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 "ASTCommon.h"
14 #include "ASTReaderInternals.h"
15 #include "MultiOnDiskHashTable.h"
16 #include "clang/AST/ASTContext.h"
17 #include "clang/AST/ASTUnresolvedSet.h"
18 #include "clang/AST/AbstractTypeWriter.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/OpenMPClause.h"
33 #include "clang/AST/RawCommentList.h"
34 #include "clang/AST/TemplateName.h"
35 #include "clang/AST/Type.h"
36 #include "clang/AST/TypeLocVisitor.h"
37 #include "clang/Basic/Diagnostic.h"
38 #include "clang/Basic/DiagnosticOptions.h"
39 #include "clang/Basic/FileManager.h"
40 #include "clang/Basic/FileSystemOptions.h"
41 #include "clang/Basic/IdentifierTable.h"
42 #include "clang/Basic/LLVM.h"
43 #include "clang/Basic/Lambda.h"
44 #include "clang/Basic/LangOptions.h"
45 #include "clang/Basic/Module.h"
46 #include "clang/Basic/ObjCRuntime.h"
47 #include "clang/Basic/OpenCLOptions.h"
48 #include "clang/Basic/SourceLocation.h"
49 #include "clang/Basic/SourceManager.h"
50 #include "clang/Basic/SourceManagerInternals.h"
51 #include "clang/Basic/Specifiers.h"
52 #include "clang/Basic/TargetInfo.h"
53 #include "clang/Basic/TargetOptions.h"
54 #include "clang/Basic/Version.h"
55 #include "clang/Lex/HeaderSearch.h"
56 #include "clang/Lex/HeaderSearchOptions.h"
57 #include "clang/Lex/MacroInfo.h"
58 #include "clang/Lex/ModuleMap.h"
59 #include "clang/Lex/PreprocessingRecord.h"
60 #include "clang/Lex/Preprocessor.h"
61 #include "clang/Lex/PreprocessorOptions.h"
62 #include "clang/Lex/Token.h"
63 #include "clang/Sema/IdentifierResolver.h"
64 #include "clang/Sema/ObjCMethodList.h"
65 #include "clang/Sema/Sema.h"
66 #include "clang/Sema/Weak.h"
67 #include "clang/Serialization/ASTBitCodes.h"
68 #include "clang/Serialization/ASTReader.h"
69 #include "clang/Serialization/ASTRecordWriter.h"
70 #include "clang/Serialization/InMemoryModuleCache.h"
71 #include "clang/Serialization/ModuleFile.h"
72 #include "clang/Serialization/ModuleFileExtension.h"
73 #include "clang/Serialization/SerializationDiagnostic.h"
74 #include "llvm/ADT/APFloat.h"
75 #include "llvm/ADT/APInt.h"
76 #include "llvm/ADT/APSInt.h"
77 #include "llvm/ADT/ArrayRef.h"
78 #include "llvm/ADT/DenseMap.h"
79 #include "llvm/ADT/Hashing.h"
80 #include "llvm/ADT/Optional.h"
81 #include "llvm/ADT/PointerIntPair.h"
82 #include "llvm/ADT/STLExtras.h"
83 #include "llvm/ADT/ScopeExit.h"
84 #include "llvm/ADT/SmallPtrSet.h"
85 #include "llvm/ADT/SmallString.h"
86 #include "llvm/ADT/SmallVector.h"
87 #include "llvm/ADT/StringMap.h"
88 #include "llvm/ADT/StringRef.h"
89 #include "llvm/Bitstream/BitCodes.h"
90 #include "llvm/Bitstream/BitstreamWriter.h"
91 #include "llvm/Support/Casting.h"
92 #include "llvm/Support/Compression.h"
93 #include "llvm/Support/DJB.h"
94 #include "llvm/Support/Endian.h"
95 #include "llvm/Support/EndianStream.h"
96 #include "llvm/Support/Error.h"
97 #include "llvm/Support/ErrorHandling.h"
98 #include "llvm/Support/LEB128.h"
99 #include "llvm/Support/MemoryBuffer.h"
100 #include "llvm/Support/OnDiskHashTable.h"
101 #include "llvm/Support/Path.h"
102 #include "llvm/Support/SHA1.h"
103 #include "llvm/Support/VersionTuple.h"
104 #include "llvm/Support/raw_ostream.h"
105 #include <algorithm>
106 #include <cassert>
107 #include <cstdint>
108 #include <cstdlib>
109 #include <cstring>
110 #include <ctime>
111 #include <deque>
112 #include <limits>
113 #include <memory>
114 #include <queue>
115 #include <tuple>
116 #include <utility>
117 #include <vector>
118 
119 using namespace clang;
120 using namespace clang::serialization;
121 
122 template <typename T, typename Allocator>
123 static StringRef bytes(const std::vector<T, Allocator> &v) {
124   if (v.empty()) return StringRef();
125   return StringRef(reinterpret_cast<const char*>(&v[0]),
126                          sizeof(T) * v.size());
127 }
128 
129 template <typename T>
130 static StringRef bytes(const SmallVectorImpl<T> &v) {
131   return StringRef(reinterpret_cast<const char*>(v.data()),
132                          sizeof(T) * v.size());
133 }
134 
135 static std::string bytes(const std::vector<bool> &V) {
136   std::string Str;
137   Str.reserve(V.size() / 8);
138   for (unsigned I = 0, E = V.size(); I < E;) {
139     char Byte = 0;
140     for (unsigned Bit = 0; Bit < 8 && I < E; ++Bit, ++I)
141       Byte |= V[I] << Bit;
142     Str += Byte;
143   }
144   return Str;
145 }
146 
147 //===----------------------------------------------------------------------===//
148 // Type serialization
149 //===----------------------------------------------------------------------===//
150 
151 static TypeCode getTypeCodeForTypeClass(Type::TypeClass id) {
152   switch (id) {
153 #define TYPE_BIT_CODE(CLASS_ID, CODE_ID, CODE_VALUE) \
154   case Type::CLASS_ID: return TYPE_##CODE_ID;
155 #include "clang/Serialization/TypeBitCodes.def"
156   case Type::Builtin:
157     llvm_unreachable("shouldn't be serializing a builtin type this way");
158   }
159   llvm_unreachable("bad type kind");
160 }
161 
162 namespace {
163 
164 std::set<const FileEntry *> GetAllModuleMaps(const HeaderSearch &HS,
165                                              Module *RootModule) {
166   std::set<const FileEntry *> ModuleMaps{};
167   std::set<const Module *> ProcessedModules;
168   SmallVector<const Module *> ModulesToProcess{RootModule};
169 
170   SmallVector<const FileEntry *, 16> FilesByUID;
171   HS.getFileMgr().GetUniqueIDMapping(FilesByUID);
172 
173   if (FilesByUID.size() > HS.header_file_size())
174     FilesByUID.resize(HS.header_file_size());
175 
176   for (unsigned UID = 0, LastUID = FilesByUID.size(); UID != LastUID; ++UID) {
