(!NestedNames.empty()) {
5333     NNS = NestedNames.pop_back_val();
5334     NestedNameSpecifier::SpecifierKind Kind
5335       = NNS.getNestedNameSpecifier()->getKind();
5336     Record->push_back(Kind);
5337     switch (Kind) {
5338     case NestedNameSpecifier::Identifier:
5339       AddIdentifierRef(NNS.getNestedNameSpecifier()->getAsIdentifier());
5340       AddSourceRange(NNS.getLocalSourceRange());
5341       break;
5342 
5343     case NestedNameSpecifier::Namespace:
5344       AddDeclRef(NNS.getNestedNameSpecifier()->getAsNamespace());
5345       AddSourceRange(NNS.getLocalSourceRange());
5346       break;
5347 
5348     case NestedNameSpecifier::NamespaceAlias:
5349       AddDeclRef(NNS.getNestedNameSpecifier()->getAsNamespaceAlias());
5350       AddSourceRange(NNS.getLocalSourceRange());
5351       break;
5352 
5353     case NestedNameSpecifier::TypeSpec:
5354     case NestedNameSpecifier::TypeSpecWithTemplate:
5355       Record->push_back(Kind == NestedNameSpecifier::TypeSpecWithTemplate);
5356       AddTypeLoc(NNS.getTypeLoc());
5357       AddSourceLocation(NNS.getLocalSourceRange().getEnd());
5358       break;
5359 
5360     case NestedNameSpecifier::Global:
5361       AddSourceLocation(NNS.getLocalSourceRange().getEnd());
5362       break;
5363 
5364     case NestedNameSpecifier::Super:
5365       AddDeclRef(NNS.getNestedNameSpecifier()->getAsRecordDecl());
5366       AddSourceRange(NNS.getLocalSourceRange());
5367       break;
5368     }
5369   }
5370 }
5371 
5372 void ASTRecordWriter::AddTemplateName(TemplateName Name) {
5373   TemplateName::NameKind Kind = Name.getKind();
5374   Record->push_back(Kind);
5375   switch (Kind) {
5376   case TemplateName::Template:
5377     AddDeclRef(Name.getAsTemplateDecl());
5378     break;
5379 
5380   case TemplateName::OverloadedTemplate: {
5381     OverloadedTemplateStorage *OvT = Name.getAsOverloadedTemplate();
5382     Record->push_back(OvT->size());
5383     for (const auto &I : *OvT)
5384       AddDeclRef(I);
5385     break;
5386   }
5387 
5388   case TemplateName::QualifiedTemplate: {
5389     QualifiedTemplateName *QualT = Name.getAsQualifiedTemplateName();
5390     AddNestedNameSpecifier(QualT->getQualifier());
5391     Record->push_back(QualT->hasTemplateKeyword());
5392     AddDeclRef(QualT->getTemplateDecl());
5393     break;
5394   }
5395 
5396   case TemplateName::DependentTemplate: {
5397     DependentTemplateName *DepT = Name.getAsDependentTemplateName();
5398     AddNestedNameSpecifier(DepT->getQualifier());
5399     Record->push_back(DepT->isIdentifier());
5400     if (DepT->isIdentifier())
5401       AddIdentifierRef(DepT->getIdentifier());
5402     else
5403       Record->push_back(DepT->getOperator());
5404     break;
5405   }
5406 
5407   case TemplateName::SubstTemplateTemplateParm: {
5408     SubstTemplateTemplateParmStorage *subst
5409       = Name.getAsSubstTemplateTemplateParm();
5410     AddDeclRef(subst->getParameter());
5411     AddTemplateName(subst->getReplacement());
5412     break;
5413   }
5414 
5415   case TemplateName::SubstTemplateTemplateParmPack: {
5416     SubstTemplateTemplateParmPackStorage *SubstPack
5417       = Name.getAsSubstTemplateTemplateParmPack();
5418     AddDeclRef(SubstPack->getParameterPack());
5419     AddTemplateArgument(SubstPack->getArgumentPack());
