xref: /freebsd/contrib/llvm-project/clang/lib/Serialization/ASTWriter.cpp (revision 4b50c451720d8b427757a6da1dd2bb4c52cd9e35)
1 //===- ASTWriter.cpp - AST File Writer ------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 //  This file defines the ASTWriter class, which writes AST files.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "clang/Serialization/ASTWriter.h"
14 #include "ASTCommon.h"
15 #include "ASTReaderInternals.h"
16 #include "MultiOnDiskHashTable.h"
17 #include "clang/AST/ASTContext.h"
18 #include "clang/AST/ASTUnresolvedSet.h"
19 #include "clang/AST/Attr.h"
20 #include "clang/AST/Decl.h"
21 #include "clang/AST/DeclBase.h"
22 #include "clang/AST/DeclCXX.h"
23 #include "clang/AST/DeclContextInternals.h"
24 #include "clang/AST/DeclFriend.h"
25 #include "clang/AST/DeclObjC.h"
26 #include "clang/AST/DeclTemplate.h"
27 #include "clang/AST/DeclarationName.h"
28 #include "clang/AST/Expr.h"
29 #include "clang/AST/ExprCXX.h"
30 #include "clang/AST/LambdaCapture.h"
31 #include "clang/AST/NestedNameSpecifier.h"
32 #include "clang/AST/RawCommentList.h"
33 #include "clang/AST/TemplateName.h"
34 #include "clang/AST/Type.h"
35 #include "clang/AST/TypeLocVisitor.h"
36 #include "clang/Basic/Diagnostic.h"
37 #include "clang/Basic/DiagnosticOptions.h"
38 #include "clang/Basic/FileManager.h"
39 #include "clang/Basic/FileSystemOptions.h"
40 #include "clang/Basic/IdentifierTable.h"
41 #include "clang/Basic/LLVM.h"
42 #include "clang/Basic/Lambda.h"
43 #include "clang/Basic/LangOptions.h"
44 #include "clang/Basic/Module.h"
45 #include "clang/Basic/ObjCRuntime.h"
46 #include "clang/Basic/OpenCLOptions.h"
47 #include "clang/Basic/SourceLocation.h"
48 #include "clang/Basic/SourceManager.h"
49 #include "clang/Basic/SourceManagerInternals.h"
50 #include "clang/Basic/Specifiers.h"
51 #include "clang/Basic/TargetInfo.h"
52 #include "clang/Basic/TargetOptions.h"
53 #include "clang/Basic/Version.h"
54 #include "clang/Lex/HeaderSearch.h"
55 #include "clang/Lex/HeaderSearchOptions.h"
56 #include "clang/Lex/MacroInfo.h"
57 #include "clang/Lex/ModuleMap.h"
58 #include "clang/Lex/PreprocessingRecord.h"
59 #include "clang/Lex/Preprocessor.h"
60 #include "clang/Lex/PreprocessorOptions.h"
61 #include "clang/Lex/Token.h"
62 #include "clang/Sema/IdentifierResolver.h"
63 #include "clang/Sema/ObjCMethodList.h"
64 #include "clang/Sema/Sema.h"
65 #include "clang/Sema/Weak.h"
66 #include "clang/Serialization/ASTReader.h"
67 #include "clang/Serialization/InMemoryModuleCache.h"
68 #include "clang/Serialization/Module.h"
69 #include "clang/Serialization/ModuleFileExtension.h"
70 #include "clang/Serialization/SerializationDiagnostic.h"
71 #include "llvm/ADT/APFloat.h"
72 #include "llvm/ADT/APInt.h"
73 #include "llvm/ADT/APSInt.h"
74 #include "llvm/ADT/ArrayRef.h"
75 #include "llvm/ADT/DenseMap.h"
76 #include "llvm/ADT/Hashing.h"
77 #include "llvm/ADT/Optional.h"
78 #include "llvm/ADT/PointerIntPair.h"
79 #include "llvm/ADT/STLExtras.h"
80 #include "llvm/ADT/ScopeExit.h"
81 #include "llvm/ADT/SmallSet.h"
82 #include "llvm/ADT/SmallString.h"
83 #include "llvm/ADT/SmallVector.h"
84 #include "llvm/ADT/StringMap.h"
85 #include "llvm/ADT/StringRef.h"
86 #include "llvm/Bitstream/BitCodes.h"
87 #include "llvm/Bitstream/BitstreamWriter.h"
88 #include "llvm/Support/Casting.h"
89 #include "llvm/Support/Compression.h"
90 #include "llvm/Support/DJB.h"
91 #include "llvm/Support/Endian.h"
92 #include "llvm/Support/EndianStream.h"
93 #include "llvm/Support/Error.h"
94 #include "llvm/Support/ErrorHandling.h"
95 #include "llvm/Support/MemoryBuffer.h"
96 #include "llvm/Support/OnDiskHashTable.h"
97 #include "llvm/Support/Path.h"
98 #include "llvm/Support/SHA1.h"
99 #include "llvm/Support/VersionTuple.h"
100 #include "llvm/Support/raw_ostream.h"
101 #include <algorithm>
102 #include <cassert>
103 #include <cstdint>
104 #include <cstdlib>
105 #include <cstring>
106 #include <ctime>
107 #include <deque>
108 #include <limits>
109 #include <memory>
110 #include <queue>
111 #include <tuple>
112 #include <utility>
113 #include <vector>
114 
115 using namespace clang;
116 using namespace clang::serialization;
117 
118 template <typename T, typename Allocator>
119 static StringRef bytes(const std::vector<T, Allocator> &v) {
120   if (v.empty()) return StringRef();
121   return StringRef(reinterpret_cast<const char*>(&v[0]),
122                          sizeof(T) * v.size());
123 }
124 
125 template <typename T>
126 static StringRef bytes(const SmallVectorImpl<T> &v) {
127   return StringRef(reinterpret_cast<const char*>(v.data()),
128                          sizeof(T) * v.size());
129 }
130 
131 //===----------------------------------------------------------------------===//
132 // Type serialization
133 //===----------------------------------------------------------------------===//
134 
135 namespace clang {
136 
137   class ASTTypeWriter {
138     ASTWriter &Writer;
139     ASTRecordWriter Record;
140 
141     /// Type code that corresponds to the record generated.
142     TypeCode Code = static_cast<TypeCode>(0);
143 
144     /// Abbreviation to use for the record, if any.
145     unsigned AbbrevToUse = 0;
146 
147   public:
148     ASTTypeWriter(ASTWriter &Writer, ASTWriter::RecordDataImpl &Record)
149       : Writer(Writer), Record(Writer, Record) {}
150 
151     uint64_t Emit() {
152       return Record.Emit(Code, AbbrevToUse);
153     }
154 
155     void Visit(QualType T) {
156       if (T.hasLocalNonFastQualifiers()) {
157         Qualifiers Qs = T.getLocalQualifiers();
158         Record.AddTypeRef(T.getLocalUnqualifiedType());
159         Record.push_back(Qs.getAsOpaqueValue());
160         Code = TYPE_EXT_QUAL;
161         AbbrevToUse = Writer.TypeExtQualAbbrev;
162       } else {
163         switch (T->getTypeClass()) {
164           // For all of the concrete, non-dependent types, call the
165           // appropriate visitor function.
166 #define TYPE(Class, Base) \
167         case Type::Class: Visit##Class##Type(cast<Class##Type>(T)); break;
168 #define ABSTRACT_TYPE(Class, Base)
169 #include "clang/AST/TypeNodes.def"
170         }
171       }
172     }
173 
174     void VisitArrayType(const ArrayType *T);
175     void VisitFunctionType(const FunctionType *T);
176     void VisitTagType(const TagType *T);
177 
178 #define TYPE(Class, Base) void Visit##Class##Type(const Class##Type *T);
179 #define ABSTRACT_TYPE(Class, Base)
180 #include "clang/AST/TypeNodes.def"
181   };
182 
183 } // namespace clang
184 
185 void ASTTypeWriter::VisitBuiltinType(const BuiltinType *T) {
186   llvm_unreachable("Built-in types are never serialized");
187 }
188 
189 void ASTTypeWriter::VisitComplexType(const ComplexType *T) {
190   Record.AddTypeRef(T->getElementType());
191   Code = TYPE_COMPLEX;
192 }
193 
194 void ASTTypeWriter::VisitPointerType(const PointerType *T) {
195   Record.AddTypeRef(T->getPointeeType());
196   Code = TYPE_POINTER;
197 }
198 
199 void ASTTypeWriter::VisitDecayedType(const DecayedType *T) {
200   Record.AddTypeRef(T->getOriginalType());
201   Code = TYPE_DECAYED;
202 }
203 
204 void ASTTypeWriter::VisitAdjustedType(const AdjustedType *T) {
205   Record.AddTypeRef(T->getOriginalType());
206   Record.AddTypeRef(T->getAdjustedType());
207   Code = TYPE_ADJUSTED;
208 }
209 
210 void ASTTypeWriter::VisitBlockPointerType(const BlockPointerType *T) {
211   Record.AddTypeRef(T->getPointeeType());
212   Code = TYPE_BLOCK_POINTER;
213 }
214 
215 void ASTTypeWriter::VisitLValueReferenceType(const LValueReferenceType *T) {
216   Record.AddTypeRef(T->getPointeeTypeAsWritten());
217   Record.push_back(T->isSpelledAsLValue());
218   Code = TYPE_LVALUE_REFERENCE;
219 }
220 
221 void ASTTypeWriter::VisitRValueReferenceType(const RValueReferenceType *T) {
222   Record.AddTypeRef(T->getPointeeTypeAsWritten());
223   Code = TYPE_RVALUE_REFERENCE;
224 }
225 
226 void ASTTypeWriter::VisitMemberPointerType(const MemberPointerType *T) {
227   Record.AddTypeRef(T->getPointeeType());
228   Record.AddTypeRef(QualType(T->getClass(), 0));
229   Code = TYPE_MEMBER_POINTER;
230 }
231 
232 void ASTTypeWriter::VisitArrayType(const ArrayType *T) {
233   Record.AddTypeRef(T->getElementType());
234   Record.push_back(T->getSizeModifier()); // FIXME: stable values
235   Record.push_back(T->getIndexTypeCVRQualifiers()); // FIXME: stable values
236 }
237 
238 void ASTTypeWriter::VisitConstantArrayType(const ConstantArrayType *T) {
239   VisitArrayType(T);
240   Record.AddAPInt(T->getSize());
241   Code = TYPE_CONSTANT_ARRAY;
242 }
243 
244 void ASTTypeWriter::VisitIncompleteArrayType(const IncompleteArrayType *T) {
245   VisitArrayType(T);
246   Code = TYPE_INCOMPLETE_ARRAY;
247 }
248 
249 void ASTTypeWriter::VisitVariableArrayType(const VariableArrayType *T) {
250   VisitArrayType(T);
251   Record.AddSourceLocation(T->getLBracketLoc());
252   Record.AddSourceLocation(T->getRBracketLoc());
253   Record.AddStmt(T->getSizeExpr());
254   Code = TYPE_VARIABLE_ARRAY;
255 }
256 
257 void ASTTypeWriter::VisitVectorType(const VectorType *T) {
258   Record.AddTypeRef(T->getElementType());
259   Record.push_back(T->getNumElements());
260   Record.push_back(T->getVectorKind());
261   Code = TYPE_VECTOR;
262 }
263 
264 void ASTTypeWriter::VisitExtVectorType(const ExtVectorType *T) {
265   VisitVectorType(T);
266   Code = TYPE_EXT_VECTOR;
267 }
268 
269 void ASTTypeWriter::VisitFunctionType(const FunctionType *T) {
270   Record.AddTypeRef(T->getReturnType());
271   FunctionType::ExtInfo C = T->getExtInfo();
272   Record.push_back(C.getNoReturn());
273   Record.push_back(C.getHasRegParm());
274   Record.push_back(C.getRegParm());
275   // FIXME: need to stabilize encoding of calling convention...
276   Record.push_back(C.getCC());
277   Record.push_back(C.getProducesResult());
278   Record.push_back(C.getNoCallerSavedRegs());
279   Record.push_back(C.getNoCfCheck());
280 
281   if (C.getHasRegParm() || C.getRegParm() || C.getProducesResult())
282     AbbrevToUse = 0;
283 }
284 
285 void ASTTypeWriter::VisitFunctionNoProtoType(const FunctionNoProtoType *T) {
286   VisitFunctionType(T);
287   Code = TYPE_FUNCTION_NO_PROTO;
288 }
289 
290 static void addExceptionSpec(const FunctionProtoType *T,
291                              ASTRecordWriter &Record) {
292   Record.push_back(T->getExceptionSpecType());
293   if (T->getExceptionSpecType() == EST_Dynamic) {
294     Record.push_back(T->getNumExceptions());
295     for (unsigned I = 0, N = T->getNumExceptions(); I != N; ++I)
296       Record.AddTypeRef(T->getExceptionType(I));
297   } else if (isComputedNoexcept(T->getExceptionSpecType())) {
298     Record.AddStmt(T->getNoexceptExpr());
299   } else if (T->getExceptionSpecType() == EST_Uninstantiated) {
300     Record.AddDeclRef(T->getExceptionSpecDecl());
301     Record.AddDeclRef(T->getExceptionSpecTemplate());
302   } else if (T->getExceptionSpecType() == EST_Unevaluated) {
303     Record.AddDeclRef(T->getExceptionSpecDecl());
304   }
305 }
306 
307 void ASTTypeWriter::VisitFunctionProtoType(const FunctionProtoType *T) {
308   VisitFunctionType(T);
309 
310   Record.push_back(T->isVariadic());
311   Record.push_back(T->hasTrailingReturn());
312   Record.push_back(T->getMethodQuals().getAsOpaqueValue());
313   Record.push_back(static_cast<unsigned>(T->getRefQualifier()));
314   addExceptionSpec(T, Record);
315 
316   Record.push_back(T->getNumParams());
317   for (unsigned I = 0, N = T->getNumParams(); I != N; ++I)
318     Record.AddTypeRef(T->getParamType(I));
319 
320   if (T->hasExtParameterInfos()) {
321     for (unsigned I = 0, N = T->getNumParams(); I != N; ++I)
322       Record.push_back(T->getExtParameterInfo(I).getOpaqueValue());
323   }
324 
325   if (T->isVariadic() || T->hasTrailingReturn() || T->getMethodQuals() ||
326       T->getRefQualifier() || T->getExceptionSpecType() != EST_None ||
327       T->hasExtParameterInfos())
328     AbbrevToUse = 0;
329 
330   Code = TYPE_FUNCTION_PROTO;
331 }
332 
333 void ASTTypeWriter::VisitUnresolvedUsingType(const UnresolvedUsingType *T) {
334   Record.AddDeclRef(T->getDecl());
335   Code = TYPE_UNRESOLVED_USING;
336 }
337 
338 void ASTTypeWriter::VisitTypedefType(const TypedefType *T) {
339   Record.AddDeclRef(T->getDecl());
340   assert(!T->isCanonicalUnqualified() && "Invalid typedef ?");
341   Record.AddTypeRef(T->getCanonicalTypeInternal());
342   Code = TYPE_TYPEDEF;
343 }
344 
345 void ASTTypeWriter::VisitTypeOfExprType(const TypeOfExprType *T) {
346   Record.AddStmt(T->getUnderlyingExpr());
347   Code = TYPE_TYPEOF_EXPR;
348 }
349 
350 void ASTTypeWriter::VisitTypeOfType(const TypeOfType *T) {
351   Record.AddTypeRef(T->getUnderlyingType());
352   Code = TYPE_TYPEOF;
353 }
354 
355 void ASTTypeWriter::VisitDecltypeType(const DecltypeType *T) {
356   Record.AddTypeRef(T->getUnderlyingType());
357   Record.AddStmt(T->getUnderlyingExpr());
358   Code = TYPE_DECLTYPE;
359 }
360 
361 void ASTTypeWriter::VisitUnaryTransformType(const UnaryTransformType *T) {
362   Record.AddTypeRef(T->getBaseType());
363   Record.AddTypeRef(T->getUnderlyingType());
364   Record.push_back(T->getUTTKind());
365   Code = TYPE_UNARY_TRANSFORM;
366 }
367 
368 void ASTTypeWriter::VisitAutoType(const AutoType *T) {
369   Record.AddTypeRef(T->getDeducedType());
370   Record.push_back((unsigned)T->getKeyword());
371   if (T->getDeducedType().isNull())
372     Record.push_back(T->containsUnexpandedParameterPack() ? 2 :
373                      T->isDependentType() ? 1 : 0);
374   Code = TYPE_AUTO;
375 }
376 
377 void ASTTypeWriter::VisitDeducedTemplateSpecializationType(
378     const DeducedTemplateSpecializationType *T) {
379   Record.AddTemplateName(T->getTemplateName());
380   Record.AddTypeRef(T->getDeducedType());
381   if (T->getDeducedType().isNull())
382     Record.push_back(T->isDependentType());
383   Code = TYPE_DEDUCED_TEMPLATE_SPECIALIZATION;
384 }
385 
386 void ASTTypeWriter::VisitTagType(const TagType *T) {
387   Record.push_back(T->isDependentType());
388   Record.AddDeclRef(T->getDecl()->getCanonicalDecl());
389   assert(!T->isBeingDefined() &&
390          "Cannot serialize in the middle of a type definition");
391 }
392 
393 void ASTTypeWriter::VisitRecordType(const RecordType *T) {
394   VisitTagType(T);
395   Code = TYPE_RECORD;
396 }
397 
398 void ASTTypeWriter::VisitEnumType(const EnumType *T) {
399   VisitTagType(T);
400   Code = TYPE_ENUM;
401 }
402 
403 void ASTTypeWriter::VisitAttributedType(const AttributedType *T) {
404   Record.AddTypeRef(T->getModifiedType());
405   Record.AddTypeRef(T->getEquivalentType());
406   Record.push_back(T->getAttrKind());
407   Code = TYPE_ATTRIBUTED;
408 }
409 
410 void
411 ASTTypeWriter::VisitSubstTemplateTypeParmType(
412                                         const SubstTemplateTypeParmType *T) {
413   Record.AddTypeRef(QualType(T->getReplacedParameter(), 0));
414   Record.AddTypeRef(T->getReplacementType());
415   Code = TYPE_SUBST_TEMPLATE_TYPE_PARM;
416 }
417 
418 void
419 ASTTypeWriter::VisitSubstTemplateTypeParmPackType(
420                                       const SubstTemplateTypeParmPackType *T) {
421   Record.AddTypeRef(QualType(T->getReplacedParameter(), 0));
422   Record.AddTemplateArgument(T->getArgumentPack());
423   Code = TYPE_SUBST_TEMPLATE_TYPE_PARM_PACK;
424 }
425 
426 void
427 ASTTypeWriter::VisitTemplateSpecializationType(
428                                        const TemplateSpecializationType *T) {
429   Record.push_back(T->isDependentType());
430   Record.AddTemplateName(T->getTemplateName());
431   Record.push_back(T->getNumArgs());
432   for (const auto &ArgI : *T)
433     Record.AddTemplateArgument(ArgI);
434   Record.AddTypeRef(T->isTypeAlias() ? T->getAliasedType()
435                                      : T->isCanonicalUnqualified()
436                                            ? QualType()
437                                            : T->getCanonicalTypeInternal());
438   Code = TYPE_TEMPLATE_SPECIALIZATION;
439 }
440 
441 void
442 ASTTypeWriter::VisitDependentSizedArrayType(const DependentSizedArrayType *T) {
443   VisitArrayType(T);
444   Record.AddStmt(T->getSizeExpr());
445   Record.AddSourceRange(T->getBracketsRange());
446   Code = TYPE_DEPENDENT_SIZED_ARRAY;
447 }
448 
449 void
450 ASTTypeWriter::VisitDependentSizedExtVectorType(
451                                         const DependentSizedExtVectorType *T) {
452   Record.AddTypeRef(T->getElementType());
453   Record.AddStmt(T->getSizeExpr());
454   Record.AddSourceLocation(T->getAttributeLoc());
455   Code = TYPE_DEPENDENT_SIZED_EXT_VECTOR;
456 }
457 
458 void ASTTypeWriter::VisitDependentVectorType(const DependentVectorType *T) {
459   Record.AddTypeRef(T->getElementType());
460   Record.AddStmt(const_cast<Expr*>(T->getSizeExpr()));
461   Record.AddSourceLocation(T->getAttributeLoc());
462   Record.push_back(T->getVectorKind());
463   Code = TYPE_DEPENDENT_SIZED_VECTOR;
464 }
465 
466 void
467 ASTTypeWriter::VisitDependentAddressSpaceType(
468     const DependentAddressSpaceType *T) {
469   Record.AddTypeRef(T->getPointeeType());
470   Record.AddStmt(T->getAddrSpaceExpr());
471   Record.AddSourceLocation(T->getAttributeLoc());
472   Code = TYPE_DEPENDENT_ADDRESS_SPACE;
473 }
474 
475 void
476 ASTTypeWriter::VisitTemplateTypeParmType(const TemplateTypeParmType *T) {
477   Record.push_back(T->getDepth());
478   Record.push_back(T->getIndex());
479   Record.push_back(T->isParameterPack());
480   Record.AddDeclRef(T->getDecl());
481   Code = TYPE_TEMPLATE_TYPE_PARM;
482 }
483 
484 void
485 ASTTypeWriter::VisitDependentNameType(const DependentNameType *T) {
486   Record.push_back(T->getKeyword());
487   Record.AddNestedNameSpecifier(T->getQualifier());
488   Record.AddIdentifierRef(T->getIdentifier());
489   Record.AddTypeRef(
490       T->isCanonicalUnqualified() ? QualType() : T->getCanonicalTypeInternal());
491   Code = TYPE_DEPENDENT_NAME;
492 }
493 
494 void
495 ASTTypeWriter::VisitDependentTemplateSpecializationType(
496                                 const DependentTemplateSpecializationType *T) {
497   Record.push_back(T->getKeyword());
498   Record.AddNestedNameSpecifier(T->getQualifier());
499   Record.AddIdentifierRef(T->getIdentifier());
500   Record.push_back(T->getNumArgs());
501   for (const auto &I : *T)
502     Record.AddTemplateArgument(I);
503   Code = TYPE_DEPENDENT_TEMPLATE_SPECIALIZATION;
504 }
505 
506 void ASTTypeWriter::VisitPackExpansionType(const PackExpansionType *T) {
507   Record.AddTypeRef(T->getPattern());
508   if (Optional<unsigned> NumExpansions = T->getNumExpansions())
509     Record.push_back(*NumExpansions + 1);
510   else
511     Record.push_back(0);
512   Code = TYPE_PACK_EXPANSION;
513 }
514 
515 void ASTTypeWriter::VisitParenType(const ParenType *T) {
516   Record.AddTypeRef(T->getInnerType());
517   Code = TYPE_PAREN;
518 }
519 
520 void ASTTypeWriter::VisitMacroQualifiedType(const MacroQualifiedType *T) {
521   Record.AddTypeRef(T->getUnderlyingType());
522   Record.AddIdentifierRef(T->getMacroIdentifier());
523   Code = TYPE_MACRO_QUALIFIED;
524 }
525 
526 void ASTTypeWriter::VisitElaboratedType(const ElaboratedType *T) {
527   Record.push_back(T->getKeyword());
528   Record.AddNestedNameSpecifier(T->getQualifier());
529   Record.AddTypeRef(T->getNamedType());
530   Record.AddDeclRef(T->getOwnedTagDecl());
531   Code = TYPE_ELABORATED;
532 }
533 
534 void ASTTypeWriter::VisitInjectedClassNameType(const InjectedClassNameType *T) {
535   Record.AddDeclRef(T->getDecl()->getCanonicalDecl());
536   Record.AddTypeRef(T->getInjectedSpecializationType());
537   Code = TYPE_INJECTED_CLASS_NAME;
538 }
539 
540 void ASTTypeWriter::VisitObjCInterfaceType(const ObjCInterfaceType *T) {
541   Record.AddDeclRef(T->getDecl()->getCanonicalDecl());
542   Code = TYPE_OBJC_INTERFACE;
543 }
544 
545 void ASTTypeWriter::VisitObjCTypeParamType(const ObjCTypeParamType *T) {
546   Record.AddDeclRef(T->getDecl());
547   Record.push_back(T->getNumProtocols());
548   for (const auto *I : T->quals())
549     Record.AddDeclRef(I);
550   Code = TYPE_OBJC_TYPE_PARAM;
551 }
552 
553 void ASTTypeWriter::VisitObjCObjectType(const ObjCObjectType *T) {
554   Record.AddTypeRef(T->getBaseType());
555   Record.push_back(T->getTypeArgsAsWritten().size());
556   for (auto TypeArg : T->getTypeArgsAsWritten())
557     Record.AddTypeRef(TypeArg);
558   Record.push_back(T->getNumProtocols());
559   for (const auto *I : T->quals())
560     Record.AddDeclRef(I);
561   Record.push_back(T->isKindOfTypeAsWritten());
562   Code = TYPE_OBJC_OBJECT;
563 }
564 
565 void
566 ASTTypeWriter::VisitObjCObjectPointerType(const ObjCObjectPointerType *T) {
567   Record.AddTypeRef(T->getPointeeType());
568   Code = TYPE_OBJC_OBJECT_POINTER;
569 }
570 
571 void
572 ASTTypeWriter::VisitAtomicType(const AtomicType *T) {
573   Record.AddTypeRef(T->getValueType());
574   Code = TYPE_ATOMIC;
575 }
576 
577 void
578 ASTTypeWriter::VisitPipeType(const PipeType *T) {
579   Record.AddTypeRef(T->getElementType());
580   Record.push_back(T->isReadOnly());
581   Code = TYPE_PIPE;
582 }
583 
584 namespace {
585 
586 class TypeLocWriter : public TypeLocVisitor<TypeLocWriter> {
587   ASTRecordWriter &Record;
588 
589 public:
590   TypeLocWriter(ASTRecordWriter &Record) : Record(Record) {}
591 
592 #define ABSTRACT_TYPELOC(CLASS, PARENT)
593 #define TYPELOC(CLASS, PARENT) \
594     void Visit##CLASS##TypeLoc(CLASS##TypeLoc TyLoc);
595 #include "clang/AST/TypeLocNodes.def"
596 
597   void VisitArrayTypeLoc(ArrayTypeLoc TyLoc);
598   void VisitFunctionTypeLoc(FunctionTypeLoc TyLoc);
599 };
600 
601 } // namespace
602 
603 void TypeLocWriter::VisitQualifiedTypeLoc(QualifiedTypeLoc TL) {
604   // nothing to do
605 }
606 
607 void TypeLocWriter::VisitBuiltinTypeLoc(BuiltinTypeLoc TL) {
608   Record.AddSourceLocation(TL.getBuiltinLoc());
609   if (TL.needsExtraLocalData()) {
610     Record.push_back(TL.getWrittenTypeSpec());
611     Record.push_back(TL.getWrittenSignSpec());
612     Record.push_back(TL.getWrittenWidthSpec());
613     Record.push_back(TL.hasModeAttr());
614   }
615 }
616 
617 void TypeLocWriter::VisitComplexTypeLoc(ComplexTypeLoc TL) {
618   Record.AddSourceLocation(TL.getNameLoc());
619 }
620 
621 void TypeLocWriter::VisitPointerTypeLoc(PointerTypeLoc TL) {
622   Record.AddSourceLocation(TL.getStarLoc());
623 }
624 
625 void TypeLocWriter::VisitDecayedTypeLoc(DecayedTypeLoc TL) {
626   // nothing to do
627 }
628 
629 void TypeLocWriter::VisitAdjustedTypeLoc(AdjustedTypeLoc TL) {
630   // nothing to do
631 }
632 
633 void TypeLocWriter::VisitBlockPointerTypeLoc(BlockPointerTypeLoc TL) {
634   Record.AddSourceLocation(TL.getCaretLoc());
635 }
636 
637 void TypeLocWriter::VisitLValueReferenceTypeLoc(LValueReferenceTypeLoc TL) {
638   Record.AddSourceLocation(TL.getAmpLoc());
639 }
640 
641 void TypeLocWriter::VisitRValueReferenceTypeLoc(RValueReferenceTypeLoc TL) {
642   Record.AddSourceLocation(TL.getAmpAmpLoc());
643 }
644 
645 void TypeLocWriter::VisitMemberPointerTypeLoc(MemberPointerTypeLoc TL) {
646   Record.AddSourceLocation(TL.getStarLoc());
647   Record.AddTypeSourceInfo(TL.getClassTInfo());
648 }
649 
650 void TypeLocWriter::VisitArrayTypeLoc(ArrayTypeLoc TL) {
651   Record.AddSourceLocation(TL.getLBracketLoc());
652   Record.AddSourceLocation(TL.getRBracketLoc());
653   Record.push_back(TL.getSizeExpr() ? 1 : 0);
654   if (TL.getSizeExpr())
655     Record.AddStmt(TL.getSizeExpr());
656 }
657 
658 void TypeLocWriter::VisitConstantArrayTypeLoc(ConstantArrayTypeLoc TL) {
659   VisitArrayTypeLoc(TL);
660 }
661 
662 void TypeLocWriter::VisitIncompleteArrayTypeLoc(IncompleteArrayTypeLoc TL) {
663   VisitArrayTypeLoc(TL);
664 }
665 
666 void TypeLocWriter::VisitVariableArrayTypeLoc(VariableArrayTypeLoc TL) {
667   VisitArrayTypeLoc(TL);
668 }
669 
670 void TypeLocWriter::VisitDependentSizedArrayTypeLoc(
671                                             DependentSizedArrayTypeLoc TL) {
672   VisitArrayTypeLoc(TL);
673 }
674 
675 void TypeLocWriter::VisitDependentAddressSpaceTypeLoc(
676     DependentAddressSpaceTypeLoc TL) {
677   Record.AddSourceLocation(TL.getAttrNameLoc());
678   SourceRange range = TL.getAttrOperandParensRange();
679   Record.AddSourceLocation(range.getBegin());
680   Record.AddSourceLocation(range.getEnd());
681   Record.AddStmt(TL.getAttrExprOperand());
682 }
683 
684 void TypeLocWriter::VisitDependentSizedExtVectorTypeLoc(
685                                         DependentSizedExtVectorTypeLoc TL) {
686   Record.AddSourceLocation(TL.getNameLoc());
687 }
688 
689 void TypeLocWriter::VisitVectorTypeLoc(VectorTypeLoc TL) {
690   Record.AddSourceLocation(TL.getNameLoc());
691 }
692 
693 void TypeLocWriter::VisitDependentVectorTypeLoc(
694     DependentVectorTypeLoc TL) {
695   Record.AddSourceLocation(TL.getNameLoc());
696 }
697 
698 void TypeLocWriter::VisitExtVectorTypeLoc(ExtVectorTypeLoc TL) {
699   Record.AddSourceLocation(TL.getNameLoc());
700 }
701 
702 void TypeLocWriter::VisitFunctionTypeLoc(FunctionTypeLoc TL) {
703   Record.AddSourceLocation(TL.getLocalRangeBegin());
704   Record.AddSourceLocation(TL.getLParenLoc());
705   Record.AddSourceLocation(TL.getRParenLoc());
706   Record.AddSourceRange(TL.getExceptionSpecRange());
707   Record.AddSourceLocation(TL.getLocalRangeEnd());
708   for (unsigned i = 0, e = TL.getNumParams(); i != e; ++i)
709     Record.AddDeclRef(TL.getParam(i));
710 }
711 
712 void TypeLocWriter::VisitFunctionProtoTypeLoc(FunctionProtoTypeLoc TL) {
713   VisitFunctionTypeLoc(TL);
714 }
715 
716 void TypeLocWriter::VisitFunctionNoProtoTypeLoc(FunctionNoProtoTypeLoc TL) {
717   VisitFunctionTypeLoc(TL);
718 }
719 
720 void TypeLocWriter::VisitUnresolvedUsingTypeLoc(UnresolvedUsingTypeLoc TL) {
721   Record.AddSourceLocation(TL.getNameLoc());
722 }
723 
724 void TypeLocWriter::VisitTypedefTypeLoc(TypedefTypeLoc TL) {
725   Record.AddSourceLocation(TL.getNameLoc());
726 }
727 
728 void TypeLocWriter::VisitObjCTypeParamTypeLoc(ObjCTypeParamTypeLoc TL) {
729   if (TL.getNumProtocols()) {
730     Record.AddSourceLocation(TL.getProtocolLAngleLoc());
731     Record.AddSourceLocation(TL.getProtocolRAngleLoc());
732   }
733   for (unsigned i = 0, e = TL.getNumProtocols(); i != e; ++i)
734     Record.AddSourceLocation(TL.getProtocolLoc(i));
735 }
736 
737 void TypeLocWriter::VisitTypeOfExprTypeLoc(TypeOfExprTypeLoc TL) {
738   Record.AddSourceLocation(TL.getTypeofLoc());
739   Record.AddSourceLocation(TL.getLParenLoc());
740   Record.AddSourceLocation(TL.getRParenLoc());
741 }
742 
743 void TypeLocWriter::VisitTypeOfTypeLoc(TypeOfTypeLoc TL) {
744   Record.AddSourceLocation(TL.getTypeofLoc());
745   Record.AddSourceLocation(TL.getLParenLoc());
746   Record.AddSourceLocation(TL.getRParenLoc());
747   Record.AddTypeSourceInfo(TL.getUnderlyingTInfo());
748 }
749 
750 void TypeLocWriter::VisitDecltypeTypeLoc(DecltypeTypeLoc TL) {
751   Record.AddSourceLocation(TL.getNameLoc());
752 }
753 
754 void TypeLocWriter::VisitUnaryTransformTypeLoc(UnaryTransformTypeLoc TL) {
755   Record.AddSourceLocation(TL.getKWLoc());
756   Record.AddSourceLocation(TL.getLParenLoc());
757   Record.AddSourceLocation(TL.getRParenLoc());
758   Record.AddTypeSourceInfo(TL.getUnderlyingTInfo());
759 }
760 
761 void TypeLocWriter::VisitAutoTypeLoc(AutoTypeLoc TL) {
762   Record.AddSourceLocation(TL.getNameLoc());
763 }
764 
765 void TypeLocWriter::VisitDeducedTemplateSpecializationTypeLoc(
766     DeducedTemplateSpecializationTypeLoc TL) {
767   Record.AddSourceLocation(TL.getTemplateNameLoc());
768 }
769 
770 void TypeLocWriter::VisitRecordTypeLoc(RecordTypeLoc TL) {
771   Record.AddSourceLocation(TL.getNameLoc());
772 }
773 
774 void TypeLocWriter::VisitEnumTypeLoc(EnumTypeLoc TL) {
775   Record.AddSourceLocation(TL.getNameLoc());
776 }
777 
778 void TypeLocWriter::VisitAttributedTypeLoc(AttributedTypeLoc TL) {
779   Record.AddAttr(TL.getAttr());
780 }
781 
782 void TypeLocWriter::VisitTemplateTypeParmTypeLoc(TemplateTypeParmTypeLoc TL) {
783   Record.AddSourceLocation(TL.getNameLoc());
784 }
785 
786 void TypeLocWriter::VisitSubstTemplateTypeParmTypeLoc(
787                                             SubstTemplateTypeParmTypeLoc TL) {
788   Record.AddSourceLocation(TL.getNameLoc());
789 }
790 
791 void TypeLocWriter::VisitSubstTemplateTypeParmPackTypeLoc(
792                                           SubstTemplateTypeParmPackTypeLoc TL) {
793   Record.AddSourceLocation(TL.getNameLoc());
794 }
795 
796 void TypeLocWriter::VisitTemplateSpecializationTypeLoc(
797                                            TemplateSpecializationTypeLoc TL) {
798   Record.AddSourceLocation(TL.getTemplateKeywordLoc());
799   Record.AddSourceLocation(TL.getTemplateNameLoc());
800   Record.AddSourceLocation(TL.getLAngleLoc());
801   Record.AddSourceLocation(TL.getRAngleLoc());
802   for (unsigned i = 0, e = TL.getNumArgs(); i != e; ++i)
803     Record.AddTemplateArgumentLocInfo(TL.getArgLoc(i).getArgument().getKind(),
804                                       TL.getArgLoc(i).getLocInfo());
805 }
806 
807 void TypeLocWriter::VisitParenTypeLoc(ParenTypeLoc TL) {
808   Record.AddSourceLocation(TL.getLParenLoc());
809   Record.AddSourceLocation(TL.getRParenLoc());
810 }
811 
812 void TypeLocWriter::VisitMacroQualifiedTypeLoc(MacroQualifiedTypeLoc TL) {
813   Record.AddSourceLocation(TL.getExpansionLoc());
814 }
815 
816 void TypeLocWriter::VisitElaboratedTypeLoc(ElaboratedTypeLoc TL) {
817   Record.AddSourceLocation(TL.getElaboratedKeywordLoc());
818   Record.AddNestedNameSpecifierLoc(TL.getQualifierLoc());
819 }
820 
821 void TypeLocWriter::VisitInjectedClassNameTypeLoc(InjectedClassNameTypeLoc TL) {
822   Record.AddSourceLocation(TL.getNameLoc());
823 }
824 
825 void TypeLocWriter::VisitDependentNameTypeLoc(DependentNameTypeLoc TL) {
826   Record.AddSourceLocation(TL.getElaboratedKeywordLoc());
827   Record.AddNestedNameSpecifierLoc(TL.getQualifierLoc());
828   Record.AddSourceLocation(TL.getNameLoc());
829 }
830 
831 void TypeLocWriter::VisitDependentTemplateSpecializationTypeLoc(
832        DependentTemplateSpecializationTypeLoc TL) {
833   Record.AddSourceLocation(TL.getElaboratedKeywordLoc());
834   Record.AddNestedNameSpecifierLoc(TL.getQualifierLoc());
835   Record.AddSourceLocation(TL.getTemplateKeywordLoc());
836   Record.AddSourceLocation(TL.getTemplateNameLoc());
837   Record.AddSourceLocation(TL.getLAngleLoc());
838   Record.AddSourceLocation(TL.getRAngleLoc());
839   for (unsigned I = 0, E = TL.getNumArgs(); I != E; ++I)
840     Record.AddTemplateArgumentLocInfo(TL.getArgLoc(I).getArgument().getKind(),
841                                       TL.getArgLoc(I).getLocInfo());
842 }
843 
844 void TypeLocWriter::VisitPackExpansionTypeLoc(PackExpansionTypeLoc TL) {
845   Record.AddSourceLocation(TL.getEllipsisLoc());
846 }
847 
848 void TypeLocWriter::VisitObjCInterfaceTypeLoc(ObjCInterfaceTypeLoc TL) {
849   Record.AddSourceLocation(TL.getNameLoc());
850 }
851 
852 void TypeLocWriter::VisitObjCObjectTypeLoc(ObjCObjectTypeLoc TL) {
853   Record.push_back(TL.hasBaseTypeAsWritten());
854   Record.AddSourceLocation(TL.getTypeArgsLAngleLoc());
855   Record.AddSourceLocation(TL.getTypeArgsRAngleLoc());
856   for (unsigned i = 0, e = TL.getNumTypeArgs(); i != e; ++i)
857     Record.AddTypeSourceInfo(TL.getTypeArgTInfo(i));
858   Record.AddSourceLocation(TL.getProtocolLAngleLoc());
859   Record.AddSourceLocation(TL.getProtocolRAngleLoc());
860   for (unsigned i = 0, e = TL.getNumProtocols(); i != e; ++i)
861     Record.AddSourceLocation(TL.getProtocolLoc(i));
862 }
863 
864 void TypeLocWriter::VisitObjCObjectPointerTypeLoc(ObjCObjectPointerTypeLoc TL) {
865   Record.AddSourceLocation(TL.getStarLoc());
866 }
867 
868 void TypeLocWriter::VisitAtomicTypeLoc(AtomicTypeLoc TL) {
869   Record.AddSourceLocation(TL.getKWLoc());
870   Record.AddSourceLocation(TL.getLParenLoc());
871   Record.AddSourceLocation(TL.getRParenLoc());
872 }
873 
874 void TypeLocWriter::VisitPipeTypeLoc(PipeTypeLoc TL) {
875   Record.AddSourceLocation(TL.getKWLoc());
876 }
877 
878 void ASTWriter::WriteTypeAbbrevs() {
879   using namespace llvm;
880 
881   std::shared_ptr<BitCodeAbbrev> Abv;
882 
883   // Abbreviation for TYPE_EXT_QUAL
884   Abv = std::make_shared<BitCodeAbbrev>();
885   Abv->Add(BitCodeAbbrevOp(serialization::TYPE_EXT_QUAL));
886   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // Type
887   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 3));   // Quals
888   TypeExtQualAbbrev = Stream.EmitAbbrev(std::move(Abv));
889 
890   // Abbreviation for TYPE_FUNCTION_PROTO
891   Abv = std::make_shared<BitCodeAbbrev>();
892   Abv->Add(BitCodeAbbrevOp(serialization::TYPE_FUNCTION_PROTO));
893   // FunctionType
894   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // ReturnType
895   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // NoReturn
896   Abv->Add(BitCodeAbbrevOp(0));                         // HasRegParm
897   Abv->Add(BitCodeAbbrevOp(0));                         // RegParm
898   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // CC
899   Abv->Add(BitCodeAbbrevOp(0));                         // ProducesResult
900   Abv->Add(BitCodeAbbrevOp(0));                         // NoCallerSavedRegs
901   Abv->Add(BitCodeAbbrevOp(0));                         // NoCfCheck
902   // FunctionProtoType
903   Abv->Add(BitCodeAbbrevOp(0));                         // IsVariadic
904   Abv->Add(BitCodeAbbrevOp(0));                         // HasTrailingReturn
905   Abv->Add(BitCodeAbbrevOp(0));                         // TypeQuals
906   Abv->Add(BitCodeAbbrevOp(0));                         // RefQualifier
907   Abv->Add(BitCodeAbbrevOp(EST_None));                  // ExceptionSpec
908   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // NumParams
909   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
910   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // Params
911   TypeFunctionProtoAbbrev = Stream.EmitAbbrev(std::move(Abv));
912 }
913 
914 //===----------------------------------------------------------------------===//
915 // ASTWriter Implementation
916 //===----------------------------------------------------------------------===//
917 
918 static void EmitBlockID(unsigned ID, const char *Name,
919                         llvm::BitstreamWriter &Stream,
920                         ASTWriter::RecordDataImpl &Record) {
921   Record.clear();
922   Record.push_back(ID);
923   Stream.EmitRecord(llvm::bitc::BLOCKINFO_CODE_SETBID, Record);
924 
925   // Emit the block name if present.