177     const FileEntry *File = FilesByUID[UID];
178     if (!File)
179       continue;
180 
181     const HeaderFileInfo *HFI =
182         HS.getExistingFileInfo(File, /*WantExternal*/ false);
183     if (!HFI || (HFI->isModuleHeader && !HFI->isCompilingModuleHeader))
184       continue;
185 
186     for (const auto &KH : HS.findAllModulesForHeader(File)) {
187       if (!KH.getModule())
188         continue;
189       ModulesToProcess.push_back(KH.getModule());
190     }
191   }
192 
193   while (!ModulesToProcess.empty()) {
194     auto *CurrentModule = ModulesToProcess.pop_back_val();
195     ProcessedModules.insert(CurrentModule);
196 
197     auto *ModuleMapFile =
198         HS.getModuleMap().getModuleMapFileForUniquing(CurrentModule);
199     if (!ModuleMapFile) {
200       continue;
201     }
202 
203     ModuleMaps.insert(ModuleMapFile);
204 
205     for (auto *ImportedModule : (CurrentModule)->Imports) {
206       if (!ImportedModule ||
207           ProcessedModules.find(ImportedModule) != ProcessedModules.end()) {
208         continue;
209       }
210       ModulesToProcess.push_back(ImportedModule);
211     }
212 
213     for (const Module *UndeclaredModule : CurrentModule->UndeclaredUses)
214       if (UndeclaredModule &&
215           ProcessedModules.find(UndeclaredModule) == ProcessedModules.end())
216         ModulesToProcess.push_back(UndeclaredModule);
217   }
218 
219   return ModuleMaps;
220 }
221 
222 class ASTTypeWriter {
223   ASTWriter &Writer;
224   ASTWriter::RecordData Record;
225   ASTRecordWriter BasicWriter;
226 
227 public:
228   ASTTypeWriter(ASTWriter &Writer)
229     : Writer(Writer), BasicWriter(Writer, Record) {}
230 
231   uint64_t write(QualType T) {
232     if (T.hasLocalNonFastQualifiers()) {
233       Qualifiers Qs = T.getLocalQualifiers();
234       BasicWriter.writeQualType(T.getLocalUnqualifiedType());
235       BasicWriter.writeQualifiers(Qs);
236       return BasicWriter.Emit(TYPE_EXT_QUAL, Writer.getTypeExtQualAbbrev());
237     }
238 
239     const Type *typePtr = T.getTypePtr();
240     serialization::AbstractTypeWriter<ASTRecordWriter> atw(BasicWriter);
241     atw.write(typePtr);
242     return BasicWriter.Emit(getTypeCodeForTypeClass(typePtr->getTypeClass()),
243                             /*abbrev*/ 0);
244   }
245 };
246 
247 class TypeLocWriter : public TypeLocVisitor<TypeLocWriter> {
248   ASTRecordWriter &Record;
249 
250 public:
251   TypeLocWriter(ASTRecordWriter &Record) : Record(Record) {}
252 
253 #define ABSTRACT_TYPELOC(CLASS, PARENT)
254 #define TYPELOC(CLASS, PARENT) \
255     void Visit##CLASS##TypeLoc(CLASS##TypeLoc TyLoc);
256 #include "clang/AST/TypeLocNodes.def"
257 
258   void VisitArrayTypeLoc(ArrayTypeLoc TyLoc);
259   void VisitFunctionTypeLoc(FunctionTypeLoc TyLoc);
260 };
261 
262 } // namespace
263 
264 void TypeLocWriter::VisitQualifiedTypeLoc(QualifiedTypeLoc TL) {
265   // nothing to do
266 }
267 
268 void TypeLocWriter::VisitBuiltinTypeLoc(BuiltinTypeLoc TL) {
269   Record.AddSourceLocation(TL.getBuiltinLoc());
270   if (TL.needsExtraLocalData()) {
271     Record.push_back(TL.getWrittenTypeSpec());
272     Record.push_back(static_cast<uint64_t>(TL.getWrittenSignSpec()));
273     Record.push_back(static_cast<uint64_t>(TL.getWrittenWidthSpec()));
274     Record.push_back(TL.hasModeAttr());
275   }
276 }
277 
278 void TypeLocWriter::VisitComplexTypeLoc(ComplexTypeLoc TL) {
279   Record.AddSourceLocation(TL.getNameLoc());
280 }
281 
282 void TypeLocWriter::VisitPointerTypeLoc(PointerTypeLoc TL) {
283   Record.AddSourceLocation(TL.getStarLoc());
284 }
285 
286 void TypeLocWriter::VisitDecayedTypeLoc(DecayedTypeLoc TL) {
287   // nothing to do
288 }
289 
290 void TypeLocWriter::VisitAdjustedTypeLoc(AdjustedTypeLoc TL) {
291   // nothing to do
292 }
293 
294 void TypeLocWriter::VisitBlockPointerTypeLoc(BlockPointerTypeLoc TL) {
295   Record.AddSourceLocation(TL.getCaretLoc());
296 }
297 
298 void TypeLocWriter::VisitLValueReferenceTypeLoc(LValueReferenceTypeLoc TL) {
299   Record.AddSourceLocation(TL.getAmpLoc());
300 }
301 
302 void TypeLocWriter::VisitRValueReferenceTypeLoc(RValueReferenceTypeLoc TL) {
303   Record.AddSourceLocation(TL.getAmpAmpLoc());
304 }
305 
306 void TypeLocWriter::VisitMemberPointerTypeLoc(MemberPointerTypeLoc TL) {
307   Record.AddSourceLocation(TL.getStarLoc());
308   Record.AddTypeSourceInfo(TL.getClassTInfo());
309 }
310 
311 void TypeLocWriter::VisitArrayTypeLoc(ArrayTypeLoc TL) {
312   Record.AddSourceLocation(TL.getLBracketLoc());
313   Record.AddSourceLocation(TL.getRBracketLoc());
314   Record.push_back(TL.getSizeExpr() ? 1 : 0);
315   if (TL.getSizeExpr())
316     Record.AddStmt(TL.getSizeExpr());
317 }
318 
319 void TypeLocWriter::VisitConstantArrayTypeLoc(ConstantArrayTypeLoc TL) {
320   VisitArrayTypeLoc(TL);
321 }
322 
323 void TypeLocWriter::VisitIncompleteArrayTypeLoc(IncompleteArrayTypeLoc TL) {
324   VisitArrayTypeLoc(TL);
325 }
326 
327 void TypeLocWriter::VisitVariableArrayTypeLoc(VariableArrayTypeLoc TL) {
328   VisitArrayTypeLoc(TL);
329 }
330 
331 void TypeLocWriter::VisitDependentSizedArrayTypeLoc(
332                                             DependentSizedArrayTypeLoc TL) {
333   VisitArrayTypeLoc(TL);
334 }
335 
336 void TypeLocWriter::VisitDependentAddressSpaceTypeLoc(
337     DependentAddressSpaceTypeLoc TL) {
338   Record.AddSourceLocation(TL.getAttrNameLoc());
339   SourceRange range = TL.getAttrOperandParensRange();
340   Record.AddSourceLocation(range.getBegin());
341   Record.AddSourceLocation(range.getEnd());
342   Record.AddStmt(TL.getAttrExprOperand());
343 }
344 