5420     break;
5421   }
5422   }
5423 }
5424 
5425 void ASTRecordWriter::AddTemplateArgument(const TemplateArgument &Arg) {
5426   Record->push_back(Arg.getKind());
5427   switch (Arg.getKind()) {
5428   case TemplateArgument::Null:
5429     break;
5430   case TemplateArgument::Type:
5431     AddTypeRef(Arg.getAsType());
5432     break;
5433   case TemplateArgument::Declaration:
5434     AddDeclRef(Arg.getAsDecl());
5435     AddTypeRef(Arg.getParamTypeForDecl());
5436     break;
5437   case TemplateArgument::NullPtr:
5438     AddTypeRef(Arg.getNullPtrType());
5439     break;
5440   case TemplateArgument::Integral:
5441     AddAPSInt(Arg.getAsIntegral());
5442     AddTypeRef(Arg.getIntegralType());
5443     break;
5444   case TemplateArgument::Template:
5445     AddTemplateName(Arg.getAsTemplateOrTemplatePattern());
5446     break;
5447   case TemplateArgument::TemplateExpansion:
5448     AddTemplateName(Arg.getAsTemplateOrTemplatePattern());
5449     if (Optional<unsigned> NumExpansions = Arg.getNumTemplateExpansions())
5450       Record->push_back(*NumExpansions + 1);
5451     else
5452       Record->push_back(0);
5453     break;
5454   case TemplateArgument::Expression:
5455     AddStmt(Arg.getAsExpr());
5456     break;
5457   case TemplateArgument::Pack:
5458     Record->push_back(Arg.pack_size());
5459     for (const auto &P : Arg.pack_elements())
5460       AddTemplateArgument(P);
5461     break;
5462   }
5463 }
5464 
5465 void ASTRecordWriter::AddTemplateParameterList(
5466     const TemplateParameterList *TemplateParams) {
5467   assert(TemplateParams && "No TemplateParams!");
5468   AddSourceLocation(TemplateParams->getTemplateLoc());
5469   AddSourceLocation(TemplateParams->getLAngleLoc());
5470   AddSourceLocation(TemplateParams->getRAngleLoc());
5471   // TODO: Concepts
5472   Record->push_back(TemplateParams->size());
5473   for (const auto &P : *TemplateParams)
5474     AddDeclRef(P);
5475 }
5476 
5477 /// \brief Emit a template argument list.
5478 void ASTRecordWriter::AddTemplateArgumentList(
5479     const TemplateArgumentList *TemplateArgs) {
5480   assert(TemplateArgs && "No TemplateArgs!");
5481   Record->push_back(TemplateArgs->size());
5482   for (int i = 0, e = TemplateArgs->size(); i != e; ++i)
5483     AddTemplateArgument(TemplateArgs->get(i));
5484 }
5485 
5486 void ASTRecordWriter::AddASTTemplateArgumentListInfo(
5487     const ASTTemplateArgumentListInfo *ASTTemplArgList) {
5488   assert(ASTTemplArgList && "No ASTTemplArgList!");
5489   AddSourceLocation(ASTTemplArgList->LAngleLoc);
5490   AddSourceLocation(ASTTemplArgList->RAngleLoc);
5491   Record->push_back(ASTTemplArgList->NumTemplateArgs);
5492   const TemplateArgumentLoc *TemplArgs = ASTTemplArgList->getTemplateArgs();
5493   for (int i = 0, e = ASTTemplArgList->NumTemplateArgs; i != e; ++i)
5494     AddTemplateArgumentLoc(TemplArgs[i]);
5495 }
5496 
5497 void ASTRecordWriter::AddUnresolvedSet(const ASTUnresolvedSet &Set) {
5498   Record->push_back(Set.size());
5499   for (ASTUnresolvedSet::const_iterator
5500          I = Set.begin(), E = Set.end(); I != E; ++I) {
5501     AddDeclRef(I.getDecl());
5502     Record->push_back(I.getAccess());
5503   }
5504 }
5505 
5506 // FIXME: Move this out of the main ASTRecordWriter interface.