926   if (!Name || Name[0] == 0)
927     return;
928   Record.clear();
929   while (*Name)
930     Record.push_back(*Name++);
931   Stream.EmitRecord(llvm::bitc::BLOCKINFO_CODE_BLOCKNAME, Record);
932 }
933 
934 static void EmitRecordID(unsigned ID, const char *Name,
935                          llvm::BitstreamWriter &Stream,
936                          ASTWriter::RecordDataImpl &Record) {
937   Record.clear();
938   Record.push_back(ID);
939   while (*Name)
940     Record.push_back(*Name++);
941   Stream.EmitRecord(llvm::bitc::BLOCKINFO_CODE_SETRECORDNAME, Record);
942 }
943 
944 static void AddStmtsExprs(llvm::BitstreamWriter &Stream,
945                           ASTWriter::RecordDataImpl &Record) {
946 #define RECORD(X) EmitRecordID(X, #X, Stream, Record)
947   RECORD(STMT_STOP);
948   RECORD(STMT_NULL_PTR);
949   RECORD(STMT_REF_PTR);
950   RECORD(STMT_NULL);
951   RECORD(STMT_COMPOUND);
952   RECORD(STMT_CASE);
953   RECORD(STMT_DEFAULT);
954   RECORD(STMT_LABEL);
955   RECORD(STMT_ATTRIBUTED);
956   RECORD(STMT_IF);
957   RECORD(STMT_SWITCH);
958   RECORD(STMT_WHILE);
959   RECORD(STMT_DO);
960   RECORD(STMT_FOR);
961   RECORD(STMT_GOTO);
962   RECORD(STMT_INDIRECT_GOTO);
963   RECORD(STMT_CONTINUE);
964   RECORD(STMT_BREAK);
965   RECORD(STMT_RETURN);
966   RECORD(STMT_DECL);
967   RECORD(STMT_GCCASM);
968   RECORD(STMT_MSASM);
969   RECORD(EXPR_PREDEFINED);
970   RECORD(EXPR_DECL_REF);
971   RECORD(EXPR_INTEGER_LITERAL);
972   RECORD(EXPR_FLOATING_LITERAL);
973   RECORD(EXPR_IMAGINARY_LITERAL);
974   RECORD(EXPR_STRING_LITERAL);
975   RECORD(EXPR_CHARACTER_LITERAL);
976   RECORD(EXPR_PAREN);
977   RECORD(EXPR_PAREN_LIST);
978   RECORD(EXPR_UNARY_OPERATOR);
979   RECORD(EXPR_SIZEOF_ALIGN_OF);
980   RECORD(EXPR_ARRAY_SUBSCRIPT);
981   RECORD(EXPR_CALL);
982   RECORD(EXPR_MEMBER);
983   RECORD(EXPR_BINARY_OPERATOR);
984   RECORD(EXPR_COMPOUND_ASSIGN_OPERATOR);
985   RECORD(EXPR_CONDITIONAL_OPERATOR);
986   RECORD(EXPR_IMPLICIT_CAST);
987   RECORD(EXPR_CSTYLE_CAST);
988   RECORD(EXPR_COMPOUND_LITERAL);
989   RECORD(EXPR_EXT_VECTOR_ELEMENT);
990   RECORD(EXPR_INIT_LIST);
991   RECORD(EXPR_DESIGNATED_INIT);
992   RECORD(EXPR_DESIGNATED_INIT_UPDATE);
993   RECORD(EXPR_IMPLICIT_VALUE_INIT);
994   RECORD(EXPR_NO_INIT);
995   RECORD(EXPR_VA_ARG);
996   RECORD(EXPR_ADDR_LABEL);
997   RECORD(EXPR_STMT);
998   RECORD(EXPR_CHOOSE);
999   RECORD(EXPR_GNU_NULL);
1000   RECORD(EXPR_SHUFFLE_VECTOR);
1001   RECORD(EXPR_BLOCK);
1002   RECORD(EXPR_GENERIC_SELECTION);
1003   RECORD(EXPR_OBJC_STRING_LITERAL);
1004   RECORD(EXPR_OBJC_BOXED_EXPRESSION);
1005   RECORD(EXPR_OBJC_ARRAY_LITERAL);
1006   RECORD(EXPR_OBJC_DICTIONARY_LITERAL);
1007   RECORD(EXPR_OBJC_ENCODE);
1008   RECORD(EXPR_OBJC_SELECTOR_EXPR);
1009   RECORD(EXPR_OBJC_PROTOCOL_EXPR);
1010   RECORD(EXPR_OBJC_IVAR_REF_EXPR);
1011   RECORD(EXPR_OBJC_PROPERTY_REF_EXPR);
1012   RECORD(EXPR_OBJC_KVC_REF_EXPR);
1013   RECORD(EXPR_OBJC_MESSAGE_EXPR);
1014   RECORD(STMT_OBJC_FOR_COLLECTION);
1015   RECORD(STMT_OBJC_CATCH);
1016   RECORD(STMT_OBJC_FINALLY);
1017   RECORD(STMT_OBJC_AT_TRY);
1018   RECORD(STMT_OBJC_AT_SYNCHRONIZED);
1019   RECORD(STMT_OBJC_AT_THROW);
1020   RECORD(EXPR_OBJC_BOOL_LITERAL);
1021   RECORD(STMT_CXX_CATCH);
1022   RECORD(STMT_CXX_TRY);
1023   RECORD(STMT_CXX_FOR_RANGE);
1024   RECORD(EXPR_CXX_OPERATOR_CALL);
1025   RECORD(EXPR_CXX_MEMBER_CALL);
1026   RECORD(EXPR_CXX_CONSTRUCT);
1027   RECORD(EXPR_CXX_TEMPORARY_OBJECT);
1028   RECORD(EXPR_CXX_STATIC_CAST);
1029   RECORD(EXPR_CXX_DYNAMIC_CAST);
1030   RECORD(EXPR_CXX_REINTERPRET_CAST);
1031   RECORD(EXPR_CXX_CONST_CAST);
1032   RECORD(EXPR_CXX_FUNCTIONAL_CAST);
1033   RECORD(EXPR_USER_DEFINED_LITERAL);
1034   RECORD(EXPR_CXX_STD_INITIALIZER_LIST);
1035   RECORD(EXPR_CXX_BOOL_LITERAL);
1036   RECORD(EXPR_CXX_NULL_PTR_LITERAL);
1037   RECORD(EXPR_CXX_TYPEID_EXPR);
1038   RECORD(EXPR_CXX_TYPEID_TYPE);
1039   RECORD(EXPR_CXX_THIS);
1040   RECORD(EXPR_CXX_THROW);
1041   RECORD(EXPR_CXX_DEFAULT_ARG);
1042   RECORD(EXPR_CXX_DEFAULT_INIT);
1043   RECORD(EXPR_CXX_BIND_TEMPORARY);
1044   RECORD(EXPR_CXX_SCALAR_VALUE_INIT);
1045   RECORD(EXPR_CXX_NEW);
1046   RECORD(EXPR_CXX_DELETE);
1047   RECORD(EXPR_CXX_PSEUDO_DESTRUCTOR);
1048   RECORD(EXPR_EXPR_WITH_CLEANUPS);
1049   RECORD(EXPR_CXX_DEPENDENT_SCOPE_MEMBER);
1050   RECORD(EXPR_CXX_DEPENDENT_SCOPE_DECL_REF);
1051   RECORD(EXPR_CXX_UNRESOLVED_CONSTRUCT);
1052   RECORD(EXPR_CXX_UNRESOLVED_MEMBER);
1053   RECORD(EXPR_CXX_UNRESOLVED_LOOKUP);
1054   RECORD(EXPR_CXX_EXPRESSION_TRAIT);
1055   RECORD(EXPR_CXX_NOEXCEPT);
1056   RECORD(EXPR_OPAQUE_VALUE);
1057   RECORD(EXPR_BINARY_CONDITIONAL_OPERATOR);
1058   RECORD(EXPR_TYPE_TRAIT);
1059   RECORD(EXPR_ARRAY_TYPE_TRAIT);
1060   RECORD(EXPR_PACK_EXPANSION);
1061   RECORD(EXPR_SIZEOF_PACK);
1062   RECORD(EXPR_SUBST_NON_TYPE_TEMPLATE_PARM);
1063   RECORD(EXPR_SUBST_NON_TYPE_TEMPLATE_PARM_PACK);
1064   RECORD(EXPR_FUNCTION_PARM_PACK);
1065   RECORD(EXPR_MATERIALIZE_TEMPORARY);
1066   RECORD(EXPR_CUDA_KERNEL_CALL);
1067   RECORD(EXPR_CXX_UUIDOF_EXPR);
1068   RECORD(EXPR_CXX_UUIDOF_TYPE);
1069   RECORD(EXPR_LAMBDA);
1070 #undef RECORD
1071 }
1072 
1073 void ASTWriter::WriteBlockInfoBlock() {
1074   RecordData Record;
1075   Stream.EnterBlockInfoBlock();
1076 
1077 #define BLOCK(X) EmitBlockID(X ## _ID, #X, Stream, Record)
1078 #define RECORD(X) EmitRecordID(X, #X, Stream, Record)
1079 
1080   // Control Block.
1081   BLOCK(CONTROL_BLOCK);
1082   RECORD(METADATA);
1083   RECORD(MODULE_NAME);
1084   RECORD(MODULE_DIRECTORY);
1085   RECORD(MODULE_MAP_FILE);
1086   RECORD(IMPORTS);
1087   RECORD(ORIGINAL_FILE);
1088   RECORD(ORIGINAL_PCH_DIR);
1089   RECORD(ORIGINAL_FILE_ID);
1090   RECORD(INPUT_FILE_OFFSETS);
1091 
1092   BLOCK(OPTIONS_BLOCK);
1093   RECORD(LANGUAGE_OPTIONS);
1094   RECORD(TARGET_OPTIONS);
1095   RECORD(FILE_SYSTEM_OPTIONS);
1096   RECORD(HEADER_SEARCH_OPTIONS);
1097   RECORD(PREPROCESSOR_OPTIONS);
1098 
1099   BLOCK(INPUT_FILES_BLOCK);
1100   RECORD(INPUT_FILE);
1101 
1102   // AST Top-Level Block.
1103   BLOCK(AST_BLOCK);
1104   RECORD(TYPE_OFFSET);
1105   RECORD(DECL_OFFSET);
1106   RECORD(IDENTIFIER_OFFSET);
1107   RECORD(IDENTIFIER_TABLE);
1108   RECORD(EAGERLY_DESERIALIZED_DECLS);
1109   RECORD(MODULAR_CODEGEN_DECLS);
1110   RECORD(SPECIAL_TYPES);
1111   RECORD(STATISTICS);
1112   RECORD(TENTATIVE_DEFINITIONS);
1113   RECORD(SELECTOR_OFFSETS);
1114   RECORD(METHOD_POOL);
1115   RECORD(PP_COUNTER_VALUE);
1116   RECORD(SOURCE_LOCATION_OFFSETS);
1117   RECORD(SOURCE_LOCATION_PRELOADS);
1118   RECORD(EXT_VECTOR_DECLS);
1119   RECORD(UNUSED_FILESCOPED_DECLS);
1120   RECORD(PPD_ENTITIES_OFFSETS);
1121   RECORD(VTABLE_USES);
1122   RECORD(PPD_SKIPPED_RANGES);
1123   RECORD(REFERENCED_SELECTOR_POOL);
1124   RECORD(TU_UPDATE_LEXICAL);
1125   RECORD(SEMA_DECL_REFS);
1126   RECORD(WEAK_UNDECLARED_IDENTIFIERS);
1127   RECORD(PENDING_IMPLICIT_INSTANTIATIONS);
1128   RECORD(UPDATE_VISIBLE);
1129   RECORD(DECL_UPDATE_OFFSETS);
1130   RECORD(DECL_UPDATES);
1131   RECORD(CUDA_SPECIAL_DECL_REFS);
1132   RECORD(HEADER_SEARCH_TABLE);
1133   RECORD(FP_PRAGMA_OPTIONS);
1134   RECORD(OPENCL_EXTENSIONS);
1135   RECORD(OPENCL_EXTENSION_TYPES);
1136   RECORD(OPENCL_EXTENSION_DECLS);
1137   RECORD(DELEGATING_CTORS);
1138   RECORD(KNOWN_NAMESPACES);
1139   RECORD(MODULE_OFFSET_MAP);
1140   RECORD(SOURCE_MANAGER_LINE_TABLE);
1141   RECORD(OBJC_CATEGORIES_MAP);
1142   RECORD(FILE_SORTED_DECLS);
1143   RECORD(IMPORTED_MODULES);
1144   RECORD(OBJC_CATEGORIES);
1145   RECORD(MACRO_OFFSET);
1146   RECORD(INTERESTING_IDENTIFIERS);
1147   RECORD(UNDEFINED_BUT_USED);
1148   RECORD(LATE_PARSED_TEMPLATE);
1149   RECORD(OPTIMIZE_PRAGMA_OPTIONS);
1150   RECORD(MSSTRUCT_PRAGMA_OPTIONS);
1151   RECORD(POINTERS_TO_MEMBERS_PRAGMA_OPTIONS);
1152   RECORD(UNUSED_LOCAL_TYPEDEF_NAME_CANDIDATES);
1153   RECORD(DELETE_EXPRS_TO_ANALYZE);
1154   RECORD(CUDA_PRAGMA_FORCE_HOST_DEVICE_DEPTH);
1155   RECORD(PP_CONDITIONAL_STACK);
1156 
1157   // SourceManager Block.
1158   BLOCK(SOURCE_MANAGER_BLOCK);
1159   RECORD(SM_SLOC_FILE_ENTRY);
1160   RECORD(SM_SLOC_BUFFER_ENTRY);
1161   RECORD(SM_SLOC_BUFFER_BLOB);
1162   RECORD(SM_SLOC_BUFFER_BLOB_COMPRESSED);
1163   RECORD(SM_SLOC_EXPANSION_ENTRY);
1164 
1165   // Preprocessor Block.
1166   BLOCK(PREPROCESSOR_BLOCK);
1167   RECORD(PP_MACRO_DIRECTIVE_HISTORY);
1168   RECORD(PP_MACRO_FUNCTION_LIKE);
1169   RECORD(PP_MACRO_OBJECT_LIKE);
1170   RECORD(PP_MODULE_MACRO);
1171   RECORD(PP_TOKEN);
1172 
1173   // Submodule Block.
1174   BLOCK(SUBMODULE_BLOCK);
1175   RECORD(SUBMODULE_METADATA);
1176   RECORD(SUBMODULE_DEFINITION);
1177   RECORD(SUBMODULE_UMBRELLA_HEADER);
1178   RECORD(SUBMODULE_HEADER);
1179   RECORD(SUBMODULE_TOPHEADER);
1180   RECORD(SUBMODULE_UMBRELLA_DIR);
1181   RECORD(SUBMODULE_IMPORTS);
1182   RECORD(SUBMODULE_EXPORTS);
1183   RECORD(SUBMODULE_REQUIRES);
1184   RECORD(SUBMODULE_EXCLUDED_HEADER);
1185   RECORD(SUBMODULE_LINK_LIBRARY);
1186   RECORD(SUBMODULE_CONFIG_MACRO);
1187   RECORD(SUBMODULE_CONFLICT);
1188   RECORD(SUBMODULE_PRIVATE_HEADER);
1189   RECORD(SUBMODULE_TEXTUAL_HEADER);
1190   RECORD(SUBMODULE_PRIVATE_TEXTUAL_HEADER);
1191   RECORD(SUBMODULE_INITIALIZERS);
1192   RECORD(SUBMODULE_EXPORT_AS);
1193 
1194   // Comments Block.
1195   BLOCK(COMMENTS_BLOCK);
1196   RECORD(COMMENTS_RAW_COMMENT);
1197 
1198   // Decls and Types block.
1199   BLOCK(DECLTYPES_BLOCK);
1200   RECORD(TYPE_EXT_QUAL);
1201   RECORD(TYPE_COMPLEX);
1202   RECORD(TYPE_POINTER);
1203   RECORD(TYPE_BLOCK_POINTER);
1204   RECORD(TYPE_LVALUE_REFERENCE);
1205   RECORD(TYPE_RVALUE_REFERENCE);
1206   RECORD(TYPE_MEMBER_POINTER);
1207   RECORD(TYPE_CONSTANT_ARRAY);
1208   RECORD(TYPE_INCOMPLETE_ARRAY);
1209   RECORD(TYPE_VARIABLE_ARRAY);
1210   RECORD(TYPE_VECTOR);
1211   RECORD(TYPE_EXT_VECTOR);
1212   RECORD(TYPE_FUNCTION_NO_PROTO);
1213   RECORD(TYPE_FUNCTION_PROTO);
1214   RECORD(TYPE_TYPEDEF);
1215   RECORD(TYPE_TYPEOF_EXPR);
1216   RECORD(TYPE_TYPEOF);
1217   RECORD(TYPE_RECORD);
1218   RECORD(TYPE_ENUM);
1219   RECORD(TYPE_OBJC_INTERFACE);
1220   RECORD(TYPE_OBJC_OBJECT_POINTER);
1221   RECORD(TYPE_DECLTYPE);
1222   RECORD(TYPE_ELABORATED);
1223   RECORD(TYPE_SUBST_TEMPLATE_TYPE_PARM);
1224   RECORD(TYPE_UNRESOLVED_USING);
1225   RECORD(TYPE_INJECTED_CLASS_NAME);
1226   RECORD(TYPE_OBJC_OBJECT);
1227   RECORD(TYPE_TEMPLATE_TYPE_PARM);
1228   RECORD(TYPE_TEMPLATE_SPECIALIZATION);
1229   RECORD(TYPE_DEPENDENT_NAME);
1230   RECORD(TYPE_DEPENDENT_TEMPLATE_SPECIALIZATION);
1231   RECORD(TYPE_DEPENDENT_SIZED_ARRAY);
1232   RECORD(TYPE_PAREN);
1233   RECORD(TYPE_MACRO_QUALIFIED);
1234   RECORD(TYPE_PACK_EXPANSION);
1235   RECORD(TYPE_ATTRIBUTED);
1236   RECORD(TYPE_SUBST_TEMPLATE_TYPE_PARM_PACK);
1237   RECORD(TYPE_AUTO);
1238   RECORD(TYPE_UNARY_TRANSFORM);
1239   RECORD(TYPE_ATOMIC);
1240   RECORD(TYPE_DECAYED);
1241   RECORD(TYPE_ADJUSTED);
1242   RECORD(TYPE_OBJC_TYPE_PARAM);
1243   RECORD(LOCAL_REDECLARATIONS);
1244   RECORD(DECL_TYPEDEF);
1245   RECORD(DECL_TYPEALIAS);
1246   RECORD(DECL_ENUM);
1247   RECORD(DECL_RECORD);
1248   RECORD(DECL_ENUM_CONSTANT);
1249   RECORD(DECL_FUNCTION);
1250   RECORD(DECL_OBJC_METHOD);
1251   RECORD(DECL_OBJC_INTERFACE);
1252   RECORD(DECL_OBJC_PROTOCOL);
1253   RECORD(DECL_OBJC_IVAR);
1254   RECORD(DECL_OBJC_AT_DEFS_FIELD);
1255   RECORD(DECL_OBJC_CATEGORY);
1256   RECORD(DECL_OBJC_CATEGORY_IMPL);
1257   RECORD(DECL_OBJC_IMPLEMENTATION);
1258   RECORD(DECL_OBJC_COMPATIBLE_ALIAS);
1259   RECORD(DECL_OBJC_PROPERTY);
1260   RECORD(DECL_OBJC_PROPERTY_IMPL);
1261   RECORD(DECL_FIELD);
1262   RECORD(DECL_MS_PROPERTY);
1263   RECORD(DECL_VAR);
1264   RECORD(DECL_IMPLICIT_PARAM);
1265   RECORD(DECL_PARM_VAR);
1266   RECORD(DECL_FILE_SCOPE_ASM);
1267   RECORD(DECL_BLOCK);
1268   RECORD(DECL_CONTEXT_LEXICAL);
1269   RECORD(DECL_CONTEXT_VISIBLE);
1270   RECORD(DECL_NAMESPACE);
1271   RECORD(DECL_NAMESPACE_ALIAS);
1272   RECORD(DECL_USING);
1273   RECORD(DECL_USING_SHADOW);
1274   RECORD(DECL_USING_DIRECTIVE);
1275   RECORD(DECL_UNRESOLVED_USING_VALUE);
1276   RECORD(DECL_UNRESOLVED_USING_TYPENAME);
1277   RECORD(DECL_LINKAGE_SPEC);
1278   RECORD(DECL_CXX_RECORD);
1279   RECORD(DECL_CXX_METHOD);
1280   RECORD(DECL_CXX_CONSTRUCTOR);
1281   RECORD(DECL_CXX_DESTRUCTOR);
1282   RECORD(DECL_CXX_CONVERSION);
1283   RECORD(DECL_ACCESS_SPEC);
1284   RECORD(DECL_FRIEND);
1285   RECORD(DECL_FRIEND_TEMPLATE);
1286   RECORD(DECL_CLASS_TEMPLATE);
1287   RECORD(DECL_CLASS_TEMPLATE_SPECIALIZATION);
1288   RECORD(DECL_CLASS_TEMPLATE_PARTIAL_SPECIALIZATION);
1289   RECORD(DECL_VAR_TEMPLATE);
1290   RECORD(DECL_VAR_TEMPLATE_SPECIALIZATION);
1291   RECORD(DECL_VAR_TEMPLATE_PARTIAL_SPECIALIZATION);
1292   RECORD(DECL_FUNCTION_TEMPLATE);
1293   RECORD(DECL_TEMPLATE_TYPE_PARM);
1294   RECORD(DECL_NON_TYPE_TEMPLATE_PARM);
1295   RECORD(DECL_TEMPLATE_TEMPLATE_PARM);
1296   RECORD(DECL_CONCEPT);
1297   RECORD(DECL_TYPE_ALIAS_TEMPLATE);
1298   RECORD(DECL_STATIC_ASSERT);
1299   RECORD(DECL_CXX_BASE_SPECIFIERS);
1300   RECORD(DECL_CXX_CTOR_INITIALIZERS);
1301   RECORD(DECL_INDIRECTFIELD);
1302   RECORD(DECL_EXPANDED_NON_TYPE_TEMPLATE_PARM_PACK);
1303   RECORD(DECL_EXPANDED_TEMPLATE_TEMPLATE_PARM_PACK);
1304   RECORD(DECL_CLASS_SCOPE_FUNCTION_SPECIALIZATION);
1305   RECORD(DECL_IMPORT);
1306   RECORD(DECL_OMP_THREADPRIVATE);
1307   RECORD(DECL_EMPTY);
1308   RECORD(DECL_OBJC_TYPE_PARAM);
1309   RECORD(DECL_OMP_CAPTUREDEXPR);
1310   RECORD(DECL_PRAGMA_COMMENT);
1311   RECORD(DECL_PRAGMA_DETECT_MISMATCH);
1312   RECORD(DECL_OMP_DECLARE_REDUCTION);
1313   RECORD(DECL_OMP_ALLOCATE);
1314 
1315   // Statements and Exprs can occur in the Decls and Types block.
1316   AddStmtsExprs(Stream, Record);
1317 
1318   BLOCK(PREPROCESSOR_DETAIL_BLOCK);
1319   RECORD(PPD_MACRO_EXPANSION);
1320   RECORD(PPD_MACRO_DEFINITION);
1321   RECORD(PPD_INCLUSION_DIRECTIVE);
1322 
1323   // Decls and Types block.
1324   BLOCK(EXTENSION_BLOCK);
1325   RECORD(EXTENSION_METADATA);
1326 
1327   BLOCK(UNHASHED_CONTROL_BLOCK);
1328   RECORD(SIGNATURE);
1329   RECORD(DIAGNOSTIC_OPTIONS);
1330   RECORD(DIAG_PRAGMA_MAPPINGS);
1331 
1332 #undef RECORD
1333 #undef BLOCK
1334   Stream.ExitBlock();
1335 }
1336 
1337 /// Prepares a path for being written to an AST file by converting it
1338 /// to an absolute path and removing nested './'s.
1339 ///
1340 /// \return \c true if the path was changed.
1341 static bool cleanPathForOutput(FileManager &FileMgr,
1342                                SmallVectorImpl<char> &Path) {
1343   bool Changed = FileMgr.makeAbsolutePath(Path);
1344   return Changed | llvm::sys::path::remove_dots(Path);
1345 }
1346 
1347 /// Adjusts the given filename to only write out the portion of the
1348 /// filename that is not part of the system root directory.
1349 ///
1350 /// \param Filename the file name to adjust.
1351 ///
1352 /// \param BaseDir When non-NULL, the PCH file is a relocatable AST file and
1353 /// the returned filename will be adjusted by this root directory.
1354 ///
1355 /// \returns either the original filename (if it needs no adjustment) or the
1356 /// adjusted filename (which points into the @p Filename parameter).
1357 static const char *
1358 adjustFilenameForRelocatableAST(const char *Filename, StringRef BaseDir) {
1359   assert(Filename && "No file name to adjust?");
1360 
1361   if (BaseDir.empty())
1362     return Filename;
1363 
1364   // Verify that the filename and the system root have the same prefix.
1365   unsigned Pos = 0;
1366   for (; Filename[Pos] && Pos < BaseDir.size(); ++Pos)
1367     if (Filename[Pos] != BaseDir[Pos])
1368       return Filename; // Prefixes don't match.
1369 
1370   // We hit the end of the filename before we hit the end of the system root.
1371   if (!Filename[Pos])
1372     return Filename;
1373 
1374   // If there's not a path separator at the end of the base directory nor
1375   // immediately after it, then this isn't within the base directory.
1376   if (!llvm::sys::path::is_separator(Filename[Pos])) {
1377     if (!llvm::sys::path::is_separator(BaseDir.back()))
1378       return Filename;
1379   } else {
1380     // If the file name has a '/' at the current position, skip over the '/'.
1381     // We distinguish relative paths from absolute paths by the
1382     // absence of '/' at the beginning of relative paths.
1383     //
1384     // FIXME: This is wrong. We distinguish them by asking if the path is
1385     // absolute, which isn't the same thing. And there might be multiple '/'s
1386     // in a row. Use a better mechanism to indicate whether we have emitted an
1387     // absolute or relative path.
1388     ++Pos;
1389   }
1390 
1391   return Filename + Pos;
1392 }
1393 
1394 ASTFileSignature ASTWriter::createSignature(StringRef Bytes) {
1395   // Calculate the hash till start of UNHASHED_CONTROL_BLOCK.
1396   llvm::SHA1 Hasher;
1397   Hasher.update(ArrayRef<uint8_t>(Bytes.bytes_begin(), Bytes.size()));
1398   auto Hash = Hasher.result();
1399 
1400   // Convert to an array [5*i32].
1401   ASTFileSignature Signature;
1402   auto LShift = [&](unsigned char Val, unsigned Shift) {
1403     return (uint32_t)Val << Shift;
1404   };
1405   for (int I = 0; I != 5; ++I)
1406     Signature[I] = LShift(Hash[I * 4 + 0], 24) | LShift(Hash[I * 4 + 1], 16) |
1407                    LShift(Hash[I * 4 + 2], 8) | LShift(Hash[I * 4 + 3], 0);
1408 
1409   return Signature;
1410 }
1411 
1412 ASTFileSignature ASTWriter::writeUnhashedControlBlock(Preprocessor &PP,
1413                                                       ASTContext &Context) {
1414   // Flush first to prepare the PCM hash (signature).
1415   Stream.FlushToWord();
1416   auto StartOfUnhashedControl = Stream.GetCurrentBitNo() >> 3;
1417 
1418   // Enter the block and prepare to write records.
1419   RecordData Record;
1420   Stream.EnterSubblock(UNHASHED_CONTROL_BLOCK_ID, 5);
1421 
1422   // For implicit modules, write the hash of the PCM as its signature.
1423   ASTFileSignature Signature;
1424   if (WritingModule &&
1425       PP.getHeaderSearchInfo().getHeaderSearchOpts().ModulesHashContent) {
1426     Signature = createSignature(StringRef(Buffer.begin(), StartOfUnhashedControl));
1427     Record.append(Signature.begin(), Signature.end());
1428     Stream.EmitRecord(SIGNATURE, Record);
1429     Record.clear();
1430   }
1431 
1432   // Diagnostic options.
1433   const auto &Diags = Context.getDiagnostics();
1434   const DiagnosticOptions &DiagOpts = Diags.getDiagnosticOptions();
1435 #define DIAGOPT(Name, Bits, Default) Record.push_back(DiagOpts.Name);
1436 #define ENUM_DIAGOPT(Name, Type, Bits, Default)                                \
1437   Record.push_back(static_cast<unsigned>(DiagOpts.get##Name()));
1438 #include "clang/Basic/DiagnosticOptions.def"
1439   Record.push_back(DiagOpts.Warnings.size());
1440   for (unsigned I = 0, N = DiagOpts.Warnings.size(); I != N; ++I)
1441     AddString(DiagOpts.Warnings[I], Record);
1442   Record.push_back(DiagOpts.Remarks.size());
1443   for (unsigned I = 0, N = DiagOpts.Remarks.size(); I != N; ++I)
1444     AddString(DiagOpts.Remarks[I], Record);
1445   // Note: we don't serialize the log or serialization file names, because they
1446   // are generally transient files and will almost always be overridden.
1447   Stream.EmitRecord(DIAGNOSTIC_OPTIONS, Record);
1448 
1449   // Write out the diagnostic/pragma mappings.
1450   WritePragmaDiagnosticMappings(Diags, /* isModule = */ WritingModule);
1451 
1452   // Leave the options block.
1453   Stream.ExitBlock();
1454   return Signature;
1455 }
1456 
1457 /// Write the control block.
1458 void ASTWriter::WriteControlBlock(Preprocessor &PP, ASTContext &Context,
1459                                   StringRef isysroot,
1460                                   const std::string &OutputFile) {
1461   using namespace llvm;
1462 
1463   Stream.EnterSubblock(CONTROL_BLOCK_ID, 5);
1464   RecordData Record;
1465 
1466   // Metadata
1467   auto MetadataAbbrev = std::make_shared<BitCodeAbbrev>();
1468   MetadataAbbrev->Add(BitCodeAbbrevOp(METADATA));
1469   MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 16)); // Major
1470   MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 16)); // Minor
1471   MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 16)); // Clang maj.
1472   MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 16)); // Clang min.
1473   MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Relocatable
1474   MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Timestamps
1475   MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // PCHHasObjectFile
1476   MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Errors
1477   MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // SVN branch/tag
1478   unsigned MetadataAbbrevCode = Stream.EmitAbbrev(std::move(MetadataAbbrev));
1479   assert((!WritingModule || isysroot.empty()) &&
1480          "writing module as a relocatable PCH?");
1481   {
1482     RecordData::value_type Record[] = {
1483         METADATA,
1484         VERSION_MAJOR,
1485         VERSION_MINOR,
1486         CLANG_VERSION_MAJOR,
1487         CLANG_VERSION_MINOR,
1488         !isysroot.empty(),
1489         IncludeTimestamps,
1490         Context.getLangOpts().BuildingPCHWithObjectFile,
1491         ASTHasCompilerErrors};
1492     Stream.EmitRecordWithBlob(MetadataAbbrevCode, Record,
1493                               getClangFullRepositoryVersion());
1494   }
1495 
1496   if (WritingModule) {
1497     // Module name
1498     auto Abbrev = std::make_shared<BitCodeAbbrev>();
1499     Abbrev->Add(BitCodeAbbrevOp(MODULE_NAME));
1500     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
1501     unsigned AbbrevCode = Stream.EmitAbbrev(std::move(Abbrev));
1502     RecordData::value_type Record[] = {MODULE_NAME};
1503     Stream.EmitRecordWithBlob(AbbrevCode, Record, WritingModule->Name);
1504   }
1505 
1506   if (WritingModule && WritingModule->Directory) {
1507     SmallString<128> BaseDir(WritingModule->Directory->getName());
1508     cleanPathForOutput(Context.getSourceManager().getFileManager(), BaseDir);
1509 
1510     // If the home of the module is the current working directory, then we
1511     // want to pick up the cwd of the build process loading the module, not
1512     // our cwd, when we load this module.
1513     if (!PP.getHeaderSearchInfo()
1514              .getHeaderSearchOpts()
1515              .ModuleMapFileHomeIsCwd ||
1516         WritingModule->Directory->getName() != StringRef(".")) {
1517       // Module directory.
1518       auto Abbrev = std::make_shared<BitCodeAbbrev>();
1519       Abbrev->Add(BitCodeAbbrevOp(MODULE_DIRECTORY));
1520       Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Directory
1521       unsigned AbbrevCode = Stream.EmitAbbrev(std::move(Abbrev));
1522 
1523       RecordData::value_type Record[] = {MODULE_DIRECTORY};
1524       Stream.EmitRecordWithBlob(AbbrevCode, Record, BaseDir);
1525     }
1526 
1527     // Write out all other paths relative to the base directory if possible.
1528     BaseDirectory.assign(BaseDir.begin(), BaseDir.end());
1529   } else if (!isysroot.empty()) {
1530     // Write out paths relative to the sysroot if possible.
1531     BaseDirectory = isysroot;
1532   }
1533 
1534   // Module map file
1535   if (WritingModule && WritingModule->Kind == Module::ModuleMapModule) {
1536     Record.clear();
1537 
1538     auto &Map = PP.getHeaderSearchInfo().getModuleMap();
1539     AddPath(WritingModule->PresumedModuleMapFile.empty()
1540                 ? Map.getModuleMapFileForUniquing(WritingModule)->getName()
1541                 : StringRef(WritingModule->PresumedModuleMapFile),
1542             Record);
1543 
1544     // Additional module map files.
1545     if (auto *AdditionalModMaps =
1546             Map.getAdditionalModuleMapFiles(WritingModule)) {
1547       Record.push_back(AdditionalModMaps->size());
1548       for (const FileEntry *F : *AdditionalModMaps)
1549         AddPath(F->getName(), Record);
1550     } else {
1551       Record.push_back(0);
1552     }
1553 
1554     Stream.EmitRecord(MODULE_MAP_FILE, Record);
1555   }
1556 
1557   // Imports
1558   if (Chain) {
1559     serialization::ModuleManager &Mgr = Chain->getModuleManager();
1560     Record.clear();
1561 
1562     for (ModuleFile &M : Mgr) {
1563       // Skip modules that weren't directly imported.
1564       if (!M.isDirectlyImported())
1565         continue;
1566 
1567       Record.push_back((unsigned)M.Kind); // FIXME: Stable encoding
1568       AddSourceLocation(M.ImportLoc, Record);
1569 
1570       // If we have calculated signature, there is no need to store
1571       // the size or timestamp.
1572       Record.push_back(M.Signature ? 0 : M.File->getSize());
1573       Record.push_back(M.Signature ? 0 : getTimestampForOutput(M.File));
1574 
1575       for (auto I : M.Signature)
1576         Record.push_back(I);
1577 
1578       AddString(M.ModuleName, Record);
1579       AddPath(M.FileName, Record);
1580     }
1581     Stream.EmitRecord(IMPORTS, Record);
1582   }
1583 
1584   // Write the options block.
1585   Stream.EnterSubblock(OPTIONS_BLOCK_ID, 4);
1586 
1587   // Language options.
1588   Record.clear();
1589   const LangOptions &LangOpts = Context.getLangOpts();
1590 #define LANGOPT(Name, Bits, Default, Description) \
1591   Record.push_back(LangOpts.Name);
1592 #define ENUM_LANGOPT(Name, Type, Bits, Default, Description) \
1593   Record.push_back(static_cast<unsigned>(LangOpts.get##Name()));
1594 #include "clang/Basic/LangOptions.def"
1595 #define SANITIZER(NAME, ID)                                                    \
1596   Record.push_back(LangOpts.Sanitize.has(SanitizerKind::ID));
1597 #include "clang/Basic/Sanitizers.def"
1598 
1599   Record.push_back(LangOpts.ModuleFeatures.size());
1600   for (StringRef Feature : LangOpts.ModuleFeatures)
1601     AddString(Feature, Record);
1602 
1603   Record.push_back((unsigned) LangOpts.ObjCRuntime.getKind());
1604   AddVersionTuple(LangOpts.ObjCRuntime.getVersion(), Record);
1605 
1606   AddString(LangOpts.CurrentModule, Record);
1607 
1608   // Comment options.
1609   Record.push_back(LangOpts.CommentOpts.BlockCommandNames.size());
1610   for (const auto &I : LangOpts.CommentOpts.BlockCommandNames) {
1611     AddString(I, Record);
1612   }
1613   Record.push_back(LangOpts.CommentOpts.ParseAllComments);
1614 
1615   // OpenMP offloading options.
1616   Record.push_back(LangOpts.OMPTargetTriples.size());
1617   for (auto &T : LangOpts.OMPTargetTriples)
1618     AddString(T.getTriple(), Record);
1619 
1620   AddString(LangOpts.OMPHostIRFile, Record);
1621 
1622   Stream.EmitRecord(LANGUAGE_OPTIONS, Record);
1623 
1624   // Target options.
1625   Record.clear();
1626   const TargetInfo &Target = Context.getTargetInfo();
1627   const TargetOptions &TargetOpts = Target.getTargetOpts();
1628   AddString(TargetOpts.Triple, Record);
1629   AddString(TargetOpts.CPU, Record);
1630   AddString(TargetOpts.ABI, Record);
1631   Record.push_back(TargetOpts.FeaturesAsWritten.size());
1632   for (unsigned I = 0, N = TargetOpts.FeaturesAsWritten.size(); I != N; ++I) {
1633     AddString(TargetOpts.FeaturesAsWritten[I], Record);
1634   }
1635   Record.push_back(TargetOpts.Features.size());
1636   for (unsigned I = 0, N = TargetOpts.Features.size(); I != N; ++I) {
1637     AddString(TargetOpts.Features[I], Record);
1638   }
1639   Stream.EmitRecord(TARGET_OPTIONS, Record);
1640 
1641   // File system options.
1642   Record.clear();
1643   const FileSystemOptions &FSOpts =
1644       Context.getSourceManager().getFileManager().getFileSystemOpts();
1645   AddString(FSOpts.WorkingDir, Record);
1646   Stream.EmitRecord(FILE_SYSTEM_OPTIONS, Record);
1647 
1648   // Header search options.
1649   Record.clear();
1650   const HeaderSearchOptions &HSOpts
1651     = PP.getHeaderSearchInfo().getHeaderSearchOpts();
1652   AddString(HSOpts.Sysroot, Record);
1653 
1654   // Include entries.
1655   Record.push_back(HSOpts.UserEntries.size());
1656   for (unsigned I = 0, N = HSOpts.UserEntries.size(); I != N; ++I) {
1657     const HeaderSearchOptions::Entry &Entry = HSOpts.UserEntries[I];
1658     AddString(Entry.Path, Record);
1659     Record.push_back(static_cast<unsigned>(Entry.Group));
1660     Record.push_back(Entry.IsFramework);
1661     Record.push_back(Entry.IgnoreSysRoot);
1662   }
1663 
1664   // System header prefixes.
1665   Record.push_back(HSOpts.SystemHeaderPrefixes.size());
1666   for (unsigned I = 0, N = HSOpts.SystemHeaderPrefixes.size(); I != N; ++I) {
1667     AddString(HSOpts.SystemHeaderPrefixes[I].Prefix, Record);
1668     Record.push_back(HSOpts.SystemHeaderPrefixes[I].IsSystemHeader);
1669   }
1670 
1671   AddString(HSOpts.ResourceDir, Record);
1672   AddString(HSOpts.ModuleCachePath, Record);
1673   AddString(HSOpts.ModuleUserBuildPath, Record);
1674   Record.push_back(HSOpts.DisableModuleHash);
1675   Record.push_back(HSOpts.ImplicitModuleMaps);
1676   Record.push_back(HSOpts.ModuleMapFileHomeIsCwd);
1677   Record.push_back(HSOpts.UseBuiltinIncludes);
1678   Record.push_back(HSOpts.UseStandardSystemIncludes);
1679   Record.push_back(HSOpts.UseStandardCXXIncludes);
1680   Record.push_back(HSOpts.UseLibcxx);
1681   // Write out the specific module cache path that contains the module files.
1682   AddString(PP.getHeaderSearchInfo().getModuleCachePath(), Record);
1683   Stream.EmitRecord(HEADER_SEARCH_OPTIONS, Record);
1684 
1685   // Preprocessor options.
1686   Record.clear();
1687   const PreprocessorOptions &PPOpts = PP.getPreprocessorOpts();
1688 
1689   // Macro definitions.