345 void TypeLocWriter::VisitDependentSizedExtVectorTypeLoc(
346                                         DependentSizedExtVectorTypeLoc TL) {
347   Record.AddSourceLocation(TL.getNameLoc());
348 }
349 
350 void TypeLocWriter::VisitVectorTypeLoc(VectorTypeLoc TL) {
351   Record.AddSourceLocation(TL.getNameLoc());
352 }
353 
354 void TypeLocWriter::VisitDependentVectorTypeLoc(
355     DependentVectorTypeLoc TL) {
356   Record.AddSourceLocation(TL.getNameLoc());
357 }
358 
359 void TypeLocWriter::VisitExtVectorTypeLoc(ExtVectorTypeLoc TL) {
360   Record.AddSourceLocation(TL.getNameLoc());
361 }
362 
363 void TypeLocWriter::VisitConstantMatrixTypeLoc(ConstantMatrixTypeLoc TL) {
364   Record.AddSourceLocation(TL.getAttrNameLoc());
365   SourceRange range = TL.getAttrOperandParensRange();
366   Record.AddSourceLocation(range.getBegin());
367   Record.AddSourceLocation(range.getEnd());
368   Record.AddStmt(TL.getAttrRowOperand());
369   Record.AddStmt(TL.getAttrColumnOperand());
370 }
371 
372 void TypeLocWriter::VisitDependentSizedMatrixTypeLoc(
373     DependentSizedMatrixTypeLoc TL) {
374   Record.AddSourceLocation(TL.getAttrNameLoc());
375   SourceRange range = TL.getAttrOperandParensRange();
376   Record.AddSourceLocation(range.getBegin());
377   Record.AddSourceLocation(range.getEnd());
378   Record.AddStmt(TL.getAttrRowOperand());
379   Record.AddStmt(TL.getAttrColumnOperand());
380 }
381 
382 void TypeLocWriter::VisitFunctionTypeLoc(FunctionTypeLoc TL) {
383   Record.AddSourceLocation(TL.getLocalRangeBegin());
384   Record.AddSourceLocation(TL.getLParenLoc());
385   Record.AddSourceLocation(TL.getRParenLoc());
386   Record.AddSourceRange(TL.getExceptionSpecRange());
387   Record.AddSourceLocation(TL.getLocalRangeEnd());
388   for (unsigned i = 0, e = TL.getNumParams(); i != e; ++i)
389     Record.AddDeclRef(TL.getParam(i));
390 }
391 
392 void TypeLocWriter::VisitFunctionProtoTypeLoc(FunctionProtoTypeLoc TL) {
393   VisitFunctionTypeLoc(TL);
394 }
395 
396 void TypeLocWriter::VisitFunctionNoProtoTypeLoc(FunctionNoProtoTypeLoc TL) {
397   VisitFunctionTypeLoc(TL);
398 }
399 
400 void TypeLocWriter::VisitUnresolvedUsingTypeLoc(UnresolvedUsingTypeLoc TL) {
401   Record.AddSourceLocation(TL.getNameLoc());
402 }
403 
404 void TypeLocWriter::VisitUsingTypeLoc(UsingTypeLoc TL) {
405   Record.AddSourceLocation(TL.getNameLoc());
406 }
407 
408 void TypeLocWriter::VisitTypedefTypeLoc(TypedefTypeLoc TL) {
409   Record.AddSourceLocation(TL.getNameLoc());
410 }
411 
412 void TypeLocWriter::VisitObjCTypeParamTypeLoc(ObjCTypeParamTypeLoc TL) {
413   if (TL.getNumProtocols()) {
414     Record.AddSourceLocation(TL.getProtocolLAngleLoc());
415     Record.AddSourceLocation(TL.getProtocolRAngleLoc());
416   }
417   for (unsigned i = 0, e = TL.getNumProtocols(); i != e; ++i)
418     Record.AddSourceLocation(TL.getProtocolLoc(i));
419 }
420 
421 void TypeLocWriter::VisitTypeOfExprTypeLoc(TypeOfExprTypeLoc TL) {
422   Record.AddSourceLocation(TL.getTypeofLoc());
423   Record.AddSourceLocation(TL.getLParenLoc());
424   Record.AddSourceLocation(TL.getRParenLoc());
425 }
426 
427 void TypeLocWriter::VisitTypeOfTypeLoc(TypeOfTypeLoc TL) {
428   Record.AddSourceLocation(TL.getTypeofLoc());
429   Record.AddSourceLocation(TL.getLParenLoc());
430   Record.AddSourceLocation(TL.getRParenLoc());
431   Record.AddTypeSourceInfo(TL.getUnderlyingTInfo());
432 }
433 
434 void TypeLocWriter::VisitDecltypeTypeLoc(DecltypeTypeLoc TL) {
435   Record.AddSourceLocation(TL.getDecltypeLoc());
436   Record.AddSourceLocation(TL.getRParenLoc());
437 }
438 
439 void TypeLocWriter::VisitUnaryTransformTypeLoc(UnaryTransformTypeLoc TL) {
440   Record.AddSourceLocation(TL.getKWLoc());
441   Record.AddSourceLocation(TL.getLParenLoc());
442   Record.AddSourceLocation(TL.getRParenLoc());
443   Record.AddTypeSourceInfo(TL.getUnderlyingTInfo());
444 }
445 
446 void TypeLocWriter::VisitAutoTypeLoc(AutoTypeLoc TL) {
447   Record.AddSourceLocation(TL.getNameLoc());
448   Record.push_back(TL.isConstrained());
449   if (TL.isConstrained()) {
450     Record.AddNestedNameSpecifierLoc(TL.getNestedNameSpecifierLoc());
451     Record.AddSourceLocation(TL.getTemplateKWLoc());
452     Record.AddSourceLocation(TL.getConceptNameLoc());
453     Record.AddDeclRef(TL.getFoundDecl());
454     Record.AddSourceLocation(TL.getLAngleLoc());
455     Record.AddSourceLocation(TL.getRAngleLoc());
456     for (unsigned I = 0; I < TL.getNumArgs(); ++I)
457       Record.AddTemplateArgumentLocInfo(TL.getTypePtr()->getArg(I).getKind(),
458                                         TL.getArgLocInfo(I));
459   }
460   Record.push_back(TL.isDecltypeAuto());
461   if (TL.isDecltypeAuto())
462     Record.AddSourceLocation(TL.getRParenLoc());
463 }
464 
465 void TypeLocWriter::VisitDeducedTemplateSpecializationTypeLoc(
466     DeducedTemplateSpecializationTypeLoc TL) {
467   Record.AddSourceLocation(TL.getTemplateNameLoc());
468 }
469 
470 void TypeLocWriter::VisitRecordTypeLoc(RecordTypeLoc TL) {
471   Record.AddSourceLocation(TL.getNameLoc());
472 }
473 
474 void TypeLocWriter::VisitEnumTypeLoc(EnumTypeLoc TL) {
475   Record.AddSourceLocation(TL.getNameLoc());
476 }
477 
478 void TypeLocWriter::VisitAttributedTypeLoc(AttributedTypeLoc TL) {
479   Record.AddAttr(TL.getAttr());
480 }
481 
482 void TypeLocWriter::VisitBTFTagAttributedTypeLoc(BTFTagAttributedTypeLoc TL) {
483   // Nothing to do.
484 }
485 
486 void TypeLocWriter::VisitTemplateTypeParmTypeLoc(TemplateTypeParmTypeLoc TL) {
487   Record.AddSourceLocation(TL.getNameLoc());
488 }
489 
490 void TypeLocWriter::VisitSubstTemplateTypeParmTypeLoc(
491                                             SubstTemplateTypeParmTypeLoc TL) {