5507 void ASTRecordWriter::AddCXXBaseSpecifier(const CXXBaseSpecifier &Base) {
5508   Record->push_back(Base.isVirtual());
5509   Record->push_back(Base.isBaseOfClass());
5510   Record->push_back(Base.getAccessSpecifierAsWritten());
5511   Record->push_back(Base.getInheritConstructors());
5512   AddTypeSourceInfo(Base.getTypeSourceInfo());
5513   AddSourceRange(Base.getSourceRange());
5514   AddSourceLocation(Base.isPackExpansion()? Base.getEllipsisLoc()
5515                                           : SourceLocation());
5516 }
5517 
5518 static uint64_t EmitCXXBaseSpecifiers(ASTWriter &W,
5519                                       ArrayRef<CXXBaseSpecifier> Bases) {
5520   ASTWriter::RecordData Record;
5521   ASTRecordWriter Writer(W, Record);
5522   Writer.push_back(Bases.size());
5523 
5524   for (auto &Base : Bases)
5525     Writer.AddCXXBaseSpecifier(Base);
5526 
5527   return Writer.Emit(serialization::DECL_CXX_BASE_SPECIFIERS);
5528 }
5529 
5530 // FIXME: Move this out of the main ASTRecordWriter interface.
5531 void ASTRecordWriter::AddCXXBaseSpecifiers(ArrayRef<CXXBaseSpecifier> Bases) {
5532   AddOffset(EmitCXXBaseSpecifiers(*Writer, Bases));
5533 }
5534 
5535 static uint64_t
5536 EmitCXXCtorInitializers(ASTWriter &W,
5537                         ArrayRef<CXXCtorInitializer *> CtorInits) {
5538   ASTWriter::RecordData Record;
5539   ASTRecordWriter Writer(W, Record);
5540   Writer.push_back(CtorInits.size());
5541 
5542   for (auto *Init : CtorInits) {
5543     if (Init->isBaseInitializer()) {
5544       Writer.push_back(CTOR_INITIALIZER_BASE);
5545       Writer.AddTypeSourceInfo(Init->getTypeSourceInfo());
5546       Writer.push_back(Init->isBaseVirtual());
5547     } else if (Init->isDelegatingInitializer()) {
5548       Writer.push_back(CTOR_INITIALIZER_DELEGATING);
5549       Writer.AddTypeSourceInfo(Init->getTypeSourceInfo());
5550     } else if (Init->isMemberInitializer()){
5551       Writer.push_back(CTOR_INITIALIZER_MEMBER);
5552       Writer.AddDeclRef(Init->getMember());
5553     } else {
5554       Writer.push_back(CTOR_INITIALIZER_INDIRECT_MEMBER);
5555       Writer.AddDeclRef(Init->getIndirectMember());
5556     }
5557 
5558     Writer.AddSourceLocation(Init->getMemberLocation());
5559     Writer.AddStmt(Init->getInit());
5560     Writer.AddSourceLocation(Init->getLParenLoc());
5561     Writer.AddSourceLocation(Init->getRParenLoc());
5562     Writer.push_back(Init->isWritten());
5563     if (Init->isWritten()) {
5564       Writer.push_back(Init->getSourceOrder());
5565     } else {
5566       Writer.push_back(Init->getNumArrayIndices());
5567       for (auto *VD : Init->getArrayIndices())
5568         Writer.AddDeclRef(VD);
5569     }
5570   }
5571 
5572   return Writer.Emit(serialization::DECL_CXX_CTOR_INITIALIZERS);
5573 }
5574 
5575 // FIXME: Move this out of the main ASTRecordWriter interface.