1690   Record.push_back(PPOpts.Macros.size());
1691   for (unsigned I = 0, N = PPOpts.Macros.size(); I != N; ++I) {
1692     AddString(PPOpts.Macros[I].first, Record);
1693     Record.push_back(PPOpts.Macros[I].second);
1694   }
1695 
1696   // Includes
1697   Record.push_back(PPOpts.Includes.size());
1698   for (unsigned I = 0, N = PPOpts.Includes.size(); I != N; ++I)
1699     AddString(PPOpts.Includes[I], Record);
1700 
1701   // Macro includes
1702   Record.push_back(PPOpts.MacroIncludes.size());
1703   for (unsigned I = 0, N = PPOpts.MacroIncludes.size(); I != N; ++I)
1704     AddString(PPOpts.MacroIncludes[I], Record);
1705 
1706   Record.push_back(PPOpts.UsePredefines);
1707   // Detailed record is important since it is used for the module cache hash.
1708   Record.push_back(PPOpts.DetailedRecord);
1709   AddString(PPOpts.ImplicitPCHInclude, Record);
1710   Record.push_back(static_cast<unsigned>(PPOpts.ObjCXXARCStandardLibrary));
1711   Stream.EmitRecord(PREPROCESSOR_OPTIONS, Record);
1712 
1713   // Leave the options block.
1714   Stream.ExitBlock();
1715 
1716   // Original file name and file ID
1717   SourceManager &SM = Context.getSourceManager();
1718   if (const FileEntry *MainFile = SM.getFileEntryForID(SM.getMainFileID())) {
1719     auto FileAbbrev = std::make_shared<BitCodeAbbrev>();
1720     FileAbbrev->Add(BitCodeAbbrevOp(ORIGINAL_FILE));
1721     FileAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // File ID
1722     FileAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // File name
1723     unsigned FileAbbrevCode = Stream.EmitAbbrev(std::move(FileAbbrev));
1724 
1725     Record.clear();
1726     Record.push_back(ORIGINAL_FILE);
1727     Record.push_back(SM.getMainFileID().getOpaqueValue());
1728     EmitRecordWithPath(FileAbbrevCode, Record, MainFile->getName());
1729   }
1730 
1731   Record.clear();
1732   Record.push_back(SM.getMainFileID().getOpaqueValue());
1733   Stream.EmitRecord(ORIGINAL_FILE_ID, Record);
1734 
1735   // Original PCH directory
1736   if (!OutputFile.empty() && OutputFile != "-") {
1737     auto Abbrev = std::make_shared<BitCodeAbbrev>();
1738     Abbrev->Add(BitCodeAbbrevOp(ORIGINAL_PCH_DIR));
1739     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // File name
1740     unsigned AbbrevCode = Stream.EmitAbbrev(std::move(Abbrev));
1741 
1742     SmallString<128> OutputPath(OutputFile);
1743 
1744     SM.getFileManager().makeAbsolutePath(OutputPath);
1745     StringRef origDir = llvm::sys::path::parent_path(OutputPath);
1746 
1747     RecordData::value_type Record[] = {ORIGINAL_PCH_DIR};
1748     Stream.EmitRecordWithBlob(AbbrevCode, Record, origDir);
1749   }
1750 
1751   WriteInputFiles(Context.SourceMgr,
1752                   PP.getHeaderSearchInfo().getHeaderSearchOpts(),
1753                   PP.getLangOpts().Modules);
1754   Stream.ExitBlock();
1755 }
1756 
1757 namespace  {
1758 
1759 /// An input file.
1760 struct InputFileEntry {
1761   const FileEntry *File;
1762   bool IsSystemFile;
1763   bool IsTransient;
1764   bool BufferOverridden;
1765   bool IsTopLevelModuleMap;
1766 };
1767 
1768 } // namespace
1769 
1770 void ASTWriter::WriteInputFiles(SourceManager &SourceMgr,
1771                                 HeaderSearchOptions &HSOpts,
1772                                 bool Modules) {
1773   using namespace llvm;
1774 
1775   Stream.EnterSubblock(INPUT_FILES_BLOCK_ID, 4);
1776 
1777   // Create input-file abbreviation.
1778   auto IFAbbrev = std::make_shared<BitCodeAbbrev>();
1779   IFAbbrev->Add(BitCodeAbbrevOp(INPUT_FILE));
1780   IFAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ID
1781   IFAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 12)); // Size
1782   IFAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 32)); // Modification time
1783   IFAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Overridden
1784   IFAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Transient
1785   IFAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Module map
1786   IFAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // File name
1787   unsigned IFAbbrevCode = Stream.EmitAbbrev(std::move(IFAbbrev));
1788 
1789   // Get all ContentCache objects for files, sorted by whether the file is a
1790   // system one or not. System files go at the back, users files at the front.
1791   std::deque<InputFileEntry> SortedFiles;
1792   for (unsigned I = 1, N = SourceMgr.local_sloc_entry_size(); I != N; ++I) {
1793     // Get this source location entry.
1794     const SrcMgr::SLocEntry *SLoc = &SourceMgr.getLocalSLocEntry(I);
1795     assert(&SourceMgr.getSLocEntry(FileID::get(I)) == SLoc);
1796 
1797     // We only care about file entries that were not overridden.
1798     if (!SLoc->isFile())
1799       continue;
1800     const SrcMgr::FileInfo &File = SLoc->getFile();
1801     const SrcMgr::ContentCache *Cache = File.getContentCache();
1802     if (!Cache->OrigEntry)
1803       continue;
1804 
1805     InputFileEntry Entry;
1806     Entry.File = Cache->OrigEntry;
1807     Entry.IsSystemFile = Cache->IsSystemFile;
1808     Entry.IsTransient = Cache->IsTransient;
1809     Entry.BufferOverridden = Cache->BufferOverridden;
1810     Entry.IsTopLevelModuleMap = isModuleMap(File.getFileCharacteristic()) &&
1811                                 File.getIncludeLoc().isInvalid();
1812     if (Cache->IsSystemFile)
1813       SortedFiles.push_back(Entry);
1814     else
1815       SortedFiles.push_front(Entry);
1816   }
1817 
1818   unsigned UserFilesNum = 0;
1819   // Write out all of the input files.
1820   std::vector<uint64_t> InputFileOffsets;
1821   for (const auto &Entry : SortedFiles) {
1822     uint32_t &InputFileID = InputFileIDs[Entry.File];
1823     if (InputFileID != 0)
1824       continue; // already recorded this file.
1825 
1826     // Record this entry's offset.
1827     InputFileOffsets.push_back(Stream.GetCurrentBitNo());
1828 
1829     InputFileID = InputFileOffsets.size();
1830 
1831     if (!Entry.IsSystemFile)
1832       ++UserFilesNum;
1833 
1834     // Emit size/modification time for this file.
1835     // And whether this file was overridden.
1836     RecordData::value_type Record[] = {
1837         INPUT_FILE,
1838         InputFileOffsets.size(),
1839         (uint64_t)Entry.File->getSize(),
1840         (uint64_t)getTimestampForOutput(Entry.File),
1841         Entry.BufferOverridden,
1842         Entry.IsTransient,
1843         Entry.IsTopLevelModuleMap};
1844 
1845     EmitRecordWithPath(IFAbbrevCode, Record, Entry.File->getName());
1846   }
1847 
1848   Stream.ExitBlock();
1849 
1850   // Create input file offsets abbreviation.
1851   auto OffsetsAbbrev = std::make_shared<BitCodeAbbrev>();
1852   OffsetsAbbrev->Add(BitCodeAbbrevOp(INPUT_FILE_OFFSETS));
1853   OffsetsAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // # input files
1854   OffsetsAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // # non-system
1855                                                                 //   input files
1856   OffsetsAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));   // Array
1857   unsigned OffsetsAbbrevCode = Stream.EmitAbbrev(std::move(OffsetsAbbrev));
1858 
1859   // Write input file offsets.
1860   RecordData::value_type Record[] = {INPUT_FILE_OFFSETS,
1861                                      InputFileOffsets.size(), UserFilesNum};
1862   Stream.EmitRecordWithBlob(OffsetsAbbrevCode, Record, bytes(InputFileOffsets));
1863 }
1864 
1865 //===----------------------------------------------------------------------===//
1866 // Source Manager Serialization
1867 //===----------------------------------------------------------------------===//
1868 
1869 /// Create an abbreviation for the SLocEntry that refers to a
1870 /// file.
1871 static unsigned CreateSLocFileAbbrev(llvm::BitstreamWriter &Stream) {
1872   using namespace llvm;
1873 
1874   auto Abbrev = std::make_shared<BitCodeAbbrev>();
1875   Abbrev->Add(BitCodeAbbrevOp(SM_SLOC_FILE_ENTRY));
1876   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Offset
1877   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Include location
1878   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // Characteristic
1879   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Line directives
1880   // FileEntry fields.
1881   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Input File ID
1882   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // NumCreatedFIDs
1883   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 24)); // FirstDeclIndex
1884   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // NumDecls
1885   return Stream.EmitAbbrev(std::move(Abbrev));
1886 }
1887 
1888 /// Create an abbreviation for the SLocEntry that refers to a
1889 /// buffer.
1890 static unsigned CreateSLocBufferAbbrev(llvm::BitstreamWriter &Stream) {
1891   using namespace llvm;
1892 
1893   auto Abbrev = std::make_shared<BitCodeAbbrev>();
1894   Abbrev->Add(BitCodeAbbrevOp(SM_SLOC_BUFFER_ENTRY));
1895   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Offset
1896   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Include location
1897   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // Characteristic
1898   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Line directives
1899   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Buffer name blob
1900   return Stream.EmitAbbrev(std::move(Abbrev));
1901 }
1902 
1903 /// Create an abbreviation for the SLocEntry that refers to a
1904 /// buffer's blob.
1905 static unsigned CreateSLocBufferBlobAbbrev(llvm::BitstreamWriter &Stream,
1906                                            bool Compressed) {
1907   using namespace llvm;
1908 
1909   auto Abbrev = std::make_shared<BitCodeAbbrev>();
1910   Abbrev->Add(BitCodeAbbrevOp(Compressed ? SM_SLOC_BUFFER_BLOB_COMPRESSED
1911                                          : SM_SLOC_BUFFER_BLOB));
1912   if (Compressed)
1913     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Uncompressed size
1914   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Blob
1915   return Stream.EmitAbbrev(std::move(Abbrev));
1916 }
1917 
1918 /// Create an abbreviation for the SLocEntry that refers to a macro
1919 /// expansion.
1920 static unsigned CreateSLocExpansionAbbrev(llvm::BitstreamWriter &Stream) {
1921   using namespace llvm;
1922 
1923   auto Abbrev = std::make_shared<BitCodeAbbrev>();
1924   Abbrev->Add(BitCodeAbbrevOp(SM_SLOC_EXPANSION_ENTRY));
1925   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Offset
1926   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Spelling location
1927   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Start location
1928   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // End location
1929   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Is token range
1930   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Token length
1931   return Stream.EmitAbbrev(std::move(Abbrev));
1932 }
1933 
1934 namespace {
1935 
1936   // Trait used for the on-disk hash table of header search information.
1937   class HeaderFileInfoTrait {
1938     ASTWriter &Writer;
1939 
1940     // Keep track of the framework names we've used during serialization.
1941     SmallVector<char, 128> FrameworkStringData;
1942     llvm::StringMap<unsigned> FrameworkNameOffset;
1943 
1944   public:
1945     HeaderFileInfoTrait(ASTWriter &Writer) : Writer(Writer) {}
1946 
1947     struct key_type {
1948       StringRef Filename;
1949       off_t Size;
1950       time_t ModTime;
1951     };
1952     using key_type_ref = const key_type &;
1953 
1954     using UnresolvedModule =
1955         llvm::PointerIntPair<Module *, 2, ModuleMap::ModuleHeaderRole>;
1956 
1957     struct data_type {
1958       const HeaderFileInfo &HFI;
1959       ArrayRef<ModuleMap::KnownHeader> KnownHeaders;
1960       UnresolvedModule Unresolved;
1961     };
1962     using data_type_ref = const data_type &;
1963 
1964     using hash_value_type = unsigned;
1965     using offset_type = unsigned;
1966 
1967     hash_value_type ComputeHash(key_type_ref key) {
1968       // The hash is based only on size/time of the file, so that the reader can
1969       // match even when symlinking or excess path elements ("foo/../", "../")
1970       // change the form of the name. However, complete path is still the key.
1971       return llvm::hash_combine(key.Size, key.ModTime);
1972     }
1973 
1974     std::pair<unsigned, unsigned>
1975     EmitKeyDataLength(raw_ostream& Out, key_type_ref key, data_type_ref Data) {
1976       using namespace llvm::support;
1977 
1978       endian::Writer LE(Out, little);
1979       unsigned KeyLen = key.Filename.size() + 1 + 8 + 8;
1980       LE.write<uint16_t>(KeyLen);
1981       unsigned DataLen = 1 + 2 + 4 + 4;
1982       for (auto ModInfo : Data.KnownHeaders)
1983         if (Writer.getLocalOrImportedSubmoduleID(ModInfo.getModule()))
1984           DataLen += 4;
1985       if (Data.Unresolved.getPointer())
1986         DataLen += 4;
1987       LE.write<uint8_t>(DataLen);
1988       return std::make_pair(KeyLen, DataLen);
1989     }
1990 
1991     void EmitKey(raw_ostream& Out, key_type_ref key, unsigned KeyLen) {
1992       using namespace llvm::support;
1993 
1994       endian::Writer LE(Out, little);
1995       LE.write<uint64_t>(key.Size);
1996       KeyLen -= 8;
1997       LE.write<uint64_t>(key.ModTime);
1998       KeyLen -= 8;
1999       Out.write(key.Filename.data(), KeyLen);
2000     }
2001 
2002     void EmitData(raw_ostream &Out, key_type_ref key,
2003                   data_type_ref Data, unsigned DataLen) {
2004       using namespace llvm::support;
2005 
2006       endian::Writer LE(Out, little);
2007       uint64_t Start = Out.tell(); (void)Start;
2008 
2009       unsigned char Flags = (Data.HFI.isImport << 5)
2010                           | (Data.HFI.isPragmaOnce << 4)
2011                           | (Data.HFI.DirInfo << 1)
2012                           | Data.HFI.IndexHeaderMapHeader;
2013       LE.write<uint8_t>(Flags);
2014       LE.write<uint16_t>(Data.HFI.NumIncludes);
2015 
2016       if (!Data.HFI.ControllingMacro)
2017         LE.write<uint32_t>(Data.HFI.ControllingMacroID);
2018       else
2019         LE.write<uint32_t>(Writer.getIdentifierRef(Data.HFI.ControllingMacro));
2020 
2021       unsigned Offset = 0;
2022       if (!Data.HFI.Framework.empty()) {
2023         // If this header refers into a framework, save the framework name.
2024         llvm::StringMap<unsigned>::iterator Pos
2025           = FrameworkNameOffset.find(Data.HFI.Framework);
2026         if (Pos == FrameworkNameOffset.end()) {
2027           Offset = FrameworkStringData.size() + 1;
2028           FrameworkStringData.append(Data.HFI.Framework.begin(),
2029                                      Data.HFI.Framework.end());
2030           FrameworkStringData.push_back(0);
2031 
2032           FrameworkNameOffset[Data.HFI.Framework] = Offset;
2033         } else
2034           Offset = Pos->second;
2035       }
2036       LE.write<uint32_t>(Offset);
2037 
2038       auto EmitModule = [&](Module *M, ModuleMap::ModuleHeaderRole Role) {
2039         if (uint32_t ModID = Writer.getLocalOrImportedSubmoduleID(M)) {
2040           uint32_t Value = (ModID << 2) | (unsigned)Role;
2041           assert((Value >> 2) == ModID && "overflow in header module info");
2042           LE.write<uint32_t>(Value);
2043         }
2044       };
2045 
2046       // FIXME: If the header is excluded, we should write out some
2047       // record of that fact.
2048       for (auto ModInfo : Data.KnownHeaders)
2049         EmitModule(ModInfo.getModule(), ModInfo.getRole());
2050       if (Data.Unresolved.getPointer())
2051         EmitModule(Data.Unresolved.getPointer(), Data.Unresolved.getInt());
2052 
2053       assert(Out.tell() - Start == DataLen && "Wrong data length");
2054     }
2055 
2056     const char *strings_begin() const { return FrameworkStringData.begin(); }
2057     const char *strings_end() const { return FrameworkStringData.end(); }
2058   };
2059 
2060 } // namespace
2061 
2062 /// Write the header search block for the list of files that
2063 ///
2064 /// \param HS The header search structure to save.
2065 void ASTWriter::WriteHeaderSearch(const HeaderSearch &HS) {
2066   HeaderFileInfoTrait GeneratorTrait(*this);
2067   llvm::OnDiskChainedHashTableGenerator<HeaderFileInfoTrait> Generator;
2068   SmallVector<const char *, 4> SavedStrings;
2069   unsigned NumHeaderSearchEntries = 0;
2070 
2071   // Find all unresolved headers for the current module. We generally will
2072   // have resolved them before we get here, but not necessarily: we might be
2073   // compiling a preprocessed module, where there is no requirement for the
2074   // original files to exist any more.
2075   const HeaderFileInfo Empty; // So we can take a reference.
2076   if (WritingModule) {
2077     llvm::SmallVector<Module *, 16> Worklist(1, WritingModule);
2078     while (!Worklist.empty()) {
2079       Module *M = Worklist.pop_back_val();
2080       if (!M->isAvailable())
2081         continue;
2082 
2083       // Map to disk files where possible, to pick up any missing stat
2084       // information. This also means we don't need to check the unresolved
2085       // headers list when emitting resolved headers in the first loop below.
2086       // FIXME: It'd be preferable to avoid doing this if we were given
2087       // sufficient stat information in the module map.
2088       HS.getModuleMap().resolveHeaderDirectives(M);
2089 
2090       // If the file didn't exist, we can still create a module if we were given
2091       // enough information in the module map.
2092       for (auto U : M->MissingHeaders) {
2093         // Check that we were given enough information to build a module
2094         // without this file existing on disk.
2095         if (!U.Size || (!U.ModTime && IncludeTimestamps)) {
2096           PP->Diag(U.FileNameLoc, diag::err_module_no_size_mtime_for_header)
2097             << WritingModule->getFullModuleName() << U.Size.hasValue()
2098             << U.FileName;
2099           continue;
2100         }
2101 
2102         // Form the effective relative pathname for the file.
2103         SmallString<128> Filename(M->Directory->getName());
2104         llvm::sys::path::append(Filename, U.FileName);
2105         PreparePathForOutput(Filename);
2106 
2107         StringRef FilenameDup = strdup(Filename.c_str());
2108         SavedStrings.push_back(FilenameDup.data());
2109 
2110         HeaderFileInfoTrait::key_type Key = {
2111           FilenameDup, *U.Size, IncludeTimestamps ? *U.ModTime : 0
2112         };
2113         HeaderFileInfoTrait::data_type Data = {
2114           Empty, {}, {M, ModuleMap::headerKindToRole(U.Kind)}
2115         };
2116         // FIXME: Deal with cases where there are multiple unresolved header
2117         // directives in different submodules for the same header.
2118         Generator.insert(Key, Data, GeneratorTrait);
2119         ++NumHeaderSearchEntries;
2120       }
2121 
2122       Worklist.append(M->submodule_begin(), M->submodule_end());
2123     }
2124   }
2125 
2126   SmallVector<const FileEntry *, 16> FilesByUID;
2127   HS.getFileMgr().GetUniqueIDMapping(FilesByUID);
2128 
2129   if (FilesByUID.size() > HS.header_file_size())
2130     FilesByUID.resize(HS.header_file_size());
2131 
2132   for (unsigned UID = 0, LastUID = FilesByUID.size(); UID != LastUID; ++UID) {
2133     const FileEntry *File = FilesByUID[UID];
2134     if (!File)
2135       continue;
2136 
2137     // Get the file info. This will load info from the external source if
2138     // necessary. Skip emitting this file if we have no information on it
2139     // as a header file (in which case HFI will be null) or if it hasn't
2140     // changed since it was loaded. Also skip it if it's for a modular header
2141     // from a different module; in that case, we rely on the module(s)
2142     // containing the header to provide this information.
2143     const HeaderFileInfo *HFI =
2144         HS.getExistingFileInfo(File, /*WantExternal*/!Chain);
2145     if (!HFI || (HFI->isModuleHeader && !HFI->isCompilingModuleHeader))
2146       continue;
2147 
2148     // Massage the file path into an appropriate form.
2149     StringRef Filename = File->getName();
2150     SmallString<128> FilenameTmp(Filename);
2151     if (PreparePathForOutput(FilenameTmp)) {
2152       // If we performed any translation on the file name at all, we need to
2153       // save this string, since the generator will refer to it later.
2154       Filename = StringRef(strdup(FilenameTmp.c_str()));
2155       SavedStrings.push_back(Filename.data());
2156     }
2157 
2158     HeaderFileInfoTrait::key_type Key = {
2159       Filename, File->getSize(), getTimestampForOutput(File)
2160     };
2161     HeaderFileInfoTrait::data_type Data = {
2162       *HFI, HS.getModuleMap().findAllModulesForHeader(File), {}
2163     };
2164     Generator.insert(Key, Data, GeneratorTrait);
2165     ++NumHeaderSearchEntries;
2166   }
2167 
2168   // Create the on-disk hash table in a buffer.
2169   SmallString<4096> TableData;
2170   uint32_t BucketOffset;
2171   {
2172     using namespace llvm::support;
2173 
2174     llvm::raw_svector_ostream Out(TableData);
2175     // Make sure that no bucket is at offset 0
2176     endian::write<uint32_t>(Out, 0, little);
2177     BucketOffset = Generator.Emit(Out, GeneratorTrait);
2178   }
2179 
2180   // Create a blob abbreviation
2181   using namespace llvm;
2182 
2183   auto Abbrev = std::make_shared<BitCodeAbbrev>();
2184   Abbrev->Add(BitCodeAbbrevOp(HEADER_SEARCH_TABLE));
2185   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
2186   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
2187   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
2188   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2189   unsigned TableAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2190 
2191   // Write the header search table
2192   RecordData::value_type Record[] = {HEADER_SEARCH_TABLE, BucketOffset,
2193                                      NumHeaderSearchEntries, TableData.size()};
2194   TableData.append(GeneratorTrait.strings_begin(),GeneratorTrait.strings_end());
2195   Stream.EmitRecordWithBlob(TableAbbrev, Record, TableData);
2196 
2197   // Free all of the strings we had to duplicate.
2198   for (unsigned I = 0, N = SavedStrings.size(); I != N; ++I)
2199     free(const_cast<char *>(SavedStrings[I]));
2200 }
2201 
2202 static void emitBlob(llvm::BitstreamWriter &Stream, StringRef Blob,
2203                      unsigned SLocBufferBlobCompressedAbbrv,
2204                      unsigned SLocBufferBlobAbbrv) {
2205   using RecordDataType = ASTWriter::RecordData::value_type;
2206 
2207   // Compress the buffer if possible. We expect that almost all PCM
2208   // consumers will not want its contents.
2209   SmallString<0> CompressedBuffer;
2210   if (llvm::zlib::isAvailable()) {
2211     llvm::Error E = llvm::zlib::compress(Blob.drop_back(1), CompressedBuffer);
2212     if (!E) {
2213       RecordDataType Record[] = {SM_SLOC_BUFFER_BLOB_COMPRESSED,
2214                                  Blob.size() - 1};
2215       Stream.EmitRecordWithBlob(SLocBufferBlobCompressedAbbrv, Record,
2216                                 CompressedBuffer);
2217       return;
2218     }
2219     llvm::consumeError(std::move(E));
2220   }
2221 
2222   RecordDataType Record[] = {SM_SLOC_BUFFER_BLOB};
2223   Stream.EmitRecordWithBlob(SLocBufferBlobAbbrv, Record, Blob);
2224 }
2225 
2226 /// Writes the block containing the serialized form of the
2227 /// source manager.
2228 ///
2229 /// TODO: We should probably use an on-disk hash table (stored in a
2230 /// blob), indexed based on the file name, so that we only create
2231 /// entries for files that we actually need. In the common case (no
2232 /// errors), we probably won't have to create file entries for any of
2233 /// the files in the AST.
2234 void ASTWriter::WriteSourceManagerBlock(SourceManager &SourceMgr,
2235                                         const Preprocessor &PP) {
2236   RecordData Record;
2237 
2238   // Enter the source manager block.
2239   Stream.EnterSubblock(SOURCE_MANAGER_BLOCK_ID, 4);
2240 
2241   // Abbreviations for the various kinds of source-location entries.
2242   unsigned SLocFileAbbrv = CreateSLocFileAbbrev(Stream);
2243   unsigned SLocBufferAbbrv = CreateSLocBufferAbbrev(Stream);
2244   unsigned SLocBufferBlobAbbrv = CreateSLocBufferBlobAbbrev(Stream, false);
2245   unsigned SLocBufferBlobCompressedAbbrv =
2246       CreateSLocBufferBlobAbbrev(Stream, true);
2247   unsigned SLocExpansionAbbrv = CreateSLocExpansionAbbrev(Stream);
2248 
2249   // Write out the source location entry table. We skip the first
2250   // entry, which is always the same dummy entry.
2251   std::vector<uint32_t> SLocEntryOffsets;
2252   RecordData PreloadSLocs;
2253   SLocEntryOffsets.reserve(SourceMgr.local_sloc_entry_size() - 1);
2254   for (unsigned I = 1, N = SourceMgr.local_sloc_entry_size();
2255        I != N; ++I) {
2256     // Get this source location entry.
2257     const SrcMgr::SLocEntry *SLoc = &SourceMgr.getLocalSLocEntry(I);
2258     FileID FID = FileID::get(I);
2259     assert(&SourceMgr.getSLocEntry(FID) == SLoc);
2260 
2261     // Record the offset of this source-location entry.
2262     SLocEntryOffsets.push_back(Stream.GetCurrentBitNo());
2263 
2264     // Figure out which record code to use.
2265     unsigned Code;
2266     if (SLoc->isFile()) {
2267       const SrcMgr::ContentCache *Cache = SLoc->getFile().getContentCache();
2268       if (Cache->OrigEntry) {
2269         Code = SM_SLOC_FILE_ENTRY;
2270       } else
2271         Code = SM_SLOC_BUFFER_ENTRY;
2272     } else
2273       Code = SM_SLOC_EXPANSION_ENTRY;
2274     Record.clear();
2275     Record.push_back(Code);
2276 
2277     // Starting offset of this entry within this module, so skip the dummy.
2278     Record.push_back(SLoc->getOffset() - 2);
2279     if (SLoc->isFile()) {
2280       const SrcMgr::FileInfo &File = SLoc->getFile();
2281       AddSourceLocation(File.getIncludeLoc(), Record);
2282       Record.push_back(File.getFileCharacteristic()); // FIXME: stable encoding
2283       Record.push_back(File.hasLineDirectives());
2284 
2285       const SrcMgr::ContentCache *Content = File.getContentCache();
2286       bool EmitBlob = false;
2287       if (Content->OrigEntry) {
2288         assert(Content->OrigEntry == Content->ContentsEntry &&
2289                "Writing to AST an overridden file is not supported");
2290 
2291         // The source location entry is a file. Emit input file ID.
2292         assert(InputFileIDs[Content->OrigEntry] != 0 && "Missed file entry");
2293         Record.push_back(InputFileIDs[Content->OrigEntry]);
2294 
2295         Record.push_back(File.NumCreatedFIDs);
2296 
2297         FileDeclIDsTy::iterator FDI = FileDeclIDs.find(FID);
2298         if (FDI != FileDeclIDs.end()) {
2299           Record.push_back(FDI->second->FirstDeclIndex);
2300           Record.push_back(FDI->second->DeclIDs.size());
2301         } else {
2302           Record.push_back(0);
2303           Record.push_back(0);
2304         }
2305 
2306         Stream.EmitRecordWithAbbrev(SLocFileAbbrv, Record);
2307 
2308         if (Content->BufferOverridden || Content->IsTransient)
2309           EmitBlob = true;
2310       } else {
2311         // The source location entry is a buffer. The blob associated
2312         // with this entry contains the contents of the buffer.
2313 
2314         // We add one to the size so that we capture the trailing NULL
2315         // that is required by llvm::MemoryBuffer::getMemBuffer (on
2316         // the reader side).
2317         const llvm::MemoryBuffer *Buffer
2318           = Content->getBuffer(PP.getDiagnostics(), PP.getSourceManager());
2319         StringRef Name = Buffer->getBufferIdentifier();
2320         Stream.EmitRecordWithBlob(SLocBufferAbbrv, Record,
2321                                   StringRef(Name.data(), Name.size() + 1));
2322         EmitBlob = true;
2323 
2324         if (Name == "<built-in>")
2325           PreloadSLocs.push_back(SLocEntryOffsets.size());
2326       }
2327 
2328       if (EmitBlob) {
2329         // Include the implicit terminating null character in the on-disk buffer
2330         // if we're writing it uncompressed.
2331         const llvm::MemoryBuffer *Buffer =
2332             Content->getBuffer(PP.getDiagnostics(), PP.getSourceManager());
2333         StringRef Blob(Buffer->getBufferStart(), Buffer->getBufferSize() + 1);
2334         emitBlob(Stream, Blob, SLocBufferBlobCompressedAbbrv,
2335                  SLocBufferBlobAbbrv);
2336       }
2337     } else {
2338       // The source location entry is a macro expansion.
2339       const SrcMgr::ExpansionInfo &Expansion = SLoc->getExpansion();
2340       AddSourceLocation(Expansion.getSpellingLoc(), Record);
2341       AddSourceLocation(Expansion.getExpansionLocStart(), Record);
2342       AddSourceLocation(Expansion.isMacroArgExpansion()
2343                             ? SourceLocation()
2344                             : Expansion.getExpansionLocEnd(),
2345                         Record);
2346       Record.push_back(Expansion.isExpansionTokenRange());
2347 
2348       // Compute the token length for this macro expansion.
2349       unsigned NextOffset = SourceMgr.getNextLocalOffset();
2350       if (I + 1 != N)
2351         NextOffset = SourceMgr.getLocalSLocEntry(I + 1).getOffset();
2352       Record.push_back(NextOffset - SLoc->getOffset() - 1);
2353       Stream.EmitRecordWithAbbrev(SLocExpansionAbbrv, Record);
2354     }
2355   }
2356 
2357   Stream.ExitBlock();
2358 
2359   if (SLocEntryOffsets.empty())
2360     return;
2361 
2362   // Write the source-location offsets table into the AST block. This
2363   // table is used for lazily loading source-location information.
2364   using namespace llvm;
2365 
2366   auto Abbrev = std::make_shared<BitCodeAbbrev>();
2367   Abbrev->Add(BitCodeAbbrevOp(SOURCE_LOCATION_OFFSETS));
2368   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 16)); // # of slocs
2369   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 16)); // total size
2370   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // offsets
2371   unsigned SLocOffsetsAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2372   {
2373     RecordData::value_type Record[] = {
2374         SOURCE_LOCATION_OFFSETS, SLocEntryOffsets.size(),
2375         SourceMgr.getNextLocalOffset() - 1 /* skip dummy */};
2376     Stream.EmitRecordWithBlob(SLocOffsetsAbbrev, Record,
2377                               bytes(SLocEntryOffsets));
2378   }
2379   // Write the source location entry preloads array, telling the AST
2380   // reader which source locations entries it should load eagerly.
2381   Stream.EmitRecord(SOURCE_LOCATION_PRELOADS, PreloadSLocs);
2382 
2383   // Write the line table. It depends on remapping working, so it must come
2384   // after the source location offsets.
2385   if (SourceMgr.hasLineTable()) {
2386     LineTableInfo &LineTable = SourceMgr.getLineTable();
2387 
2388     Record.clear();
2389 
2390     // Emit the needed file names.
2391     llvm::DenseMap<int, int> FilenameMap;
2392     FilenameMap[-1] = -1; // For unspecified filenames.
2393     for (const auto &L : LineTable) {
2394       if (L.first.ID < 0)
2395         continue;
2396       for (auto &LE : L.second) {
2397         if (FilenameMap.insert(std::make_pair(LE.FilenameID,
2398                                               FilenameMap.size() - 1)).second)
2399           AddPath(LineTable.getFilename(LE.FilenameID), Record);
2400       }
2401     }
2402     Record.push_back(0);
2403 
2404     // Emit the line entries
2405     for (const auto &L : LineTable) {
2406       // Only emit entries for local files.
2407       if (L.first.ID < 0)
2408         continue;
2409 
2410       // Emit the file ID
2411       Record.push_back(L.first.ID);
2412 
2413       // Emit the line entries
2414       Record.push_back(L.second.size());
2415       for (const auto &LE : L.second) {
2416         Record.push_back(LE.FileOffset);
2417         Record.push_back(LE.LineNo);
2418         Record.push_back(FilenameMap[LE.FilenameID]);
2419         Record.push_back((unsigned)LE.FileKind);
2420         Record.push_back(LE.IncludeOffset);
2421       }
2422     }
2423 
2424     Stream.EmitRecord(SOURCE_MANAGER_LINE_TABLE, Record);
2425   }
2426 }
2427 
2428 //===----------------------------------------------------------------------===//
2429 // Preprocessor Serialization
2430 //===----------------------------------------------------------------------===//
2431 
2432 static bool shouldIgnoreMacro(MacroDirective *MD, bool IsModule,
2433                               const Preprocessor &PP) {
2434   if (MacroInfo *MI = MD->getMacroInfo())
2435     if (MI->isBuiltinMacro())
2436       return true;
2437 
2438   if (IsModule) {
2439     SourceLocation Loc = MD->getLocation();
2440     if (Loc.isInvalid())
2441       return true;
2442     if (PP.getSourceManager().getFileID(Loc) == PP.getPredefinesFileID())
2443       return true;
2444   }
2445 
2446   return false;
2447 }
2448 
2449 /// Writes the block containing the serialized form of the
2450 /// preprocessor.
2451 void ASTWriter::WritePreprocessor(const Preprocessor &PP, bool IsModule) {
2452   PreprocessingRecord *PPRec = PP.getPreprocessingRecord();
2453   if (PPRec)
2454     WritePreprocessorDetail(*PPRec);
2455 
2456   RecordData Record;
2457   RecordData ModuleMacroRecord;
2458 
2459   // If the preprocessor __COUNTER__ value has been bumped, remember it.
2460   if (PP.getCounterValue() != 0) {
2461     RecordData::value_type Record[] = {PP.getCounterValue()};
2462     Stream.EmitRecord(PP_COUNTER_VALUE, Record);
2463   }
2464 
2465   if (PP.isRecordingPreamble() && PP.hasRecordedPreamble()) {
2466     assert(!IsModule);
2467     auto SkipInfo = PP.getPreambleSkipInfo();
2468     if (SkipInfo.hasValue()) {
2469       Record.push_back(true);
2470       AddSourceLocation(SkipInfo->HashTokenLoc, Record);
2471       AddSourceLocation(SkipInfo->IfTokenLoc, Record);
2472       Record.push_back(SkipInfo->FoundNonSkipPortion);
2473       Record.push_back(SkipInfo->FoundElse);
2474       AddSourceLocation(SkipInfo->ElseLoc, Record);
2475     } else {
2476       Record.push_back(false);
2477     }
2478     for (const auto &Cond : PP.getPreambleConditionalStack()) {
2479       AddSourceLocation(Cond.IfLoc, Record);
2480       Record.push_back(Cond.WasSkipping);
2481       Record.push_back(Cond.FoundNonSkip);
2482       Record.push_back(Cond.FoundElse);
2483     }
2484     Stream.EmitRecord(PP_CONDITIONAL_STACK, Record);
2485     Record.clear();
2486   }
2487 
2488   // Enter the preprocessor block.
2489   Stream.EnterSubblock(PREPROCESSOR_BLOCK_ID, 3);
2490 
2491   // If the AST file contains __DATE__ or __TIME__ emit a warning about this.
2492   // FIXME: Include a location for the use, and say which one was used.
2493   if (PP.SawDateOrTime())
2494     PP.Diag(SourceLocation(), diag::warn_module_uses_date_time) << IsModule;
2495 
2496   // Loop over all the macro directives that are live at the end of the file,
2497   // emitting each to the PP section.
2498 
2499   // Construct the list of identifiers with macro directives that need to be
2500   // serialized.
2501   SmallVector<const IdentifierInfo *, 128> MacroIdentifiers;
2502   for (auto &Id : PP.getIdentifierTable())
2503     if (Id.second->hadMacroDefinition() &&
2504         (!Id.second->isFromAST() ||
2505          Id.second->hasChangedSinceDeserialization()))
2506       MacroIdentifiers.push_back(Id.second);
2507   // Sort the set of macro definitions that need to be serialized by the
2508   // name of the macro, to provide a stable ordering.
2509   llvm::sort(MacroIdentifiers, llvm::less_ptr<IdentifierInfo>());
2510 
2511   // Emit the macro directives as a list and associate the offset with the
2512   // identifier they belong to.
2513   for (const IdentifierInfo *Name : MacroIdentifiers) {
2514     MacroDirective *MD = PP.getLocalMacroDirectiveHistory(Name);
2515     auto StartOffset = Stream.GetCurrentBitNo();
2516 
2517     // Emit the macro directives in reverse source order.
2518     for (; MD; MD = MD->getPrevious()) {
2519       // Once we hit an ignored macro, we're done: the rest of the chain
2520       // will all be ignored macros.
2521       if (shouldIgnoreMacro(MD, IsModule, PP))
2522         break;
2523 
2524       AddSourceLocation(MD->getLocation(), Record);
2525       Record.push_back(MD->getKind());
2526       if (auto *DefMD = dyn_cast<DefMacroDirective>(MD)) {
2527         Record.push_back(getMacroRef(DefMD->getInfo(), Name));
2528       } else if (auto *VisMD = dyn_cast<VisibilityMacroDirective>(MD)) {
2529         Record.push_back(VisMD->isPublic());
2530       }
2531     }
2532 
2533     // Write out any exported module macros.
2534     bool EmittedModuleMacros = false;
2535     // We write out exported module macros for PCH as well.
2536     auto Leafs = PP.getLeafModuleMacros(Name);
2537     SmallVector<ModuleMacro*, 8> Worklist(Leafs.begin(), Leafs.end());
2538     llvm::DenseMap<ModuleMacro*, unsigned> Visits;
2539     while (!Worklist.empty()) {
2540       auto *Macro = Worklist.pop_back_val();
2541 
2542       // Emit a record indicating this submodule exports this macro.
2543       ModuleMacroRecord.push_back(
2544           getSubmoduleID(Macro->getOwningModule()));
2545       ModuleMacroRecord.push_back(getMacroRef(Macro->getMacroInfo(), Name));
2546       for (auto *M : Macro->overrides())
2547         ModuleMacroRecord.push_back(getSubmoduleID(M->getOwningModule()));
2548 
2549       Stream.EmitRecord(PP_MODULE_MACRO, ModuleMacroRecord);
2550       ModuleMacroRecord.clear();
2551 
2552       // Enqueue overridden macros once we've visited all their ancestors.
2553       for (auto *M : Macro->overrides())
2554         if (++Visits[M] == M->getNumOverridingMacros())
2555           Worklist.push_back(M);
2556 
2557       EmittedModuleMacros = true;
2558     }
2559 
2560     if (Record.empty() && !EmittedModuleMacros)
2561       continue;
2562 
2563     IdentMacroDirectivesOffsetMap[Name] = StartOffset;
2564     Stream.EmitRecord(PP_MACRO_DIRECTIVE_HISTORY, Record);
2565     Record.clear();
2566   }
2567 
2568   /// Offsets of each of the macros into the bitstream, indexed by
2569   /// the local macro ID
2570   ///
2571   /// For each identifier that is associated with a macro, this map
2572   /// provides the offset into the bitstream where that macro is
2573   /// defined.
2574   std::vector<uint32_t> MacroOffsets;
2575 
2576   for (unsigned I = 0, N = MacroInfosToEmit.size(); I != N; ++I) {
2577     const IdentifierInfo *Name = MacroInfosToEmit[I].Name;
2578     MacroInfo *MI = MacroInfosToEmit[I].MI;
2579     MacroID ID = MacroInfosToEmit[I].ID;
2580 
2581     if (ID < FirstMacroID) {
2582       assert(0 && "Loaded MacroInfo entered MacroInfosToEmit ?");
2583       continue;
2584     }
2585 
2586     // Record the local offset of this macro.
2587     unsigned Index = ID - FirstMacroID;
2588     if (Index == MacroOffsets.size())
2589       MacroOffsets.push_back(Stream.GetCurrentBitNo());
2590     else {
2591       if (Index > MacroOffsets.size())
2592         MacroOffsets.resize(Index + 1);
2593 
2594       MacroOffsets[Index] = Stream.GetCurrentBitNo();
2595     }
2596 
2597     AddIdentifierRef(Name, Record);
2598     AddSourceLocation(MI->getDefinitionLoc(), Record);
2599     AddSourceLocation(MI->getDefinitionEndLoc(), Record);
2600     Record.push_back(MI->isUsed());
2601     Record.push_back(MI->isUsedForHeaderGuard());
2602     unsigned Code;
2603     if (MI->isObjectLike()) {
2604       Code = PP_MACRO_OBJECT_LIKE;
2605     } else {
2606       Code = PP_MACRO_FUNCTION_LIKE;
2607 
2608       Record.push_back(MI->isC99Varargs());
2609       Record.push_back(MI->isGNUVarargs());
2610       Record.push_back(MI->hasCommaPasting());
2611       Record.push_back(MI->getNumParams());
2612       for (const IdentifierInfo *Param : MI->params())
2613         AddIdentifierRef(Param, Record);
2614     }
2615 
2616     // If we have a detailed preprocessing record, record the macro definition
2617     // ID that corresponds to this macro.