492   Record.AddSourceLocation(TL.getNameLoc());
493 }
494 
495 void TypeLocWriter::VisitSubstTemplateTypeParmPackTypeLoc(
496                                           SubstTemplateTypeParmPackTypeLoc TL) {
497   Record.AddSourceLocation(TL.getNameLoc());
498 }
499 
500 void TypeLocWriter::VisitTemplateSpecializationTypeLoc(
501                                            TemplateSpecializationTypeLoc TL) {
502   Record.AddSourceLocation(TL.getTemplateKeywordLoc());
503   Record.AddSourceLocation(TL.getTemplateNameLoc());
504   Record.AddSourceLocation(TL.getLAngleLoc());
505   Record.AddSourceLocation(TL.getRAngleLoc());
506   for (unsigned i = 0, e = TL.getNumArgs(); i != e; ++i)
507     Record.AddTemplateArgumentLocInfo(TL.getArgLoc(i).getArgument().getKind(),
508                                       TL.getArgLoc(i).getLocInfo());
509 }
510 
511 void TypeLocWriter::VisitParenTypeLoc(ParenTypeLoc TL) {
512   Record.AddSourceLocation(TL.getLParenLoc());
513   Record.AddSourceLocation(TL.getRParenLoc());
514 }
515 
516 void TypeLocWriter::VisitMacroQualifiedTypeLoc(MacroQualifiedTypeLoc TL) {
517   Record.AddSourceLocation(TL.getExpansionLoc());
518 }
519 
520 void TypeLocWriter::VisitElaboratedTypeLoc(ElaboratedTypeLoc TL) {
521   Record.AddSourceLocation(TL.getElaboratedKeywordLoc());
522   Record.AddNestedNameSpecifierLoc(TL.getQualifierLoc());
523 }
524 
525 void TypeLocWriter::VisitInjectedClassNameTypeLoc(InjectedClassNameTypeLoc TL) {
526   Record.AddSourceLocation(TL.getNameLoc());
527 }
528 
529 void TypeLocWriter::VisitDependentNameTypeLoc(DependentNameTypeLoc TL) {
530   Record.AddSourceLocation(TL.getElaboratedKeywordLoc());
531   Record.AddNestedNameSpecifierLoc(TL.getQualifierLoc());
532   Record.AddSourceLocation(TL.getNameLoc());
533 }
534 
535 void TypeLocWriter::VisitDependentTemplateSpecializationTypeLoc(
536        DependentTemplateSpecializationTypeLoc TL) {
537   Record.AddSourceLocation(TL.getElaboratedKeywordLoc());
538   Record.AddNestedNameSpecifierLoc(TL.getQualifierLoc());
539   Record.AddSourceLocation(TL.getTemplateKeywordLoc());
540   Record.AddSourceLocation(TL.getTemplateNameLoc());
541   Record.AddSourceLocation(TL.getLAngleLoc());
542   Record.AddSourceLocation(TL.getRAngleLoc());
543   for (unsigned I = 0, E = TL.getNumArgs(); I != E; ++I)
544     Record.AddTemplateArgumentLocInfo(TL.getArgLoc(I).getArgument().getKind(),
545                                       TL.getArgLoc(I).getLocInfo());
546 }
547 
548 void TypeLocWriter::VisitPackExpansionTypeLoc(PackExpansionTypeLoc TL) {
549   Record.AddSourceLocation(TL.getEllipsisLoc());
550 }
551 
552 void TypeLocWriter::VisitObjCInterfaceTypeLoc(ObjCInterfaceTypeLoc TL) {
553   Record.AddSourceLocation(TL.getNameLoc());
554 }
555 
556 void TypeLocWriter::VisitObjCObjectTypeLoc(ObjCObjectTypeLoc TL) {
557   Record.push_back(TL.hasBaseTypeAsWritten());
558   Record.AddSourceLocation(TL.getTypeArgsLAngleLoc());
559   Record.AddSourceLocation(TL.getTypeArgsRAngleLoc());
560   for (unsigned i = 0, e = TL.getNumTypeArgs(); i != e; ++i)
561     Record.AddTypeSourceInfo(TL.getTypeArgTInfo(i));
562   Record.AddSourceLocation(TL.getProtocolLAngleLoc());
563   Record.AddSourceLocation(TL.getProtocolRAngleLoc());
564   for (unsigned i = 0, e = TL.getNumProtocols(); i != e; ++i)
565     Record.AddSourceLocation(TL.getProtocolLoc(i));
566 }
567 
568 void TypeLocWriter::VisitObjCObjectPointerTypeLoc(ObjCObjectPointerTypeLoc TL) {
569   Record.AddSourceLocation(TL.getStarLoc());
570 }
571 
572 void TypeLocWriter::VisitAtomicTypeLoc(AtomicTypeLoc TL) {
573   Record.AddSourceLocation(TL.getKWLoc());
574   Record.AddSourceLocation(TL.getLParenLoc());
575   Record.AddSourceLocation(TL.getRParenLoc());
576 }
577 
578 void TypeLocWriter::VisitPipeTypeLoc(PipeTypeLoc TL) {
579   Record.AddSourceLocation(TL.getKWLoc());
580 }
581 
582 void TypeLocWriter::VisitBitIntTypeLoc(clang::BitIntTypeLoc TL) {
583   Record.AddSourceLocation(TL.getNameLoc());
584 }
585 void TypeLocWriter::VisitDependentBitIntTypeLoc(
586     clang::DependentBitIntTypeLoc TL) {
587   Record.AddSourceLocation(TL.getNameLoc());
588 }
589 
590 void ASTWriter::WriteTypeAbbrevs() {
591   using namespace llvm;
592 
593   std::shared_ptr<BitCodeAbbrev> Abv;
594 
595   // Abbreviation for TYPE_EXT_QUAL
596   Abv = std::make_shared<BitCodeAbbrev>();
597   Abv->Add(BitCodeAbbrevOp(serialization::TYPE_EXT_QUAL));
598   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // Type
599   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 3));   // Quals
600   TypeExtQualAbbrev = Stream.EmitAbbrev(std::move(Abv));
601 }
602 
603 //===----------------------------------------------------------------------===//
604 // ASTWriter Implementation
605 //===----------------------------------------------------------------------===//
606 
607 static void EmitBlockID(unsigned ID, const char *Name,
608                         llvm::BitstreamWriter &Stream,
609                         ASTWriter::RecordDataImpl &Record) {
610   Record.clear();
611   Record.push_back(ID);
612   Stream.EmitRecord(llvm::bitc::BLOCKINFO_CODE_SETBID, Record);
613 
614   // Emit the block name if present.
615   if (!Name || Name[0] == 0)
616     return;
617   Record.clear();
618   while (*Name)
619     Record.push_back(*Name++);
620   Stream.EmitRecord(llvm::bitc::BLOCKINFO_CODE_BLOCKNAME, Record);
621 }
622 
623 static void EmitRecordID(unsigned ID, const char *Name,
624                          llvm::BitstreamWriter &Stream,
625                          ASTWriter::RecordDataImpl &Record) {
626   Record.clear();
627   Record.push_back(ID);