5576 void ASTRecordWriter::AddCXXCtorInitializers(
5577     ArrayRef<CXXCtorInitializer *> CtorInits) {
5578   AddOffset(EmitCXXCtorInitializers(*Writer, CtorInits));
5579 }
5580 
5581 void ASTRecordWriter::AddCXXDefinitionData(const CXXRecordDecl *D) {
5582   auto &Data = D->data();
5583   Record->push_back(Data.IsLambda);
5584   Record->push_back(Data.UserDeclaredConstructor);
5585   Record->push_back(Data.UserDeclaredSpecialMembers);
5586   Record->push_back(Data.Aggregate);
5587   Record->push_back(Data.PlainOldData);
5588   Record->push_back(Data.Empty);
5589   Record->push_back(Data.Polymorphic);
5590   Record->push_back(Data.Abstract);
5591   Record->push_back(Data.IsStandardLayout);
5592   Record->push_back(Data.HasNoNonEmptyBases);
5593   Record->push_back(Data.HasPrivateFields);
5594   Record->push_back(Data.HasProtectedFields);
5595   Record->push_back(Data.HasPublicFields);
5596   Record->push_back(Data.HasMutableFields);
5597   Record->push_back(Data.HasVariantMembers);
5598   Record->push_back(Data.HasOnlyCMembers);
5599   Record->push_back(Data.HasInClassInitializer);
5600   Record->push_back(Data.HasUninitializedReferenceMember);
5601   Record->push_back(Data.HasUninitializedFields);
5602   Record->push_back(Data.HasInheritedConstructor);
5603   Record->push_back(Data.HasInheritedAssignment);
5604   Record->push_back(Data.NeedOverloadResolutionForMoveConstructor);
5605   Record->push_back(Data.NeedOverloadResolutionForMoveAssignment);
5606   Record->push_back(Data.NeedOverloadResolutionForDestructor);
5607   Record->push_back(Data.DefaultedMoveConstructorIsDeleted);
5608   Record->push_back(Data.DefaultedMoveAssignmentIsDeleted);
5609   Record->push_back(Data.DefaultedDestructorIsDeleted);
5610   Record->push_back(Data.HasTrivialSpecialMembers);
5611   Record->push_back(Data.DeclaredNonTrivialSpecialMembers);
5612   Record->push_back(Data.HasIrrelevantDestructor);
5613   Record->push_back(Data.HasConstexprNonCopyMoveConstructor);
5614   Record->push_back(Data.HasDefaultedDefaultConstructor);
5615   Record->push_back(Data.DefaultedDefaultConstructorIsConstexpr);
5616   Record->push_back(Data.HasConstexprDefaultConstructor);
5617   Record->push_back(Data.HasNonLiteralTypeFieldsOrBases);
5618   Record->push_back(Data.ComputedVisibleConversions);
5619   Record->push_back(Data.UserProvidedDefaultConstructor);
5620   Record->push_back(Data.DeclaredSpecialMembers);
5621   Record->push_back(Data.ImplicitCopyConstructorHasConstParam);
5622   Record->push_back(Data.ImplicitCopyAssignmentHasConstParam);
5623   Record->push_back(Data.HasDeclaredCopyConstructorWithConstParam);
5624   Record->push_back(Data.HasDeclaredCopyAssignmentWithConstParam);
5625   // IsLambda bit is already saved.
5626 
5627   Record->push_back(Data.NumBases);
5628   if (Data.NumBases > 0)
5629     AddCXXBaseSpecifiers(Data.bases());
5630 
5631   // FIXME: Make VBases lazily computed when needed to avoid storing them.
5632   Record->push_back(Data.NumVBases);
5633   if (Data.NumVBases > 0)
5634     AddCXXBaseSpecifiers(Data.vbases());
5635 
5636   AddUnresolvedSet(Data.Conversions.get(*Writer->Context));
5637   AddUnresolvedSet(Data.VisibleConversions.get(*Writer->Context));
5638   // Data.Definition is the owning decl, no need to write it.
5639   AddDeclRef(D->getFirstFriend());
5640 
5641   // Add lambda-specific data.