2618     if (PPRec)
2619       Record.push_back(MacroDefinitions[PPRec->findMacroDefinition(MI)]);
2620 
2621     Stream.EmitRecord(Code, Record);
2622     Record.clear();
2623 
2624     // Emit the tokens array.
2625     for (unsigned TokNo = 0, e = MI->getNumTokens(); TokNo != e; ++TokNo) {
2626       // Note that we know that the preprocessor does not have any annotation
2627       // tokens in it because they are created by the parser, and thus can't
2628       // be in a macro definition.
2629       const Token &Tok = MI->getReplacementToken(TokNo);
2630       AddToken(Tok, Record);
2631       Stream.EmitRecord(PP_TOKEN, Record);
2632       Record.clear();
2633     }
2634     ++NumMacros;
2635   }
2636 
2637   Stream.ExitBlock();
2638 
2639   // Write the offsets table for macro IDs.
2640   using namespace llvm;
2641 
2642   auto Abbrev = std::make_shared<BitCodeAbbrev>();
2643   Abbrev->Add(BitCodeAbbrevOp(MACRO_OFFSET));
2644   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // # of macros
2645   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // first ID
2646   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2647 
2648   unsigned MacroOffsetAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2649   {
2650     RecordData::value_type Record[] = {MACRO_OFFSET, MacroOffsets.size(),
2651                                        FirstMacroID - NUM_PREDEF_MACRO_IDS};
2652     Stream.EmitRecordWithBlob(MacroOffsetAbbrev, Record, bytes(MacroOffsets));
2653   }
2654 }
2655 
2656 void ASTWriter::WritePreprocessorDetail(PreprocessingRecord &PPRec) {
2657   if (PPRec.local_begin() == PPRec.local_end())
2658     return;
2659 
2660   SmallVector<PPEntityOffset, 64> PreprocessedEntityOffsets;
2661 
2662   // Enter the preprocessor block.
2663   Stream.EnterSubblock(PREPROCESSOR_DETAIL_BLOCK_ID, 3);
2664 
2665   // If the preprocessor has a preprocessing record, emit it.
2666   unsigned NumPreprocessingRecords = 0;
2667   using namespace llvm;
2668 
2669   // Set up the abbreviation for
2670   unsigned InclusionAbbrev = 0;
2671   {
2672     auto Abbrev = std::make_shared<BitCodeAbbrev>();
2673     Abbrev->Add(BitCodeAbbrevOp(PPD_INCLUSION_DIRECTIVE));
2674     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // filename length
2675     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // in quotes
2676     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // kind
2677     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // imported module
2678     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2679     InclusionAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2680   }
2681 
2682   unsigned FirstPreprocessorEntityID
2683     = (Chain ? PPRec.getNumLoadedPreprocessedEntities() : 0)
2684     + NUM_PREDEF_PP_ENTITY_IDS;
2685   unsigned NextPreprocessorEntityID = FirstPreprocessorEntityID;
2686   RecordData Record;
2687   for (PreprocessingRecord::iterator E = PPRec.local_begin(),
2688                                   EEnd = PPRec.local_end();
2689        E != EEnd;
2690        (void)++E, ++NumPreprocessingRecords, ++NextPreprocessorEntityID) {
2691     Record.clear();
2692 
2693     PreprocessedEntityOffsets.push_back(
2694         PPEntityOffset((*E)->getSourceRange(), Stream.GetCurrentBitNo()));
2695 
2696     if (auto *MD = dyn_cast<MacroDefinitionRecord>(*E)) {
2697       // Record this macro definition's ID.
2698       MacroDefinitions[MD] = NextPreprocessorEntityID;
2699 
2700       AddIdentifierRef(MD->getName(), Record);
2701       Stream.EmitRecord(PPD_MACRO_DEFINITION, Record);
2702       continue;
2703     }
2704 
2705     if (auto *ME = dyn_cast<MacroExpansion>(*E)) {
2706       Record.push_back(ME->isBuiltinMacro());
2707       if (ME->isBuiltinMacro())
2708         AddIdentifierRef(ME->getName(), Record);
2709       else
2710         Record.push_back(MacroDefinitions[ME->getDefinition()]);
2711       Stream.EmitRecord(PPD_MACRO_EXPANSION, Record);
2712       continue;
2713     }
2714 
2715     if (auto *ID = dyn_cast<InclusionDirective>(*E)) {
2716       Record.push_back(PPD_INCLUSION_DIRECTIVE);
2717       Record.push_back(ID->getFileName().size());
2718       Record.push_back(ID->wasInQuotes());
2719       Record.push_back(static_cast<unsigned>(ID->getKind()));
2720       Record.push_back(ID->importedModule());
2721       SmallString<64> Buffer;
2722       Buffer += ID->getFileName();
2723       // Check that the FileEntry is not null because it was not resolved and
2724       // we create a PCH even with compiler errors.
2725       if (ID->getFile())
2726         Buffer += ID->getFile()->getName();
2727       Stream.EmitRecordWithBlob(InclusionAbbrev, Record, Buffer);
2728       continue;
2729     }
2730 
2731     llvm_unreachable("Unhandled PreprocessedEntity in ASTWriter");
2732   }
2733   Stream.ExitBlock();
2734 
2735   // Write the offsets table for the preprocessing record.
2736   if (NumPreprocessingRecords > 0) {
2737     assert(PreprocessedEntityOffsets.size() == NumPreprocessingRecords);
2738 
2739     // Write the offsets table for identifier IDs.
2740     using namespace llvm;
2741 
2742     auto Abbrev = std::make_shared<BitCodeAbbrev>();
2743     Abbrev->Add(BitCodeAbbrevOp(PPD_ENTITIES_OFFSETS));
2744     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // first pp entity
2745     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2746     unsigned PPEOffsetAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2747 
2748     RecordData::value_type Record[] = {PPD_ENTITIES_OFFSETS,
2749                                        FirstPreprocessorEntityID -
2750                                            NUM_PREDEF_PP_ENTITY_IDS};
2751     Stream.EmitRecordWithBlob(PPEOffsetAbbrev, Record,
2752                               bytes(PreprocessedEntityOffsets));
2753   }
2754 
2755   // Write the skipped region table for the preprocessing record.
2756   ArrayRef<SourceRange> SkippedRanges = PPRec.getSkippedRanges();
2757   if (SkippedRanges.size() > 0) {
2758     std::vector<PPSkippedRange> SerializedSkippedRanges;
2759     SerializedSkippedRanges.reserve(SkippedRanges.size());
2760     for (auto const& Range : SkippedRanges)
2761       SerializedSkippedRanges.emplace_back(Range);
2762 
2763     using namespace llvm;
2764     auto Abbrev = std::make_shared<BitCodeAbbrev>();
2765     Abbrev->Add(BitCodeAbbrevOp(PPD_SKIPPED_RANGES));
2766     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2767     unsigned PPESkippedRangeAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2768 
2769     Record.clear();
2770     Record.push_back(PPD_SKIPPED_RANGES);
2771     Stream.EmitRecordWithBlob(PPESkippedRangeAbbrev, Record,
2772                               bytes(SerializedSkippedRanges));
2773   }
2774 }
2775 
2776 unsigned ASTWriter::getLocalOrImportedSubmoduleID(Module *Mod) {
2777   if (!Mod)
2778     return 0;
2779 
2780   llvm::DenseMap<Module *, unsigned>::iterator Known = SubmoduleIDs.find(Mod);
2781   if (Known != SubmoduleIDs.end())
2782     return Known->second;
2783 
2784   auto *Top = Mod->getTopLevelModule();
2785   if (Top != WritingModule &&
2786       (getLangOpts().CompilingPCH ||
2787        !Top->fullModuleNameIs(StringRef(getLangOpts().CurrentModule))))
2788     return 0;
2789 
2790   return SubmoduleIDs[Mod] = NextSubmoduleID++;
2791 }
2792 
2793 unsigned ASTWriter::getSubmoduleID(Module *Mod) {
2794   // FIXME: This can easily happen, if we have a reference to a submodule that
2795   // did not result in us loading a module file for that submodule. For
2796   // instance, a cross-top-level-module 'conflict' declaration will hit this.
2797   unsigned ID = getLocalOrImportedSubmoduleID(Mod);
2798   assert((ID || !Mod) &&
2799          "asked for module ID for non-local, non-imported module");
2800   return ID;
2801 }
2802 
2803 /// Compute the number of modules within the given tree (including the
2804 /// given module).
2805 static unsigned getNumberOfModules(Module *Mod) {
2806   unsigned ChildModules = 0;
2807   for (auto Sub = Mod->submodule_begin(), SubEnd = Mod->submodule_end();
2808        Sub != SubEnd; ++Sub)
2809     ChildModules += getNumberOfModules(*Sub);
2810 
2811   return ChildModules + 1;
2812 }
2813 
2814 void ASTWriter::WriteSubmodules(Module *WritingModule) {
2815   // Enter the submodule description block.
2816   Stream.EnterSubblock(SUBMODULE_BLOCK_ID, /*bits for abbreviations*/5);
2817 
2818   // Write the abbreviations needed for the submodules block.
2819   using namespace llvm;
2820 
2821   auto Abbrev = std::make_shared<BitCodeAbbrev>();
2822   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_DEFINITION));
2823   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ID
2824   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Parent
2825   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // Kind
2826   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsFramework
2827   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsExplicit
2828   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsSystem
2829   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsExternC
2830   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // InferSubmodules...
2831   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // InferExplicit...
2832   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // InferExportWild...
2833   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // ConfigMacrosExh...
2834   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // ModuleMapIsPriv...
2835   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2836   unsigned DefinitionAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2837 
2838   Abbrev = std::make_shared<BitCodeAbbrev>();
2839   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_UMBRELLA_HEADER));
2840   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2841   unsigned UmbrellaAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2842 
2843   Abbrev = std::make_shared<BitCodeAbbrev>();
2844   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_HEADER));
2845   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2846   unsigned HeaderAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2847 
2848   Abbrev = std::make_shared<BitCodeAbbrev>();
2849   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_TOPHEADER));
2850   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2851   unsigned TopHeaderAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2852 
2853   Abbrev = std::make_shared<BitCodeAbbrev>();
2854   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_UMBRELLA_DIR));
2855   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2856   unsigned UmbrellaDirAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2857 
2858   Abbrev = std::make_shared<BitCodeAbbrev>();
2859   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_REQUIRES));
2860   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // State
2861   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));     // Feature
2862   unsigned RequiresAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2863 
2864   Abbrev = std::make_shared<BitCodeAbbrev>();
2865   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_EXCLUDED_HEADER));
2866   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2867   unsigned ExcludedHeaderAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2868 
2869   Abbrev = std::make_shared<BitCodeAbbrev>();
2870   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_TEXTUAL_HEADER));
2871   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2872   unsigned TextualHeaderAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2873 
2874   Abbrev = std::make_shared<BitCodeAbbrev>();
2875   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_PRIVATE_HEADER));
2876   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2877   unsigned PrivateHeaderAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2878 
2879   Abbrev = std::make_shared<BitCodeAbbrev>();
2880   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_PRIVATE_TEXTUAL_HEADER));
2881   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2882   unsigned PrivateTextualHeaderAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2883 
2884   Abbrev = std::make_shared<BitCodeAbbrev>();
2885   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_LINK_LIBRARY));
2886   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsFramework
2887   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));     // Name
2888   unsigned LinkLibraryAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2889 
2890   Abbrev = std::make_shared<BitCodeAbbrev>();
2891   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_CONFIG_MACRO));
2892   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));    // Macro name
2893   unsigned ConfigMacroAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2894 
2895   Abbrev = std::make_shared<BitCodeAbbrev>();
2896   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_CONFLICT));
2897   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));  // Other module
2898   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));    // Message
2899   unsigned ConflictAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2900 
2901   Abbrev = std::make_shared<BitCodeAbbrev>();
2902   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_EXPORT_AS));
2903   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));    // Macro name
2904   unsigned ExportAsAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2905 
2906   // Write the submodule metadata block.
2907   RecordData::value_type Record[] = {
2908       getNumberOfModules(WritingModule),
2909       FirstSubmoduleID - NUM_PREDEF_SUBMODULE_IDS};
2910   Stream.EmitRecord(SUBMODULE_METADATA, Record);
2911 
2912   // Write all of the submodules.
2913   std::queue<Module *> Q;
2914   Q.push(WritingModule);
2915   while (!Q.empty()) {
2916     Module *Mod = Q.front();
2917     Q.pop();
2918     unsigned ID = getSubmoduleID(Mod);
2919 
2920     uint64_t ParentID = 0;
2921     if (Mod->Parent) {
2922       assert(SubmoduleIDs[Mod->Parent] && "Submodule parent not written?");
2923       ParentID = SubmoduleIDs[Mod->Parent];
2924     }
2925 
2926     // Emit the definition of the block.
2927     {
2928       RecordData::value_type Record[] = {SUBMODULE_DEFINITION,
2929                                          ID,
2930                                          ParentID,
2931                                          (RecordData::value_type)Mod->Kind,
2932                                          Mod->IsFramework,
2933                                          Mod->IsExplicit,
2934                                          Mod->IsSystem,
2935                                          Mod->IsExternC,
2936                                          Mod->InferSubmodules,
2937                                          Mod->InferExplicitSubmodules,
2938                                          Mod->InferExportWildcard,
2939                                          Mod->ConfigMacrosExhaustive,
2940                                          Mod->ModuleMapIsPrivate};
2941       Stream.EmitRecordWithBlob(DefinitionAbbrev, Record, Mod->Name);
2942     }
2943 
2944     // Emit the requirements.
2945     for (const auto &R : Mod->Requirements) {
2946       RecordData::value_type Record[] = {SUBMODULE_REQUIRES, R.second};
2947       Stream.EmitRecordWithBlob(RequiresAbbrev, Record, R.first);
2948     }
2949 
2950     // Emit the umbrella header, if there is one.
2951     if (auto UmbrellaHeader = Mod->getUmbrellaHeader()) {
2952       RecordData::value_type Record[] = {SUBMODULE_UMBRELLA_HEADER};
2953       Stream.EmitRecordWithBlob(UmbrellaAbbrev, Record,
2954                                 UmbrellaHeader.NameAsWritten);
2955     } else if (auto UmbrellaDir = Mod->getUmbrellaDir()) {
2956       RecordData::value_type Record[] = {SUBMODULE_UMBRELLA_DIR};
2957       Stream.EmitRecordWithBlob(UmbrellaDirAbbrev, Record,
2958                                 UmbrellaDir.NameAsWritten);
2959     }
2960 
2961     // Emit the headers.
2962     struct {
2963       unsigned RecordKind;
2964       unsigned Abbrev;
2965       Module::HeaderKind HeaderKind;
2966     } HeaderLists[] = {
2967       {SUBMODULE_HEADER, HeaderAbbrev, Module::HK_Normal},
2968       {SUBMODULE_TEXTUAL_HEADER, TextualHeaderAbbrev, Module::HK_Textual},
2969       {SUBMODULE_PRIVATE_HEADER, PrivateHeaderAbbrev, Module::HK_Private},
2970       {SUBMODULE_PRIVATE_TEXTUAL_HEADER, PrivateTextualHeaderAbbrev,
2971         Module::HK_PrivateTextual},
2972       {SUBMODULE_EXCLUDED_HEADER, ExcludedHeaderAbbrev, Module::HK_Excluded}
2973     };
2974     for (auto &HL : HeaderLists) {
2975       RecordData::value_type Record[] = {HL.RecordKind};
2976       for (auto &H : Mod->Headers[HL.HeaderKind])
2977         Stream.EmitRecordWithBlob(HL.Abbrev, Record, H.NameAsWritten);
2978     }
2979 
2980     // Emit the top headers.
2981     {
2982       auto TopHeaders = Mod->getTopHeaders(PP->getFileManager());
2983       RecordData::value_type Record[] = {SUBMODULE_TOPHEADER};
2984       for (auto *H : TopHeaders)
2985         Stream.EmitRecordWithBlob(TopHeaderAbbrev, Record, H->getName());
2986     }
2987 
2988     // Emit the imports.
2989     if (!Mod->Imports.empty()) {
2990       RecordData Record;
2991       for (auto *I : Mod->Imports)
2992         Record.push_back(getSubmoduleID(I));
2993       Stream.EmitRecord(SUBMODULE_IMPORTS, Record);
2994     }
2995 
2996     // Emit the exports.
2997     if (!Mod->Exports.empty()) {
2998       RecordData Record;
2999       for (const auto &E : Mod->Exports) {
3000         // FIXME: This may fail; we don't require that all exported modules
3001         // are local or imported.
3002         Record.push_back(getSubmoduleID(E.getPointer()));
3003         Record.push_back(E.getInt());
3004       }
3005       Stream.EmitRecord(SUBMODULE_EXPORTS, Record);
3006     }
3007 
3008     //FIXME: How do we emit the 'use'd modules?  They may not be submodules.
3009     // Might be unnecessary as use declarations are only used to build the
3010     // module itself.
3011 
3012     // Emit the link libraries.
3013     for (const auto &LL : Mod->LinkLibraries) {
3014       RecordData::value_type Record[] = {SUBMODULE_LINK_LIBRARY,
3015                                          LL.IsFramework};
3016       Stream.EmitRecordWithBlob(LinkLibraryAbbrev, Record, LL.Library);
3017     }
3018 
3019     // Emit the conflicts.
3020     for (const auto &C : Mod->Conflicts) {
3021       // FIXME: This may fail; we don't require that all conflicting modules
3022       // are local or imported.
3023       RecordData::value_type Record[] = {SUBMODULE_CONFLICT,
3024                                          getSubmoduleID(C.Other)};
3025       Stream.EmitRecordWithBlob(ConflictAbbrev, Record, C.Message);
3026     }
3027 
3028     // Emit the configuration macros.
3029     for (const auto &CM : Mod->ConfigMacros) {
3030       RecordData::value_type Record[] = {SUBMODULE_CONFIG_MACRO};
3031       Stream.EmitRecordWithBlob(ConfigMacroAbbrev, Record, CM);
3032     }
3033 
3034     // Emit the initializers, if any.
3035     RecordData Inits;
3036     for (Decl *D : Context->getModuleInitializers(Mod))
3037       Inits.push_back(GetDeclRef(D));
3038     if (!Inits.empty())
3039       Stream.EmitRecord(SUBMODULE_INITIALIZERS, Inits);
3040 
3041     // Emit the name of the re-exported module, if any.
3042     if (!Mod->ExportAsModule.empty()) {
3043       RecordData::value_type Record[] = {SUBMODULE_EXPORT_AS};
3044       Stream.EmitRecordWithBlob(ExportAsAbbrev, Record, Mod->ExportAsModule);
3045     }
3046 
3047     // Queue up the submodules of this module.
3048     for (auto *M : Mod->submodules())
3049       Q.push(M);
3050   }
3051 
3052   Stream.ExitBlock();
3053 
3054   assert((NextSubmoduleID - FirstSubmoduleID ==
3055           getNumberOfModules(WritingModule)) &&
3056          "Wrong # of submodules; found a reference to a non-local, "
3057          "non-imported submodule?");
3058 }
3059 
3060 void ASTWriter::WritePragmaDiagnosticMappings(const DiagnosticsEngine &Diag,
3061                                               bool isModule) {
3062   llvm::SmallDenseMap<const DiagnosticsEngine::DiagState *, unsigned, 64>
3063       DiagStateIDMap;
3064   unsigned CurrID = 0;
3065   RecordData Record;
3066 
3067   auto EncodeDiagStateFlags =
3068       [](const DiagnosticsEngine::DiagState *DS) -> unsigned {
3069     unsigned Result = (unsigned)DS->ExtBehavior;
3070     for (unsigned Val :
3071          {(unsigned)DS->IgnoreAllWarnings, (unsigned)DS->EnableAllWarnings,
3072           (unsigned)DS->WarningsAsErrors, (unsigned)DS->ErrorsAsFatal,
3073           (unsigned)DS->SuppressSystemWarnings})
3074       Result = (Result << 1) | Val;
3075     return Result;
3076   };
3077 
3078   unsigned Flags = EncodeDiagStateFlags(Diag.DiagStatesByLoc.FirstDiagState);
3079   Record.push_back(Flags);
3080 
3081   auto AddDiagState = [&](const DiagnosticsEngine::DiagState *State,
3082                           bool IncludeNonPragmaStates) {
3083     // Ensure that the diagnostic state wasn't modified since it was created.
3084     // We will not correctly round-trip this information otherwise.
3085     assert(Flags == EncodeDiagStateFlags(State) &&
3086            "diag state flags vary in single AST file");
3087 
3088     unsigned &DiagStateID = DiagStateIDMap[State];
3089     Record.push_back(DiagStateID);
3090 
3091     if (DiagStateID == 0) {
3092       DiagStateID = ++CurrID;
3093 
3094       // Add a placeholder for the number of mappings.
3095       auto SizeIdx = Record.size();
3096       Record.emplace_back();
3097       for (const auto &I : *State) {
3098         if (I.second.isPragma() || IncludeNonPragmaStates) {
3099           Record.push_back(I.first);
3100           Record.push_back(I.second.serialize());
3101         }
3102       }
3103       // Update the placeholder.
3104       Record[SizeIdx] = (Record.size() - SizeIdx) / 2;
3105     }
3106   };
3107 
3108   AddDiagState(Diag.DiagStatesByLoc.FirstDiagState, isModule);
3109 
3110   // Reserve a spot for the number of locations with state transitions.
3111   auto NumLocationsIdx = Record.size();
3112   Record.emplace_back();
3113 
3114   // Emit the state transitions.
3115   unsigned NumLocations = 0;
3116   for (auto &FileIDAndFile : Diag.DiagStatesByLoc.Files) {
3117     if (!FileIDAndFile.first.isValid() ||
3118         !FileIDAndFile.second.HasLocalTransitions)
3119       continue;
3120     ++NumLocations;
3121 
3122     SourceLocation Loc = Diag.SourceMgr->getComposedLoc(FileIDAndFile.first, 0);
3123     assert(!Loc.isInvalid() && "start loc for valid FileID is invalid");
3124     AddSourceLocation(Loc, Record);
3125 
3126     Record.push_back(FileIDAndFile.second.StateTransitions.size());
3127     for (auto &StatePoint : FileIDAndFile.second.StateTransitions) {
3128       Record.push_back(StatePoint.Offset);
3129       AddDiagState(StatePoint.State, false);
3130     }
3131   }
3132 
3133   // Backpatch the number of locations.
3134   Record[NumLocationsIdx] = NumLocations;
3135 
3136   // Emit CurDiagStateLoc.  Do it last in order to match source order.
3137   //
3138   // This also protects against a hypothetical corner case with simulating
3139   // -Werror settings for implicit modules in the ASTReader, where reading
3140   // CurDiagState out of context could change whether warning pragmas are
3141   // treated as errors.
3142   AddSourceLocation(Diag.DiagStatesByLoc.CurDiagStateLoc, Record);
3143   AddDiagState(Diag.DiagStatesByLoc.CurDiagState, false);
3144 
3145   Stream.EmitRecord(DIAG_PRAGMA_MAPPINGS, Record);
3146 }
3147 
3148 //===----------------------------------------------------------------------===//
3149 // Type Serialization
3150 //===----------------------------------------------------------------------===//
3151 
3152 /// Write the representation of a type to the AST stream.
3153 void ASTWriter::WriteType(QualType T) {
3154   TypeIdx &IdxRef = TypeIdxs[T];
3155   if (IdxRef.getIndex() == 0) // we haven't seen this type before.
3156     IdxRef = TypeIdx(NextTypeID++);
3157   TypeIdx Idx = IdxRef;
3158 
3159   assert(Idx.getIndex() >= FirstTypeID && "Re-writing a type from a prior AST");
3160 
3161   RecordData Record;
3162 
3163   // Emit the type's representation.
3164   ASTTypeWriter W(*this, Record);
3165   W.Visit(T);
3166   uint64_t Offset = W.Emit();
3167 
3168   // Record the offset for this type.
3169   unsigned Index = Idx.getIndex() - FirstTypeID;
3170   if (TypeOffsets.size() == Index)
3171     TypeOffsets.push_back(Offset);
3172   else if (TypeOffsets.size() < Index) {
3173     TypeOffsets.resize(Index + 1);
3174     TypeOffsets[Index] = Offset;
3175   } else {
3176     llvm_unreachable("Types emitted in wrong order");
3177   }
3178 }
3179 
3180 //===----------------------------------------------------------------------===//
3181 // Declaration Serialization
3182 //===----------------------------------------------------------------------===//
3183 
3184 /// Write the block containing all of the declaration IDs
3185 /// lexically declared within the given DeclContext.
3186 ///
3187 /// \returns the offset of the DECL_CONTEXT_LEXICAL block within the
3188 /// bitstream, or 0 if no block was written.
3189 uint64_t ASTWriter::WriteDeclContextLexicalBlock(ASTContext &Context,
3190                                                  DeclContext *DC) {
3191   if (DC->decls_empty())
3192     return 0;
3193 
3194   uint64_t Offset = Stream.GetCurrentBitNo();
3195   SmallVector<uint32_t, 128> KindDeclPairs;
3196   for (const auto *D : DC->decls()) {
3197     KindDeclPairs.push_back(D->getKind());
3198     KindDeclPairs.push_back(GetDeclRef(D));
3199   }
3200 
3201   ++NumLexicalDeclContexts;
3202   RecordData::value_type Record[] = {DECL_CONTEXT_LEXICAL};
3203   Stream.EmitRecordWithBlob(DeclContextLexicalAbbrev, Record,
3204                             bytes(KindDeclPairs));
3205   return Offset;
3206 }
3207 
3208 void ASTWriter::WriteTypeDeclOffsets() {
3209   using namespace llvm;
3210 
3211   // Write the type offsets array
3212   auto Abbrev = std::make_shared<BitCodeAbbrev>();
3213   Abbrev->Add(BitCodeAbbrevOp(TYPE_OFFSET));
3214   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // # of types
3215   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // base type index
3216   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // types block
3217   unsigned TypeOffsetAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
3218   {
3219     RecordData::value_type Record[] = {TYPE_OFFSET, TypeOffsets.size(),
3220                                        FirstTypeID - NUM_PREDEF_TYPE_IDS};
3221     Stream.EmitRecordWithBlob(TypeOffsetAbbrev, Record, bytes(TypeOffsets));
3222   }
3223 
3224   // Write the declaration offsets array
3225   Abbrev = std::make_shared<BitCodeAbbrev>();
3226   Abbrev->Add(BitCodeAbbrevOp(DECL_OFFSET));
3227   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // # of declarations
3228   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // base decl ID
3229   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // declarations block
3230   unsigned DeclOffsetAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
3231   {
3232     RecordData::value_type Record[] = {DECL_OFFSET, DeclOffsets.size(),
3233                                        FirstDeclID - NUM_PREDEF_DECL_IDS};
3234     Stream.EmitRecordWithBlob(DeclOffsetAbbrev, Record, bytes(DeclOffsets));
3235   }
3236 }
3237 
3238 void ASTWriter::WriteFileDeclIDsMap() {
3239   using namespace llvm;
3240 
3241   SmallVector<std::pair<FileID, DeclIDInFileInfo *>, 64> SortedFileDeclIDs(
3242       FileDeclIDs.begin(), FileDeclIDs.end());
3243   llvm::sort(SortedFileDeclIDs, llvm::less_first());
3244 
3245   // Join the vectors of DeclIDs from all files.
3246   SmallVector<DeclID, 256> FileGroupedDeclIDs;
3247   for (auto &FileDeclEntry : SortedFileDeclIDs) {
3248     DeclIDInFileInfo &Info = *FileDeclEntry.second;
3249     Info.FirstDeclIndex = FileGroupedDeclIDs.size();
3250     for (auto &LocDeclEntry : Info.DeclIDs)
3251       FileGroupedDeclIDs.push_back(LocDeclEntry.second);
3252   }
3253 
3254   auto Abbrev = std::make_shared<BitCodeAbbrev>();
3255   Abbrev->Add(BitCodeAbbrevOp(FILE_SORTED_DECLS));
3256   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
3257   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
3258   unsigned AbbrevCode = Stream.EmitAbbrev(std::move(Abbrev));
3259   RecordData::value_type Record[] = {FILE_SORTED_DECLS,
3260                                      FileGroupedDeclIDs.size()};
3261   Stream.EmitRecordWithBlob(AbbrevCode, Record, bytes(FileGroupedDeclIDs));
3262 }
3263 
3264 void ASTWriter::WriteComments() {
3265   Stream.EnterSubblock(COMMENTS_BLOCK_ID, 3);
3266   auto _ = llvm::make_scope_exit([this] { Stream.ExitBlock(); });
3267   if (!PP->getPreprocessorOpts().WriteCommentListToPCH)
3268     return;
3269   ArrayRef<RawComment *> RawComments = Context->Comments.getComments();
3270   RecordData Record;
3271   for (const auto *I : RawComments) {
3272     Record.clear();
3273     AddSourceRange(I->getSourceRange(), Record);
3274     Record.push_back(I->getKind());
3275     Record.push_back(I->isTrailingComment());
3276     Record.push_back(I->isAlmostTrailingComment());
3277     Stream.EmitRecord(COMMENTS_RAW_COMMENT, Record);
3278   }
3279 }
3280 
3281 //===----------------------------------------------------------------------===//
3282 // Global Method Pool and Selector Serialization
3283 //===----------------------------------------------------------------------===//
3284 
3285 namespace {
3286 
3287 // Trait used for the on-disk hash table used in the method pool.
3288 class ASTMethodPoolTrait {
3289   ASTWriter &Writer;
3290 
3291 public:
3292   using key_type = Selector;
3293   using key_type_ref = key_type;
3294 
3295   struct data_type {
3296     SelectorID ID;
3297     ObjCMethodList Instance, Factory;
3298   };
3299   using data_type_ref = const data_type &;
3300 
3301   using hash_value_type = unsigned;
3302   using offset_type = unsigned;
3303 
3304   explicit ASTMethodPoolTrait(ASTWriter &Writer) : Writer(Writer) {}
3305 
3306   static hash_value_type ComputeHash(Selector Sel) {
3307     return serialization::ComputeHash(Sel);
3308   }
3309 
3310   std::pair<unsigned, unsigned>
3311     EmitKeyDataLength(raw_ostream& Out, Selector Sel,
3312                       data_type_ref Methods) {
3313     using namespace llvm::support;
3314 
3315     endian::Writer LE(Out, little);
3316     unsigned KeyLen = 2 + (Sel.getNumArgs()? Sel.getNumArgs() * 4 : 4);
3317     LE.write<uint16_t>(KeyLen);
3318     unsigned DataLen = 4 + 2 + 2; // 2 bytes for each of the method counts
3319     for (const ObjCMethodList *Method = &Methods.Instance; Method;
3320          Method = Method->getNext())
3321       if (Method->getMethod())
3322         DataLen += 4;
3323     for (const ObjCMethodList *Method = &Methods.Factory; Method;
3324          Method = Method->getNext())
3325       if (Method->getMethod())
3326         DataLen += 4;
3327     LE.write<uint16_t>(DataLen);
3328     return std::make_pair(KeyLen, DataLen);
3329   }
3330 
3331   void EmitKey(raw_ostream& Out, Selector Sel, unsigned) {
3332     using namespace llvm::support;
3333 
3334     endian::Writer LE(Out, little);
3335     uint64_t Start = Out.tell();
3336     assert((Start >> 32) == 0 && "Selector key offset too large");
3337     Writer.SetSelectorOffset(Sel, Start);
3338     unsigned N = Sel.getNumArgs();
3339     LE.write<uint16_t>(N);
3340     if (N == 0)
3341       N = 1;
3342     for (unsigned I = 0; I != N; ++I)
3343       LE.write<uint32_t>(
3344           Writer.getIdentifierRef(Sel.getIdentifierInfoForSlot(I)));
3345   }
3346 
3347   void EmitData(raw_ostream& Out, key_type_ref,
3348                 data_type_ref Methods, unsigned DataLen) {
3349     using namespace llvm::support;
3350 
3351     endian::Writer LE(Out, little);
3352     uint64_t Start = Out.tell(); (void)Start;
3353     LE.write<uint32_t>(Methods.ID);
3354     unsigned NumInstanceMethods = 0;
3355     for (const ObjCMethodList *Method = &Methods.Instance; Method;
3356          Method = Method->getNext())
3357       if (Method->getMethod())
3358         ++NumInstanceMethods;
3359 
3360     unsigned NumFactoryMethods = 0;
3361     for (const ObjCMethodList *Method = &Methods.Factory; Method;
3362          Method = Method->getNext())
3363       if (Method->getMethod())
3364         ++NumFactoryMethods;
3365 
3366     unsigned InstanceBits = Methods.Instance.getBits();
3367     assert(InstanceBits < 4);
3368     unsigned InstanceHasMoreThanOneDeclBit =
3369         Methods.Instance.hasMoreThanOneDecl();
3370     unsigned FullInstanceBits = (NumInstanceMethods << 3) |
3371                                 (InstanceHasMoreThanOneDeclBit << 2) |
3372                                 InstanceBits;
3373     unsigned FactoryBits = Methods.Factory.getBits();
3374     assert(FactoryBits < 4);
3375     unsigned FactoryHasMoreThanOneDeclBit =
3376         Methods.Factory.hasMoreThanOneDecl();
3377     unsigned FullFactoryBits = (NumFactoryMethods << 3) |
3378                                (FactoryHasMoreThanOneDeclBit << 2) |
3379                                FactoryBits;
3380     LE.write<uint16_t>(FullInstanceBits);
3381     LE.write<uint16_t>(FullFactoryBits);
3382     for (const ObjCMethodList *Method = &Methods.Instance; Method;
3383          Method = Method->getNext())
3384       if (Method->getMethod())
3385         LE.write<uint32_t>(Writer.getDeclID(Method->getMethod()));
3386     for (const ObjCMethodList *Method = &Methods.Factory; Method;
3387          Method = Method->getNext())
3388       if (Method->getMethod())
3389         LE.write<uint32_t>(Writer.getDeclID(Method->getMethod()));
3390 
3391     assert(Out.tell() - Start == DataLen && "Data length is wrong");
3392   }
3393 };
3394 
3395 } // namespace
3396 
3397 /// Write ObjC data: selectors and the method pool.
3398 ///
3399 /// The method pool contains both instance and factory methods, stored
3400 /// in an on-disk hash table indexed by the selector. The hash table also
3401 /// contains an empty entry for every other selector known to Sema.
3402 void ASTWriter::WriteSelectors(Sema &SemaRef) {
3403   using namespace llvm;
3404 
3405   // Do we have to do anything at all?
3406   if (SemaRef.MethodPool.empty() && SelectorIDs.empty())
3407     return;
3408   unsigned NumTableEntries = 0;
3409   // Create and write out the blob that contains selectors and the method pool.
3410   {
3411     llvm::OnDiskChainedHashTableGenerator<ASTMethodPoolTrait> Generator;
3412     ASTMethodPoolTrait Trait(*this);
3413 
3414     // Create the on-disk hash table representation. We walk through every
3415     // selector we've seen and look it up in the method pool.
3416     SelectorOffsets.resize(NextSelectorID - FirstSelectorID);
3417     for (auto &SelectorAndID : SelectorIDs) {
3418       Selector S = SelectorAndID.first;
3419       SelectorID ID = SelectorAndID.second;
3420       Sema::GlobalMethodPool::iterator F = SemaRef.MethodPool.find(S);
3421       ASTMethodPoolTrait::data_type Data = {
3422         ID,
3423         ObjCMethodList(),
3424         ObjCMethodList()
3425       };
3426       if (F != SemaRef.MethodPool.end()) {
3427         Data.Instance = F->second.first;
3428         Data.Factory = F->second.second;
3429       }
3430       // Only write this selector if it's not in an existing AST or something
3431       // changed.
3432       if (Chain && ID < FirstSelectorID) {
3433         // Selector already exists. Did it change?
3434         bool changed = false;
3435         for (ObjCMethodList *M = &Data.Instance;
3436              !changed && M && M->getMethod(); M = M->getNext()) {
3437           if (!M->getMethod()->isFromASTFile())
3438             changed = true;
3439         }
3440         for (ObjCMethodList *M = &Data.Factory; !changed && M && M->getMethod();
3441              M = M->getNext()) {
3442           if (!M->getMethod()->isFromASTFile())
3443             changed = true;
3444         }
3445         if (!changed)
3446           continue;
3447       } else if (Data.Instance.getMethod() || Data.Factory.getMethod()) {
3448         // A new method pool entry.
3449         ++NumTableEntries;
3450       }
3451       Generator.insert(S, Data, Trait);
3452     }
3453 
3454     // Create the on-disk hash table in a buffer.
3455     SmallString<4096> MethodPool;
3456     uint32_t BucketOffset;
3457     {
3458       using namespace llvm::support;
3459 
3460       ASTMethodPoolTrait Trait(*this);
3461       llvm::raw_svector_ostream Out(MethodPool);
3462       // Make sure that no bucket is at offset 0
3463       endian::write<uint32_t>(Out, 0, little);
3464       BucketOffset = Generator.Emit(Out, Trait);
3465     }
3466 
3467     // Create a blob abbreviation
3468     auto Abbrev = std::make_shared<BitCodeAbbrev>();
3469     Abbrev->Add(BitCodeAbbrevOp(METHOD_POOL));
3470     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
3471     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
3472     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
3473     unsigned MethodPoolAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
3474 
3475     // Write the method pool
3476     {
3477       RecordData::value_type Record[] = {METHOD_POOL, BucketOffset,
3478                                          NumTableEntries};
3479       Stream.EmitRecordWithBlob(MethodPoolAbbrev, Record, MethodPool);
3480     }
3481 
3482     // Create a blob abbreviation for the selector table offsets.
3483     Abbrev = std::make_shared<BitCodeAbbrev>();
3484     Abbrev->Add(BitCodeAbbrevOp(SELECTOR_OFFSETS));
3485     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // size
3486     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // first ID
3487     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
3488     unsigned SelectorOffsetAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
3489 
3490     // Write the selector offsets table.
3491     {
3492       RecordData::value_type Record[] = {
3493           SELECTOR_OFFSETS, SelectorOffsets.size(),
3494           FirstSelectorID - NUM_PREDEF_SELECTOR_IDS};
3495       Stream.EmitRecordWithBlob(SelectorOffsetAbbrev, Record,
3496                                 bytes(SelectorOffsets));
3497     }
3498   }
3499 }
3500 
3501 /// Write the selectors referenced in @selector expression into AST file.
3502 void ASTWriter::WriteReferencedSelectorsPool(Sema &SemaRef) {
3503   using namespace llvm;
3504 
3505   if (SemaRef.ReferencedSelectors.empty())
3506     return;
3507 
3508   RecordData Record;
3509   ASTRecordWriter Writer(*this, Record);
3510 
3511   // Note: this writes out all references even for a dependent AST. But it is
3512   // very tricky to fix, and given that @selector shouldn't really appear in
3513   // headers, probably not worth it. It's not a correctness issue.
3514   for (auto &SelectorAndLocation : SemaRef.ReferencedSelectors) {
3515     Selector Sel = SelectorAndLocation.first;
3516     SourceLocation Loc = SelectorAndLocation.second;
3517     Writer.AddSelectorRef(Sel);
3518     Writer.AddSourceLocation(Loc);
3519   }
3520   Writer.Emit(REFERENCED_SELECTOR_POOL);
3521 }
3522 
3523 //===----------------------------------------------------------------------===//
3524 // Identifier Table Serialization
3525 //===----------------------------------------------------------------------===//
3526 
3527 /// Determine the declaration that should be put into the name lookup table to
3528 /// represent the given declaration in this module. This is usually D itself,
3529 /// but if D was imported and merged into a local declaration, we want the most
3530 /// recent local declaration instead. The chosen declaration will be the most
3531 /// recent declaration in any module that imports this one.
3532 static NamedDecl *getDeclForLocalLookup(const LangOptions &LangOpts,
3533                                         NamedDecl *D) {
3534   if (!LangOpts.Modules || !D->isFromASTFile())
3535     return D;
3536 
3537   if (Decl *Redecl = D->getPreviousDecl()) {
3538     // For Redeclarable decls, a prior declaration might be local.
3539     for (; Redecl; Redecl = Redecl->getPreviousDecl()) {
3540       // If we find a local decl, we're done.
3541       if (!Redecl->isFromASTFile()) {
3542         // Exception: in very rare cases (for injected-class-names), not all
3543         // redeclarations are in the same semantic context. Skip ones in a
3544         // different context. They don't go in this lookup table at all.
3545         if (!Redecl->getDeclContext()->getRedeclContext()->Equals(
3546                 D->getDeclContext()->getRedeclContext()))
3547           continue;
3548         return cast<NamedDecl>(Redecl);
3549       }
3550 
3551       // If we find a decl from a (chained-)PCH stop since we won't find a
3552       // local one.
3553       if (Redecl->getOwningModuleID() == 0)
3554         break;
3555     }
3556   } else if (Decl *First = D->getCanonicalDecl()) {
3557     // For Mergeable decls, the first decl might be local.
3558     if (!First->isFromASTFile())
3559       return cast<NamedDecl>(First);
3560   }
3561 
3562   // All declarations are imported. Our most recent declaration will also be
3563   // the most recent one in anyone who imports us.