628   while (*Name)
629     Record.push_back(*Name++);
630   Stream.EmitRecord(llvm::bitc::BLOCKINFO_CODE_SETRECORDNAME, Record);
631 }
632 
633 static void AddStmtsExprs(llvm::BitstreamWriter &Stream,
634                           ASTWriter::RecordDataImpl &Record) {
635 #define RECORD(X) EmitRecordID(X, #X, Stream, Record)
636   RECORD(STMT_STOP);
637   RECORD(STMT_NULL_PTR);
638   RECORD(STMT_REF_PTR);
639   RECORD(STMT_NULL);
640   RECORD(STMT_COMPOUND);
641   RECORD(STMT_CASE);
642   RECORD(STMT_DEFAULT);
643   RECORD(STMT_LABEL);
644   RECORD(STMT_ATTRIBUTED);
645   RECORD(STMT_IF);
646   RECORD(STMT_SWITCH);
647   RECORD(STMT_WHILE);
648   RECORD(STMT_DO);
649   RECORD(STMT_FOR);
650   RECORD(STMT_GOTO);
651   RECORD(STMT_INDIRECT_GOTO);
652   RECORD(STMT_CONTINUE);
653   RECORD(STMT_BREAK);
654   RECORD(STMT_RETURN);
655   RECORD(STMT_DECL);
656   RECORD(STMT_GCCASM);
657   RECORD(STMT_MSASM);
658   RECORD(EXPR_PREDEFINED);
659   RECORD(EXPR_DECL_REF);
660   RECORD(EXPR_INTEGER_LITERAL);
661   RECORD(EXPR_FIXEDPOINT_LITERAL);
662   RECORD(EXPR_FLOATING_LITERAL);
663   RECORD(EXPR_IMAGINARY_LITERAL);
664   RECORD(EXPR_STRING_LITERAL);
665   RECORD(EXPR_CHARACTER_LITERAL);
666   RECORD(EXPR_PAREN);
667   RECORD(EXPR_PAREN_LIST);
668   RECORD(EXPR_UNARY_OPERATOR);
669   RECORD(EXPR_SIZEOF_ALIGN_OF);
670   RECORD(EXPR_ARRAY_SUBSCRIPT);
671   RECORD(EXPR_CALL);
672   RECORD(EXPR_MEMBER);
673   RECORD(EXPR_BINARY_OPERATOR);
674   RECORD(EXPR_COMPOUND_ASSIGN_OPERATOR);
675   RECORD(EXPR_CONDITIONAL_OPERATOR);
676   RECORD(EXPR_IMPLICIT_CAST);
677   RECORD(EXPR_CSTYLE_CAST);
678   RECORD(EXPR_COMPOUND_LITERAL);
679   RECORD(EXPR_EXT_VECTOR_ELEMENT);
680   RECORD(EXPR_INIT_LIST);
681   RECORD(EXPR_DESIGNATED_INIT);
682   RECORD(EXPR_DESIGNATED_INIT_UPDATE);
683   RECORD(EXPR_IMPLICIT_VALUE_INIT);
684   RECORD(EXPR_NO_INIT);
685   RECORD(EXPR_VA_ARG);
686   RECORD(EXPR_ADDR_LABEL);
687   RECORD(EXPR_STMT);
688   RECORD(EXPR_CHOOSE);
689   RECORD(EXPR_GNU_NULL);
690   RECORD(EXPR_SHUFFLE_VECTOR);
691   RECORD(EXPR_BLOCK);
692   RECORD(EXPR_GENERIC_SELECTION);
693   RECORD(EXPR_OBJC_STRING_LITERAL);
694   RECORD(EXPR_OBJC_BOXED_EXPRESSION);
695   RECORD(EXPR_OBJC_ARRAY_LITERAL);
696   RECORD(EXPR_OBJC_DICTIONARY_LITERAL);
697   RECORD(EXPR_OBJC_ENCODE);
698   RECORD(EXPR_OBJC_SELECTOR_EXPR);
699   RECORD(EXPR_OBJC_PROTOCOL_EXPR);
700   RECORD(EXPR_OBJC_IVAR_REF_EXPR);
701   RECORD(EXPR_OBJC_PROPERTY_REF_EXPR);
702   RECORD(EXPR_OBJC_KVC_REF_EXPR);
703   RECORD(EXPR_OBJC_MESSAGE_EXPR);
704   RECORD(STMT_OBJC_FOR_COLLECTION);
705   RECORD(STMT_OBJC_CATCH);
706   RECORD(STMT_OBJC_FINALLY);
707   RECORD(STMT_OBJC_AT_TRY);
708   RECORD(STMT_OBJC_AT_SYNCHRONIZED);
709   RECORD(STMT_OBJC_AT_THROW);
710   RECORD(EXPR_OBJC_BOOL_LITERAL);
711   RECORD(STMT_CXX_CATCH);
712   RECORD(STMT_CXX_TRY);
713   RECORD(STMT_CXX_FOR_RANGE);
714   RECORD(EXPR_CXX_OPERATOR_CALL);
715   RECORD(EXPR_CXX_MEMBER_CALL);
716   RECORD(EXPR_CXX_REWRITTEN_BINARY_OPERATOR);
717   RECORD(EXPR_CXX_CONSTRUCT);
718   RECORD(EXPR_CXX_TEMPORARY_OBJECT);
719   RECORD(EXPR_CXX_STATIC_CAST);
720   RECORD(EXPR_CXX_DYNAMIC_CAST);
721   RECORD(EXPR_CXX_REINTERPRET_CAST);
722   RECORD(EXPR_CXX_CONST_CAST);
723   RECORD(EXPR_CXX_ADDRSPACE_CAST);
724   RECORD(EXPR_CXX_FUNCTIONAL_CAST);
725   RECORD(EXPR_USER_DEFINED_LITERAL);
726   RECORD(EXPR_CXX_STD_INITIALIZER_LIST);
727   RECORD(EXPR_CXX_BOOL_LITERAL);
728   RECORD(EXPR_CXX_NULL_PTR_LITERAL);
729   RECORD(EXPR_CXX_TYPEID_EXPR);
730   RECORD(EXPR_CXX_TYPEID_TYPE);
731   RECORD(EXPR_CXX_THIS);
732   RECORD(EXPR_CXX_THROW);
733   RECORD(EXPR_CXX_DEFAULT_ARG);
734   RECORD(EXPR_CXX_DEFAULT_INIT);
735   RECORD(EXPR_CXX_BIND_TEMPORARY);
736   RECORD(EXPR_CXX_SCALAR_VALUE_INIT);
737   RECORD(EXPR_CXX_NEW);
738   RECORD(EXPR_CXX_DELETE);
739   RECORD(EXPR_CXX_PSEUDO_DESTRUCTOR);
740   RECORD(EXPR_EXPR_WITH_CLEANUPS);
741   RECORD(EXPR_CXX_DEPENDENT_SCOPE_MEMBER);
742   RECORD(EXPR_CXX_DEPENDENT_SCOPE_DECL_REF);
743   RECORD(EXPR_CXX_UNRESOLVED_CONSTRUCT);
744   RECORD(EXPR_CXX_UNRESOLVED_MEMBER);
745   RECORD(EXPR_CXX_UNRESOLVED_LOOKUP);
746   RECORD(EXPR_CXX_EXPRESSION_TRAIT);
747   RECORD(EXPR_CXX_NOEXCEPT);
748   RECORD(EXPR_OPAQUE_VALUE);
749   RECORD(EXPR_BINARY_CONDITIONAL_OPERATOR);
750   RECORD(EXPR_TYPE_TRAIT);
751   RECORD(EXPR_ARRAY_TYPE_TRAIT);
752   RECORD(EXPR_PACK_EXPANSION);
753   RECORD(EXPR_SIZEOF_PACK);
754   RECORD(EXPR_SUBST_NON_TYPE_TEMPLATE_PARM);
755   RECORD(EXPR_SUBST_NON_TYPE_TEMPLATE_PARM_PACK);
756   RECORD(EXPR_FUNCTION_PARM_PACK);
757   RECORD(EXPR_MATERIALIZE_TEMPORARY);
758   RECORD(EXPR_CUDA_KERNEL_CALL);
759   RECORD(EXPR_CXX_UUIDOF_EXPR);
760   RECORD(EXPR_CXX_UUIDOF_TYPE);
761   RECORD(EXPR_LAMBDA);
762 #undef RECORD
763 }
764 
765 void ASTWriter::WriteBlockInfoBlock() {
766   RecordData Record;
767   Stream.EnterBlockInfoBlock();
768 
769 #define BLOCK(X) EmitBlockID(X ## _ID, #X, Stream, Record)
770 #define RECORD(X) EmitRecordID(X, #X, Stream, Record)
771 
772   // Control Block.
773   BLOCK(CONTROL_BLOCK);
774   RECORD(METADATA);
775   RECORD(MODULE_NAME);
776   RECORD(MODULE_DIRECTORY);
777   RECORD(MODULE_MAP_FILE);
778   RECORD(IMPORTS);
779   RECORD(ORIGINAL_FILE);
780   RECORD(ORIGINAL_PCH_DIR);
781   RECORD(ORIGINAL_FILE_ID);
782   RECORD(INPUT_FILE_OFFSETS);
783 
784   BLOCK(OPTIONS_BLOCK);
785   RECORD(LANGUAGE_OPTIONS);
786   RECORD(TARGET_OPTIONS);
787   RECORD(FILE_SYSTEM_OPTIONS);
788   RECORD(HEADER_SEARCH_OPTIONS);
789   RECORD(PREPROCESSOR_OPTIONS);
790 
791   BLOCK(INPUT_FILES_BLOCK);
792   RECORD(INPUT_FILE);
793   RECORD(INPUT_FILE_HASH);
794 
795   // AST Top-Level Block.