5642   if (Data.IsLambda) {
5643     auto &Lambda = D->getLambdaData();
5644     Record->push_back(Lambda.Dependent);
5645     Record->push_back(Lambda.IsGenericLambda);
5646     Record->push_back(Lambda.CaptureDefault);
5647     Record->push_back(Lambda.NumCaptures);
5648     Record->push_back(Lambda.NumExplicitCaptures);
5649     Record->push_back(Lambda.ManglingNumber);
5650     AddDeclRef(D->getLambdaContextDecl());
5651     AddTypeSourceInfo(Lambda.MethodTyInfo);
5652     for (unsigned I = 0, N = Lambda.NumCaptures; I != N; ++I) {
5653       const LambdaCapture &Capture = Lambda.Captures[I];
5654       AddSourceLocation(Capture.getLocation());
5655       Record->push_back(Capture.isImplicit());
5656       Record->push_back(Capture.getCaptureKind());
5657       switch (Capture.getCaptureKind()) {
5658       case LCK_StarThis:
5659       case LCK_This:
5660       case LCK_VLAType:
5661         break;
5662       case LCK_ByCopy:
5663       case LCK_ByRef:
5664         VarDecl *Var =
5665             Capture.capturesVariable() ? Capture.getCapturedVar() : nullptr;
5666         AddDeclRef(Var);
5667         AddSourceLocation(Capture.isPackExpansion() ? Capture.getEllipsisLoc()
5668                                                     : SourceLocation());
5669         break;
5670       }
5671     }
5672   }
5673 }
5674 
5675 void ASTWriter::ReaderInitialized(ASTReader *Reader) {
5676   assert(Reader && "Cannot remove chain");
5677   assert((!Chain || Chain == Reader) && "Cannot replace chain");
5678   assert(FirstDeclID == NextDeclID &&
5679          FirstTypeID == NextTypeID &&
5680          FirstIdentID == NextIdentID &&
5681          FirstMacroID == NextMacroID &&
5682          FirstSubmoduleID == NextSubmoduleID &&
5683          FirstSelectorID == NextSelectorID &&
5684          "Setting chain after writing has started.");
5685 
5686   Chain = Reader;
5687 
5688   // Note, this will get called multiple times, once one the reader starts up
5689   // and again each time it's done reading a PCH or module.
5690   FirstDeclID = NUM_PREDEF_DECL_IDS + Chain->getTotalNumDecls();
5691   FirstTypeID = NUM_PREDEF_TYPE_IDS + Chain->getTotalNumTypes();
5692   FirstIdentID = NUM_PREDEF_IDENT_IDS + Chain->getTotalNumIdentifiers();
5693   FirstMacroID = NUM_PREDEF_MACRO_IDS + Chain->getTotalNumMacros();
5694   FirstSubmoduleID = NUM_PREDEF_SUBMODULE_IDS + Chain->getTotalNumSubmodules();
5695   FirstSelectorID = NUM_PREDEF_SELECTOR_IDS + Chain->getTotalNumSelectors();
5696   NextDeclID = FirstDeclID;
5697   NextTypeID = FirstTypeID;
5698   NextIdentID = FirstIdentID;
5699   NextMacroID = FirstMacroID;
5700   NextSelectorID = FirstSelectorID;
5701   NextSubmoduleID = FirstSubmoduleID;
5702 }
5703 
5704 void ASTWriter::IdentifierRead(IdentID ID, IdentifierInfo *II) {
5705   // Always keep the highest ID. See \p TypeRead() for more information.
5706   IdentID &StoredID = IdentifierIDs[II];
5707   if (ID > StoredID)
5708     StoredID = ID;
5709 }
5710 
5711 void ASTWriter::MacroRead(serialization::MacroID ID, MacroInfo *MI) {
5712   // Always keep the highest ID. See \p TypeRead() for more information.
5713   MacroID &StoredID = MacroIDs[MI];
5714   if (ID > StoredID)
5715     StoredID = ID;
5716 }
5717 
5718 void ASTWriter::TypeRead(TypeIdx Idx, QualType T) {
5719   // Always take the highest-numbered type index. This copes with an interesting
5720   // case for chained AST writing where we schedule writing the type and then,
5721   // later, deserialize the type from another AST. In this case, we want to
5722   // keep the higher-numbered entry so that we can properly write it out to
5723   // the AST file.
5724   TypeIdx &StoredIdx = TypeIdxs[T];
5725   if (Idx.getIndex() >= StoredIdx.getIndex())
5726     StoredIdx = Idx;
5727 }
5728 
5729 void ASTWriter::SelectorRead(SelectorID ID, Selector S) {
5730   // Always keep the highest ID. See \p TypeRead() for more information.