3564   return D;
3565 }
3566 
3567 namespace {
3568 
3569 class ASTIdentifierTableTrait {
3570   ASTWriter &Writer;
3571   Preprocessor &PP;
3572   IdentifierResolver &IdResolver;
3573   bool IsModule;
3574   bool NeedDecls;
3575   ASTWriter::RecordData *InterestingIdentifierOffsets;
3576 
3577   /// Determines whether this is an "interesting" identifier that needs a
3578   /// full IdentifierInfo structure written into the hash table. Notably, this
3579   /// doesn't check whether the name has macros defined; use PublicMacroIterator
3580   /// to check that.
3581   bool isInterestingIdentifier(const IdentifierInfo *II, uint64_t MacroOffset) {
3582     if (MacroOffset ||
3583         II->isPoisoned() ||
3584         (IsModule ? II->hasRevertedBuiltin() : II->getObjCOrBuiltinID()) ||
3585         II->hasRevertedTokenIDToIdentifier() ||
3586         (NeedDecls && II->getFETokenInfo()))
3587       return true;
3588 
3589     return false;
3590   }
3591 
3592 public:
3593   using key_type = IdentifierInfo *;
3594   using key_type_ref = key_type;
3595 
3596   using data_type = IdentID;
3597   using data_type_ref = data_type;
3598 
3599   using hash_value_type = unsigned;
3600   using offset_type = unsigned;
3601 
3602   ASTIdentifierTableTrait(ASTWriter &Writer, Preprocessor &PP,
3603                           IdentifierResolver &IdResolver, bool IsModule,
3604                           ASTWriter::RecordData *InterestingIdentifierOffsets)
3605       : Writer(Writer), PP(PP), IdResolver(IdResolver), IsModule(IsModule),
3606         NeedDecls(!IsModule || !Writer.getLangOpts().CPlusPlus),
3607         InterestingIdentifierOffsets(InterestingIdentifierOffsets) {}
3608 
3609   bool needDecls() const { return NeedDecls; }
3610 
3611   static hash_value_type ComputeHash(const IdentifierInfo* II) {
3612     return llvm::djbHash(II->getName());
3613   }
3614 
3615   bool isInterestingIdentifier(const IdentifierInfo *II) {
3616     auto MacroOffset = Writer.getMacroDirectivesOffset(II);
3617     return isInterestingIdentifier(II, MacroOffset);
3618   }
3619 
3620   bool isInterestingNonMacroIdentifier(const IdentifierInfo *II) {
3621     return isInterestingIdentifier(II, 0);
3622   }
3623 
3624   std::pair<unsigned, unsigned>
3625   EmitKeyDataLength(raw_ostream& Out, IdentifierInfo* II, IdentID ID) {
3626     unsigned KeyLen = II->getLength() + 1;
3627     unsigned DataLen = 4; // 4 bytes for the persistent ID << 1
3628     auto MacroOffset = Writer.getMacroDirectivesOffset(II);
3629     if (isInterestingIdentifier(II, MacroOffset)) {
3630       DataLen += 2; // 2 bytes for builtin ID
3631       DataLen += 2; // 2 bytes for flags
3632       if (MacroOffset)
3633         DataLen += 4; // MacroDirectives offset.
3634 
3635       if (NeedDecls) {
3636         for (IdentifierResolver::iterator D = IdResolver.begin(II),
3637                                        DEnd = IdResolver.end();
3638              D != DEnd; ++D)
3639           DataLen += 4;
3640       }
3641     }
3642 
3643     using namespace llvm::support;
3644 
3645     endian::Writer LE(Out, little);
3646 
3647     assert((uint16_t)DataLen == DataLen && (uint16_t)KeyLen == KeyLen);
3648     LE.write<uint16_t>(DataLen);
3649     // We emit the key length after the data length so that every
3650     // string is preceded by a 16-bit length. This matches the PTH
3651     // format for storing identifiers.
3652     LE.write<uint16_t>(KeyLen);
3653     return std::make_pair(KeyLen, DataLen);
3654   }
3655 
3656   void EmitKey(raw_ostream& Out, const IdentifierInfo* II,
3657                unsigned KeyLen) {
3658     // Record the location of the key data.  This is used when generating
3659     // the mapping from persistent IDs to strings.
3660     Writer.SetIdentifierOffset(II, Out.tell());
3661 
3662     // Emit the offset of the key/data length information to the interesting
3663     // identifiers table if necessary.
3664     if (InterestingIdentifierOffsets && isInterestingIdentifier(II))
3665       InterestingIdentifierOffsets->push_back(Out.tell() - 4);
3666 
3667     Out.write(II->getNameStart(), KeyLen);
3668   }
3669 
3670   void EmitData(raw_ostream& Out, IdentifierInfo* II,
3671                 IdentID ID, unsigned) {
3672     using namespace llvm::support;
3673 
3674     endian::Writer LE(Out, little);
3675 
3676     auto MacroOffset = Writer.getMacroDirectivesOffset(II);
3677     if (!isInterestingIdentifier(II, MacroOffset)) {
3678       LE.write<uint32_t>(ID << 1);
3679       return;
3680     }
3681 
3682     LE.write<uint32_t>((ID << 1) | 0x01);
3683     uint32_t Bits = (uint32_t)II->getObjCOrBuiltinID();
3684     assert((Bits & 0xffff) == Bits && "ObjCOrBuiltinID too big for ASTReader.");
3685     LE.write<uint16_t>(Bits);
3686     Bits = 0;
3687     bool HadMacroDefinition = MacroOffset != 0;
3688     Bits = (Bits << 1) | unsigned(HadMacroDefinition);
3689     Bits = (Bits << 1) | unsigned(II->isExtensionToken());
3690     Bits = (Bits << 1) | unsigned(II->isPoisoned());
3691     Bits = (Bits << 1) | unsigned(II->hasRevertedBuiltin());
3692     Bits = (Bits << 1) | unsigned(II->hasRevertedTokenIDToIdentifier());
3693     Bits = (Bits << 1) | unsigned(II->isCPlusPlusOperatorKeyword());
3694     LE.write<uint16_t>(Bits);
3695 
3696     if (HadMacroDefinition)
3697       LE.write<uint32_t>(MacroOffset);
3698 
3699     if (NeedDecls) {
3700       // Emit the declaration IDs in reverse order, because the
3701       // IdentifierResolver provides the declarations as they would be
3702       // visible (e.g., the function "stat" would come before the struct
3703       // "stat"), but the ASTReader adds declarations to the end of the list
3704       // (so we need to see the struct "stat" before the function "stat").
3705       // Only emit declarations that aren't from a chained PCH, though.
3706       SmallVector<NamedDecl *, 16> Decls(IdResolver.begin(II),
3707                                          IdResolver.end());
3708       for (SmallVectorImpl<NamedDecl *>::reverse_iterator D = Decls.rbegin(),
3709                                                           DEnd = Decls.rend();
3710            D != DEnd; ++D)
3711         LE.write<uint32_t>(
3712             Writer.getDeclID(getDeclForLocalLookup(PP.getLangOpts(), *D)));
3713     }
3714   }
3715 };
3716 
3717 } // namespace
3718 
3719 /// Write the identifier table into the AST file.
3720 ///
3721 /// The identifier table consists of a blob containing string data
3722 /// (the actual identifiers themselves) and a separate "offsets" index
3723 /// that maps identifier IDs to locations within the blob.
3724 void ASTWriter::WriteIdentifierTable(Preprocessor &PP,
3725                                      IdentifierResolver &IdResolver,
3726                                      bool IsModule) {
3727   using namespace llvm;
3728 
3729   RecordData InterestingIdents;
3730 
3731   // Create and write out the blob that contains the identifier
3732   // strings.
3733   {
3734     llvm::OnDiskChainedHashTableGenerator<ASTIdentifierTableTrait> Generator;
3735     ASTIdentifierTableTrait Trait(
3736         *this, PP, IdResolver, IsModule,
3737         (getLangOpts().CPlusPlus && IsModule) ? &InterestingIdents : nullptr);
3738 
3739     // Look for any identifiers that were named while processing the
3740     // headers, but are otherwise not needed. We add these to the hash
3741     // table to enable checking of the predefines buffer in the case
3742     // where the user adds new macro definitions when building the AST
3743     // file.
3744     SmallVector<const IdentifierInfo *, 128> IIs;
3745     for (const auto &ID : PP.getIdentifierTable())
3746       IIs.push_back(ID.second);
3747     // Sort the identifiers lexicographically before getting them references so
3748     // that their order is stable.
3749     llvm::sort(IIs, llvm::less_ptr<IdentifierInfo>());
3750     for (const IdentifierInfo *II : IIs)
3751       if (Trait.isInterestingNonMacroIdentifier(II))
3752         getIdentifierRef(II);
3753 
3754     // Create the on-disk hash table representation. We only store offsets
3755     // for identifiers that appear here for the first time.
3756     IdentifierOffsets.resize(NextIdentID - FirstIdentID);
3757     for (auto IdentIDPair : IdentifierIDs) {
3758       auto *II = const_cast<IdentifierInfo *>(IdentIDPair.first);
3759       IdentID ID = IdentIDPair.second;
3760       assert(II && "NULL identifier in identifier table");
3761       // Write out identifiers if either the ID is local or the identifier has
3762       // changed since it was loaded.
3763       if (ID >= FirstIdentID || !Chain || !II->isFromAST()
3764           || II->hasChangedSinceDeserialization() ||
3765           (Trait.needDecls() &&
3766            II->hasFETokenInfoChangedSinceDeserialization()))
3767         Generator.insert(II, ID, Trait);
3768     }
3769 
3770     // Create the on-disk hash table in a buffer.
3771     SmallString<4096> IdentifierTable;
3772     uint32_t BucketOffset;
3773     {
3774       using namespace llvm::support;
3775 
3776       llvm::raw_svector_ostream Out(IdentifierTable);
3777       // Make sure that no bucket is at offset 0
3778       endian::write<uint32_t>(Out, 0, little);
3779       BucketOffset = Generator.Emit(Out, Trait);
3780     }
3781 
3782     // Create a blob abbreviation
3783     auto Abbrev = std::make_shared<BitCodeAbbrev>();
3784     Abbrev->Add(BitCodeAbbrevOp(IDENTIFIER_TABLE));
3785     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
3786     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
3787     unsigned IDTableAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
3788 
3789     // Write the identifier table
3790     RecordData::value_type Record[] = {IDENTIFIER_TABLE, BucketOffset};
3791     Stream.EmitRecordWithBlob(IDTableAbbrev, Record, IdentifierTable);
3792   }
3793 
3794   // Write the offsets table for identifier IDs.
3795   auto Abbrev = std::make_shared<BitCodeAbbrev>();
3796   Abbrev->Add(BitCodeAbbrevOp(IDENTIFIER_OFFSET));
3797   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // # of identifiers
3798   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // first ID
3799   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
3800   unsigned IdentifierOffsetAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
3801 
3802 #ifndef NDEBUG
3803   for (unsigned I = 0, N = IdentifierOffsets.size(); I != N; ++I)
3804     assert(IdentifierOffsets[I] && "Missing identifier offset?");
3805 #endif
3806 
3807   RecordData::value_type Record[] = {IDENTIFIER_OFFSET,
3808                                      IdentifierOffsets.size(),
3809                                      FirstIdentID - NUM_PREDEF_IDENT_IDS};
3810   Stream.EmitRecordWithBlob(IdentifierOffsetAbbrev, Record,
3811                             bytes(IdentifierOffsets));
3812 
3813   // In C++, write the list of interesting identifiers (those that are
3814   // defined as macros, poisoned, or similar unusual things).
3815   if (!InterestingIdents.empty())
3816     Stream.EmitRecord(INTERESTING_IDENTIFIERS, InterestingIdents);
3817 }
3818 
3819 //===----------------------------------------------------------------------===//
3820 // DeclContext's Name Lookup Table Serialization
3821 //===----------------------------------------------------------------------===//
3822 
3823 namespace {
3824 
3825 // Trait used for the on-disk hash table used in the method pool.
3826 class ASTDeclContextNameLookupTrait {
3827   ASTWriter &Writer;
3828   llvm::SmallVector<DeclID, 64> DeclIDs;
3829 
3830 public:
3831   using key_type = DeclarationNameKey;
3832   using key_type_ref = key_type;
3833 
3834   /// A start and end index into DeclIDs, representing a sequence of decls.
3835   using data_type = std::pair<unsigned, unsigned>;
3836   using data_type_ref = const data_type &;
3837 
3838   using hash_value_type = unsigned;
3839   using offset_type = unsigned;
3840 
3841   explicit ASTDeclContextNameLookupTrait(ASTWriter &Writer) : Writer(Writer) {}
3842 
3843   template<typename Coll>
3844   data_type getData(const Coll &Decls) {
3845     unsigned Start = DeclIDs.size();
3846     for (NamedDecl *D : Decls) {
3847       DeclIDs.push_back(
3848           Writer.GetDeclRef(getDeclForLocalLookup(Writer.getLangOpts(), D)));
3849     }
3850     return std::make_pair(Start, DeclIDs.size());
3851   }
3852 
3853   data_type ImportData(const reader::ASTDeclContextNameLookupTrait::data_type &FromReader) {
3854     unsigned Start = DeclIDs.size();
3855     for (auto ID : FromReader)
3856       DeclIDs.push_back(ID);
3857     return std::make_pair(Start, DeclIDs.size());
3858   }
3859 
3860   static bool EqualKey(key_type_ref a, key_type_ref b) {
3861     return a == b;
3862   }
3863 
3864   hash_value_type ComputeHash(DeclarationNameKey Name) {
3865     return Name.getHash();
3866   }
3867 
3868   void EmitFileRef(raw_ostream &Out, ModuleFile *F) const {
3869     assert(Writer.hasChain() &&
3870            "have reference to loaded module file but no chain?");
3871 
3872     using namespace llvm::support;
3873 
3874     endian::write<uint32_t>(Out, Writer.getChain()->getModuleFileID(F), little);
3875   }
3876 
3877   std::pair<unsigned, unsigned> EmitKeyDataLength(raw_ostream &Out,
3878                                                   DeclarationNameKey Name,
3879                                                   data_type_ref Lookup) {
3880     using namespace llvm::support;
3881 
3882     endian::Writer LE(Out, little);
3883     unsigned KeyLen = 1;
3884     switch (Name.getKind()) {
3885     case DeclarationName::Identifier:
3886     case DeclarationName::ObjCZeroArgSelector:
3887     case DeclarationName::ObjCOneArgSelector:
3888     case DeclarationName::ObjCMultiArgSelector:
3889     case DeclarationName::CXXLiteralOperatorName:
3890     case DeclarationName::CXXDeductionGuideName:
3891       KeyLen += 4;
3892       break;
3893     case DeclarationName::CXXOperatorName:
3894       KeyLen += 1;
3895       break;
3896     case DeclarationName::CXXConstructorName:
3897     case DeclarationName::CXXDestructorName:
3898     case DeclarationName::CXXConversionFunctionName:
3899     case DeclarationName::CXXUsingDirective:
3900       break;
3901     }
3902     LE.write<uint16_t>(KeyLen);
3903 
3904     // 4 bytes for each DeclID.
3905     unsigned DataLen = 4 * (Lookup.second - Lookup.first);
3906     assert(uint16_t(DataLen) == DataLen &&
3907            "too many decls for serialized lookup result");
3908     LE.write<uint16_t>(DataLen);
3909 
3910     return std::make_pair(KeyLen, DataLen);
3911   }
3912 
3913   void EmitKey(raw_ostream &Out, DeclarationNameKey Name, unsigned) {
3914     using namespace llvm::support;
3915 
3916     endian::Writer LE(Out, little);
3917     LE.write<uint8_t>(Name.getKind());
3918     switch (Name.getKind()) {
3919     case DeclarationName::Identifier:
3920     case DeclarationName::CXXLiteralOperatorName:
3921     case DeclarationName::CXXDeductionGuideName:
3922       LE.write<uint32_t>(Writer.getIdentifierRef(Name.getIdentifier()));
3923       return;
3924     case DeclarationName::ObjCZeroArgSelector:
3925     case DeclarationName::ObjCOneArgSelector:
3926     case DeclarationName::ObjCMultiArgSelector:
3927       LE.write<uint32_t>(Writer.getSelectorRef(Name.getSelector()));
3928       return;
3929     case DeclarationName::CXXOperatorName:
3930       assert(Name.getOperatorKind() < NUM_OVERLOADED_OPERATORS &&
3931              "Invalid operator?");
3932       LE.write<uint8_t>(Name.getOperatorKind());
3933       return;
3934     case DeclarationName::CXXConstructorName:
3935     case DeclarationName::CXXDestructorName:
3936     case DeclarationName::CXXConversionFunctionName:
3937     case DeclarationName::CXXUsingDirective:
3938       return;
3939     }
3940 
3941     llvm_unreachable("Invalid name kind?");
3942   }
3943 
3944   void EmitData(raw_ostream &Out, key_type_ref, data_type Lookup,
3945                 unsigned DataLen) {
3946     using namespace llvm::support;
3947 
3948     endian::Writer LE(Out, little);
3949     uint64_t Start = Out.tell(); (void)Start;
3950     for (unsigned I = Lookup.first, N = Lookup.second; I != N; ++I)
3951       LE.write<uint32_t>(DeclIDs[I]);
3952     assert(Out.tell() - Start == DataLen && "Data length is wrong");
3953   }
3954 };
3955 
3956 } // namespace
3957 
3958 bool ASTWriter::isLookupResultExternal(StoredDeclsList &Result,
3959                                        DeclContext *DC) {
3960   return Result.hasExternalDecls() &&
3961          DC->hasNeedToReconcileExternalVisibleStorage();
3962 }
3963 
3964 bool ASTWriter::isLookupResultEntirelyExternal(StoredDeclsList &Result,
3965                                                DeclContext *DC) {
3966   for (auto *D : Result.getLookupResult())
3967     if (!getDeclForLocalLookup(getLangOpts(), D)->isFromASTFile())
3968       return false;
3969 
3970   return true;
3971 }
3972 
3973 void
3974 ASTWriter::GenerateNameLookupTable(const DeclContext *ConstDC,
3975                                    llvm::SmallVectorImpl<char> &LookupTable) {
3976   assert(!ConstDC->hasLazyLocalLexicalLookups() &&
3977          !ConstDC->hasLazyExternalLexicalLookups() &&
3978          "must call buildLookups first");
3979 
3980   // FIXME: We need to build the lookups table, which is logically const.
3981   auto *DC = const_cast<DeclContext*>(ConstDC);
3982   assert(DC == DC->getPrimaryContext() && "only primary DC has lookup table");
3983 
3984   // Create the on-disk hash table representation.
3985   MultiOnDiskHashTableGenerator<reader::ASTDeclContextNameLookupTrait,
3986                                 ASTDeclContextNameLookupTrait> Generator;
3987   ASTDeclContextNameLookupTrait Trait(*this);
3988 
3989   // The first step is to collect the declaration names which we need to
3990   // serialize into the name lookup table, and to collect them in a stable
3991   // order.
3992   SmallVector<DeclarationName, 16> Names;
3993 
3994   // We also build up small sets of the constructor and conversion function
3995   // names which are visible.
3996   llvm::SmallSet<DeclarationName, 8> ConstructorNameSet, ConversionNameSet;
3997 
3998   for (auto &Lookup : *DC->buildLookup()) {
3999     auto &Name = Lookup.first;
4000     auto &Result = Lookup.second;
4001 
4002     // If there are no local declarations in our lookup result, we
4003     // don't need to write an entry for the name at all. If we can't
4004     // write out a lookup set without performing more deserialization,
4005     // just skip this entry.
4006     if (isLookupResultExternal(Result, DC) &&
4007         isLookupResultEntirelyExternal(Result, DC))
4008       continue;
4009 
4010     // We also skip empty results. If any of the results could be external and
4011     // the currently available results are empty, then all of the results are
4012     // external and we skip it above. So the only way we get here with an empty
4013     // results is when no results could have been external *and* we have
4014     // external results.
4015     //
4016     // FIXME: While we might want to start emitting on-disk entries for negative
4017     // lookups into a decl context as an optimization, today we *have* to skip
4018     // them because there are names with empty lookup results in decl contexts
4019     // which we can't emit in any stable ordering: we lookup constructors and
4020     // conversion functions in the enclosing namespace scope creating empty
4021     // results for them. This in almost certainly a bug in Clang's name lookup,
4022     // but that is likely to be hard or impossible to fix and so we tolerate it
4023     // here by omitting lookups with empty results.
4024     if (Lookup.second.getLookupResult().empty())
4025       continue;
4026 
4027     switch (Lookup.first.getNameKind()) {
4028     default:
4029       Names.push_back(Lookup.first);
4030       break;
4031 
4032     case DeclarationName::CXXConstructorName:
4033       assert(isa<CXXRecordDecl>(DC) &&
4034              "Cannot have a constructor name outside of a class!");
4035       ConstructorNameSet.insert(Name);
4036       break;
4037 
4038     case DeclarationName::CXXConversionFunctionName:
4039       assert(isa<CXXRecordDecl>(DC) &&
4040              "Cannot have a conversion function name outside of a class!");
4041       ConversionNameSet.insert(Name);
4042       break;
4043     }
4044   }
4045 
4046   // Sort the names into a stable order.
4047   llvm::sort(Names);
4048 
4049   if (auto *D = dyn_cast<CXXRecordDecl>(DC)) {
4050     // We need to establish an ordering of constructor and conversion function
4051     // names, and they don't have an intrinsic ordering.
4052 
4053     // First we try the easy case by forming the current context's constructor
4054     // name and adding that name first. This is a very useful optimization to
4055     // avoid walking the lexical declarations in many cases, and it also
4056     // handles the only case where a constructor name can come from some other
4057     // lexical context -- when that name is an implicit constructor merged from
4058     // another declaration in the redecl chain. Any non-implicit constructor or
4059     // conversion function which doesn't occur in all the lexical contexts
4060     // would be an ODR violation.
4061     auto ImplicitCtorName = Context->DeclarationNames.getCXXConstructorName(
4062         Context->getCanonicalType(Context->getRecordType(D)));
4063     if (ConstructorNameSet.erase(ImplicitCtorName))
4064       Names.push_back(ImplicitCtorName);
4065 
4066     // If we still have constructors or conversion functions, we walk all the
4067     // names in the decl and add the constructors and conversion functions
4068     // which are visible in the order they lexically occur within the context.
4069     if (!ConstructorNameSet.empty() || !ConversionNameSet.empty())
4070       for (Decl *ChildD : cast<CXXRecordDecl>(DC)->decls())
4071         if (auto *ChildND = dyn_cast<NamedDecl>(ChildD)) {
4072           auto Name = ChildND->getDeclName();
4073           switch (Name.getNameKind()) {
4074           default:
4075             continue;
4076 
4077           case DeclarationName::CXXConstructorName:
4078             if (ConstructorNameSet.erase(Name))
4079               Names.push_back(Name);
4080             break;
4081 
4082           case DeclarationName::CXXConversionFunctionName:
4083             if (ConversionNameSet.erase(Name))
4084               Names.push_back(Name);
4085             break;
4086           }
4087 
4088           if (ConstructorNameSet.empty() && ConversionNameSet.empty())
4089             break;
4090         }
4091 
4092     assert(ConstructorNameSet.empty() && "Failed to find all of the visible "
4093                                          "constructors by walking all the "
4094                                          "lexical members of the context.");
4095     assert(ConversionNameSet.empty() && "Failed to find all of the visible "
4096                                         "conversion functions by walking all "
4097                                         "the lexical members of the context.");
4098   }
4099 
4100   // Next we need to do a lookup with each name into this decl context to fully
4101   // populate any results from external sources. We don't actually use the
4102   // results of these lookups because we only want to use the results after all
4103   // results have been loaded and the pointers into them will be stable.
4104   for (auto &Name : Names)
4105     DC->lookup(Name);
4106 
4107   // Now we need to insert the results for each name into the hash table. For
4108   // constructor names and conversion function names, we actually need to merge
4109   // all of the results for them into one list of results each and insert
4110   // those.
4111   SmallVector<NamedDecl *, 8> ConstructorDecls;
4112   SmallVector<NamedDecl *, 8> ConversionDecls;
4113 
4114   // Now loop over the names, either inserting them or appending for the two
4115   // special cases.
4116   for (auto &Name : Names) {
4117     DeclContext::lookup_result Result = DC->noload_lookup(Name);
4118 
4119     switch (Name.getNameKind()) {
4120     default:
4121       Generator.insert(Name, Trait.getData(Result), Trait);
4122       break;
4123 
4124     case DeclarationName::CXXConstructorName:
4125       ConstructorDecls.append(Result.begin(), Result.end());
4126       break;
4127 
4128     case DeclarationName::CXXConversionFunctionName:
4129       ConversionDecls.append(Result.begin(), Result.end());
4130       break;
4131     }
4132   }
4133 
4134   // Handle our two special cases if we ended up having any. We arbitrarily use
4135   // the first declaration's name here because the name itself isn't part of
4136   // the key, only the kind of name is used.
4137   if (!ConstructorDecls.empty())
4138     Generator.insert(ConstructorDecls.front()->getDeclName(),
4139                      Trait.getData(ConstructorDecls), Trait);
4140   if (!ConversionDecls.empty())
4141     Generator.insert(ConversionDecls.front()->getDeclName(),
4142                      Trait.getData(ConversionDecls), Trait);
4143 
4144   // Create the on-disk hash table. Also emit the existing imported and
4145   // merged table if there is one.
4146   auto *Lookups = Chain ? Chain->getLoadedLookupTables(DC) : nullptr;
4147   Generator.emit(LookupTable, Trait, Lookups ? &Lookups->Table : nullptr);
4148 }
4149 
4150 /// Write the block containing all of the declaration IDs
4151 /// visible from the given DeclContext.
4152 ///
4153 /// \returns the offset of the DECL_CONTEXT_VISIBLE block within the
4154 /// bitstream, or 0 if no block was written.
4155 uint64_t ASTWriter::WriteDeclContextVisibleBlock(ASTContext &Context,
4156                                                  DeclContext *DC) {
4157   // If we imported a key declaration of this namespace, write the visible
4158   // lookup results as an update record for it rather than including them
4159   // on this declaration. We will only look at key declarations on reload.
4160   if (isa<NamespaceDecl>(DC) && Chain &&
4161       Chain->getKeyDeclaration(cast<Decl>(DC))->isFromASTFile()) {
4162     // Only do this once, for the first local declaration of the namespace.
4163     for (auto *Prev = cast<NamespaceDecl>(DC)->getPreviousDecl(); Prev;
4164          Prev = Prev->getPreviousDecl())
4165       if (!Prev->isFromASTFile())
4166         return 0;
4167 
4168     // Note that we need to emit an update record for the primary context.
4169     UpdatedDeclContexts.insert(DC->getPrimaryContext());
4170 
4171     // Make sure all visible decls are written. They will be recorded later. We
4172     // do this using a side data structure so we can sort the names into
4173     // a deterministic order.
4174     StoredDeclsMap *Map = DC->getPrimaryContext()->buildLookup();
4175     SmallVector<std::pair<DeclarationName, DeclContext::lookup_result>, 16>
4176         LookupResults;
4177     if (Map) {
4178       LookupResults.reserve(Map->size());
4179       for (auto &Entry : *Map)
4180         LookupResults.push_back(
4181             std::make_pair(Entry.first, Entry.second.getLookupResult()));
4182     }
4183 
4184     llvm::sort(LookupResults, llvm::less_first());
4185     for (auto &NameAndResult : LookupResults) {
4186       DeclarationName Name = NameAndResult.first;
4187       DeclContext::lookup_result Result = NameAndResult.second;
4188       if (Name.getNameKind() == DeclarationName::CXXConstructorName ||
4189           Name.getNameKind() == DeclarationName::CXXConversionFunctionName) {
4190         // We have to work around a name lookup bug here where negative lookup
4191         // results for these names get cached in namespace lookup tables (these
4192         // names should never be looked up in a namespace).
4193         assert(Result.empty() && "Cannot have a constructor or conversion "
4194                                  "function name in a namespace!");
4195         continue;
4196       }
4197 
4198       for (NamedDecl *ND : Result)
4199         if (!ND->isFromASTFile())
4200           GetDeclRef(ND);
4201     }
4202 
4203     return 0;
4204   }
4205 
4206   if (DC->getPrimaryContext() != DC)
4207     return 0;
4208 
4209   // Skip contexts which don't support name lookup.
4210   if (!DC->isLookupContext())
4211     return 0;
4212 
4213   // If not in C++, we perform name lookup for the translation unit via the
4214   // IdentifierInfo chains, don't bother to build a visible-declarations table.
4215   if (DC->isTranslationUnit() && !Context.getLangOpts().CPlusPlus)
4216     return 0;
4217 
4218   // Serialize the contents of the mapping used for lookup. Note that,
4219   // although we have two very different code paths, the serialized
4220   // representation is the same for both cases: a declaration name,
4221   // followed by a size, followed by references to the visible
4222   // declarations that have that name.
4223   uint64_t Offset = Stream.GetCurrentBitNo();
4224   StoredDeclsMap *Map = DC->buildLookup();
4225   if (!Map || Map->empty())
4226     return 0;
4227 
4228   // Create the on-disk hash table in a buffer.
4229   SmallString<4096> LookupTable;
4230   GenerateNameLookupTable(DC, LookupTable);
4231 
4232   // Write the lookup table
4233   RecordData::value_type Record[] = {DECL_CONTEXT_VISIBLE};
4234   Stream.EmitRecordWithBlob(DeclContextVisibleLookupAbbrev, Record,
4235                             LookupTable);
4236   ++NumVisibleDeclContexts;
4237   return Offset;
4238 }
4239 
4240 /// Write an UPDATE_VISIBLE block for the given context.
4241 ///
4242 /// UPDATE_VISIBLE blocks contain the declarations that are added to an existing
4243 /// DeclContext in a dependent AST file. As such, they only exist for the TU
4244 /// (in C++), for namespaces, and for classes with forward-declared unscoped
4245 /// enumeration members (in C++11).
4246 void ASTWriter::WriteDeclContextVisibleUpdate(const DeclContext *DC) {
4247   StoredDeclsMap *Map = DC->getLookupPtr();
4248   if (!Map || Map->empty())
4249     return;
4250 
4251   // Create the on-disk hash table in a buffer.
4252   SmallString<4096> LookupTable;
4253   GenerateNameLookupTable(DC, LookupTable);
4254 
4255   // If we're updating a namespace, select a key declaration as the key for the
4256   // update record; those are the only ones that will be checked on reload.
4257   if (isa<NamespaceDecl>(DC))
4258     DC = cast<DeclContext>(Chain->getKeyDeclaration(cast<Decl>(DC)));
4259 
4260   // Write the lookup table
4261   RecordData::value_type Record[] = {UPDATE_VISIBLE, getDeclID(cast<Decl>(DC))};
4262   Stream.EmitRecordWithBlob(UpdateVisibleAbbrev, Record, LookupTable);
4263 }
4264 
4265 /// Write an FP_PRAGMA_OPTIONS block for the given FPOptions.
4266 void ASTWriter::WriteFPPragmaOptions(const FPOptions &Opts) {
4267   RecordData::value_type Record[] = {Opts.getInt()};
4268   Stream.EmitRecord(FP_PRAGMA_OPTIONS, Record);
4269 }
4270 
4271 /// Write an OPENCL_EXTENSIONS block for the given OpenCLOptions.
4272 void ASTWriter::WriteOpenCLExtensions(Sema &SemaRef) {
4273   if (!SemaRef.Context.getLangOpts().OpenCL)
4274     return;
4275 
4276   const OpenCLOptions &Opts = SemaRef.getOpenCLOptions();
4277   RecordData Record;
4278   for (const auto &I:Opts.OptMap) {
4279     AddString(I.getKey(), Record);
4280     auto V = I.getValue();
4281     Record.push_back(V.Supported ? 1 : 0);
4282     Record.push_back(V.Enabled ? 1 : 0);
4283     Record.push_back(V.Avail);
4284     Record.push_back(V.Core);
4285   }
4286   Stream.EmitRecord(OPENCL_EXTENSIONS, Record);
4287 }
4288 
4289 void ASTWriter::WriteOpenCLExtensionTypes(Sema &SemaRef) {
4290   if (!SemaRef.Context.getLangOpts().OpenCL)
4291     return;
4292 
4293   // Sort the elements of the map OpenCLTypeExtMap by TypeIDs,
4294   // without copying them.
4295   const llvm::DenseMap<const Type *, std::set<std::string>> &OpenCLTypeExtMap =
4296       SemaRef.OpenCLTypeExtMap;
4297   using ElementTy = std::pair<TypeID, const std::set<std::string> *>;
4298   llvm::SmallVector<ElementTy, 8> StableOpenCLTypeExtMap;
4299   StableOpenCLTypeExtMap.reserve(OpenCLTypeExtMap.size());
4300 
4301   for (const auto &I : OpenCLTypeExtMap)
4302     StableOpenCLTypeExtMap.emplace_back(
4303         getTypeID(I.first->getCanonicalTypeInternal()), &I.second);
4304 
4305   auto CompareByTypeID = [](const ElementTy &E1, const ElementTy &E2) -> bool {
4306     return E1.first < E2.first;
4307   };
4308   llvm::sort(StableOpenCLTypeExtMap, CompareByTypeID);
4309 
4310   RecordData Record;
4311   for (const ElementTy &E : StableOpenCLTypeExtMap) {
4312     Record.push_back(E.first); // TypeID
4313     const std::set<std::string> *ExtSet = E.second;
4314     Record.push_back(static_cast<unsigned>(ExtSet->size()));
4315     for (const std::string &Ext : *ExtSet)
4316       AddString(Ext, Record);
4317   }
4318 
4319   Stream.EmitRecord(OPENCL_EXTENSION_TYPES, Record);
4320 }
4321 
4322 void ASTWriter::WriteOpenCLExtensionDecls(Sema &SemaRef) {
4323   if (!SemaRef.Context.getLangOpts().OpenCL)
4324     return;
4325 
4326   // Sort the elements of the map OpenCLDeclExtMap by DeclIDs,
4327   // without copying them.
4328   const llvm::DenseMap<const Decl *, std::set<std::string>> &OpenCLDeclExtMap =
4329       SemaRef.OpenCLDeclExtMap;
4330   using ElementTy = std::pair<DeclID, const std::set<std::string> *>;
4331   llvm::SmallVector<ElementTy, 8> StableOpenCLDeclExtMap;
4332   StableOpenCLDeclExtMap.reserve(OpenCLDeclExtMap.size());
4333 
4334   for (const auto &I : OpenCLDeclExtMap)
4335     StableOpenCLDeclExtMap.emplace_back(getDeclID(I.first), &I.second);
4336 
4337   auto CompareByDeclID = [](const ElementTy &E1, const ElementTy &E2) -> bool {
4338     return E1.first < E2.first;
4339   };
4340   llvm::sort(StableOpenCLDeclExtMap, CompareByDeclID);
4341 
4342   RecordData Record;
4343   for (const ElementTy &E : StableOpenCLDeclExtMap) {
4344     Record.push_back(E.first); // DeclID
4345     const std::set<std::string> *ExtSet = E.second;
4346     Record.push_back(static_cast<unsigned>(ExtSet->size()));
4347     for (const std::string &Ext : *ExtSet)
4348       AddString(Ext, Record);
4349   }
4350 
4351   Stream.EmitRecord(OPENCL_EXTENSION_DECLS, Record);
4352 }
4353 
4354 void ASTWriter::WriteCUDAPragmas(Sema &SemaRef) {
4355   if (SemaRef.ForceCUDAHostDeviceDepth > 0) {
4356     RecordData::value_type Record[] = {SemaRef.ForceCUDAHostDeviceDepth};
4357     Stream.EmitRecord(CUDA_PRAGMA_FORCE_HOST_DEVICE_DEPTH, Record);
4358   }
4359 }
4360 
4361 void ASTWriter::WriteObjCCategories() {
4362   SmallVector<ObjCCategoriesInfo, 2> CategoriesMap;
4363   RecordData Categories;
4364 
4365   for (unsigned I = 0, N = ObjCClassesWithCategories.size(); I != N; ++I) {
4366     unsigned Size = 0;
4367     unsigned StartIndex = Categories.size();
4368 
4369     ObjCInterfaceDecl *Class = ObjCClassesWithCategories[I];
4370 
4371     // Allocate space for the size.
4372     Categories.push_back(0);
4373 
4374     // Add the categories.
4375     for (ObjCInterfaceDecl::known_categories_iterator
4376            Cat = Class->known_categories_begin(),
4377            CatEnd = Class->known_categories_end();
4378          Cat != CatEnd; ++Cat, ++Size) {
4379       assert(getDeclID(*Cat) != 0 && "Bogus category");
4380       AddDeclRef(*Cat, Categories);
4381     }
4382 
4383     // Update the size.
4384     Categories[StartIndex] = Size;
4385 
4386     // Record this interface -> category map.
4387     ObjCCategoriesInfo CatInfo = { getDeclID(Class), StartIndex };
4388     CategoriesMap.push_back(CatInfo);
4389   }
4390 
4391   // Sort the categories map by the definition ID, since the reader will be
4392   // performing binary searches on this information.
4393   llvm::array_pod_sort(CategoriesMap.begin(), CategoriesMap.end());
4394 
4395   // Emit the categories map.
4396   using namespace llvm;
4397 
4398   auto Abbrev = std::make_shared<BitCodeAbbrev>();
4399   Abbrev->Add(BitCodeAbbrevOp(OBJC_CATEGORIES_MAP));
4400   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // # of entries
4401   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
4402   unsigned AbbrevID = Stream.EmitAbbrev(std::move(Abbrev));
4403 
4404   RecordData::value_type Record[] = {OBJC_CATEGORIES_MAP, CategoriesMap.size()};
4405   Stream.EmitRecordWithBlob(AbbrevID, Record,
4406                             reinterpret_cast<char *>(CategoriesMap.data()),
4407                             CategoriesMap.size() * sizeof(ObjCCategoriesInfo));
4408 
4409   // Emit the category lists.
4410   Stream.EmitRecord(OBJC_CATEGORIES, Categories);
4411 }
4412 
4413 void ASTWriter::WriteLateParsedTemplates(Sema &SemaRef) {
4414   Sema::LateParsedTemplateMapT &LPTMap = SemaRef.LateParsedTemplateMap;
4415 
4416   if (LPTMap.empty())
4417     return;
4418 
4419   RecordData Record;
4420   for (auto &LPTMapEntry : LPTMap) {
4421     const FunctionDecl *FD = LPTMapEntry.first;
4422     LateParsedTemplate &LPT = *LPTMapEntry.second;
4423     AddDeclRef(FD, Record);
4424     AddDeclRef(LPT.D, Record);
4425     Record.push_back(LPT.Toks.size());
4426 
4427     for (const auto &Tok : LPT.Toks) {
4428       AddToken(Tok, Record);
4429     }
4430   }
4431   Stream.EmitRecord(LATE_PARSED_TEMPLATE, Record);
4432 }
4433 
4434 /// Write the state of 'pragma clang optimize' at the end of the module.
4435 void ASTWriter::WriteOptimizePragmaOptions(Sema &SemaRef) {
4436   RecordData Record;
4437   SourceLocation PragmaLoc = SemaRef.getOptimizeOffPragmaLocation();
4438   AddSourceLocation(PragmaLoc, Record);
4439   Stream.EmitRecord(OPTIMIZE_PRAGMA_OPTIONS, Record);
4440 }
4441 
4442 /// Write the state of 'pragma ms_struct' at the end of the module.
4443 void ASTWriter::WriteMSStructPragmaOptions(Sema &SemaRef) {
4444   RecordData Record;
4445   Record.push_back(SemaRef.MSStructPragmaOn ? PMSST_ON : PMSST_OFF);
4446   Stream.EmitRecord(MSSTRUCT_PRAGMA_OPTIONS, Record);
4447 }
4448 
4449 /// Write the state of 'pragma pointers_to_members' at the end of the
4450 //module.
4451 void ASTWriter::WriteMSPointersToMembersPragmaOptions(Sema &SemaRef) {
4452   RecordData Record;
4453   Record.push_back(SemaRef.MSPointerToMemberRepresentationMethod);
4454   AddSourceLocation(SemaRef.ImplicitMSInheritanceAttrLoc, Record);
4455   Stream.EmitRecord(POINTERS_TO_MEMBERS_PRAGMA_OPTIONS, Record);
4456 }
4457 
4458 /// Write the state of 'pragma pack' at the end of the module.
4459 void ASTWriter::WritePackPragmaOptions(Sema &SemaRef) {
4460   // Don't serialize pragma pack state for modules, since it should only take
4461   // effect on a per-submodule basis.
4462   if (WritingModule)
4463     return;
4464 
4465   RecordData Record;
4466   Record.push_back(SemaRef.PackStack.CurrentValue);
4467   AddSourceLocation(SemaRef.PackStack.CurrentPragmaLocation, Record);
4468   Record.push_back(SemaRef.PackStack.Stack.size());
4469   for (const auto &StackEntry : SemaRef.PackStack.Stack) {
4470     Record.push_back(StackEntry.Value);
4471     AddSourceLocation(StackEntry.PragmaLocation, Record);
4472     AddSourceLocation(StackEntry.PragmaPushLocation, Record);
4473     AddString(StackEntry.StackSlotLabel, Record);
4474   }
4475   Stream.EmitRecord(PACK_PRAGMA_OPTIONS, Record);
4476 }
4477 
4478 void ASTWriter::WriteModuleFileExtension(Sema &SemaRef,
4479                                          ModuleFileExtensionWriter &Writer) {
4480   // Enter the extension block.
4481   Stream.EnterSubblock(EXTENSION_BLOCK_ID, 4);
4482 
4483   // Emit the metadata record abbreviation.