796   BLOCK(AST_BLOCK);
797   RECORD(TYPE_OFFSET);
798   RECORD(DECL_OFFSET);
799   RECORD(IDENTIFIER_OFFSET);
800   RECORD(IDENTIFIER_TABLE);
801   RECORD(EAGERLY_DESERIALIZED_DECLS);
802   RECORD(MODULAR_CODEGEN_DECLS);
803   RECORD(SPECIAL_TYPES);
804   RECORD(STATISTICS);
805   RECORD(TENTATIVE_DEFINITIONS);
806   RECORD(SELECTOR_OFFSETS);
807   RECORD(METHOD_POOL);
808   RECORD(PP_COUNTER_VALUE);
809   RECORD(SOURCE_LOCATION_OFFSETS);
810   RECORD(SOURCE_LOCATION_PRELOADS);
811   RECORD(EXT_VECTOR_DECLS);
812   RECORD(UNUSED_FILESCOPED_DECLS);
813   RECORD(PPD_ENTITIES_OFFSETS);
814   RECORD(VTABLE_USES);
815   RECORD(PPD_SKIPPED_RANGES);
816   RECORD(REFERENCED_SELECTOR_POOL);
817   RECORD(TU_UPDATE_LEXICAL);
818   RECORD(SEMA_DECL_REFS);
819   RECORD(WEAK_UNDECLARED_IDENTIFIERS);
820   RECORD(PENDING_IMPLICIT_INSTANTIATIONS);
821   RECORD(UPDATE_VISIBLE);
822   RECORD(DECL_UPDATE_OFFSETS);
823   RECORD(DECL_UPDATES);
824   RECORD(CUDA_SPECIAL_DECL_REFS);
825   RECORD(HEADER_SEARCH_TABLE);
826   RECORD(FP_PRAGMA_OPTIONS);
827   RECORD(OPENCL_EXTENSIONS);
828   RECORD(OPENCL_EXTENSION_TYPES);
829   RECORD(OPENCL_EXTENSION_DECLS);
830   RECORD(DELEGATING_CTORS);
831   RECORD(KNOWN_NAMESPACES);
832   RECORD(MODULE_OFFSET_MAP);
833   RECORD(SOURCE_MANAGER_LINE_TABLE);
834   RECORD(OBJC_CATEGORIES_MAP);
835   RECORD(FILE_SORTED_DECLS);
836   RECORD(IMPORTED_MODULES);
837   RECORD(OBJC_CATEGORIES);
838   RECORD(MACRO_OFFSET);
839   RECORD(INTERESTING_IDENTIFIERS);
840   RECORD(UNDEFINED_BUT_USED);
841   RECORD(LATE_PARSED_TEMPLATE);
842   RECORD(OPTIMIZE_PRAGMA_OPTIONS);
843   RECORD(MSSTRUCT_PRAGMA_OPTIONS);
844   RECORD(POINTERS_TO_MEMBERS_PRAGMA_OPTIONS);
845   RECORD(UNUSED_LOCAL_TYPEDEF_NAME_CANDIDATES);
846   RECORD(DELETE_EXPRS_TO_ANALYZE);
847   RECORD(CUDA_PRAGMA_FORCE_HOST_DEVICE_DEPTH);
848   RECORD(PP_CONDITIONAL_STACK);
849   RECORD(DECLS_TO_CHECK_FOR_DEFERRED_DIAGS);
850   RECORD(PP_INCLUDED_FILES);
851   RECORD(PP_ASSUME_NONNULL_LOC);
852 
853   // SourceManager Block.
854   BLOCK(SOURCE_MANAGER_BLOCK);
855   RECORD(SM_SLOC_FILE_ENTRY);
856   RECORD(SM_SLOC_BUFFER_ENTRY);
857   RECORD(SM_SLOC_BUFFER_BLOB);
858   RECORD(SM_SLOC_BUFFER_BLOB_COMPRESSED);
859   RECORD(SM_SLOC_EXPANSION_ENTRY);
860 
861   // Preprocessor Block.
862   BLOCK(PREPROCESSOR_BLOCK);
863   RECORD(PP_MACRO_DIRECTIVE_HISTORY);
864   RECORD(PP_MACRO_FUNCTION_LIKE);
865   RECORD(PP_MACRO_OBJECT_LIKE);
866   RECORD(PP_MODULE_MACRO);
867   RECORD(PP_TOKEN);
868 
869   // Submodule Block.
870   BLOCK(SUBMODULE_BLOCK);
871   RECORD(SUBMODULE_METADATA);
872   RECORD(SUBMODULE_DEFINITION);
873   RECORD(SUBMODULE_UMBRELLA_HEADER);
874   RECORD(SUBMODULE_HEADER);
875   RECORD(SUBMODULE_TOPHEADER);
876   RECORD(SUBMODULE_UMBRELLA_DIR);
877   RECORD(SUBMODULE_IMPORTS);
878   RECORD(SUBMODULE_EXPORTS);
879   RECORD(SUBMODULE_REQUIRES);
880   RECORD(SUBMODULE_EXCLUDED_HEADER);
881   RECORD(SUBMODULE_LINK_LIBRARY);
882   RECORD(SUBMODULE_CONFIG_MACRO);
883   RECORD(SUBMODULE_CONFLICT);
884   RECORD(SUBMODULE_PRIVATE_HEADER);
885   RECORD(SUBMODULE_TEXTUAL_HEADER);
886   RECORD(SUBMODULE_PRIVATE_TEXTUAL_HEADER);
887   RECORD(SUBMODULE_INITIALIZERS);
888   RECORD(SUBMODULE_EXPORT_AS);
889 
890   // Comments Block.
891   BLOCK(COMMENTS_BLOCK);
892   RECORD(COMMENTS_RAW_COMMENT);
893 
894   // Decls and Types block.
895   BLOCK(DECLTYPES_BLOCK);
896   RECORD(TYPE_EXT_QUAL);
897   RECORD(TYPE_COMPLEX);
898   RECORD(TYPE_POINTER);
899   RECORD(TYPE_BLOCK_POINTER);
900   RECORD(TYPE_LVALUE_REFERENCE);
901   RECORD(TYPE_RVALUE_REFERENCE);
902   RECORD(TYPE_MEMBER_POINTER);
903   RECORD(TYPE_CONSTANT_ARRAY);
904   RECORD(TYPE_INCOMPLETE_ARRAY);
905   RECORD(TYPE_VARIABLE_ARRAY);
906   RECORD(TYPE_VECTOR);
907   RECORD(TYPE_EXT_VECTOR);
908   RECORD(TYPE_FUNCTION_NO_PROTO);
909   RECORD(TYPE_FUNCTION_PROTO);
910   RECORD(TYPE_TYPEDEF);
911   RECORD(TYPE_TYPEOF_EXPR);
912   RECORD(TYPE_TYPEOF);
913   RECORD(TYPE_RECORD);
914   RECORD(TYPE_ENUM);
915   RECORD(TYPE_OBJC_INTERFACE);
916   RECORD(TYPE_OBJC_OBJECT_POINTER);
917   RECORD(TYPE_DECLTYPE);
918   RECORD(TYPE_ELABORATED);
919   RECORD(TYPE_SUBST_TEMPLATE_TYPE_PARM);
920   RECORD(TYPE_UNRESOLVED_USING);
921   RECORD(TYPE_INJECTED_CLASS_NAME);
922   RECORD(TYPE_OBJC_OBJECT);
923   RECORD(TYPE_TEMPLATE_TYPE_PARM);
924   RECORD(TYPE_TEMPLATE_SPECIALIZATION);
925   RECORD(TYPE_DEPENDENT_NAME);
926   RECORD(TYPE_DEPENDENT_TEMPLATE_SPECIALIZATION);
927   RECORD(TYPE_DEPENDENT_SIZED_ARRAY);
928   RECORD(TYPE_PAREN);
929   RECORD(TYPE_MACRO_QUALIFIED);
930   RECORD(TYPE_PACK_EXPANSION);
931   RECORD(TYPE_ATTRIBUTED);
932   RECORD(TYPE_SUBST_TEMPLATE_TYPE_PARM_PACK);
933   RECORD(TYPE_AUTO);
934   RECORD(TYPE_UNARY_TRANSFORM);
935   RECORD(TYPE_ATOMIC);
936   RECORD(TYPE_DECAYED);
937   RECORD(TYPE_ADJUSTED);
938   RECORD(TYPE_OBJC_TYPE_PARAM);
939   RECORD(LOCAL_REDECLARATIONS);
940   RECORD(DECL_TYPEDEF);
941   RECORD(DECL_TYPEALIAS);
942   RECORD(DECL_ENUM);
943   RECORD(DECL_RECORD);
944   RECORD(DECL_ENUM_CONSTANT);
945   RECORD(DECL_FUNCTION);
946   RECORD(DECL_OBJC_METHOD);
947   RECORD(DECL_OBJC_INTERFACE);
948   RECORD(DECL_OBJC_PROTOCOL);
949   RECORD(DECL_OBJC_IVAR);
950   RECORD(DECL_OBJC_AT_DEFS_FIELD);
951   RECORD(DECL_OBJC_CATEGORY);
952   RECORD(DECL_OBJC_CATEGORY_IMPL);
953   RECORD(DECL_OBJC_IMPLEMENTATION);
954   RECORD(DECL_OBJC_COMPATIBLE_ALIAS);
955   RECORD(DECL_OBJC_PROPERTY);
956   RECORD(DECL_OBJC_PROPERTY_IMPL);
957   RECORD(DECL_FIELD);
958   RECORD(DECL_MS_PROPERTY);
959   RECORD(DECL_VAR);
960   RECORD(DECL_IMPLICIT_PARAM);
961   RECORD(DECL_PARM_VAR);
962   RECORD(DECL_FILE_SCOPE_ASM);
963   RECORD(DECL_BLOCK);
964   RECORD(DECL_CONTEXT_LEXICAL);
965   RECORD(DECL_CONTEXT_VISIBLE);
966   RECORD(DECL_NAMESPACE);
967   RECORD(DECL_NAMESPACE_ALIAS);
968   RECORD(DECL_USING);
969   RECORD(DECL_USING_SHADOW);
970   RECORD(DECL_USING_DIRECTIVE);