5731   SelectorID &StoredID = SelectorIDs[S];
5732   if (ID > StoredID)
5733     StoredID = ID;
5734 }
5735 
5736 void ASTWriter::MacroDefinitionRead(serialization::PreprocessedEntityID ID,
5737                                     MacroDefinitionRecord *MD) {
5738   assert(MacroDefinitions.find(MD) == MacroDefinitions.end());
5739   MacroDefinitions[MD] = ID;
5740 }
5741 
5742 void ASTWriter::ModuleRead(serialization::SubmoduleID ID, Module *Mod) {
5743   assert(SubmoduleIDs.find(Mod) == SubmoduleIDs.end());
5744   SubmoduleIDs[Mod] = ID;
5745 }
5746 
5747 void ASTWriter::CompletedTagDefinition(const TagDecl *D) {
5748   if (Chain && Chain->isProcessingUpdateRecords()) return;
5749   assert(D->isCompleteDefinition());
5750   assert(!WritingAST && "Already writing the AST!");
5751   if (auto *RD = dyn_cast<CXXRecordDecl>(D)) {
5752     // We are interested when a PCH decl is modified.
5753     if (RD->isFromASTFile()) {
5754       // A forward reference was mutated into a definition. Rewrite it.
5755       // FIXME: This happens during template instantiation, should we
5756       // have created a new definition decl instead ?
5757       assert(isTemplateInstantiation(RD->getTemplateSpecializationKind()) &&
5758              "completed a tag from another module but not by instantiation?");
5759       DeclUpdates[RD].push_back(
5760           DeclUpdate(UPD_CXX_INSTANTIATED_CLASS_DEFINITION));
5761     }
5762   }
5763 }
5764 
5765 static bool isImportedDeclContext(ASTReader *Chain, const Decl *D) {
5766   if (D->isFromASTFile())
5767     return true;
5768 
5769   // The predefined __va_list_tag struct is imported if we imported any decls.
5770   // FIXME: This is a gross hack.
5771   return D == D->getASTContext().getVaListTagDecl();
5772 }
5773 
5774 void ASTWriter::AddedVisibleDecl(const DeclContext *DC, const Decl *D) {
5775   if (Chain && Chain->isProcessingUpdateRecords()) return;
5776   assert(DC->isLookupContext() &&
5777           "Should not add lookup results to non-lookup contexts!");
5778 
5779   // TU is handled elsewhere.
5780   if (isa<TranslationUnitDecl>(DC))
5781     return;
5782 
5783   // Namespaces are handled elsewhere, except for template instantiations of
5784   // FunctionTemplateDecls in namespaces. We are interested in cases where the
5785   // local instantiations are added to an imported context. Only happens when
5786   // adding ADL lookup candidates, for example templated friends.
5787   if (isa<NamespaceDecl>(DC) && D->getFriendObjectKind() == Decl::FOK_None &&
5788       !isa<FunctionTemplateDecl>(D))
5789     return;
5790 
5791   // We're only interested in cases where a local declaration is added to an
5792   // imported context.
5793   if (D->isFromASTFile() || !isImportedDeclContext(Chain, cast<Decl>(DC)))
5794     return;
5795 
5796   assert(DC == DC->getPrimaryContext() && "added to non-primary context");
5797   assert(!getDefinitiveDeclContext(DC) && "DeclContext not definitive!");
5798   assert(!WritingAST && "Already writing the AST!");
5799   if (UpdatedDeclContexts.insert(DC) && !cast<Decl>(DC)->isFromASTFile()) {
5800     // We're adding a visible declaration to a predefined decl context. Ensure
5801     // that we write out all of its lookup results so we don't get a nasty
5802     // surprise when we try to emit its lookup table.
5803     for (auto *Child : DC->decls())
5804       UpdatingVisibleDecls.push_back(Child);
5805   }
5806   UpdatingVisibleDecls.push_back(D);
5807 }
5808 
5809 void ASTWriter::AddedCXXImplicitMember(const CXXRecordDecl *RD, const Decl *D) {
5810   if (Chain && Chain->isProcessingUpdateRecords()) return;
5811   assert(D->isImplicit());
5812 
5813   // We're only interested in cases where a local declaration is added to an
5814   // imported context.
5815   if (D->isFromASTFile() || !isImportedDeclContext(Chain, RD))
5816     return;
5817 
5818   if (!isa<CXXMethodDecl>(D))
5819     return;
5820 
5821   // A decl coming from PCH was modified.