4484   auto Abv = std::make_shared<llvm::BitCodeAbbrev>();
4485   Abv->Add(llvm::BitCodeAbbrevOp(EXTENSION_METADATA));
4486   Abv->Add(llvm::BitCodeAbbrevOp(llvm::BitCodeAbbrevOp::VBR, 6));
4487   Abv->Add(llvm::BitCodeAbbrevOp(llvm::BitCodeAbbrevOp::VBR, 6));
4488   Abv->Add(llvm::BitCodeAbbrevOp(llvm::BitCodeAbbrevOp::VBR, 6));
4489   Abv->Add(llvm::BitCodeAbbrevOp(llvm::BitCodeAbbrevOp::VBR, 6));
4490   Abv->Add(llvm::BitCodeAbbrevOp(llvm::BitCodeAbbrevOp::Blob));
4491   unsigned Abbrev = Stream.EmitAbbrev(std::move(Abv));
4492 
4493   // Emit the metadata record.
4494   RecordData Record;
4495   auto Metadata = Writer.getExtension()->getExtensionMetadata();
4496   Record.push_back(EXTENSION_METADATA);
4497   Record.push_back(Metadata.MajorVersion);
4498   Record.push_back(Metadata.MinorVersion);
4499   Record.push_back(Metadata.BlockName.size());
4500   Record.push_back(Metadata.UserInfo.size());
4501   SmallString<64> Buffer;
4502   Buffer += Metadata.BlockName;
4503   Buffer += Metadata.UserInfo;
4504   Stream.EmitRecordWithBlob(Abbrev, Record, Buffer);
4505 
4506   // Emit the contents of the extension block.
4507   Writer.writeExtensionContents(SemaRef, Stream);
4508 
4509   // Exit the extension block.
4510   Stream.ExitBlock();
4511 }
4512 
4513 //===----------------------------------------------------------------------===//
4514 // General Serialization Routines
4515 //===----------------------------------------------------------------------===//
4516 
4517 void ASTRecordWriter::AddAttr(const Attr *A) {
4518   auto &Record = *this;
4519   if (!A)
4520     return Record.push_back(0);
4521   Record.push_back(A->getKind() + 1); // FIXME: stable encoding, target attrs
4522   Record.AddSourceRange(A->getRange());
4523 
4524 #include "clang/Serialization/AttrPCHWrite.inc"
4525 }
4526 
4527 /// Emit the list of attributes to the specified record.
4528 void ASTRecordWriter::AddAttributes(ArrayRef<const Attr *> Attrs) {
4529   push_back(Attrs.size());
4530   for (const auto *A : Attrs)
4531     AddAttr(A);
4532 }
4533 
4534 void ASTWriter::AddToken(const Token &Tok, RecordDataImpl &Record) {
4535   AddSourceLocation(Tok.getLocation(), Record);
4536   Record.push_back(Tok.getLength());
4537 
4538   // FIXME: When reading literal tokens, reconstruct the literal pointer
4539   // if it is needed.
4540   AddIdentifierRef(Tok.getIdentifierInfo(), Record);
4541   // FIXME: Should translate token kind to a stable encoding.
4542   Record.push_back(Tok.getKind());
4543   // FIXME: Should translate token flags to a stable encoding.
4544   Record.push_back(Tok.getFlags());
4545 }
4546 
4547 void ASTWriter::AddString(StringRef Str, RecordDataImpl &Record) {
4548   Record.push_back(Str.size());
4549   Record.insert(Record.end(), Str.begin(), Str.end());
4550 }
4551 
4552 bool ASTWriter::PreparePathForOutput(SmallVectorImpl<char> &Path) {
4553   assert(Context && "should have context when outputting path");
4554 
4555   bool Changed =
4556       cleanPathForOutput(Context->getSourceManager().getFileManager(), Path);
4557 
4558   // Remove a prefix to make the path relative, if relevant.
4559   const char *PathBegin = Path.data();
4560   const char *PathPtr =
4561       adjustFilenameForRelocatableAST(PathBegin, BaseDirectory);
4562   if (PathPtr != PathBegin) {
4563     Path.erase(Path.begin(), Path.begin() + (PathPtr - PathBegin));
4564     Changed = true;
4565   }
4566 
4567   return Changed;
4568 }
4569 
4570 void ASTWriter::AddPath(StringRef Path, RecordDataImpl &Record) {
4571   SmallString<128> FilePath(Path);
4572   PreparePathForOutput(FilePath);
4573   AddString(FilePath, Record);
4574 }
4575 
4576 void ASTWriter::EmitRecordWithPath(unsigned Abbrev, RecordDataRef Record,
4577                                    StringRef Path) {
4578   SmallString<128> FilePath(Path);
4579   PreparePathForOutput(FilePath);
4580   Stream.EmitRecordWithBlob(Abbrev, Record, FilePath);
4581 }
4582 
4583 void ASTWriter::AddVersionTuple(const VersionTuple &Version,
4584                                 RecordDataImpl &Record) {
4585   Record.push_back(Version.getMajor());
4586   if (Optional<unsigned> Minor = Version.getMinor())
4587     Record.push_back(*Minor + 1);
4588   else
4589     Record.push_back(0);
4590   if (Optional<unsigned> Subminor = Version.getSubminor())
4591     Record.push_back(*Subminor + 1);
4592   else
4593     Record.push_back(0);
4594 }
4595 
4596 /// Note that the identifier II occurs at the given offset
4597 /// within the identifier table.
4598 void ASTWriter::SetIdentifierOffset(const IdentifierInfo *II, uint32_t Offset) {
4599   IdentID ID = IdentifierIDs[II];
4600   // Only store offsets new to this AST file. Other identifier names are looked
4601   // up earlier in the chain and thus don't need an offset.
4602   if (ID >= FirstIdentID)
4603     IdentifierOffsets[ID - FirstIdentID] = Offset;
4604 }
4605 
4606 /// Note that the selector Sel occurs at the given offset
4607 /// within the method pool/selector table.
4608 void ASTWriter::SetSelectorOffset(Selector Sel, uint32_t Offset) {
4609   unsigned ID = SelectorIDs[Sel];
4610   assert(ID && "Unknown selector");
4611   // Don't record offsets for selectors that are also available in a different
4612   // file.
4613   if (ID < FirstSelectorID)
4614     return;
4615   SelectorOffsets[ID - FirstSelectorID] = Offset;
4616 }
4617 
4618 ASTWriter::ASTWriter(llvm::BitstreamWriter &Stream,
4619                      SmallVectorImpl<char> &Buffer,
4620                      InMemoryModuleCache &ModuleCache,
4621                      ArrayRef<std::shared_ptr<ModuleFileExtension>> Extensions,
4622                      bool IncludeTimestamps)
4623     : Stream(Stream), Buffer(Buffer), ModuleCache(ModuleCache),
4624       IncludeTimestamps(IncludeTimestamps) {
4625   for (const auto &Ext : Extensions) {
4626     if (auto Writer = Ext->createExtensionWriter(*this))
4627       ModuleFileExtensionWriters.push_back(std::move(Writer));
4628   }
4629 }
4630 
4631 ASTWriter::~ASTWriter() {
4632   llvm::DeleteContainerSeconds(FileDeclIDs);
4633 }
4634 
4635 const LangOptions &ASTWriter::getLangOpts() const {
4636   assert(WritingAST && "can't determine lang opts when not writing AST");
4637   return Context->getLangOpts();
4638 }
4639 
4640 time_t ASTWriter::getTimestampForOutput(const FileEntry *E) const {
4641   return IncludeTimestamps ? E->getModificationTime() : 0;
4642 }
4643 
4644 ASTFileSignature ASTWriter::WriteAST(Sema &SemaRef,
4645                                      const std::string &OutputFile,
4646                                      Module *WritingModule, StringRef isysroot,
4647                                      bool hasErrors,
4648                                      bool ShouldCacheASTInMemory) {
4649   WritingAST = true;
4650 
4651   ASTHasCompilerErrors = hasErrors;
4652 
4653   // Emit the file header.
4654   Stream.Emit((unsigned)'C', 8);
4655   Stream.Emit((unsigned)'P', 8);
4656   Stream.Emit((unsigned)'C', 8);
4657   Stream.Emit((unsigned)'H', 8);
4658 
4659   WriteBlockInfoBlock();
4660 
4661   Context = &SemaRef.Context;
4662   PP = &SemaRef.PP;
4663   this->WritingModule = WritingModule;
4664   ASTFileSignature Signature =
4665       WriteASTCore(SemaRef, isysroot, OutputFile, WritingModule);
4666   Context = nullptr;
4667   PP = nullptr;
4668   this->WritingModule = nullptr;
4669   this->BaseDirectory.clear();
4670 
4671   WritingAST = false;
4672   if (ShouldCacheASTInMemory) {
4673     // Construct MemoryBuffer and update buffer manager.
4674     ModuleCache.addBuiltPCM(OutputFile,
4675                             llvm::MemoryBuffer::getMemBufferCopy(
4676                                 StringRef(Buffer.begin(), Buffer.size())));
4677   }
4678   return Signature;
4679 }
4680 
4681 template<typename Vector>
4682 static void AddLazyVectorDecls(ASTWriter &Writer, Vector &Vec,
4683                                ASTWriter::RecordData &Record) {
4684   for (typename Vector::iterator I = Vec.begin(nullptr, true), E = Vec.end();
4685        I != E; ++I) {
4686     Writer.AddDeclRef(*I, Record);
4687   }
4688 }
4689 
4690 ASTFileSignature ASTWriter::WriteASTCore(Sema &SemaRef, StringRef isysroot,
4691                                          const std::string &OutputFile,
4692                                          Module *WritingModule) {
4693   using namespace llvm;
4694 
4695   bool isModule = WritingModule != nullptr;
4696 
4697   // Make sure that the AST reader knows to finalize itself.
4698   if (Chain)
4699     Chain->finalizeForWriting();
4700 
4701   ASTContext &Context = SemaRef.Context;
4702   Preprocessor &PP = SemaRef.PP;
4703 
4704   // Set up predefined declaration IDs.
4705   auto RegisterPredefDecl = [&] (Decl *D, PredefinedDeclIDs ID) {
4706     if (D) {
4707       assert(D->isCanonicalDecl() && "predefined decl is not canonical");
4708       DeclIDs[D] = ID;
4709     }
4710   };
4711   RegisterPredefDecl(Context.getTranslationUnitDecl(),
4712                      PREDEF_DECL_TRANSLATION_UNIT_ID);
4713   RegisterPredefDecl(Context.ObjCIdDecl, PREDEF_DECL_OBJC_ID_ID);
4714   RegisterPredefDecl(Context.ObjCSelDecl, PREDEF_DECL_OBJC_SEL_ID);
4715   RegisterPredefDecl(Context.ObjCClassDecl, PREDEF_DECL_OBJC_CLASS_ID);
4716   RegisterPredefDecl(Context.ObjCProtocolClassDecl,
4717                      PREDEF_DECL_OBJC_PROTOCOL_ID);
4718   RegisterPredefDecl(Context.Int128Decl, PREDEF_DECL_INT_128_ID);
4719   RegisterPredefDecl(Context.UInt128Decl, PREDEF_DECL_UNSIGNED_INT_128_ID);
4720   RegisterPredefDecl(Context.ObjCInstanceTypeDecl,
4721                      PREDEF_DECL_OBJC_INSTANCETYPE_ID);
4722   RegisterPredefDecl(Context.BuiltinVaListDecl, PREDEF_DECL_BUILTIN_VA_LIST_ID);
4723   RegisterPredefDecl(Context.VaListTagDecl, PREDEF_DECL_VA_LIST_TAG);
4724   RegisterPredefDecl(Context.BuiltinMSVaListDecl,
4725                      PREDEF_DECL_BUILTIN_MS_VA_LIST_ID);
4726   RegisterPredefDecl(Context.ExternCContext, PREDEF_DECL_EXTERN_C_CONTEXT_ID);
4727   RegisterPredefDecl(Context.MakeIntegerSeqDecl,
4728                      PREDEF_DECL_MAKE_INTEGER_SEQ_ID);
4729   RegisterPredefDecl(Context.CFConstantStringTypeDecl,
4730                      PREDEF_DECL_CF_CONSTANT_STRING_ID);
4731   RegisterPredefDecl(Context.CFConstantStringTagDecl,
4732                      PREDEF_DECL_CF_CONSTANT_STRING_TAG_ID);
4733   RegisterPredefDecl(Context.TypePackElementDecl,
4734                      PREDEF_DECL_TYPE_PACK_ELEMENT_ID);
4735 
4736   // Build a record containing all of the tentative definitions in this file, in
4737   // TentativeDefinitions order.  Generally, this record will be empty for
4738   // headers.
4739   RecordData TentativeDefinitions;
4740   AddLazyVectorDecls(*this, SemaRef.TentativeDefinitions, TentativeDefinitions);
4741 
4742   // Build a record containing all of the file scoped decls in this file.
4743   RecordData UnusedFileScopedDecls;
4744   if (!isModule)
4745     AddLazyVectorDecls(*this, SemaRef.UnusedFileScopedDecls,
4746                        UnusedFileScopedDecls);
4747 
4748   // Build a record containing all of the delegating constructors we still need
4749   // to resolve.
4750   RecordData DelegatingCtorDecls;
4751   if (!isModule)
4752     AddLazyVectorDecls(*this, SemaRef.DelegatingCtorDecls, DelegatingCtorDecls);
4753 
4754   // Write the set of weak, undeclared identifiers. We always write the
4755   // entire table, since later PCH files in a PCH chain are only interested in
4756   // the results at the end of the chain.
4757   RecordData WeakUndeclaredIdentifiers;
4758   for (auto &WeakUndeclaredIdentifier : SemaRef.WeakUndeclaredIdentifiers) {
4759     IdentifierInfo *II = WeakUndeclaredIdentifier.first;
4760     WeakInfo &WI = WeakUndeclaredIdentifier.second;
4761     AddIdentifierRef(II, WeakUndeclaredIdentifiers);
4762     AddIdentifierRef(WI.getAlias(), WeakUndeclaredIdentifiers);
4763     AddSourceLocation(WI.getLocation(), WeakUndeclaredIdentifiers);
4764     WeakUndeclaredIdentifiers.push_back(WI.getUsed());
4765   }
4766 
4767   // Build a record containing all of the ext_vector declarations.
4768   RecordData ExtVectorDecls;
4769   AddLazyVectorDecls(*this, SemaRef.ExtVectorDecls, ExtVectorDecls);
4770 
4771   // Build a record containing all of the VTable uses information.
4772   RecordData VTableUses;
4773   if (!SemaRef.VTableUses.empty()) {
4774     for (unsigned I = 0, N = SemaRef.VTableUses.size(); I != N; ++I) {
4775       AddDeclRef(SemaRef.VTableUses[I].first, VTableUses);
4776       AddSourceLocation(SemaRef.VTableUses[I].second, VTableUses);
4777       VTableUses.push_back(SemaRef.VTablesUsed[SemaRef.VTableUses[I].first]);
4778     }
4779   }
4780 
4781   // Build a record containing all of the UnusedLocalTypedefNameCandidates.
4782   RecordData UnusedLocalTypedefNameCandidates;
4783   for (const TypedefNameDecl *TD : SemaRef.UnusedLocalTypedefNameCandidates)
4784     AddDeclRef(TD, UnusedLocalTypedefNameCandidates);
4785 
4786   // Build a record containing all of pending implicit instantiations.
4787   RecordData PendingInstantiations;
4788   for (const auto &I : SemaRef.PendingInstantiations) {
4789     AddDeclRef(I.first, PendingInstantiations);
4790     AddSourceLocation(I.second, PendingInstantiations);
4791   }
4792   assert(SemaRef.PendingLocalImplicitInstantiations.empty() &&
4793          "There are local ones at end of translation unit!");
4794 
4795   // Build a record containing some declaration references.
4796   RecordData SemaDeclRefs;
4797   if (SemaRef.StdNamespace || SemaRef.StdBadAlloc || SemaRef.StdAlignValT) {
4798     AddDeclRef(SemaRef.getStdNamespace(), SemaDeclRefs);
4799     AddDeclRef(SemaRef.getStdBadAlloc(), SemaDeclRefs);
4800     AddDeclRef(SemaRef.getStdAlignValT(), SemaDeclRefs);
4801   }
4802 
4803   RecordData CUDASpecialDeclRefs;
4804   if (Context.getcudaConfigureCallDecl()) {
4805     AddDeclRef(Context.getcudaConfigureCallDecl(), CUDASpecialDeclRefs);
4806   }
4807 
4808   // Build a record containing all of the known namespaces.
4809   RecordData KnownNamespaces;
4810   for (const auto &I : SemaRef.KnownNamespaces) {
4811     if (!I.second)
4812       AddDeclRef(I.first, KnownNamespaces);
4813   }
4814 
4815   // Build a record of all used, undefined objects that require definitions.
4816   RecordData UndefinedButUsed;
4817 
4818   SmallVector<std::pair<NamedDecl *, SourceLocation>, 16> Undefined;
4819   SemaRef.getUndefinedButUsed(Undefined);
4820   for (const auto &I : Undefined) {
4821     AddDeclRef(I.first, UndefinedButUsed);
4822     AddSourceLocation(I.second, UndefinedButUsed);
4823   }
4824 
4825   // Build a record containing all delete-expressions that we would like to
4826   // analyze later in AST.
4827   RecordData DeleteExprsToAnalyze;
4828 
4829   if (!isModule) {
4830     for (const auto &DeleteExprsInfo :
4831          SemaRef.getMismatchingDeleteExpressions()) {
4832       AddDeclRef(DeleteExprsInfo.first, DeleteExprsToAnalyze);
4833       DeleteExprsToAnalyze.push_back(DeleteExprsInfo.second.size());
4834       for (const auto &DeleteLoc : DeleteExprsInfo.second) {
4835         AddSourceLocation(DeleteLoc.first, DeleteExprsToAnalyze);
4836         DeleteExprsToAnalyze.push_back(DeleteLoc.second);
4837       }
4838     }
4839   }
4840 
4841   // Write the control block
4842   WriteControlBlock(PP, Context, isysroot, OutputFile);
4843 
4844   // Write the remaining AST contents.
4845   Stream.EnterSubblock(AST_BLOCK_ID, 5);
4846 
4847   // This is so that older clang versions, before the introduction
4848   // of the control block, can read and reject the newer PCH format.
4849   {
4850     RecordData Record = {VERSION_MAJOR};
4851     Stream.EmitRecord(METADATA_OLD_FORMAT, Record);
4852   }
4853 
4854   // Create a lexical update block containing all of the declarations in the
4855   // translation unit that do not come from other AST files.
4856   const TranslationUnitDecl *TU = Context.getTranslationUnitDecl();
4857   SmallVector<uint32_t, 128> NewGlobalKindDeclPairs;
4858   for (const auto *D : TU->noload_decls()) {
4859     if (!D->isFromASTFile()) {
4860       NewGlobalKindDeclPairs.push_back(D->getKind());
4861       NewGlobalKindDeclPairs.push_back(GetDeclRef(D));
4862     }
4863   }
4864 
4865   auto Abv = std::make_shared<BitCodeAbbrev>();
4866   Abv->Add(llvm::BitCodeAbbrevOp(TU_UPDATE_LEXICAL));
4867   Abv->Add(llvm::BitCodeAbbrevOp(llvm::BitCodeAbbrevOp::Blob));
4868   unsigned TuUpdateLexicalAbbrev = Stream.EmitAbbrev(std::move(Abv));
4869   {
4870     RecordData::value_type Record[] = {TU_UPDATE_LEXICAL};
4871     Stream.EmitRecordWithBlob(TuUpdateLexicalAbbrev, Record,
4872                               bytes(NewGlobalKindDeclPairs));
4873   }
4874 
4875   // And a visible updates block for the translation unit.
4876   Abv = std::make_shared<BitCodeAbbrev>();
4877   Abv->Add(llvm::BitCodeAbbrevOp(UPDATE_VISIBLE));
4878   Abv->Add(llvm::BitCodeAbbrevOp(llvm::BitCodeAbbrevOp::VBR, 6));
4879   Abv->Add(llvm::BitCodeAbbrevOp(llvm::BitCodeAbbrevOp::Blob));
4880   UpdateVisibleAbbrev = Stream.EmitAbbrev(std::move(Abv));
4881   WriteDeclContextVisibleUpdate(TU);
4882 
4883   // If we have any extern "C" names, write out a visible update for them.
4884   if (Context.ExternCContext)
4885     WriteDeclContextVisibleUpdate(Context.ExternCContext);
4886 
4887   // If the translation unit has an anonymous namespace, and we don't already
4888   // have an update block for it, write it as an update block.
4889   // FIXME: Why do we not do this if there's already an update block?
4890   if (NamespaceDecl *NS = TU->getAnonymousNamespace()) {
4891     ASTWriter::UpdateRecord &Record = DeclUpdates[TU];
4892     if (Record.empty())
4893       Record.push_back(DeclUpdate(UPD_CXX_ADDED_ANONYMOUS_NAMESPACE, NS));
4894   }
4895 
4896   // Add update records for all mangling numbers and static local numbers.
4897   // These aren't really update records, but this is a convenient way of
4898   // tagging this rare extra data onto the declarations.
4899   for (const auto &Number : Context.MangleNumbers)
4900     if (!Number.first->isFromASTFile())
4901       DeclUpdates[Number.first].push_back(DeclUpdate(UPD_MANGLING_NUMBER,
4902                                                      Number.second));
4903   for (const auto &Number : Context.StaticLocalNumbers)
4904     if (!Number.first->isFromASTFile())
4905       DeclUpdates[Number.first].push_back(DeclUpdate(UPD_STATIC_LOCAL_NUMBER,
4906                                                      Number.second));
4907 
4908   // Make sure visible decls, added to DeclContexts previously loaded from
4909   // an AST file, are registered for serialization. Likewise for template
4910   // specializations added to imported templates.
4911   for (const auto *I : DeclsToEmitEvenIfUnreferenced) {
4912     GetDeclRef(I);
4913   }
4914 
4915   // Make sure all decls associated with an identifier are registered for
4916   // serialization, if we're storing decls with identifiers.
4917   if (!WritingModule || !getLangOpts().CPlusPlus) {
4918     llvm::SmallVector<const IdentifierInfo*, 256> IIs;
4919     for (const auto &ID : PP.getIdentifierTable()) {
4920       const IdentifierInfo *II = ID.second;
4921       if (!Chain || !II->isFromAST() || II->hasChangedSinceDeserialization())
4922         IIs.push_back(II);
4923     }
4924     // Sort the identifiers to visit based on their name.
4925     llvm::sort(IIs, llvm::less_ptr<IdentifierInfo>());
4926     for (const IdentifierInfo *II : IIs) {
4927       for (IdentifierResolver::iterator D = SemaRef.IdResolver.begin(II),
4928                                      DEnd = SemaRef.IdResolver.end();
4929            D != DEnd; ++D) {
4930         GetDeclRef(*D);
4931       }
4932     }
4933   }
4934 
4935   // For method pool in the module, if it contains an entry for a selector,
4936   // the entry should be complete, containing everything introduced by that
4937   // module and all modules it imports. It's possible that the entry is out of
4938   // date, so we need to pull in the new content here.
4939 
4940   // It's possible that updateOutOfDateSelector can update SelectorIDs. To be
4941   // safe, we copy all selectors out.
4942   llvm::SmallVector<Selector, 256> AllSelectors;
4943   for (auto &SelectorAndID : SelectorIDs)
4944     AllSelectors.push_back(SelectorAndID.first);
4945   for (auto &Selector : AllSelectors)
4946     SemaRef.updateOutOfDateSelector(Selector);
4947 
4948   // Form the record of special types.
4949   RecordData SpecialTypes;
4950   AddTypeRef(Context.getRawCFConstantStringType(), SpecialTypes);
4951   AddTypeRef(Context.getFILEType(), SpecialTypes);
4952   AddTypeRef(Context.getjmp_bufType(), SpecialTypes);
4953   AddTypeRef(Context.getsigjmp_bufType(), SpecialTypes);
4954   AddTypeRef(Context.ObjCIdRedefinitionType, SpecialTypes);
4955   AddTypeRef(Context.ObjCClassRedefinitionType, SpecialTypes);
4956   AddTypeRef(Context.ObjCSelRedefinitionType, SpecialTypes);
4957   AddTypeRef(Context.getucontext_tType(), SpecialTypes);
4958 
4959   if (Chain) {
4960     // Write the mapping information describing our module dependencies and how
4961     // each of those modules were mapped into our own offset/ID space, so that
4962     // the reader can build the appropriate mapping to its own offset/ID space.
4963     // The map consists solely of a blob with the following format:
4964     // *(module-kind:i8
4965     //   module-name-len:i16 module-name:len*i8
4966     //   source-location-offset:i32
4967     //   identifier-id:i32
4968     //   preprocessed-entity-id:i32
4969     //   macro-definition-id:i32
4970     //   submodule-id:i32
4971     //   selector-id:i32
4972     //   declaration-id:i32
4973     //   c++-base-specifiers-id:i32
4974     //   type-id:i32)
4975     //
4976     // module-kind is the ModuleKind enum value. If it is MK_PrebuiltModule or
4977     // MK_ExplicitModule, then the module-name is the module name. Otherwise,
4978     // it is the module file name.
4979     auto Abbrev = std::make_shared<BitCodeAbbrev>();
4980     Abbrev->Add(BitCodeAbbrevOp(MODULE_OFFSET_MAP));
4981     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
4982     unsigned ModuleOffsetMapAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
4983     SmallString<2048> Buffer;
4984     {
4985       llvm::raw_svector_ostream Out(Buffer);
4986       for (ModuleFile &M : Chain->ModuleMgr) {
4987         using namespace llvm::support;
4988 
4989         endian::Writer LE(Out, little);
4990         LE.write<uint8_t>(static_cast<uint8_t>(M.Kind));
4991         StringRef Name =
4992           M.Kind == MK_PrebuiltModule || M.Kind == MK_ExplicitModule
4993           ? M.ModuleName
4994           : M.FileName;
4995         LE.write<uint16_t>(Name.size());
4996         Out.write(Name.data(), Name.size());
4997 
4998         // Note: if a base ID was uint max, it would not be possible to load
4999         // another module after it or have more than one entity inside it.
5000         uint32_t None = std::numeric_limits<uint32_t>::max();
5001 
5002         auto writeBaseIDOrNone = [&](uint32_t BaseID, bool ShouldWrite) {
5003           assert(BaseID < std::numeric_limits<uint32_t>::max() && "base id too high");
5004           if (ShouldWrite)
5005             LE.write<uint32_t>(BaseID);
5006           else
5007             LE.write<uint32_t>(None);
5008         };
5009 
5010         // These values should be unique within a chain, since they will be read
5011         // as keys into ContinuousRangeMaps.
5012         writeBaseIDOrNone(M.SLocEntryBaseOffset, M.LocalNumSLocEntries);
5013         writeBaseIDOrNone(M.BaseIdentifierID, M.LocalNumIdentifiers);
5014         writeBaseIDOrNone(M.BaseMacroID, M.LocalNumMacros);
5015         writeBaseIDOrNone(M.BasePreprocessedEntityID,
5016                           M.NumPreprocessedEntities);
5017         writeBaseIDOrNone(M.BaseSubmoduleID, M.LocalNumSubmodules);
5018         writeBaseIDOrNone(M.BaseSelectorID, M.LocalNumSelectors);
5019         writeBaseIDOrNone(M.BaseDeclID, M.LocalNumDecls);
5020         writeBaseIDOrNone(M.BaseTypeIndex, M.LocalNumTypes);
5021       }
5022     }
5023     RecordData::value_type Record[] = {MODULE_OFFSET_MAP};
5024     Stream.EmitRecordWithBlob(ModuleOffsetMapAbbrev, Record,
5025                               Buffer.data(), Buffer.size());
5026   }
5027 
5028   RecordData DeclUpdatesOffsetsRecord;
5029 
5030   // Keep writing types, declarations, and declaration update records
5031   // until we've emitted all of them.
5032   Stream.EnterSubblock(DECLTYPES_BLOCK_ID, /*bits for abbreviations*/5);
5033   WriteTypeAbbrevs();
5034   WriteDeclAbbrevs();
5035   do {
5036     WriteDeclUpdatesBlocks(DeclUpdatesOffsetsRecord);
5037     while (!DeclTypesToEmit.empty()) {
5038       DeclOrType DOT = DeclTypesToEmit.front();
5039       DeclTypesToEmit.pop();
5040       if (DOT.isType())
5041         WriteType(DOT.getType());
5042       else
5043         WriteDecl(Context, DOT.getDecl());
5044     }
5045   } while (!DeclUpdates.empty());
5046   Stream.ExitBlock();
5047 
5048   DoneWritingDeclsAndTypes = true;
5049 
5050   // These things can only be done once we've written out decls and types.
5051   WriteTypeDeclOffsets();
5052   if (!DeclUpdatesOffsetsRecord.empty())
5053     Stream.EmitRecord(DECL_UPDATE_OFFSETS, DeclUpdatesOffsetsRecord);
5054   WriteFileDeclIDsMap();
5055   WriteSourceManagerBlock(Context.getSourceManager(), PP);
5056   WriteComments();
5057   WritePreprocessor(PP, isModule);
5058   WriteHeaderSearch(PP.getHeaderSearchInfo());
5059   WriteSelectors(SemaRef);
5060   WriteReferencedSelectorsPool(SemaRef);
5061   WriteLateParsedTemplates(SemaRef);
5062   WriteIdentifierTable(PP, SemaRef.IdResolver, isModule);
5063   WriteFPPragmaOptions(SemaRef.getFPOptions());
5064   WriteOpenCLExtensions(SemaRef);
5065   WriteOpenCLExtensionTypes(SemaRef);
5066   WriteCUDAPragmas(SemaRef);
5067 
5068   // If we're emitting a module, write out the submodule information.
5069   if (WritingModule)
5070     WriteSubmodules(WritingModule);
5071 
5072   // We need to have information about submodules to correctly deserialize
5073   // decls from OpenCLExtensionDecls block
5074   WriteOpenCLExtensionDecls(SemaRef);
5075 
5076   Stream.EmitRecord(SPECIAL_TYPES, SpecialTypes);
5077 
5078   // Write the record containing external, unnamed definitions.
5079   if (!EagerlyDeserializedDecls.empty())
5080     Stream.EmitRecord(EAGERLY_DESERIALIZED_DECLS, EagerlyDeserializedDecls);
5081 
5082   if (!ModularCodegenDecls.empty())
5083     Stream.EmitRecord(MODULAR_CODEGEN_DECLS, ModularCodegenDecls);
5084 
5085   // Write the record containing tentative definitions.
5086   if (!TentativeDefinitions.empty())
5087     Stream.EmitRecord(TENTATIVE_DEFINITIONS, TentativeDefinitions);
5088 
5089   // Write the record containing unused file scoped decls.
5090   if (!UnusedFileScopedDecls.empty())
5091     Stream.EmitRecord(UNUSED_FILESCOPED_DECLS, UnusedFileScopedDecls);
5092 
5093   // Write the record containing weak undeclared identifiers.
5094   if (!WeakUndeclaredIdentifiers.empty())
5095     Stream.EmitRecord(WEAK_UNDECLARED_IDENTIFIERS,
5096                       WeakUndeclaredIdentifiers);
5097 
5098   // Write the record containing ext_vector type names.
5099   if (!ExtVectorDecls.empty())
5100     Stream.EmitRecord(EXT_VECTOR_DECLS, ExtVectorDecls);
5101 
5102   // Write the record containing VTable uses information.
5103   if (!VTableUses.empty())
5104     Stream.EmitRecord(VTABLE_USES, VTableUses);
5105 
5106   // Write the record containing potentially unused local typedefs.
5107   if (!UnusedLocalTypedefNameCandidates.empty())
5108     Stream.EmitRecord(UNUSED_LOCAL_TYPEDEF_NAME_CANDIDATES,
5109                       UnusedLocalTypedefNameCandidates);
5110 
5111   // Write the record containing pending implicit instantiations.
5112   if (!PendingInstantiations.empty())
5113     Stream.EmitRecord(PENDING_IMPLICIT_INSTANTIATIONS, PendingInstantiations);
5114 
5115   // Write the record containing declaration references of Sema.
5116   if (!SemaDeclRefs.empty())
5117     Stream.EmitRecord(SEMA_DECL_REFS, SemaDeclRefs);
5118 
5119   // Write the record containing CUDA-specific declaration references.
5120   if (!CUDASpecialDeclRefs.empty())
5121     Stream.EmitRecord(CUDA_SPECIAL_DECL_REFS, CUDASpecialDeclRefs);
5122 
5123   // Write the delegating constructors.
5124   if (!DelegatingCtorDecls.empty())
5125     Stream.EmitRecord(DELEGATING_CTORS, DelegatingCtorDecls);
5126 
5127   // Write the known namespaces.
5128   if (!KnownNamespaces.empty())
5129     Stream.EmitRecord(KNOWN_NAMESPACES, KnownNamespaces);
5130 
5131   // Write the undefined internal functions and variables, and inline functions.
5132   if (!UndefinedButUsed.empty())
5133     Stream.EmitRecord(UNDEFINED_BUT_USED, UndefinedButUsed);
5134 
5135   if (!DeleteExprsToAnalyze.empty())
5136     Stream.EmitRecord(DELETE_EXPRS_TO_ANALYZE, DeleteExprsToAnalyze);
5137 
5138   // Write the visible updates to DeclContexts.
5139   for (auto *DC : UpdatedDeclContexts)
5140     WriteDeclContextVisibleUpdate(DC);
5141 
5142   if (!WritingModule) {
5143     // Write the submodules that were imported, if any.
5144     struct ModuleInfo {
5145       uint64_t ID;
5146       Module *M;
5147       ModuleInfo(uint64_t ID, Module *M) : ID(ID), M(M) {}
5148     };
5149     llvm::SmallVector<ModuleInfo, 64> Imports;
5150     for (const auto *I : Context.local_imports()) {
5151       assert(SubmoduleIDs.find(I->getImportedModule()) != SubmoduleIDs.end());
5152       Imports.push_back(ModuleInfo(SubmoduleIDs[I->getImportedModule()],
5153                          I->getImportedModule()));
5154     }
5155 
5156     if (!Imports.empty()) {
5157       auto Cmp = [](const ModuleInfo &A, const ModuleInfo &B) {
5158         return A.ID < B.ID;
5159       };
5160       auto Eq = [](const ModuleInfo &A, const ModuleInfo &B) {
5161         return A.ID == B.ID;
5162       };
5163 
5164       // Sort and deduplicate module IDs.
5165       llvm::sort(Imports, Cmp);
5166       Imports.erase(std::unique(Imports.begin(), Imports.end(), Eq),
5167                     Imports.end());
5168 
5169       RecordData ImportedModules;
5170       for (const auto &Import : Imports) {
5171         ImportedModules.push_back(Import.ID);
5172         // FIXME: If the module has macros imported then later has declarations
5173         // imported, this location won't be the right one as a location for the
5174         // declaration imports.
5175         AddSourceLocation(PP.getModuleImportLoc(Import.M), ImportedModules);
5176       }
5177 
5178       Stream.EmitRecord(IMPORTED_MODULES, ImportedModules);
5179     }
5180   }
5181 
5182   WriteObjCCategories();
5183   if(!WritingModule) {
5184     WriteOptimizePragmaOptions(SemaRef);
5185     WriteMSStructPragmaOptions(SemaRef);
5186     WriteMSPointersToMembersPragmaOptions(SemaRef);
5187   }
5188   WritePackPragmaOptions(SemaRef);
5189 
5190   // Some simple statistics
5191   RecordData::value_type Record[] = {
5192       NumStatements, NumMacros, NumLexicalDeclContexts, NumVisibleDeclContexts};
5193   Stream.EmitRecord(STATISTICS, Record);
5194   Stream.ExitBlock();
5195 
5196   // Write the module file extension blocks.
5197   for (const auto &ExtWriter : ModuleFileExtensionWriters)
5198     WriteModuleFileExtension(SemaRef, *ExtWriter);
5199 
5200   return writeUnhashedControlBlock(PP, Context);
5201 }
5202 
5203 void ASTWriter::WriteDeclUpdatesBlocks(RecordDataImpl &OffsetsRecord) {
5204   if (DeclUpdates.empty())
5205     return;
5206 
5207   DeclUpdateMap LocalUpdates;
5208   LocalUpdates.swap(DeclUpdates);
5209 
5210   for (auto &DeclUpdate : LocalUpdates) {
5211     const Decl *D = DeclUpdate.first;
5212 
5213     bool HasUpdatedBody = false;
5214     RecordData RecordData;
5215     ASTRecordWriter Record(*this, RecordData);
5216     for (auto &Update : DeclUpdate.second) {
5217       DeclUpdateKind Kind = (DeclUpdateKind)Update.getKind();
5218 
5219       // An updated body is emitted last, so that the reader doesn't need
5220       // to skip over the lazy body to reach statements for other records.
5221       if (Kind == UPD_CXX_ADDED_FUNCTION_DEFINITION)
5222         HasUpdatedBody = true;
5223       else
5224         Record.push_back(Kind);
5225 
5226       switch (Kind) {
5227       case UPD_CXX_ADDED_IMPLICIT_MEMBER:
5228       case UPD_CXX_ADDED_TEMPLATE_SPECIALIZATION:
5229       case UPD_CXX_ADDED_ANONYMOUS_NAMESPACE:
5230         assert(Update.getDecl() && "no decl to add?");
5231         Record.push_back(GetDeclRef(Update.getDecl()));
5232         break;
5233 
5234       case UPD_CXX_ADDED_FUNCTION_DEFINITION:
5235         break;
5236 
5237       case UPD_CXX_POINT_OF_INSTANTIATION:
5238         // FIXME: Do we need to also save the template specialization kind here?
5239         Record.AddSourceLocation(Update.getLoc());
5240         break;
5241 
5242       case UPD_CXX_ADDED_VAR_DEFINITION: {
5243         const VarDecl *VD = cast<VarDecl>(D);
5244         Record.push_back(VD->isInline());
5245         Record.push_back(VD->isInlineSpecified());
5246         if (VD->getInit()) {
5247           Record.push_back(!VD->isInitKnownICE() ? 1
5248                                                  : (VD->isInitICE() ? 3 : 2));
5249           Record.AddStmt(const_cast<Expr*>(VD->getInit()));
5250         } else {
5251           Record.push_back(0);
5252         }
5253         break;
5254       }
5255 
5256       case UPD_CXX_INSTANTIATED_DEFAULT_ARGUMENT:
5257         Record.AddStmt(const_cast<Expr *>(
5258             cast<ParmVarDecl>(Update.getDecl())->getDefaultArg()));
5259         break;
5260 
5261       case UPD_CXX_INSTANTIATED_DEFAULT_MEMBER_INITIALIZER:
5262         Record.AddStmt(
5263             cast<FieldDecl>(Update.getDecl())->getInClassInitializer());
5264         break;
5265 
5266       case UPD_CXX_INSTANTIATED_CLASS_DEFINITION: {
5267         auto *RD = cast<CXXRecordDecl>(D);
5268         UpdatedDeclContexts.insert(RD->getPrimaryContext());
5269         Record.push_back(RD->isParamDestroyedInCallee());
5270         Record.push_back(RD->getArgPassingRestrictions());
5271         Record.AddCXXDefinitionData(RD);
5272         Record.AddOffset(WriteDeclContextLexicalBlock(
5273             *Context, const_cast<CXXRecordDecl *>(RD)));
5274 
5275         // This state is sometimes updated by template instantiation, when we
5276         // switch from the specialization referring to the template declaration
5277         // to it referring to the template definition.
5278         if (auto *MSInfo = RD->getMemberSpecializationInfo()) {
5279           Record.push_back(MSInfo->getTemplateSpecializationKind());
5280           Record.AddSourceLocation(MSInfo->getPointOfInstantiation());
5281         } else {
5282           auto *Spec = cast<ClassTemplateSpecializationDecl>(RD);
5283           Record.push_back(Spec->getTemplateSpecializationKind());
5284           Record.AddSourceLocation(Spec->getPointOfInstantiation());
5285 
5286           // The instantiation might have been resolved to a partial
5287           // specialization. If so, record which one.
5288           auto From = Spec->getInstantiatedFrom();
5289           if (auto PartialSpec =
5290                 From.dyn_cast<ClassTemplatePartialSpecializationDecl*>()) {
5291             Record.push_back(true);
5292             Record.AddDeclRef(PartialSpec);
5293             Record.AddTemplateArgumentList(
5294                 &Spec->getTemplateInstantiationArgs());
5295           } else {
5296             Record.push_back(false);
5297           }
5298         }
5299         Record.push_back(RD->getTagKind());
5300         Record.AddSourceLocation(RD->getLocation());
5301         Record.AddSourceLocation(RD->getBeginLoc());
5302         Record.AddSourceRange(RD->getBraceRange());
5303 
5304         // Instantiation may change attributes; write them all out afresh.
5305         Record.push_back(D->hasAttrs());
5306         if (D->hasAttrs())
5307           Record.AddAttributes(D->getAttrs());
5308 
5309         // FIXME: Ensure we don't get here for explicit instantiations.