971   RECORD(DECL_UNRESOLVED_USING_VALUE);
972   RECORD(DECL_UNRESOLVED_USING_TYPENAME);
973   RECORD(DECL_LINKAGE_SPEC);
974   RECORD(DECL_CXX_RECORD);
975   RECORD(DECL_CXX_METHOD);
976   RECORD(DECL_CXX_CONSTRUCTOR);
977   RECORD(DECL_CXX_DESTRUCTOR);
978   RECORD(DECL_CXX_CONVERSION);
979   RECORD(DECL_ACCESS_SPEC);
980   RECORD(DECL_FRIEND);
981   RECORD(DECL_FRIEND_TEMPLATE);
982   RECORD(DECL_CLASS_TEMPLATE);
983   RECORD(DECL_CLASS_TEMPLATE_SPECIALIZATION);
984   RECORD(DECL_CLASS_TEMPLATE_PARTIAL_SPECIALIZATION);
985   RECORD(DECL_VAR_TEMPLATE);
986   RECORD(DECL_VAR_TEMPLATE_SPECIALIZATION);
987   RECORD(DECL_VAR_TEMPLATE_PARTIAL_SPECIALIZATION);
988   RECORD(DECL_FUNCTION_TEMPLATE);
989   RECORD(DECL_TEMPLATE_TYPE_PARM);
990   RECORD(DECL_NON_TYPE_TEMPLATE_PARM);
991   RECORD(DECL_TEMPLATE_TEMPLATE_PARM);
992   RECORD(DECL_CONCEPT);
993   RECORD(DECL_REQUIRES_EXPR_BODY);
994   RECORD(DECL_TYPE_ALIAS_TEMPLATE);
995   RECORD(DECL_STATIC_ASSERT);
996   RECORD(DECL_CXX_BASE_SPECIFIERS);
997   RECORD(DECL_CXX_CTOR_INITIALIZERS);
998   RECORD(DECL_INDIRECTFIELD);
999   RECORD(DECL_EXPANDED_NON_TYPE_TEMPLATE_PARM_PACK);
1000   RECORD(DECL_EXPANDED_TEMPLATE_TEMPLATE_PARM_PACK);
1001   RECORD(DECL_CLASS_SCOPE_FUNCTION_SPECIALIZATION);
1002   RECORD(DECL_IMPORT);
1003   RECORD(DECL_OMP_THREADPRIVATE);
1004   RECORD(DECL_EMPTY);
1005   RECORD(DECL_OBJC_TYPE_PARAM);
1006   RECORD(DECL_OMP_CAPTUREDEXPR);
1007   RECORD(DECL_PRAGMA_COMMENT);
1008   RECORD(DECL_PRAGMA_DETECT_MISMATCH);
1009   RECORD(DECL_OMP_DECLARE_REDUCTION);
1010   RECORD(DECL_OMP_ALLOCATE);
1011 
1012   // Statements and Exprs can occur in the Decls and Types block.
1013   AddStmtsExprs(Stream, Record);
1014 
1015   BLOCK(PREPROCESSOR_DETAIL_BLOCK);
1016   RECORD(PPD_MACRO_EXPANSION);
1017   RECORD(PPD_MACRO_DEFINITION);
1018   RECORD(PPD_INCLUSION_DIRECTIVE);
1019 
1020   // Decls and Types block.
1021   BLOCK(EXTENSION_BLOCK);
1022   RECORD(EXTENSION_METADATA);
1023 
1024   BLOCK(UNHASHED_CONTROL_BLOCK);
1025   RECORD(SIGNATURE);
1026   RECORD(AST_BLOCK_HASH);
1027   RECORD(DIAGNOSTIC_OPTIONS);
1028   RECORD(DIAG_PRAGMA_MAPPINGS);
1029 
1030 #undef RECORD
1031 #undef BLOCK
1032   Stream.ExitBlock();
1033 }
1034 
1035 /// Prepares a path for being written to an AST file by converting it
1036 /// to an absolute path and removing nested './'s.
1037 ///
1038 /// \return \c true if the path was changed.
1039 static bool cleanPathForOutput(FileManager &FileMgr,
1040                                SmallVectorImpl<char> &Path) {
1041   bool Changed = FileMgr.makeAbsolutePath(Path);
1042   return Changed | llvm::sys::path::remove_dots(Path);
1043 }
1044 
1045 /// Adjusts the given filename to only write out the portion of the
1046 /// filename that is not part of the system root directory.
1047 ///
1048 /// \param Filename the file name to adjust.
1049 ///
1050 /// \param BaseDir When non-NULL, the PCH file is a relocatable AST file and
1051 /// the returned filename will be adjusted by this root directory.
1052 ///
1053 /// \returns either the original filename (if it needs no adjustment) or the
1054 /// adjusted filename (which points into the @p Filename parameter).
1055 static const char *
1056 adjustFilenameForRelocatableAST(const char *Filename, StringRef BaseDir) {
1057   assert(Filename && "No file name to adjust?");
1058 
1059   if (BaseDir.empty())
1060     return Filename;
1061 
1062   // Verify that the filename and the system root have the same prefix.
1063   unsigned Pos = 0;
1064   for (; Filename[Pos] && Pos < BaseDir.size(); ++Pos)
1065     if (Filename[Pos] != BaseDir[Pos])
1066       return Filename; // Prefixes don't match.
1067 
1068   // We hit the end of the filename before we hit the end of the system root.
1069   if (!Filename[Pos])
1070     return Filename;
1071 
1072   // If there's not a path separator at the end of the base directory nor
1073   // immediately after it, then this isn't within the base directory.
1074   if (!llvm::sys::path::is_separator(Filename[Pos])) {
1075     if (!llvm::sys::path::is_separator(BaseDir.back()))
1076       return Filename;
1077   } else {
1078     // If the file name has a '/' at the current position, skip over the '/'.
1079     // We distinguish relative paths from absolute paths by the
1080     // absence of '/' at the beginning of relative paths.
1081     //
1082     // FIXME: This is wrong. We distinguish them by asking if the path is
1083     // absolute, which isn't the same thing. And there might be multiple '/'s
1084     // in a row. Use a better mechanism to indicate whether we have emitted an
1085     // absolute or relative path.
1086     ++Pos;
1087   }
1088 
1089   return Filename + Pos;
1090 }
1091 
1092 std::pair<ASTFileSignature, ASTFileSignature>
1093 ASTWriter::createSignature(StringRef AllBytes, StringRef ASTBlockBytes) {
1094   llvm::SHA1 Hasher;
1095   Hasher.update(ASTBlockBytes);
1096   ASTFileSignature ASTBlockHash = ASTFileSignature::create(Hasher.result());
1097 
1098   // Add the remaining bytes (i.e. bytes before the unhashed control block that
1099   // are not part of the AST block).
1100   Hasher.update(
1101       AllBytes.take_front(ASTBlockBytes.bytes_end() - AllBytes.bytes_begin()));
1102   Hasher.update(
1103       AllBytes.take_back(AllBytes.bytes_end() - ASTBlockBytes.bytes_end()));
1104   ASTFileSignature Signature = ASTFileSignature::create(Hasher.result());
1105 
1106   return std::make_pair(ASTBlockHash, Signature);
1107 }
1108 
1109 ASTFileSignature ASTWriter::writeUnhashedControlBlock(Preprocessor &PP,
1110                                                       ASTContext &Context) {
1111   using namespace llvm;
1112 
1113   // Flush first to prepare the PCM hash (signature).
1114   Stream.FlushToWord();
1115   auto StartOfUnhashedControl = Stream.GetCurrentBitNo() >> 3;
1116 
1117   // Enter the block and prepare to write records.