5822   assert(RD->isCompleteDefinition());
5823   assert(!WritingAST && "Already writing the AST!");
5824   DeclUpdates[RD].push_back(DeclUpdate(UPD_CXX_ADDED_IMPLICIT_MEMBER, D));
5825 }
5826 
5827 void ASTWriter::ResolvedExceptionSpec(const FunctionDecl *FD) {
5828   if (Chain && Chain->isProcessingUpdateRecords()) return;
5829   assert(!DoneWritingDeclsAndTypes && "Already done writing updates!");
5830   if (!Chain) return;
5831   Chain->forEachImportedKeyDecl(FD, [&](const Decl *D) {
5832     // If we don't already know the exception specification for this redecl
5833     // chain, add an update record for it.
5834     if (isUnresolvedExceptionSpec(cast<FunctionDecl>(D)
5835                                       ->getType()
5836                                       ->castAs<FunctionProtoType>()
5837                                       ->getExceptionSpecType()))
5838       DeclUpdates[D].push_back(UPD_CXX_RESOLVED_EXCEPTION_SPEC);
5839   });
5840 }
5841 
5842 void ASTWriter::DeducedReturnType(const FunctionDecl *FD, QualType ReturnType) {
5843   if (Chain && Chain->isProcessingUpdateRecords()) return;
5844   assert(!WritingAST && "Already writing the AST!");
5845   if (!Chain) return;
5846   Chain->forEachImportedKeyDecl(FD, [&](const Decl *D) {
5847     DeclUpdates[D].push_back(
5848         DeclUpdate(UPD_CXX_DEDUCED_RETURN_TYPE, ReturnType));
5849   });
5850 }
5851 
5852 void ASTWriter::ResolvedOperatorDelete(const CXXDestructorDecl *DD,
5853                                        const FunctionDecl *Delete) {
5854   if (Chain && Chain->isProcessingUpdateRecords()) return;
5855   assert(!WritingAST && "Already writing the AST!");
5856   assert(Delete && "Not given an operator delete");
5857   if (!Chain) return;
5858   Chain->forEachImportedKeyDecl(DD, [&](const Decl *D) {
5859     DeclUpdates[D].push_back(DeclUpdate(UPD_CXX_RESOLVED_DTOR_DELETE, Delete));
5860   });
5861 }
5862 
5863 void ASTWriter::CompletedImplicitDefinition(const FunctionDecl *D) {
5864   if (Chain && Chain->isProcessingUpdateRecords()) return;
5865   assert(!WritingAST && "Already writing the AST!");
5866   if (!D->isFromASTFile())
5867     return; // Declaration not imported from PCH.
5868 
5869   // Implicit function decl from a PCH was defined.
5870   DeclUpdates[D].push_back(DeclUpdate(UPD_CXX_ADDED_FUNCTION_DEFINITION));
5871 }
5872 
5873 void ASTWriter::FunctionDefinitionInstantiated(const FunctionDecl *D) {
5874   if (Chain && Chain->isProcessingUpdateRecords()) return;
5875   assert(!WritingAST && "Already writing the AST!");
5876   if (!D->isFromASTFile())
5877     return;
5878 
5879   DeclUpdates[D].push_back(DeclUpdate(UPD_CXX_ADDED_FUNCTION_DEFINITION));
5880 }
5881 
5882 void ASTWriter::StaticDataMemberInstantiated(const VarDecl *D) {
5883   if (Chain && Chain->isProcessingUpdateRecords()) return;
5884   assert(!WritingAST && "Already writing the AST!");
5885   if (!D->isFromASTFile())
5886     return;
5887 
5888   // Since the actual instantiation is delayed, this really means that we need
5889   // to update the instantiation location.