5310         break;
5311       }
5312 
5313       case UPD_CXX_RESOLVED_DTOR_DELETE:
5314         Record.AddDeclRef(Update.getDecl());
5315         Record.AddStmt(cast<CXXDestructorDecl>(D)->getOperatorDeleteThisArg());
5316         break;
5317 
5318       case UPD_CXX_RESOLVED_EXCEPTION_SPEC:
5319         addExceptionSpec(
5320             cast<FunctionDecl>(D)->getType()->castAs<FunctionProtoType>(),
5321             Record);
5322         break;
5323 
5324       case UPD_CXX_DEDUCED_RETURN_TYPE:
5325         Record.push_back(GetOrCreateTypeID(Update.getType()));
5326         break;
5327 
5328       case UPD_DECL_MARKED_USED:
5329         break;
5330 
5331       case UPD_MANGLING_NUMBER:
5332       case UPD_STATIC_LOCAL_NUMBER:
5333         Record.push_back(Update.getNumber());
5334         break;
5335 
5336       case UPD_DECL_MARKED_OPENMP_THREADPRIVATE:
5337         Record.AddSourceRange(
5338             D->getAttr<OMPThreadPrivateDeclAttr>()->getRange());
5339         break;
5340 
5341       case UPD_DECL_MARKED_OPENMP_ALLOCATE: {
5342         auto *A = D->getAttr<OMPAllocateDeclAttr>();
5343         Record.push_back(A->getAllocatorType());
5344         Record.AddStmt(A->getAllocator());
5345         Record.AddSourceRange(A->getRange());
5346         break;
5347       }
5348 
5349       case UPD_DECL_MARKED_OPENMP_DECLARETARGET:
5350         Record.push_back(D->getAttr<OMPDeclareTargetDeclAttr>()->getMapType());
5351         Record.AddSourceRange(
5352             D->getAttr<OMPDeclareTargetDeclAttr>()->getRange());
5353         break;
5354 
5355       case UPD_DECL_EXPORTED:
5356         Record.push_back(getSubmoduleID(Update.getModule()));
5357         break;
5358 
5359       case UPD_ADDED_ATTR_TO_RECORD:
5360         Record.AddAttributes(llvm::makeArrayRef(Update.getAttr()));
5361         break;
5362       }
5363     }
5364 
5365     if (HasUpdatedBody) {
5366       const auto *Def = cast<FunctionDecl>(D);
5367       Record.push_back(UPD_CXX_ADDED_FUNCTION_DEFINITION);
5368       Record.push_back(Def->isInlined());
5369       Record.AddSourceLocation(Def->getInnerLocStart());
5370       Record.AddFunctionDefinition(Def);
5371     }
5372 
5373     OffsetsRecord.push_back(GetDeclRef(D));
5374     OffsetsRecord.push_back(Record.Emit(DECL_UPDATES));
5375   }
5376 }
5377 
5378 void ASTWriter::AddSourceLocation(SourceLocation Loc, RecordDataImpl &Record) {
5379   uint32_t Raw = Loc.getRawEncoding();
5380   Record.push_back((Raw << 1) | (Raw >> 31));
5381 }
5382 
5383 void ASTWriter::AddSourceRange(SourceRange Range, RecordDataImpl &Record) {
5384   AddSourceLocation(Range.getBegin(), Record);
5385   AddSourceLocation(Range.getEnd(), Record);
5386 }
5387 
5388 void ASTRecordWriter::AddAPInt(const llvm::APInt &Value) {
5389   Record->push_back(Value.getBitWidth());
5390   const uint64_t *Words = Value.getRawData();
5391   Record->append(Words, Words + Value.getNumWords());
5392 }
5393 
5394 void ASTRecordWriter::AddAPSInt(const llvm::APSInt &Value) {
5395   Record->push_back(Value.isUnsigned());
5396   AddAPInt(Value);
5397 }
5398 
5399 void ASTRecordWriter::AddAPFloat(const llvm::APFloat &Value) {
5400   AddAPInt(Value.bitcastToAPInt());
5401 }
5402 
5403 static void WriteFixedPointSemantics(ASTRecordWriter &Record,
5404                                      FixedPointSemantics FPSema) {
5405   Record.push_back(FPSema.getWidth());
5406   Record.push_back(FPSema.getScale());
5407   Record.push_back(FPSema.isSigned() | FPSema.isSaturated() << 1 |
5408                    FPSema.hasUnsignedPadding() << 2);
5409 }
5410 
5411 void ASTRecordWriter::AddAPValue(const APValue &Value) {
5412   APValue::ValueKind Kind = Value.getKind();
5413   push_back(static_cast<uint64_t>(Kind));
5414   switch (Kind) {
5415   case APValue::None:
5416   case APValue::Indeterminate:
5417     return;
5418   case APValue::Int:
5419     AddAPSInt(Value.getInt());
5420     return;
5421   case APValue::Float:
5422     push_back(static_cast<uint64_t>(
5423         llvm::APFloatBase::SemanticsToEnum(Value.getFloat().getSemantics())));
5424     AddAPFloat(Value.getFloat());
5425     return;
5426   case APValue::FixedPoint: {
5427     WriteFixedPointSemantics(*this, Value.getFixedPoint().getSemantics());
5428     AddAPSInt(Value.getFixedPoint().getValue());
5429     return;
5430   }
5431   case APValue::ComplexInt: {
5432     AddAPSInt(Value.getComplexIntReal());
5433     AddAPSInt(Value.getComplexIntImag());
5434     return;
5435   }
5436   case APValue::ComplexFloat: {
5437     push_back(static_cast<uint64_t>(llvm::APFloatBase::SemanticsToEnum(
5438         Value.getComplexFloatReal().getSemantics())));
5439     AddAPFloat(Value.getComplexFloatReal());
5440     push_back(static_cast<uint64_t>(llvm::APFloatBase::SemanticsToEnum(
5441         Value.getComplexFloatImag().getSemantics())));
5442     AddAPFloat(Value.getComplexFloatImag());
5443     return;
5444   }
5445   case APValue::LValue:
5446   case APValue::Vector:
5447   case APValue::Array:
5448   case APValue::Struct:
5449   case APValue::Union:
5450   case APValue::MemberPointer:
5451   case APValue::AddrLabelDiff:
5452     // TODO : Handle all these APValue::ValueKind.
5453     return;
5454   }
5455   llvm_unreachable("Invalid APValue::ValueKind");
5456 }
5457 
5458 void ASTWriter::AddIdentifierRef(const IdentifierInfo *II, RecordDataImpl &Record) {
5459   Record.push_back(getIdentifierRef(II));
5460 }
5461 
5462 IdentID ASTWriter::getIdentifierRef(const IdentifierInfo *II) {
5463   if (!II)
5464     return 0;
5465 
5466   IdentID &ID = IdentifierIDs[II];
5467   if (ID == 0)
5468     ID = NextIdentID++;
5469   return ID;
5470 }
5471 
5472 MacroID ASTWriter::getMacroRef(MacroInfo *MI, const IdentifierInfo *Name) {
5473   // Don't emit builtin macros like __LINE__ to the AST file unless they
5474   // have been redefined by the header (in which case they are not
5475   // isBuiltinMacro).
5476   if (!MI || MI->isBuiltinMacro())
5477     return 0;
5478 
5479   MacroID &ID = MacroIDs[MI];
5480   if (ID == 0) {
5481     ID = NextMacroID++;
5482     MacroInfoToEmitData Info = { Name, MI, ID };
5483     MacroInfosToEmit.push_back(Info);
5484   }
5485   return ID;
5486 }
5487 
5488 MacroID ASTWriter::getMacroID(MacroInfo *MI) {
5489   if (!MI || MI->isBuiltinMacro())
5490     return 0;
5491 
5492   assert(MacroIDs.find(MI) != MacroIDs.end() && "Macro not emitted!");
5493   return MacroIDs[MI];
5494 }
5495 
5496 uint64_t ASTWriter::getMacroDirectivesOffset(const IdentifierInfo *Name) {
5497   return IdentMacroDirectivesOffsetMap.lookup(Name);
5498 }
5499 
5500 void ASTRecordWriter::AddSelectorRef(const Selector SelRef) {
5501   Record->push_back(Writer->getSelectorRef(SelRef));
5502 }
5503 
5504 SelectorID ASTWriter::getSelectorRef(Selector Sel) {
5505   if (Sel.getAsOpaquePtr() == nullptr) {
5506     return 0;
5507   }
5508 
5509   SelectorID SID = SelectorIDs[Sel];
5510   if (SID == 0 && Chain) {
5511     // This might trigger a ReadSelector callback, which will set the ID for
5512     // this selector.
5513     Chain->LoadSelector(Sel);
5514     SID = SelectorIDs[Sel];
5515   }
5516   if (SID == 0) {
5517     SID = NextSelectorID++;
5518     SelectorIDs[Sel] = SID;
5519   }
5520   return SID;
5521 }
5522 
5523 void ASTRecordWriter::AddCXXTemporary(const CXXTemporary *Temp) {
5524   AddDeclRef(Temp->getDestructor());
5525 }
5526 
5527 void ASTRecordWriter::AddTemplateArgumentLocInfo(
5528     TemplateArgument::ArgKind Kind, const TemplateArgumentLocInfo &Arg) {
5529   switch (Kind) {
5530   case TemplateArgument::Expression:
5531     AddStmt(Arg.getAsExpr());
5532     break;
5533   case TemplateArgument::Type:
5534     AddTypeSourceInfo(Arg.getAsTypeSourceInfo());
5535     break;
5536   case TemplateArgument::Template:
5537     AddNestedNameSpecifierLoc(Arg.getTemplateQualifierLoc());
5538     AddSourceLocation(Arg.getTemplateNameLoc());
5539     break;
5540   case TemplateArgument::TemplateExpansion:
5541     AddNestedNameSpecifierLoc(Arg.getTemplateQualifierLoc());
5542     AddSourceLocation(Arg.getTemplateNameLoc());
5543     AddSourceLocation(Arg.getTemplateEllipsisLoc());
5544     break;
5545   case TemplateArgument::Null:
5546   case TemplateArgument::Integral:
5547   case TemplateArgument::Declaration:
5548   case TemplateArgument::NullPtr:
5549   case TemplateArgument::Pack:
5550     // FIXME: Is this right?
5551     break;
5552   }
5553 }
5554 
5555 void ASTRecordWriter::AddTemplateArgumentLoc(const TemplateArgumentLoc &Arg) {
5556   AddTemplateArgument(Arg.getArgument());
5557 
5558   if (Arg.getArgument().getKind() == TemplateArgument::Expression) {
5559     bool InfoHasSameExpr
5560       = Arg.getArgument().getAsExpr() == Arg.getLocInfo().getAsExpr();
5561     Record->push_back(InfoHasSameExpr);
5562     if (InfoHasSameExpr)
5563       return; // Avoid storing the same expr twice.
5564   }
5565   AddTemplateArgumentLocInfo(Arg.getArgument().getKind(), Arg.getLocInfo());
5566 }
5567 
5568 void ASTRecordWriter::AddTypeSourceInfo(TypeSourceInfo *TInfo) {
5569   if (!TInfo) {
5570     AddTypeRef(QualType());
5571     return;
5572   }
5573 
5574   AddTypeRef(TInfo->getType());
5575   AddTypeLoc(TInfo->getTypeLoc());
5576 }
5577 
5578 void ASTRecordWriter::AddTypeLoc(TypeLoc TL) {
5579   TypeLocWriter TLW(*this);
5580   for (; !TL.isNull(); TL = TL.getNextTypeLoc())
5581     TLW.Visit(TL);
5582 }
5583 
5584 void ASTWriter::AddTypeRef(QualType T, RecordDataImpl &Record) {
5585   Record.push_back(GetOrCreateTypeID(T));
5586 }
5587 
5588 TypeID ASTWriter::GetOrCreateTypeID(QualType T) {
5589   assert(Context);
5590   return MakeTypeID(*Context, T, [&](QualType T) -> TypeIdx {
5591     if (T.isNull())
5592       return TypeIdx();
5593     assert(!T.getLocalFastQualifiers());
5594 
5595     TypeIdx &Idx = TypeIdxs[T];
5596     if (Idx.getIndex() == 0) {
5597       if (DoneWritingDeclsAndTypes) {
5598         assert(0 && "New type seen after serializing all the types to emit!");
5599         return TypeIdx();
5600       }
5601 
5602       // We haven't seen this type before. Assign it a new ID and put it
5603       // into the queue of types to emit.
5604       Idx = TypeIdx(NextTypeID++);
5605       DeclTypesToEmit.push(T);
5606     }
5607     return Idx;
5608   });
5609 }
5610 
5611 TypeID ASTWriter::getTypeID(QualType T) const {
5612   assert(Context);
5613   return MakeTypeID(*Context, T, [&](QualType T) -> TypeIdx {
5614     if (T.isNull())
5615       return TypeIdx();
5616     assert(!T.getLocalFastQualifiers());
5617 
5618     TypeIdxMap::const_iterator I = TypeIdxs.find(T);
5619     assert(I != TypeIdxs.end() && "Type not emitted!");
5620     return I->second;
5621   });
5622 }
5623 
5624 void ASTWriter::AddDeclRef(const Decl *D, RecordDataImpl &Record) {
5625   Record.push_back(GetDeclRef(D));
5626 }
5627 
5628 DeclID ASTWriter::GetDeclRef(const Decl *D) {
5629   assert(WritingAST && "Cannot request a declaration ID before AST writing");
5630 
5631   if (!D) {
5632     return 0;
5633   }
5634 
5635   // If D comes from an AST file, its declaration ID is already known and
5636   // fixed.
5637   if (D->isFromASTFile())
5638     return D->getGlobalID();
5639 
5640   assert(!(reinterpret_cast<uintptr_t>(D) & 0x01) && "Invalid decl pointer");
5641   DeclID &ID = DeclIDs[D];
5642   if (ID == 0) {
5643     if (DoneWritingDeclsAndTypes) {
5644       assert(0 && "New decl seen after serializing all the decls to emit!");
5645       return 0;
5646     }
5647 
5648     // We haven't seen this declaration before. Give it a new ID and
5649     // enqueue it in the list of declarations to emit.
5650     ID = NextDeclID++;
5651     DeclTypesToEmit.push(const_cast<Decl *>(D));
5652   }
5653 
5654   return ID;
5655 }
5656 
5657 DeclID ASTWriter::getDeclID(const Decl *D) {
5658   if (!D)
5659     return 0;
5660 
5661   // If D comes from an AST file, its declaration ID is already known and
5662   // fixed.
5663   if (D->isFromASTFile())
5664     return D->getGlobalID();
5665 
5666   assert(DeclIDs.find(D) != DeclIDs.end() && "Declaration not emitted!");
5667   return DeclIDs[D];
5668 }
5669 
5670 void ASTWriter::associateDeclWithFile(const Decl *D, DeclID ID) {
5671   assert(ID);
5672   assert(D);
5673 
5674   SourceLocation Loc = D->getLocation();
5675   if (Loc.isInvalid())
5676     return;
5677 
5678   // We only keep track of the file-level declarations of each file.
5679   if (!D->getLexicalDeclContext()->isFileContext())
5680     return;
5681   // FIXME: ParmVarDecls that are part of a function type of a parameter of
5682   // a function/objc method, should not have TU as lexical context.
5683   // TemplateTemplateParmDecls that are part of an alias template, should not
5684   // have TU as lexical context.
5685   if (isa<ParmVarDecl>(D) || isa<TemplateTemplateParmDecl>(D))
5686     return;
5687 
5688   SourceManager &SM = Context->getSourceManager();
5689   SourceLocation FileLoc = SM.getFileLoc(Loc);
5690   assert(SM.isLocalSourceLocation(FileLoc));
5691   FileID FID;
5692   unsigned Offset;
5693   std::tie(FID, Offset) = SM.getDecomposedLoc(FileLoc);
5694   if (FID.isInvalid())
5695     return;
5696   assert(SM.getSLocEntry(FID).isFile());
5697 
5698   DeclIDInFileInfo *&Info = FileDeclIDs[FID];
5699   if (!Info)
5700     Info = new DeclIDInFileInfo();
5701 
5702   std::pair<unsigned, serialization::DeclID> LocDecl(Offset, ID);
5703   LocDeclIDsTy &Decls = Info->DeclIDs;
5704 
5705   if (Decls.empty() || Decls.back().first <= Offset) {
5706     Decls.push_back(LocDecl);
5707     return;
5708   }
5709 
5710   LocDeclIDsTy::iterator I =
5711       llvm::upper_bound(Decls, LocDecl, llvm::less_first());
5712 
5713   Decls.insert(I, LocDecl);
5714 }
5715 
5716 void ASTRecordWriter::AddDeclarationName(DeclarationName Name) {
5717   // FIXME: Emit a stable enum for NameKind.  0 = Identifier etc.
5718   Record->push_back(Name.getNameKind());
5719   switch (Name.getNameKind()) {
5720   case DeclarationName::Identifier:
5721     AddIdentifierRef(Name.getAsIdentifierInfo());
5722     break;
5723 
5724   case DeclarationName::ObjCZeroArgSelector:
5725   case DeclarationName::ObjCOneArgSelector:
5726   case DeclarationName::ObjCMultiArgSelector:
5727     AddSelectorRef(Name.getObjCSelector());
5728     break;
5729 
5730   case DeclarationName::CXXConstructorName:
5731   case DeclarationName::CXXDestructorName:
5732   case DeclarationName::CXXConversionFunctionName:
5733     AddTypeRef(Name.getCXXNameType());
5734     break;
5735 
5736   case DeclarationName::CXXDeductionGuideName:
5737     AddDeclRef(Name.getCXXDeductionGuideTemplate());
5738     break;
5739 
5740   case DeclarationName::CXXOperatorName:
5741     Record->push_back(Name.getCXXOverloadedOperator());
5742     break;
5743 
5744   case DeclarationName::CXXLiteralOperatorName:
5745     AddIdentifierRef(Name.getCXXLiteralIdentifier());
5746     break;
5747 
5748   case DeclarationName::CXXUsingDirective:
5749     // No extra data to emit
5750     break;
5751   }
5752 }
5753 
5754 unsigned ASTWriter::getAnonymousDeclarationNumber(const NamedDecl *D) {
5755   assert(needsAnonymousDeclarationNumber(D) &&
5756          "expected an anonymous declaration");
5757 
5758   // Number the anonymous declarations within this context, if we've not
5759   // already done so.
5760   auto It = AnonymousDeclarationNumbers.find(D);
5761   if (It == AnonymousDeclarationNumbers.end()) {
5762     auto *DC = D->getLexicalDeclContext();
5763     numberAnonymousDeclsWithin(DC, [&](const NamedDecl *ND, unsigned Number) {
5764       AnonymousDeclarationNumbers[ND] = Number;
5765     });
5766 
5767     It = AnonymousDeclarationNumbers.find(D);
5768     assert(It != AnonymousDeclarationNumbers.end() &&
5769            "declaration not found within its lexical context");
5770   }
5771 
5772   return It->second;
5773 }
5774 
5775 void ASTRecordWriter::AddDeclarationNameLoc(const DeclarationNameLoc &DNLoc,
5776                                             DeclarationName Name) {
5777   switch (Name.getNameKind()) {
5778   case DeclarationName::CXXConstructorName:
5779   case DeclarationName::CXXDestructorName:
5780   case DeclarationName::CXXConversionFunctionName:
5781     AddTypeSourceInfo(DNLoc.NamedType.TInfo);
5782     break;
5783 
5784   case DeclarationName::CXXOperatorName:
5785     AddSourceLocation(SourceLocation::getFromRawEncoding(
5786         DNLoc.CXXOperatorName.BeginOpNameLoc));
5787     AddSourceLocation(
5788         SourceLocation::getFromRawEncoding(DNLoc.CXXOperatorName.EndOpNameLoc));
5789     break;
5790 
5791   case DeclarationName::CXXLiteralOperatorName:
5792     AddSourceLocation(SourceLocation::getFromRawEncoding(
5793         DNLoc.CXXLiteralOperatorName.OpNameLoc));
5794     break;
5795 
5796   case DeclarationName::Identifier:
5797   case DeclarationName::ObjCZeroArgSelector:
5798   case DeclarationName::ObjCOneArgSelector:
5799   case DeclarationName::ObjCMultiArgSelector:
5800   case DeclarationName::CXXUsingDirective:
5801   case DeclarationName::CXXDeductionGuideName:
5802     break;
5803   }
5804 }
5805 
5806 void ASTRecordWriter::AddDeclarationNameInfo(
5807     const DeclarationNameInfo &NameInfo) {
5808   AddDeclarationName(NameInfo.getName());
5809   AddSourceLocation(NameInfo.getLoc());
5810   AddDeclarationNameLoc(NameInfo.getInfo(), NameInfo.getName());
5811 }
5812 
5813 void ASTRecordWriter::AddQualifierInfo(const QualifierInfo &Info) {
5814   AddNestedNameSpecifierLoc(Info.QualifierLoc);
5815   Record->push_back(Info.NumTemplParamLists);
5816   for (unsigned i = 0, e = Info.NumTemplParamLists; i != e; ++i)
5817     AddTemplateParameterList(Info.TemplParamLists[i]);
5818 }
5819 
5820 void ASTRecordWriter::AddNestedNameSpecifier(NestedNameSpecifier *NNS) {
5821   // Nested name specifiers usually aren't too long. I think that 8 would
5822   // typically accommodate the vast majority.
5823   SmallVector<NestedNameSpecifier *, 8> NestedNames;
5824 
5825   // Push each of the NNS's onto a stack for serialization in reverse order.
5826   while (NNS) {
5827     NestedNames.push_back(NNS);
5828     NNS = NNS->getPrefix();
5829   }
5830 
5831   Record->push_back(NestedNames.size());
5832   while(!NestedNames.empty()) {
5833     NNS = NestedNames.pop_back_val();
5834     NestedNameSpecifier::SpecifierKind Kind = NNS->getKind();
5835     Record->push_back(Kind);
5836     switch (Kind) {
5837     case NestedNameSpecifier::Identifier:
5838       AddIdentifierRef(NNS->getAsIdentifier());
5839       break;
5840 
5841     case NestedNameSpecifier::Namespace:
5842       AddDeclRef(NNS->getAsNamespace());
5843       break;
5844 
5845     case NestedNameSpecifier::NamespaceAlias:
5846       AddDeclRef(NNS->getAsNamespaceAlias());
5847       break;
5848 
5849     case NestedNameSpecifier::TypeSpec:
5850     case NestedNameSpecifier::TypeSpecWithTemplate:
5851       AddTypeRef(QualType(NNS->getAsType(), 0));
5852       Record->push_back(Kind == NestedNameSpecifier::TypeSpecWithTemplate);
5853       break;
5854 
5855     case NestedNameSpecifier::Global:
5856       // Don't need to write an associated value.
5857       break;
5858 
5859     case NestedNameSpecifier::Super:
5860       AddDeclRef(NNS->getAsRecordDecl());
5861       break;
5862     }
5863   }
5864 }
5865 
5866 void ASTRecordWriter::AddNestedNameSpecifierLoc(NestedNameSpecifierLoc NNS) {
5867   // Nested name specifiers usually aren't too long. I think that 8 would
5868   // typically accommodate the vast majority.
5869   SmallVector<NestedNameSpecifierLoc , 8> NestedNames;
5870 
5871   // Push each of the nested-name-specifiers's onto a stack for
5872   // serialization in reverse order.
5873   while (NNS) {
5874     NestedNames.push_back(NNS);
5875     NNS = NNS.getPrefix();
5876   }
5877 
5878   Record->push_back(NestedNames.size());
5879   while(!NestedNames.empty()) {
5880     NNS = NestedNames.pop_back_val();
5881     NestedNameSpecifier::SpecifierKind Kind
5882       = NNS.getNestedNameSpecifier()->getKind();
5883     Record->push_back(Kind);
5884     switch (Kind) {
5885     case NestedNameSpecifier::Identifier:
5886       AddIdentifierRef(NNS.getNestedNameSpecifier()->getAsIdentifier());
5887       AddSourceRange(NNS.getLocalSourceRange());
5888       break;
5889 
5890     case NestedNameSpecifier::Namespace:
5891       AddDeclRef(NNS.getNestedNameSpecifier()->getAsNamespace());
5892       AddSourceRange(NNS.getLocalSourceRange());
5893       break;
5894 
5895     case NestedNameSpecifier::NamespaceAlias:
5896       AddDeclRef(NNS.getNestedNameSpecifier()->getAsNamespaceAlias());
5897       AddSourceRange(NNS.getLocalSourceRange());
5898       break;
5899 
5900     case NestedNameSpecifier::TypeSpec:
5901     case NestedNameSpecifier::TypeSpecWithTemplate:
5902       Record->push_back(Kind == NestedNameSpecifier::TypeSpecWithTemplate);
5903       AddTypeRef(NNS.getTypeLoc().getType());
5904       AddTypeLoc(NNS.getTypeLoc());
5905       AddSourceLocation(NNS.getLocalSourceRange().getEnd());
5906       break;
5907 
5908     case NestedNameSpecifier::Global:
5909       AddSourceLocation(NNS.getLocalSourceRange().getEnd());
5910       break;
5911 
5912     case NestedNameSpecifier::Super:
5913       AddDeclRef(NNS.getNestedNameSpecifier()->getAsRecordDecl());
5914       AddSourceRange(NNS.getLocalSourceRange());
5915       break;
5916     }
5917   }
5918 }
5919 
5920 void ASTRecordWriter::AddTemplateName(TemplateName Name) {
5921   TemplateName::NameKind Kind = Name.getKind();
5922   Record->push_back(Kind);
5923   switch (Kind) {
5924   case TemplateName::Template:
5925     AddDeclRef(Name.getAsTemplateDecl());
5926     break;
5927 
5928   case TemplateName::OverloadedTemplate: {
5929     OverloadedTemplateStorage *OvT = Name.getAsOverloadedTemplate();
5930     Record->push_back(OvT->size());
5931     for (const auto &I : *OvT)
5932       AddDeclRef(I);
5933     break;
5934   }
5935 
5936   case TemplateName::AssumedTemplate: {
5937     AssumedTemplateStorage *ADLT = Name.getAsAssumedTemplateName();
5938     AddDeclarationName(ADLT->getDeclName());
5939     break;
5940   }
5941 
5942   case TemplateName::QualifiedTemplate: {
5943     QualifiedTemplateName *QualT = Name.getAsQualifiedTemplateName();
5944     AddNestedNameSpecifier(QualT->getQualifier());
5945     Record->push_back(QualT->hasTemplateKeyword());
5946     AddDeclRef(QualT->getTemplateDecl());
5947     break;
5948   }
5949 
5950   case TemplateName::DependentTemplate: {
5951     DependentTemplateName *DepT = Name.getAsDependentTemplateName();
5952     AddNestedNameSpecifier(DepT->getQualifier());
5953     Record->push_back(DepT->isIdentifier());
5954     if (DepT->isIdentifier())
5955       AddIdentifierRef(DepT->getIdentifier());
5956     else
5957       Record->push_back(DepT->getOperator());
5958     break;
5959   }
5960 
5961   case TemplateName::SubstTemplateTemplateParm: {
5962     SubstTemplateTemplateParmStorage *subst
5963       = Name.getAsSubstTemplateTemplateParm();
5964     AddDeclRef(subst->getParameter());
5965     AddTemplateName(subst->getReplacement());
5966     break;
5967   }
5968 
5969   case TemplateName::SubstTemplateTemplateParmPack: {
5970     SubstTemplateTemplateParmPackStorage *SubstPack
5971       = Name.getAsSubstTemplateTemplateParmPack();
5972     AddDeclRef(SubstPack->getParameterPack());
5973     AddTemplateArgument(SubstPack->getArgumentPack());
5974     break;
5975   }
5976   }
5977 }
5978 
5979 void ASTRecordWriter::AddTemplateArgument(const TemplateArgument &Arg) {
5980   Record->push_back(Arg.getKind());
5981   switch (Arg.getKind()) {
5982   case TemplateArgument::Null:
5983     break;
5984   case TemplateArgument::Type:
5985     AddTypeRef(Arg.getAsType());
5986     break;
5987   case TemplateArgument::Declaration:
5988     AddDeclRef(Arg.getAsDecl());
5989     AddTypeRef(Arg.getParamTypeForDecl());
5990     break;
5991   case TemplateArgument::NullPtr:
5992     AddTypeRef(Arg.getNullPtrType());
5993     break;
5994   case TemplateArgument::Integral:
5995     AddAPSInt(Arg.getAsIntegral());
5996     AddTypeRef(Arg.getIntegralType());
5997     break;
5998   case TemplateArgument::Template:
5999     AddTemplateName(Arg.getAsTemplateOrTemplatePattern());
6000     break;
6001   case TemplateArgument::TemplateExpansion:
6002     AddTemplateName(Arg.getAsTemplateOrTemplatePattern());
6003     if (Optional<unsigned> NumExpansions = Arg.getNumTemplateExpansions())
6004       Record->push_back(*NumExpansions + 1);
6005     else
6006       Record->push_back(0);
6007     break;
6008   case TemplateArgument::Expression:
6009     AddStmt(Arg.getAsExpr());
6010     break;
6011   case TemplateArgument::Pack:
6012     Record->push_back(Arg.pack_size());
6013     for (const auto &P : Arg.pack_elements())
6014       AddTemplateArgument(P);
6015     break;
6016   }
6017 }
6018 
6019 void ASTRecordWriter::AddTemplateParameterList(
6020     const TemplateParameterList *TemplateParams) {
6021   assert(TemplateParams && "No TemplateParams!");
6022   AddSourceLocation(TemplateParams->getTemplateLoc());
6023   AddSourceLocation(TemplateParams->getLAngleLoc());
6024   AddSourceLocation(TemplateParams->getRAngleLoc());
6025   // TODO: Concepts
6026   Record->push_back(TemplateParams->size());
6027   for (const auto &P : *TemplateParams)
6028     AddDeclRef(P);
6029 }
6030 
6031 /// Emit a template argument list.
6032 void ASTRecordWriter::AddTemplateArgumentList(
6033     const TemplateArgumentList *TemplateArgs) {
6034   assert(TemplateArgs && "No TemplateArgs!");
6035   Record->push_back(TemplateArgs->size());
6036   for (int i = 0, e = TemplateArgs->size(); i != e; ++i)
6037     AddTemplateArgument(TemplateArgs->get(i));
6038 }
6039 
6040 void ASTRecordWriter::AddASTTemplateArgumentListInfo(
6041     const ASTTemplateArgumentListInfo *ASTTemplArgList) {
6042   assert(ASTTemplArgList && "No ASTTemplArgList!");
6043   AddSourceLocation(ASTTemplArgList->LAngleLoc);
6044   AddSourceLocation(ASTTemplArgList->RAngleLoc);
6045   Record->push_back(ASTTemplArgList->NumTemplateArgs);
6046   const TemplateArgumentLoc *TemplArgs = ASTTemplArgList->getTemplateArgs();
6047   for (int i = 0, e = ASTTemplArgList->NumTemplateArgs; i != e; ++i)
6048     AddTemplateArgumentLoc(TemplArgs[i]);
6049 }
6050 
6051 void ASTRecordWriter::AddUnresolvedSet(const ASTUnresolvedSet &Set) {
6052   Record->push_back(Set.size());
6053   for (ASTUnresolvedSet::const_iterator
6054          I = Set.begin(), E = Set.end(); I != E; ++I) {
6055     AddDeclRef(I.getDecl());
6056     Record->push_back(I.getAccess());
6057   }
6058 }
6059 
6060 // FIXME: Move this out of the main ASTRecordWriter interface.
6061 void ASTRecordWriter::AddCXXBaseSpecifier(const CXXBaseSpecifier &Base) {
6062   Record->push_back(Base.isVirtual());
6063   Record->push_back(Base.isBaseOfClass());
6064   Record->push_back(Base.getAccessSpecifierAsWritten());
6065   Record->push_back(Base.getInheritConstructors());
6066   AddTypeSourceInfo(Base.getTypeSourceInfo());
6067   AddSourceRange(Base.getSourceRange());
6068   AddSourceLocation(Base.isPackExpansion()? Base.getEllipsisLoc()
6069                                           : SourceLocation());
6070 }
6071 
6072 static uint64_t EmitCXXBaseSpecifiers(ASTWriter &W,
6073                                       ArrayRef<CXXBaseSpecifier> Bases) {
6074   ASTWriter::RecordData Record;
6075   ASTRecordWriter Writer(W, Record);
6076   Writer.push_back(Bases.size());
6077 
6078   for (auto &Base : Bases)
6079     Writer.AddCXXBaseSpecifier(Base);
6080 
6081   return Writer.Emit(serialization::DECL_CXX_BASE_SPECIFIERS);
6082 }
6083 
6084 // FIXME: Move this out of the main ASTRecordWriter interface.
6085 void ASTRecordWriter::AddCXXBaseSpecifiers(ArrayRef<CXXBaseSpecifier> Bases) {
6086   AddOffset(EmitCXXBaseSpecifiers(*Writer, Bases));
6087 }
6088 
6089 static uint64_t
6090 EmitCXXCtorInitializers(ASTWriter &W,
6091                         ArrayRef<CXXCtorInitializer *> CtorInits) {
6092   ASTWriter::RecordData Record;
6093   ASTRecordWriter Writer(W, Record);
6094   Writer.push_back(CtorInits.size());
6095 
6096   for (auto *Init : CtorInits) {
6097     if (Init->isBaseInitializer()) {
6098       Writer.push_back(CTOR_INITIALIZER_BASE);
6099       Writer.AddTypeSourceInfo(Init->getTypeSourceInfo());
6100       Writer.push_back(Init->isBaseVirtual());
6101     } else if (Init->isDelegatingInitializer()) {
6102       Writer.push_back(CTOR_INITIALIZER_DELEGATING);
6103       Writer.AddTypeSourceInfo(Init->getTypeSourceInfo());
6104     } else if (Init->isMemberInitializer()){
6105       Writer.push_back(CTOR_INITIALIZER_MEMBER);
6106       Writer.AddDeclRef(Init->getMember());
6107     } else {
6108       Writer.push_back(CTOR_INITIALIZER_INDIRECT_MEMBER);
6109       Writer.AddDeclRef(Init->getIndirectMember());
6110     }
6111 
6112     Writer.AddSourceLocation(Init->getMemberLocation());
6113     Writer.AddStmt(Init->getInit());
6114     Writer.AddSourceLocation(Init->getLParenLoc());
6115     Writer.AddSourceLocation(Init->getRParenLoc());
6116     Writer.push_back(Init->isWritten());
6117     if (Init->isWritten())
6118       Writer.push_back(Init->getSourceOrder());
6119   }
6120 
6121   return Writer.Emit(serialization::DECL_CXX_CTOR_INITIALIZERS);
6122 }
6123 
6124 // FIXME: Move this out of the main ASTRecordWriter interface.
6125 void ASTRecordWriter::AddCXXCtorInitializers(
6126     ArrayRef<CXXCtorInitializer *> CtorInits) {
6127   AddOffset(EmitCXXCtorInitializers(*Writer, CtorInits));
6128 }
6129 
6130 void ASTRecordWriter::AddCXXDefinitionData(const CXXRecordDecl *D) {
6131   auto &Data = D->data();
6132   Record->push_back(Data.IsLambda);
6133   Record->push_back(Data.UserDeclaredConstructor);
6134   Record->push_back(Data.UserDeclaredSpecialMembers);
6135   Record->push_back(Data.Aggregate);
6136   Record->push_back(Data.PlainOldData);
6137   Record->push_back(Data.Empty);
6138   Record->push_back(Data.Polymorphic);
6139   Record->push_back(Data.Abstract);
6140   Record->push_back(Data.IsStandardLayout);
6141   Record->push_back(Data.IsCXX11StandardLayout);
6142   Record->push_back(Data.HasBasesWithFields);
6143   Record->push_back(Data.HasBasesWithNonStaticDataMembers);
6144   Record->push_back(Data.HasPrivateFields);
6145   Record->push_back(Data.HasProtectedFields);
6146   Record->push_back(Data.HasPublicFields);
6147   Record->push_back(Data.HasMutableFields);
6148   Record->push_back(Data.HasVariantMembers);
6149   Record->push_back(Data.HasOnlyCMembers);
6150   Record->push_back(Data.HasInClassInitializer);
6151   Record->push_back(Data.HasUninitializedReferenceMember);
6152   Record->push_back(Data.HasUninitializedFields);
6153   Record->push_back(Data.HasInheritedConstructor);
6154   Record->push_back(Data.HasInheritedAssignment);
6155   Record->push_back(Data.NeedOverloadResolutionForCopyConstructor);
6156   Record->push_back(Data.NeedOverloadResolutionForMoveConstructor);
6157   Record->push_back(Data.NeedOverloadResolutionForMoveAssignment);
6158   Record->push_back(Data.NeedOverloadResolutionForDestructor);
6159   Record->push_back(Data.DefaultedCopyConstructorIsDeleted);
6160   Record->push_back(Data.DefaultedMoveConstructorIsDeleted);
6161   Record->push_back(Data.DefaultedMoveAssignmentIsDeleted);
6162   Record->push_back(Data.DefaultedDestructorIsDeleted);
6163   Record->push_back(Data.HasTrivialSpecialMembers);
6164   Record->push_back(Data.HasTrivialSpecialMembersForCall);
6165   Record->push_back(Data.DeclaredNonTrivialSpecialMembers);
6166   Record->push_back(Data.DeclaredNonTrivialSpecialMembersForCall);
6167   Record->push_back(Data.HasIrrelevantDestructor);
6168   Record->push_back(Data.HasConstexprNonCopyMoveConstructor);
6169   Record->push_back(Data.HasDefaultedDefaultConstructor);
6170   Record->push_back(Data.DefaultedDefaultConstructorIsConstexpr);
6171   Record->push_back(Data.HasConstexprDefaultConstructor);
6172   Record->push_back(Data.HasNonLiteralTypeFieldsOrBases);
6173   Record->push_back(Data.ComputedVisibleConversions);
6174   Record->push_back(Data.UserProvidedDefaultConstructor);
6175   Record->push_back(Data.DeclaredSpecialMembers);
6176   Record->push_back(Data.ImplicitCopyConstructorCanHaveConstParamForVBase);
6177   Record->push_back(Data.ImplicitCopyConstructorCanHaveConstParamForNonVBase);
6178   Record->push_back(Data.ImplicitCopyAssignmentHasConstParam);
6179   Record->push_back(Data.HasDeclaredCopyConstructorWithConstParam);
6180   Record->push_back(Data.HasDeclaredCopyAssignmentWithConstParam);
6181 
6182   // getODRHash will compute the ODRHash if it has not been previously computed.
6183   Record->push_back(D->getODRHash());
6184   bool ModulesDebugInfo = Writer->Context->getLangOpts().ModulesDebugInfo &&
6185                           Writer->WritingModule && !D->isDependentType();
6186   Record->push_back(ModulesDebugInfo);
6187   if (ModulesDebugInfo)
6188     Writer->ModularCodegenDecls.push_back(Writer->GetDeclRef(D));
6189 
6190   // IsLambda bit is already saved.
6191 
6192   Record->push_back(Data.NumBases);
6193   if (Data.NumBases > 0)
6194     AddCXXBaseSpecifiers(Data.bases());
6195 
6196   // FIXME: Make VBases lazily computed when needed to avoid storing them.
6197   Record->push_back(Data.NumVBases);
6198   if (Data.NumVBases > 0)
6199     AddCXXBaseSpecifiers(Data.vbases());
6200 
6201   AddUnresolvedSet(Data.Conversions.get(*Writer->Context));
6202   AddUnresolvedSet(Data.VisibleConversions.get(*Writer->Context));
6203   // Data.Definition is the owning decl, no need to write it.
6204   AddDeclRef(D->getFirstFriend());
6205 
6206   // Add lambda-specific data.
6207   if (Data.IsLambda) {
6208     auto &Lambda = D->getLambdaData();
6209     Record->push_back(Lambda.Dependent);
6210     Record->push_back(Lambda.IsGenericLambda);
6211     Record->push_back(Lambda.CaptureDefault);
6212     Record->push_back(Lambda.NumCaptures);
6213     Record->push_back(Lambda.NumExplicitCaptures);
6214     Record->push_back(Lambda.ManglingNumber);
6215     AddDeclRef(D->getLambdaContextDecl());
6216     AddTypeSourceInfo(Lambda.MethodTyInfo);
6217     for (unsigned I = 0, N = Lambda.NumCaptures; I != N; ++I) {
6218       const LambdaCapture &Capture = Lambda.Captures[I];
6219       AddSourceLocation(Capture.getLocation());
6220       Record->push_back(Capture.isImplicit());
6221       Record->push_back(Capture.getCaptureKind());
6222       switch (Capture.getCaptureKind()) {
6223       case LCK_StarThis:
6224       case LCK_This:
6225       case LCK_VLAType:
6226         break;
6227       case LCK_ByCopy:
6228       case LCK_ByRef:
6229         VarDecl *Var =
6230             Capture.capturesVariable() ? Capture.getCapturedVar() : nullptr;
6231         AddDeclRef(Var);
6232         AddSourceLocation(Capture.isPackExpansion() ? Capture.getEllipsisLoc()
6233                                                     : SourceLocation());
6234         break;
6235       }
6236     }
6237   }
6238 }
6239 
6240 void ASTWriter::ReaderInitialized(ASTReader *Reader) {
6241   assert(Reader && "Cannot remove chain");
6242   assert((!Chain || Chain == Reader) && "Cannot replace chain");
6243   assert(FirstDeclID == NextDeclID &&
6244          FirstTypeID == NextTypeID &&
6245          FirstIdentID == NextIdentID &&
6246          FirstMacroID == NextMacroID &&
6247          FirstSubmoduleID == NextSubmoduleID &&
6248          FirstSelectorID == NextSelectorID &&
6249          "Setting chain after writing has started.");
6250 
6251   Chain = Reader;
6252 
6253   // Note, this will get called multiple times, once one the reader starts up
6254   // and again each time it's done reading a PCH or module.
6255   FirstDeclID = NUM_PREDEF_DECL_IDS + Chain->getTotalNumDecls();
6256   FirstTypeID = NUM_PREDEF_TYPE_IDS + Chain->getTotalNumTypes();
6257   FirstIdentID = NUM_PREDEF_IDENT_IDS + Chain->getTotalNumIdentifiers();
6258   FirstMacroID = NUM_PREDEF_MACRO_IDS + Chain->getTotalNumMacros();
6259   FirstSubmoduleID = NUM_PREDEF_SUBMODULE_IDS + Chain->getTotalNumSubmodules();
6260   FirstSelectorID = NUM_PREDEF_SELECTOR_IDS + Chain->getTotalNumSelectors();
6261   NextDeclID = FirstDeclID;
6262   NextTypeID = FirstTypeID;
6263   NextIdentID = FirstIdentID;
6264   NextMacroID = FirstMacroID;
6265   NextSelectorID = FirstSelectorID;
6266   NextSubmoduleID = FirstSubmoduleID;
6267 }
6268 
6269 void ASTWriter::IdentifierRead(IdentID ID, IdentifierInfo *II) {
6270   // Always keep the highest ID. See \p TypeRead() for more information.
6271   IdentID &StoredID = IdentifierIDs[II];
6272   if (ID > StoredID)
6273     StoredID = ID;
6274 }
6275 
6276 void ASTWriter::MacroRead(serialization::MacroID ID, MacroInfo *MI) {
6277   // Always keep the highest ID. See \p TypeRead() for more information.
6278   MacroID &StoredID = MacroIDs[MI];
6279   if (ID > StoredID)
6280     StoredID = ID;
6281 }
6282 
6283 void ASTWriter::TypeRead(TypeIdx Idx, QualType T) {
6284   // Always take the highest-numbered type index. This copes with an interesting
6285   // case for chained AST writing where we schedule writing the type and then,
6286   // later, deserialize the type from another AST. In this case, we want to
6287   // keep the higher-numbered entry so that we can properly write it out to
6288   // the AST file.
6289   TypeIdx &StoredIdx = TypeIdxs[T];
6290   if (Idx.getIndex() >= StoredIdx.getIndex())
6291     StoredIdx = Idx;
6292 }
6293 
6294 void ASTWriter::SelectorRead(SelectorID ID, Selector S) {
6295   // Always keep the highest ID. See \p TypeRead() for more information.
6296   SelectorID &StoredID = SelectorIDs[S];
6297   if (ID > StoredID)
6298     StoredID = ID;
6299 }
6300 
6301 void ASTWriter::MacroDefinitionRead(serialization::PreprocessedEntityID ID,
6302                                     MacroDefinitionRecord *MD) {
6303   assert(MacroDefinitions.find(MD) == MacroDefinitions.end());
6304   MacroDefinitions[MD] = ID;
6305 }
6306 
6307 void ASTWriter::ModuleRead(serialization::SubmoduleID ID, Module *Mod) {
6308   assert(SubmoduleIDs.find(Mod) == SubmoduleIDs.end());
6309   SubmoduleIDs[Mod] = ID;
6310 }
6311 
6312 void ASTWriter::CompletedTagDefinition(const TagDecl *D) {
6313   if (Chain && Chain->isProcessingUpdateRecords()) return;
6314   assert(D->isCompleteDefinition());
6315   assert(!WritingAST && "Already writing the AST!");
6316   if (auto *RD = dyn_cast<CXXRecordDecl>(D)) {
6317     // We are interested when a PCH decl is modified.
6318     if (RD->isFromASTFile()) {
6319       // A forward reference was mutated into a definition. Rewrite it.
6320       // FIXME: This happens during template instantiation, should we
6321       // have created a new definition decl instead ?
6322       assert(isTemplateInstantiation(RD->getTemplateSpecializationKind()) &&
6323              "completed a tag from another module but not by instantiation?");
6324       DeclUpdates[RD].push_back(
6325           DeclUpdate(UPD_CXX_INSTANTIATED_CLASS_DEFINITION));
6326     }
6327   }
6328 }
6329 
6330 static bool isImportedDeclContext(ASTReader *Chain, const Decl *D) {
6331   if (D->isFromASTFile())
6332     return true;
6333 
6334   // The predefined __va_list_tag struct is imported if we imported any decls.
6335   // FIXME: This is a gross hack.
6336   return D == D->getASTContext().getVaListTagDecl();
6337 }
6338 
6339 void ASTWriter::AddedVisibleDecl(const DeclContext *DC, const Decl *D) {
6340   if (Chain && Chain->isProcessingUpdateRecords()) return;
6341   assert(DC->isLookupContext() &&
6342           "Should not add lookup results to non-lookup contexts!");
6343 
6344   // TU is handled elsewhere.
6345   if (isa<TranslationUnitDecl>(DC))
6346     return;
6347 
6348   // Namespaces are handled elsewhere, except for template instantiations of
6349   // FunctionTemplateDecls in namespaces. We are interested in cases where the
6350   // local instantiations are added to an imported context. Only happens when
6351   // adding ADL lookup candidates, for example templated friends.
6352   if (isa<NamespaceDecl>(DC) && D->getFriendObjectKind() == Decl::FOK_None &&
6353       !isa<FunctionTemplateDecl>(D))
6354     return;
6355 
6356   // We're only interested in cases where a local declaration is added to an
6357   // imported context.
6358   if (D->isFromASTFile() || !isImportedDeclContext(Chain, cast<Decl>(DC)))
6359     return;
6360 
6361   assert(DC == DC->getPrimaryContext() && "added to non-primary context");
6362   assert(!getDefinitiveDeclContext(DC) && "DeclContext not definitive!");
6363   assert(!WritingAST && "Already writing the AST!");
6364   if (UpdatedDeclContexts.insert(DC) && !cast<Decl>(DC)->isFromASTFile()) {
6365     // We're adding a visible declaration to a predefined decl context. Ensure
6366     // that we write out all of its lookup results so we don't get a nasty
6367     // surprise when we try to emit its lookup table.
6368     for (auto *Child : DC->decls())
6369       DeclsToEmitEvenIfUnreferenced.push_back(Child);
6370   }
6371   DeclsToEmitEvenIfUnreferenced.push_back(D);
6372 }
6373 
6374 void ASTWriter::AddedCXXImplicitMember(const CXXRecordDecl *RD, const Decl *D) {
6375   if (Chain && Chain->isProcessingUpdateRecords()) return;
6376   assert(D->isImplicit());
6377 
6378   // We're only interested in cases where a local declaration is added to an
6379   // imported context.
6380   if (D->isFromASTFile() || !isImportedDeclContext(Chain, RD))
6381     return;
6382 
6383   if (!isa<CXXMethodDecl>(D))
6384     return;
6385 
6386   // A decl coming from PCH was modified.
6387   assert(RD->isCompleteDefinition());
6388   assert(!WritingAST && "Already writing the AST!");
6389   DeclUpdates[RD].push_back(DeclUpdate(UPD_CXX_ADDED_IMPLICIT_MEMBER, D));
6390 }
6391 
6392 void ASTWriter::ResolvedExceptionSpec(const FunctionDecl *FD) {
6393   if (Chain && Chain->isProcessingUpdateRecords()) return;
6394   assert(!DoneWritingDeclsAndTypes && "Already done writing updates!");
6395   if (!Chain) return;
6396   Chain->forEachImportedKeyDecl(FD, [&](const Decl *D) {
6397     // If we don't already know the exception specification for this redecl
6398     // chain, add an update record for it.
6399     if (isUnresolvedExceptionSpec(cast<FunctionDecl>(D)
6400                                       ->getType()
6401                                       ->castAs<FunctionProtoType>()
6402                                       ->getExceptionSpecType()))
6403       DeclUpdates[D].push_back(UPD_CXX_RESOLVED_EXCEPTION_SPEC);
6404   });
6405 }
6406 
6407 void ASTWriter::DeducedReturnType(const FunctionDecl *FD, QualType ReturnType) {
6408   if (Chain && Chain->isProcessingUpdateRecords()) return;
6409   assert(!WritingAST && "Already writing the AST!");
6410   if (!Chain) return;
6411   Chain->forEachImportedKeyDecl(FD, [&](const Decl *D) {
6412     DeclUpdates[D].push_back(
6413         DeclUpdate(UPD_CXX_DEDUCED_RETURN_TYPE, ReturnType));
6414   });
6415 }
6416 
6417 void ASTWriter::ResolvedOperatorDelete(const CXXDestructorDecl *DD,
6418                                        const FunctionDecl *Delete,
6419                                        Expr *ThisArg) {
6420   if (Chain && Chain->isProcessingUpdateRecords()) return;
6421   assert(!WritingAST && "Already writing the AST!");
6422   assert(Delete && "Not given an operator delete");
6423   if (!Chain) return;
6424   Chain->forEachImportedKeyDecl(DD, [&](const Decl *D) {
6425     DeclUpdates[D].push_back(DeclUpdate(UPD_CXX_RESOLVED_DTOR_DELETE, Delete));
6426   });
6427 }
6428 
6429 void ASTWriter::CompletedImplicitDefinition(const FunctionDecl *D) {
6430   if (Chain && Chain->isProcessingUpdateRecords()) return;
6431   assert(!WritingAST && "Already writing the AST!");
6432   if (!D->isFromASTFile())
6433     return; // Declaration not imported from PCH.
6434 
6435   // Implicit function decl from a PCH was defined.
6436   DeclUpdates[D].push_back(DeclUpdate(UPD_CXX_ADDED_FUNCTION_DEFINITION));
6437 }
6438 
6439 void ASTWriter::VariableDefinitionInstantiated(const VarDecl *D) {
6440   if (Chain && Chain->isProcessingUpdateRecords()) return;
6441   assert(!WritingAST && "Already writing the AST!");
6442   if (!D->isFromASTFile())
6443     return;
6444 
6445   DeclUpdates[D].push_back(DeclUpdate(UPD_CXX_ADDED_VAR_DEFINITION));
6446 }
6447 
6448 void ASTWriter::FunctionDefinitionInstantiated(const FunctionDecl *D) {
6449   if (Chain && Chain->isProcessingUpdateRecords()) return;
6450   assert(!WritingAST && "Already writing the AST!");
6451   if (!D->isFromASTFile())
6452     return;
6453 
6454   DeclUpdates[D].push_back(DeclUpdate(UPD_CXX_ADDED_FUNCTION_DEFINITION));
6455 }
6456 
6457 void ASTWriter::InstantiationRequested(const ValueDecl *D) {
6458   if (Chain && Chain->isProcessingUpdateRecords()) return;
6459   assert(!WritingAST && "Already writing the AST!");
6460   if (!D->isFromASTFile())
6461     return;
6462 
6463   // Since the actual instantiation is delayed, this really means that we need
6464   // to update the instantiation location.
6465   SourceLocation POI;
6466   if (auto *VD = dyn_cast<VarDecl>(D))
6467     POI = VD->getPointOfInstantiation();
6468   else
6469     POI = cast<FunctionDecl>(D)->getPointOfInstantiation();
6470   DeclUpdates[D].push_back(DeclUpdate(UPD_CXX_POINT_OF_INSTANTIATION, POI));
6471 }
6472 
6473 void ASTWriter::DefaultArgumentInstantiated(const ParmVarDecl *D) {
6474   if (Chain && Chain->isProcessingUpdateRecords()) return;
6475   assert(!WritingAST && "Already writing the AST!");
6476   if (!D->isFromASTFile())
6477     return;
6478 
6479   DeclUpdates[D].push_back(
6480       DeclUpdate(UPD_CXX_INSTANTIATED_DEFAULT_ARGUMENT, D));
6481 }
6482 
6483 void ASTWriter::DefaultMemberInitializerInstantiated(const FieldDecl *D) {
6484   assert(!WritingAST && "Already writing the AST!");
6485   if (!D->isFromASTFile())
6486     return;
6487 
6488   DeclUpdates[D].push_back(
6489       DeclUpdate(UPD_CXX_INSTANTIATED_DEFAULT_MEMBER_INITIALIZER, D));
6490 }
6491 
6492 void ASTWriter::AddedObjCCategoryToInterface(const ObjCCategoryDecl *CatD,
6493                                              const ObjCInterfaceDecl *IFD) {
6494   if (Chain && Chain->isProcessingUpdateRecords()) return;
6495   assert(!WritingAST && "Already writing the AST!");
6496   if (!IFD->isFromASTFile())
6497     return; // Declaration not imported from PCH.
6498 
6499   assert(IFD->getDefinition() && "Category on a class without a definition?");
6500   ObjCClassesWithCategories.insert(
6501     const_cast<ObjCInterfaceDecl *>(IFD->getDefinition()));
6502 }
6503 
6504 void ASTWriter::DeclarationMarkedUsed(const Decl *D) {
6505   if (Chain && Chain->isProcessingUpdateRecords()) return;
6506   assert(!WritingAST && "Already writing the AST!");
6507 
6508   // If there is *any* declaration of the entity that's not from an AST file,
6509   // we can skip writing the update record. We make sure that isUsed() triggers
6510   // completion of the redeclaration chain of the entity.
6511   for (auto Prev = D->getMostRecentDecl(); Prev; Prev = Prev->getPreviousDecl())
6512     if (IsLocalDecl(Prev))
6513       return;
6514 
6515   DeclUpdates[D].push_back(DeclUpdate(UPD_DECL_MARKED_USED));
6516 }
6517 
6518 void ASTWriter::DeclarationMarkedOpenMPThreadPrivate(const Decl *D) {
6519   if (Chain && Chain->isProcessingUpdateRecords()) return;
6520   assert(!WritingAST && "Already writing the AST!");
6521   if (!D->isFromASTFile())
6522     return;
6523 
6524   DeclUpdates[D].push_back(DeclUpdate(UPD_DECL_MARKED_OPENMP_THREADPRIVATE));
6525 }
6526 
6527 void ASTWriter::DeclarationMarkedOpenMPAllocate(const Decl *D, const Attr *A) {
6528   if (Chain && Chain->isProcessingUpdateRecords()) return;
6529   assert(!WritingAST && "Already writing the AST!");
6530   if (!D->isFromASTFile())
6531     return;
6532 
6533   DeclUpdates[D].push_back(DeclUpdate(UPD_DECL_MARKED_OPENMP_ALLOCATE, A));
6534 }
6535 
6536 void ASTWriter::DeclarationMarkedOpenMPDeclareTarget(const Decl *D,
6537                                                      const Attr *Attr) {
6538   if (Chain && Chain->isProcessingUpdateRecords()) return;
6539   assert(!WritingAST && "Already writing the AST!");
6540   if (!D->isFromASTFile())
6541     return;
6542 
6543   DeclUpdates[D].push_back(
6544       DeclUpdate(UPD_DECL_MARKED_OPENMP_DECLARETARGET, Attr));
6545 }
6546 
6547 void ASTWriter::RedefinedHiddenDefinition(const NamedDecl *D, Module *M) {
6548   if (Chain && Chain->isProcessingUpdateRecords()) return;
6549   assert(!WritingAST && "Already writing the AST!");
6550   assert(D->isHidden() && "expected a hidden declaration");
6551   DeclUpdates[D].push_back(DeclUpdate(UPD_DECL_EXPORTED, M));
6552 }
6553 
6554 void ASTWriter::AddedAttributeToRecord(const Attr *Attr,
6555                                        const RecordDecl *Record) {
6556   if (Chain && Chain->isProcessingUpdateRecords()) return;
6557   assert(!WritingAST && "Already writing the AST!");
6558   if (!Record->isFromASTFile())
6559     return;
6560   DeclUpdates[Record].push_back(DeclUpdate(UPD_ADDED_ATTR_TO_RECORD, Attr));
6561 }
6562 
6563 void ASTWriter::AddedCXXTemplateSpecialization(
6564     const ClassTemplateDecl *TD, const ClassTemplateSpecializationDecl *D) {
6565   assert(!WritingAST && "Already writing the AST!");
6566 
6567   if (!TD->getFirstDecl()->isFromASTFile())
6568     return;
6569   if (Chain && Chain->isProcessingUpdateRecords())
6570     return;
6571 
6572   DeclsToEmitEvenIfUnreferenced.push_back(D);
6573 }
6574 
6575 void ASTWriter::AddedCXXTemplateSpecialization(
6576     const VarTemplateDecl *TD, const VarTemplateSpecializationDecl *D) {
6577   assert(!WritingAST && "Already writing the AST!");
6578 
6579   if (!TD->getFirstDecl()->isFromASTFile())
6580     return;
6581   if (Chain && Chain->isProcessingUpdateRecords())
6582     return;
6583 
6584   DeclsToEmitEvenIfUnreferenced.push_back(D);
6585 }
6586 
6587 void ASTWriter::AddedCXXTemplateSpecialization(const FunctionTemplateDecl *TD,
6588                                                const FunctionDecl *D) {
6589   assert(!WritingAST && "Already writing the AST!");
6590 
6591   if (!TD->getFirstDecl()->isFromASTFile())
6592     return;
6593   if (Chain && Chain->isProcessingUpdateRecords())
6594     return;
6595 
6596   DeclsToEmitEvenIfUnreferenced.push_back(D);
6597 }
6598 
6599 //===----------------------------------------------------------------------===//
6600 //// OMPClause Serialization
6601 ////===----------------------------------------------------------------------===//
6602 
6603 void OMPClauseWriter::writeClause(OMPClause *C) {
6604   Record.push_back(C->getClauseKind());
6605   Visit(C);
6606   Record.AddSourceLocation(C->getBeginLoc());
6607   Record.AddSourceLocation(C->getEndLoc());
6608 }
6609 
6610 void OMPClauseWriter::VisitOMPClauseWithPreInit(OMPClauseWithPreInit *C) {
6611   Record.push_back(C->getCaptureRegion());
6612   Record.AddStmt(C->getPreInitStmt());
6613 }
6614 
6615 void OMPClauseWriter::VisitOMPClauseWithPostUpdate(OMPClauseWithPostUpdate *C) {
6616   VisitOMPClauseWithPreInit(C);
6617   Record.AddStmt(C->getPostUpdateExpr());
6618 }
6619 
6620 void OMPClauseWriter::VisitOMPIfClause(OMPIfClause *C) {
6621   VisitOMPClauseWithPreInit(C);
6622   Record.push_back(C->getNameModifier());
6623   Record.AddSourceLocation(C->getNameModifierLoc());
6624   Record.AddSourceLocation(C->getColonLoc());
6625   Record.AddStmt(C->getCondition());
6626   Record.AddSourceLocation(C->getLParenLoc());
6627 }
6628 
6629 void OMPClauseWriter::VisitOMPFinalClause(OMPFinalClause *C) {
6630   Record.AddStmt(C->getCondition());
6631   Record.AddSourceLocation(C->getLParenLoc());
6632 }
6633 
6634 void OMPClauseWriter::VisitOMPNumThreadsClause(OMPNumThreadsClause *C) {
6635   VisitOMPClauseWithPreInit(C);
6636   Record.AddStmt(C->getNumThreads());
6637   Record.AddSourceLocation(C->getLParenLoc());
6638 }
6639 
6640 void OMPClauseWriter::VisitOMPSafelenClause(OMPSafelenClause *C) {
6641   Record.AddStmt(C->getSafelen());
6642   Record.AddSourceLocation(C->getLParenLoc());
6643 }
6644 
6645 void OMPClauseWriter::VisitOMPSimdlenClause(OMPSimdlenClause *C) {
6646   Record.AddStmt(C->getSimdlen());
6647   Record.AddSourceLocation(C->getLParenLoc());
6648 }
6649 
6650 void OMPClauseWriter::VisitOMPAllocatorClause(OMPAllocatorClause *C) {
6651   Record.AddStmt(C->getAllocator());
6652   Record.AddSourceLocation(C->getLParenLoc());
6653 }
6654 
6655 void OMPClauseWriter::VisitOMPCollapseClause(OMPCollapseClause *C) {
6656   Record.AddStmt(C->getNumForLoops());
6657   Record.AddSourceLocation(C->getLParenLoc());
6658 }
6659 
6660 void OMPClauseWriter::VisitOMPDefaultClause(OMPDefaultClause *C) {
6661   Record.push_back(C->getDefaultKind());
6662   Record.AddSourceLocation(C->getLParenLoc());
6663   Record.AddSourceLocation(C->getDefaultKindKwLoc());
6664 }
6665 
6666 void OMPClauseWriter::VisitOMPProcBindClause(OMPProcBindClause *C) {
6667   Record.push_back(C->getProcBindKind());
6668   Record.AddSourceLocation(C->getLParenLoc());
6669   Record.AddSourceLocation(C->getProcBindKindKwLoc());
6670 }
6671 
6672 void OMPClauseWriter::VisitOMPScheduleClause(OMPScheduleClause *C) {
6673   VisitOMPClauseWithPreInit(C);
6674   Record.push_back(C->getScheduleKind());
6675   Record.push_back(C->getFirstScheduleModifier());
6676   Record.push_back(C->getSecondScheduleModifier());
6677   Record.AddStmt(C->getChunkSize());
6678   Record.AddSourceLocation(C->getLParenLoc());
6679   Record.AddSourceLocation(C->getFirstScheduleModifierLoc());
6680   Record.AddSourceLocation(C->getSecondScheduleModifierLoc());
6681   Record.AddSourceLocation(C->getScheduleKindLoc());
6682   Record.AddSourceLocation(C->getCommaLoc());
6683 }
6684 
6685 void OMPClauseWriter::VisitOMPOrderedClause(OMPOrderedClause *C) {
6686   Record.push_back(C->getLoopNumIterations().size());
6687   Record.AddStmt(C->getNumForLoops());
6688   for (Expr *NumIter : C->getLoopNumIterations())
6689     Record.AddStmt(NumIter);
6690   for (unsigned I = 0, E = C->getLoopNumIterations().size(); I <E; ++I)
6691     Record.AddStmt(C->getLoopCounter(I));
6692   Record.AddSourceLocation(C->getLParenLoc());
6693 }
6694 
6695 void OMPClauseWriter::VisitOMPNowaitClause(OMPNowaitClause *) {}
6696 
6697 void OMPClauseWriter::VisitOMPUntiedClause(OMPUntiedClause *) {}
6698 
6699 void OMPClauseWriter::VisitOMPMergeableClause(OMPMergeableClause *) {}
6700 
6701 void OMPClauseWriter::VisitOMPReadClause(OMPReadClause *) {}
6702 
6703 void OMPClauseWriter::VisitOMPWriteClause(OMPWriteClause *) {}
6704 
6705 void OMPClauseWriter::VisitOMPUpdateClause(OMPUpdateClause *) {}
6706 
6707 void OMPClauseWriter::VisitOMPCaptureClause(OMPCaptureClause *) {}
6708 
6709 void OMPClauseWriter::VisitOMPSeqCstClause(OMPSeqCstClause *) {}
6710 
6711 void OMPClauseWriter::VisitOMPThreadsClause(OMPThreadsClause *) {}
6712 
6713 void OMPClauseWriter::VisitOMPSIMDClause(OMPSIMDClause *) {}
6714 
6715 void OMPClauseWriter::VisitOMPNogroupClause(OMPNogroupClause *) {}
6716 
6717 void OMPClauseWriter::VisitOMPPrivateClause(OMPPrivateClause *C) {
6718   Record.push_back(C->varlist_size());
6719   Record.AddSourceLocation(C->getLParenLoc());
6720   for (auto *VE : C->varlists()) {
6721     Record.AddStmt(VE);
6722   }
6723   for (auto *VE : C->private_copies()) {
6724     Record.AddStmt(VE);
6725   }
6726 }
6727 
6728 void OMPClauseWriter::VisitOMPFirstprivateClause(OMPFirstprivateClause *C) {
6729   Record.push_back(C->varlist_size());
6730   VisitOMPClauseWithPreInit(C);
6731   Record.AddSourceLocation(C->getLParenLoc());
6732   for (auto *VE : C->varlists()) {
6733     Record.AddStmt(VE);
6734   }
6735   for (auto *VE : C->private_copies()) {
6736     Record.AddStmt(VE);
6737   }
6738   for (auto *VE : C->inits()) {
6739     Record.AddStmt(VE);
6740   }
6741 }
6742 
6743 void OMPClauseWriter::VisitOMPLastprivateClause(OMPLastprivateClause *C) {
6744   Record.push_back(C->varlist_size());
6745   VisitOMPClauseWithPostUpdate(C);
6746   Record.AddSourceLocation(C->getLParenLoc());
6747   for (auto *VE : C->varlists())
6748     Record.AddStmt(VE);
6749   for (auto *E : C->private_copies())
6750     Record.AddStmt(E);
6751   for (auto *E : C->source_exprs())
6752     Record.AddStmt(E);
6753   for (auto *E : C->destination_exprs())
6754     Record.AddStmt(E);
6755   for (auto *E : C->assignment_ops())
6756     Record.AddStmt(E);
6757 }
6758 
6759 void OMPClauseWriter::VisitOMPSharedClause(OMPSharedClause *C) {
6760   Record.push_back(C->varlist_size());
6761   Record.AddSourceLocation(C->getLParenLoc());
6762   for (auto *VE : C->varlists())
6763     Record.AddStmt(VE);
6764 }
6765 
6766 void OMPClauseWriter::VisitOMPReductionClause(OMPReductionClause *C) {
6767   Record.push_back(C->varlist_size());
6768   VisitOMPClauseWithPostUpdate(C);
6769   Record.AddSourceLocation(C->getLParenLoc());
6770   Record.AddSourceLocation(C->getColonLoc());
6771   Record.AddNestedNameSpecifierLoc(C->getQualifierLoc());
6772   Record.AddDeclarationNameInfo(C->getNameInfo());
6773   for (auto *VE : C->varlists())
6774     Record.AddStmt(VE);
6775   for (auto *VE : C->privates())
6776     Record.AddStmt(VE);
6777   for (auto *E : C->lhs_exprs())
6778     Record.AddStmt(E);
6779   for (auto *E : C->rhs_exprs())
6780     Record.AddStmt(E);
6781   for (auto *E : C->reduction_ops())
6782     Record.AddStmt(E);
6783 }
6784 
6785 void OMPClauseWriter::VisitOMPTaskReductionClause(OMPTaskReductionClause *C) {
6786   Record.push_back(C->varlist_size());
6787   VisitOMPClauseWithPostUpdate(C);
6788   Record.AddSourceLocation(C->getLParenLoc());
6789   Record.AddSourceLocation(C->getColonLoc());
6790   Record.AddNestedNameSpecifierLoc(C->getQualifierLoc());
6791   Record.AddDeclarationNameInfo(C->getNameInfo());
6792   for (auto *VE : C->varlists())
6793     Record.AddStmt(VE);
6794   for (auto *VE : C->privates())
6795     Record.AddStmt(VE);
6796   for (auto *E : C->lhs_exprs())
6797     Record.AddStmt(E);
6798   for (auto *E : C->rhs_exprs())
6799     Record.AddStmt(E);
6800   for (auto *E : C->reduction_ops())
6801     Record.AddStmt(E);
6802 }
6803 
6804 void OMPClauseWriter::VisitOMPInReductionClause(OMPInReductionClause *C) {
6805   Record.push_back(C->varlist_size());
6806   VisitOMPClauseWithPostUpdate(C);
6807   Record.AddSourceLocation(C->getLParenLoc());
6808   Record.AddSourceLocation(C->getColonLoc());
6809   Record.AddNestedNameSpecifierLoc(C->getQualifierLoc());
6810   Record.AddDeclarationNameInfo(C->getNameInfo());
6811   for (auto *VE : C->varlists())
6812     Record.AddStmt(VE);
6813   for (auto *VE : C->privates())
6814     Record.AddStmt(VE);
6815   for (auto *E : C->lhs_exprs())
6816     Record.AddStmt(E);
6817   for (auto *E : C->rhs_exprs())
6818     Record.AddStmt(E);
6819   for (auto *E : C->reduction_ops())
6820     Record.AddStmt(E);
6821   for (auto *E : C->taskgroup_descriptors())
6822     Record.AddStmt(E);
6823 }
6824 
6825 void OMPClauseWriter::VisitOMPLinearClause(OMPLinearClause *C) {
6826   Record.push_back(C->varlist_size());
6827   VisitOMPClauseWithPostUpdate(C);
6828   Record.AddSourceLocation(C->getLParenLoc());
6829   Record.AddSourceLocation(C->getColonLoc());
6830   Record.push_back(C->getModifier());
6831   Record.AddSourceLocation(C->getModifierLoc());
6832   for (auto *VE : C->varlists()) {
6833     Record.AddStmt(VE);
6834   }
6835   for (auto *VE : C->privates()) {
6836     Record.AddStmt(VE);
6837   }
6838   for (auto *VE : C->inits()) {
6839     Record.AddStmt(VE);
6840   }
6841   for (auto *VE : C->updates()) {
6842     Record.AddStmt(VE);
6843   }
6844   for (auto *VE : C->finals()) {
6845     Record.AddStmt(VE);
6846   }
6847   Record.AddStmt(C->getStep());
6848   Record.AddStmt(C->getCalcStep());
6849 }
6850 
6851 void OMPClauseWriter::VisitOMPAlignedClause(OMPAlignedClause *C) {
6852   Record.push_back(C->varlist_size());
6853   Record.AddSourceLocation(C->getLParenLoc());
6854   Record.AddSourceLocation(C->getColonLoc());
6855   for (auto *VE : C->varlists())
6856     Record.AddStmt(VE);
6857   Record.AddStmt(C->getAlignment());
6858 }
6859 
6860 void OMPClauseWriter::VisitOMPCopyinClause(OMPCopyinClause *C) {
6861   Record.push_back(C->varlist_size());
6862   Record.AddSourceLocation(C->getLParenLoc());
6863   for (auto *VE : C->varlists())
6864     Record.AddStmt(VE);
6865   for (auto *E : C->source_exprs())
6866     Record.AddStmt(E);
6867   for (auto *E : C->destination_exprs())
6868     Record.AddStmt(E);
6869   for (auto *E : C->assignment_ops())
6870     Record.AddStmt(E);
6871 }
6872 
6873 void OMPClauseWriter::VisitOMPCopyprivateClause(OMPCopyprivateClause *C) {
6874   Record.push_back(C->varlist_size());
6875   Record.AddSourceLocation(C->getLParenLoc());
6876   for (auto *VE : C->varlists())
6877     Record.AddStmt(VE);
6878   for (auto *E : C->source_exprs())
6879     Record.AddStmt(E);
6880   for (auto *E : C->destination_exprs())
6881     Record.AddStmt(E);
6882   for (auto *E : C->assignment_ops())
6883     Record.AddStmt(E);
6884 }
6885 
6886 void OMPClauseWriter::VisitOMPFlushClause(OMPFlushClause *C) {
6887   Record.push_back(C->varlist_size());
6888   Record.AddSourceLocation(C->getLParenLoc());
6889   for (auto *VE : C->varlists())
6890     Record.AddStmt(VE);
6891 }
6892 
6893 void OMPClauseWriter::VisitOMPDependClause(OMPDependClause *C) {
6894   Record.push_back(C->varlist_size());
6895   Record.push_back(C->getNumLoops());
6896   Record.AddSourceLocation(C->getLParenLoc());
6897   Record.push_back(C->getDependencyKind());
6898   Record.AddSourceLocation(C->getDependencyLoc());
6899   Record.AddSourceLocation(C->getColonLoc());
6900   for (auto *VE : C->varlists())
6901     Record.AddStmt(VE);
6902   for (unsigned I = 0, E = C->getNumLoops(); I < E; ++I)
6903     Record.AddStmt(C->getLoopData(I));
6904 }
6905 
6906 void OMPClauseWriter::VisitOMPDeviceClause(OMPDeviceClause *C) {
6907   VisitOMPClauseWithPreInit(C);
6908   Record.AddStmt(C->getDevice());
6909   Record.AddSourceLocation(C->getLParenLoc());
6910 }
6911 
6912 void OMPClauseWriter::VisitOMPMapClause(OMPMapClause *C) {
6913   Record.push_back(C->varlist_size());
6914   Record.push_back(C->getUniqueDeclarationsNum());
6915   Record.push_back(C->getTotalComponentListNum());
6916   Record.push_back(C->getTotalComponentsNum());
6917   Record.AddSourceLocation(C->getLParenLoc());
6918   for (unsigned I = 0; I < OMPMapClause::NumberOfModifiers; ++I) {
6919     Record.push_back(C->getMapTypeModifier(I));
6920     Record.AddSourceLocation(C->getMapTypeModifierLoc(I));
6921   }
6922   Record.AddNestedNameSpecifierLoc(C->getMapperQualifierLoc());
6923   Record.AddDeclarationNameInfo(C->getMapperIdInfo());
6924   Record.push_back(C->getMapType());
6925   Record.AddSourceLocation(C->getMapLoc());
6926   Record.AddSourceLocation(C->getColonLoc());
6927   for (auto *E : C->varlists())
6928     Record.AddStmt(E);
6929   for (auto *E : C->mapperlists())
6930     Record.AddStmt(E);
6931   for (auto *D : C->all_decls())
6932     Record.AddDeclRef(D);
6933   for (auto N : C->all_num_lists())
6934     Record.push_back(N);
6935   for (auto N : C->all_lists_sizes())
6936     Record.push_back(N);
6937   for (auto &M : C->all_components()) {
6938     Record.AddStmt(M.getAssociatedExpression());
6939     Record.AddDeclRef(M.getAssociatedDeclaration());
6940   }
6941 }
6942 
6943 void OMPClauseWriter::VisitOMPAllocateClause(OMPAllocateClause *C) {
6944   Record.push_back(C->varlist_size());
6945   Record.AddSourceLocation(C->getLParenLoc());
6946   Record.AddSourceLocation(C->getColonLoc());
6947   Record.AddStmt(C->getAllocator());
6948   for (auto *VE : C->varlists())
6949     Record.AddStmt(VE);
6950 }
6951 
6952 void OMPClauseWriter::VisitOMPNumTeamsClause(OMPNumTeamsClause *C) {
6953   VisitOMPClauseWithPreInit(C);
6954   Record.AddStmt(C->getNumTeams());
6955   Record.AddSourceLocation(C->getLParenLoc());
6956 }
6957 
6958 void OMPClauseWriter::VisitOMPThreadLimitClause(OMPThreadLimitClause *C) {
6959   VisitOMPClauseWithPreInit(C);
6960   Record.AddStmt(C->getThreadLimit());
6961   Record.AddSourceLocation(C->getLParenLoc());
6962 }
6963 
6964 void OMPClauseWriter::VisitOMPPriorityClause(OMPPriorityClause *C) {
6965   Record.AddStmt(C->getPriority());
6966   Record.AddSourceLocation(C->getLParenLoc());
6967 }
6968 
6969 void OMPClauseWriter::VisitOMPGrainsizeClause(OMPGrainsizeClause *C) {
6970   Record.AddStmt(C->getGrainsize());
6971   Record.AddSourceLocation(C->getLParenLoc());
6972 }
6973 
6974 void OMPClauseWriter::VisitOMPNumTasksClause(OMPNumTasksClause *C) {
6975   Record.AddStmt(C->getNumTasks());
6976   Record.AddSourceLocation(C->getLParenLoc());
6977 }
6978 
6979 void OMPClauseWriter::VisitOMPHintClause(OMPHintClause *C) {
6980   Record.AddStmt(C->getHint());
6981   Record.AddSourceLocation(C->getLParenLoc());
6982 }
6983 
6984 void OMPClauseWriter::VisitOMPDistScheduleClause(OMPDistScheduleClause *C) {
6985   VisitOMPClauseWithPreInit(C);
6986   Record.push_back(C->getDistScheduleKind());
6987   Record.AddStmt(C->getChunkSize());
6988   Record.AddSourceLocation(C->getLParenLoc());
6989   Record.AddSourceLocation(C->getDistScheduleKindLoc());
6990   Record.AddSourceLocation(C->getCommaLoc());
6991 }
6992 
6993 void OMPClauseWriter::VisitOMPDefaultmapClause(OMPDefaultmapClause *C) {
6994   Record.push_back(C->getDefaultmapKind());
6995   Record.push_back(C->getDefaultmapModifier());
6996   Record.AddSourceLocation(C->getLParenLoc());
6997   Record.AddSourceLocation(C->getDefaultmapModifierLoc());
6998   Record.AddSourceLocation(C->getDefaultmapKindLoc());
6999 }
7000 
7001 void OMPClauseWriter::VisitOMPToClause(OMPToClause *C) {
7002   Record.push_back(C->varlist_size());
7003   Record.push_back(C->getUniqueDeclarationsNum());
7004   Record.push_back(C->getTotalComponentListNum());
7005   Record.push_back(C->getTotalComponentsNum());
7006   Record.AddSourceLocation(C->getLParenLoc());
7007   Record.AddNestedNameSpecifierLoc(C->getMapperQualifierLoc());
7008   Record.AddDeclarationNameInfo(C->getMapperIdInfo());
7009   for (auto *E : C->varlists())
7010     Record.AddStmt(E);
7011   for (auto *E : C->mapperlists())
7012     Record.AddStmt(E);
7013   for (auto *D : C->all_decls())
7014     Record.AddDeclRef(D);
7015   for (auto N : C->all_num_lists())
7016     Record.push_back(N);
7017   for (auto N : C->all_lists_sizes())
7018     Record.push_back(N);
7019   for (auto &M : C->all_components()) {
7020     Record.AddStmt(M.getAssociatedExpression());
7021     Record.AddDeclRef(M.getAssociatedDeclaration());
7022   }
7023 }
7024 
7025 void OMPClauseWriter::VisitOMPFromClause(OMPFromClause *C) {
7026   Record.push_back(C->varlist_size());
7027   Record.push_back(C->getUniqueDeclarationsNum());
7028   Record.push_back(C->getTotalComponentListNum());
7029   Record.push_back(C->getTotalComponentsNum());
7030   Record.AddSourceLocation(C->getLParenLoc());
7031   Record.AddNestedNameSpecifierLoc(C->getMapperQualifierLoc());
7032   Record.AddDeclarationNameInfo(C->getMapperIdInfo());
7033   for (auto *E : C->varlists())
7034     Record.AddStmt(E);
7035   for (auto *E : C->mapperlists())
7036     Record.AddStmt(E);
7037   for (auto *D : C->all_decls())
7038     Record.AddDeclRef(D);
7039   for (auto N : C->all_num_lists())
7040     Record.push_back(N);
7041   for (auto N : C->all_lists_sizes())
7042     Record.push_back(N);
7043   for (auto &M : C->all_components()) {
7044     Record.AddStmt(M.getAssociatedExpression());
7045     Record.AddDeclRef(M.getAssociatedDeclaration());
7046   }
7047 }
7048 
7049 void OMPClauseWriter::VisitOMPUseDevicePtrClause(OMPUseDevicePtrClause *C) {
7050   Record.push_back(C->varlist_size());
7051   Record.push_back(C->getUniqueDeclarationsNum());
7052   Record.push_back(C->getTotalComponentListNum());
7053   Record.push_back(C->getTotalComponentsNum());
7054   Record.AddSourceLocation(C->getLParenLoc());
7055   for (auto *E : C->varlists())
7056     Record.AddStmt(E);
7057   for (auto *VE : C->private_copies())
7058     Record.AddStmt(VE);
7059   for (auto *VE : C->inits())
7060     Record.AddStmt(VE);
7061   for (auto *D : C->all_decls())
7062     Record.AddDeclRef(D);
7063   for (auto N : C->all_num_lists())
7064     Record.push_back(N);
7065   for (auto N : C->all_lists_sizes())
7066     Record.push_back(N);
7067   for (auto &M : C->all_components()) {
7068     Record.AddStmt(M.getAssociatedExpression());
7069     Record.AddDeclRef(M.getAssociatedDeclaration());
7070   }
7071 }
7072 
7073 void OMPClauseWriter::VisitOMPIsDevicePtrClause(OMPIsDevicePtrClause *C) {
7074   Record.push_back(C->varlist_size());
7075   Record.push_back(C->getUniqueDeclarationsNum());
7076   Record.push_back(C->getTotalComponentListNum());
7077   Record.push_back(C->getTotalComponentsNum());
7078   Record.AddSourceLocation(C->getLParenLoc());
7079   for (auto *E : C->varlists())
7080     Record.AddStmt(E);
7081   for (auto *D : C->all_decls())
7082     Record.AddDeclRef(D);
7083   for (auto N : C->all_num_lists())
7084     Record.push_back(N);
7085   for (auto N : C->all_lists_sizes())
7086     Record.push_back(N);
7087   for (auto &M : C->all_components()) {
7088     Record.AddStmt(M.getAssociatedExpression());
7089     Record.AddDeclRef(M.getAssociatedDeclaration());
7090   }
7091 }
7092 
7093 void OMPClauseWriter::VisitOMPUnifiedAddressClause(OMPUnifiedAddressClause *) {}
7094 
7095 void OMPClauseWriter::VisitOMPUnifiedSharedMemoryClause(
7096     OMPUnifiedSharedMemoryClause *) {}
7097 
7098 void OMPClauseWriter::VisitOMPReverseOffloadClause(OMPReverseOffloadClause *) {}
7099 
7100 void
7101 OMPClauseWriter::VisitOMPDynamicAllocatorsClause(OMPDynamicAllocatorsClause *) {
7102 }
7103 
7104 void OMPClauseWriter::VisitOMPAtomicDefaultMemOrderClause(
7105     OMPAtomicDefaultMemOrderClause *C) {
7106   Record.push_back(C->getAtomicDefaultMemOrderKind());
7107   Record.AddSourceLocation(C->getLParenLoc());
7108   Record.AddSourceLocation(C->getAtomicDefaultMemOrderKindKwLoc());
7109 }
7110