5890   DeclUpdates[D].push_back(
5891       DeclUpdate(UPD_CXX_INSTANTIATED_STATIC_DATA_MEMBER,
5892        D->getMemberSpecializationInfo()->getPointOfInstantiation()));
5893 }
5894 
5895 void ASTWriter::DefaultArgumentInstantiated(const ParmVarDecl *D) {
5896   if (Chain && Chain->isProcessingUpdateRecords()) return;
5897   assert(!WritingAST && "Already writing the AST!");
5898   if (!D->isFromASTFile())
5899     return;
5900 
5901   DeclUpdates[D].push_back(
5902       DeclUpdate(UPD_CXX_INSTANTIATED_DEFAULT_ARGUMENT, D));
5903 }
5904 
5905 void ASTWriter::DefaultMemberInitializerInstantiated(const FieldDecl *D) {
5906   assert(!WritingAST && "Already writing the AST!");
5907   if (!D->isFromASTFile())
5908     return;
5909 
5910   DeclUpdates[D].push_back(
5911       DeclUpdate(UPD_CXX_INSTANTIATED_DEFAULT_MEMBER_INITIALIZER, D));
5912 }
5913 
5914 void ASTWriter::AddedObjCCategoryToInterface(const ObjCCategoryDecl *CatD,
5915                                              const ObjCInterfaceDecl *IFD) {
5916   if (Chain && Chain->isProcessingUpdateRecords()) return;
5917   assert(!WritingAST && "Already writing the AST!");
5918   if (!IFD->isFromASTFile())
5919     return; // Declaration not imported from PCH.
5920 
5921   assert(IFD->getDefinition() && "Category on a class without a definition?");
5922   ObjCClassesWithCategories.insert(
5923     const_cast<ObjCInterfaceDecl *>(IFD->getDefinition()));
5924 }
5925 
5926 void ASTWriter::DeclarationMarkedUsed(const Decl *D) {
5927   if (Chain && Chain->isProcessingUpdateRecords()) return;
5928   assert(!WritingAST && "Already writing the AST!");
5929 
5930   // If there is *any* declaration of the entity that's not from an AST file,
5931   // we can skip writing the update record. We make sure that isUsed() triggers
5932   // completion of the redeclaration chain of the entity.
5933   for (auto Prev = D->getMostRecentDecl(); Prev; Prev = Prev->getPreviousDecl())
5934     if (IsLocalDecl(Prev))
5935       return;
5936 
5937   DeclUpdates[D].push_back(DeclUpdate(UPD_DECL_MARKED_USED));
5938 }
5939 
5940 void ASTWriter::DeclarationMarkedOpenMPThreadPrivate(const Decl *D) {
5941   if (Chain && Chain->isProcessingUpdateRecords()) return;
5942   assert(!WritingAST && "Already writing the AST!");
5943   if (!D->isFromASTFile())
5944     return;
5945 
5946   DeclUpdates[D].push_back(DeclUpdate(UPD_DECL_MARKED_OPENMP_THREADPRIVATE));
5947 }
5948 
5949 void ASTWriter::DeclarationMarkedOpenMPDeclareTarget(const Decl *D,
5950                                                      const Attr *Attr) {
5951   if (Chain && Chain->isProcessingUpdateRecords()) return;
5952   assert(!WritingAST && "Already writing the AST!");
5953   if (!D->isFromASTFile())
5954     return;
5955 
5956   DeclUpdates[D].push_back(
5957       DeclUpdate(UPD_DECL_MARKED_OPENMP_DECLARETARGET, Attr));
5958 }
5959 
5960 void ASTWriter::RedefinedHiddenDefinition(const NamedDecl *D, Module *M) {
5961   if (Chain && Chain->isProcessingUpdateRecords()) return;
5962   assert(!WritingAST && "Already writing the AST!");
5963   assert(D->isHidden() && "expected a hidden declaration");
5964   DeclUpdates[D].push_back(DeclUpdate(UPD_DECL_EXPORTED, M));
5965 }
5966 
5967 void ASTWriter::AddedAttributeToRecord(const Attr *Attr,
5968                                        const RecordDecl *Record) {
5969   if (Chain && Chain->isProcessingUpdateRecords()) return;
5970   assert(!WritingAST && "Already writing the AST!");
5971   if (!Record->isFromASTFile())
5972     return;
5973   DeclUpdates[Record].push_back(DeclUpdate(UPD_ADDED_ATTR_TO_RECORD, Attr));
5974 }
5975