1118   RecordData Record;
1119   Stream.EnterSubblock(UNHASHED_CONTROL_BLOCK_ID, 5);
1120 
1121   // For implicit modules, write the hash of the PCM as its signature.
1122   ASTFileSignature Signature;
1123   if (WritingModule &&
1124       PP.getHeaderSearchInfo().getHeaderSearchOpts().ModulesHashContent) {
1125     ASTFileSignature ASTBlockHash;
1126     auto ASTBlockStartByte = ASTBlockRange.first >> 3;
1127     auto ASTBlockByteLength = (ASTBlockRange.second >> 3) - ASTBlockStartByte;
1128     std::tie(ASTBlockHash, Signature) = createSignature(
1129         StringRef(Buffer.begin(), StartOfUnhashedControl),
1130         StringRef(Buffer.begin() + ASTBlockStartByte, ASTBlockByteLength));
1131 
1132     Record.append(ASTBlockHash.begin(), ASTBlockHash.end());
1133     Stream.EmitRecord(AST_BLOCK_HASH, Record);
1134     Record.clear();
1135     Record.append(Signature.begin(), Signature.end());
1136     Stream.EmitRecord(SIGNATURE, Record);
1137     Record.clear();
1138   }
1139 
1140   // Diagnostic options.
1141   const auto &Diags = Context.getDiagnostics();
1142   const DiagnosticOptions &DiagOpts = Diags.getDiagnosticOptions();
1143 #define DIAGOPT(Name, Bits, Default) Record.push_back(DiagOpts.Name);
1144 #define ENUM_DIAGOPT(Name, Type, Bits, Default)                                \
1145   Record.push_back(static_cast<unsigned>(DiagOpts.get##Name()));
1146 #include "clang/Basic/DiagnosticOptions.def"
1147   Record.push_back(DiagOpts.Warnings.size());
1148   for (unsigned I = 0, N = DiagOpts.Warnings.size(); I != N; ++I)
1149     AddString(DiagOpts.Warnings[I], Record);
1150   Record.push_back(DiagOpts.Remarks.size());
1151   for (unsigned I = 0, N = DiagOpts.Remarks.size(); I != N; ++I)
1152     AddString(DiagOpts.Remarks[I], Record);
1153   // Note: we don't serialize the log or serialization file names, because they
1154   // are generally transient files and will almost always be overridden.
1155   Stream.EmitRecord(DIAGNOSTIC_OPTIONS, Record);
1156   Record.clear();
1157 
1158   // Write out the diagnostic/pragma mappings.
1159   WritePragmaDiagnosticMappings(Diags, /* isModule = */ WritingModule);
1160 
1161   // Header search entry usage.
1162   auto HSEntryUsage = PP.getHeaderSearchInfo().computeUserEntryUsage();
1163   auto Abbrev = std::make_shared<BitCodeAbbrev>();
1164   Abbrev->Add(BitCodeAbbrevOp(HEADER_SEARCH_ENTRY_USAGE));
1165   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // Number of bits.
1166   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));      // Bit vector.
1167   unsigned HSUsageAbbrevCode = Stream.EmitAbbrev(std::move(Abbrev));
1168   {
1169     RecordData::value_type Record[] = {HEADER_SEARCH_ENTRY_USAGE,
1170                                        HSEntryUsage.size()};
1171     Stream.EmitRecordWithBlob(HSUsageAbbrevCode, Record, bytes(HSEntryUsage));
1172   }
1173 
1174   // Leave the options block.
1175   Stream.ExitBlock();
1176   return Signature;
1177 }
1178 
1179 /// Write the control block.
1180 void ASTWriter::WriteControlBlock(Preprocessor &PP, ASTContext &Context,
1181                                   StringRef isysroot,
1182                                   const std::string &OutputFile) {
1183   using namespace llvm;
1184 
1185   Stream.EnterSubblock(CONTROL_BLOCK_ID, 5);
1186   RecordData Record;
1187 
1188   // Metadata
1189   auto MetadataAbbrev = std::make_shared<BitCodeAbbrev>();
1190   MetadataAbbrev->Add(BitCodeAbbrevOp(METADATA));
1191   MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 16)); // Major
1192   MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 16)); // Minor
1193   MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 16)); // Clang maj.
1194   MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 16)); // Clang min.
1195   MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Relocatable
1196   MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Timestamps
1197   MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Errors
1198   MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // SVN branch/tag
1199   unsigned MetadataAbbrevCode = Stream.EmitAbbrev(std::move(MetadataAbbrev));
1200   assert((!WritingModule || isysroot.empty()) &&
1201          "writing module as a relocatable PCH?");
1202   {
1203     RecordData::value_type Record[] = {
1204         METADATA,
1205         VERSION_MAJOR,
1206         VERSION_MINOR,
1207         CLANG_VERSION_MAJOR,
1208         CLANG_VERSION_MINOR,
1209         !isysroot.empty(),
1210         IncludeTimestamps,
1211         ASTHasCompilerErrors};
1212     Stream.EmitRecordWithBlob(MetadataAbbrevCode, Record,
1213                               getClangFullRepositoryVersion());
1214   }
1215 
1216   if (WritingModule) {
1217     // Module name
1218     auto Abbrev = std::make_shared<BitCodeAbbrev>();
1219     Abbrev->Add(BitCodeAbbrevOp(MODULE_NAME));
1220     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
1221     unsigned AbbrevCode = Stream.EmitAbbrev(std::move(Abbrev));
1222     RecordData::value_type Record[] = {MODULE_NAME};
1223     Stream.EmitRecordWithBlob(AbbrevCode, Record, WritingModule->Name);
1224   }
1225 
1226   if (WritingModule && WritingModule->Directory) {
1227     SmallString<128> BaseDir;
1228     if (PP.getHeaderSearchInfo().getHeaderSearchOpts().ModuleFileHomeIsCwd) {
1229       // Use the current working directory as the base path for all inputs.
1230       auto *CWD =
1231           Context.getSourceManager().getFileManager().getDirectory(".").get();
1232       BaseDir.assign(CWD->getName());
1233     } else {
1234       BaseDir.assign(WritingModule->Directory->getName());
1235     }
1236     cleanPathForOutput(Context.getSourceManager().getFileManager(), BaseDir);
1237 
1238     // If the home of the module is the current working directory, then we
1239     // want to pick up the cwd of the build process loading the module, not
1240     // our cwd, when we load this module.
1241     if (!(PP.getHeaderSearchInfo()
1242               .getHeaderSearchOpts()
1243               .ModuleMapFileHomeIsCwd ||
1244           PP.getHeaderSearchInfo().getHeaderSearchOpts().ModuleFileHomeIsCwd) ||
1245         WritingModule->Directory->getName() != StringRef(".")) {
1246       // Module directory.
1247       auto Abbrev = std::make_shared<BitCodeAbbrev>();
1248       Abbrev->Add(BitCodeAbbrevOp(MODULE_DIRECTORY));
1249       Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Directory
1250       unsigned AbbrevCode = Stream.EmitAbbrev(std::move(Abbrev));
1251 
1252       RecordData::value_type Record[] = {MODULE_DIRECTORY};
1253       Stream.EmitRecordWithBlob(AbbrevCode, Record, BaseDir);
1254     }
1255 
1256     // Write out all other paths relative to the base directory if possible.
1257     BaseDirectory.assign(BaseDir.begin(), BaseDir.end());
1258   } else if (!isysroot.empty()) {
1259     // Write out paths relative to the sysroot if possible.
1260     BaseDirectory = std::string(isysroot);
1261   }
1262 
1263   // Module map file
1264   if (WritingModule && WritingModule->Kind == Module::ModuleMapModule) {
1265     Record.clear();
1266 
1267     auto &Map = PP.getHeaderSearchInfo().getModuleMap();
1268     AddPath(WritingModule->PresumedModuleMapFile.empty()
1269                 ? Map.getModuleMapFileForUniquing(WritingModule)->getName()
1270                 : StringRef(WritingModule->PresumedModuleMapFile),
1271             Record);
1272 
1273     // Additional module map files.
1274     if (auto *AdditionalModMaps =
1275             Map.getAdditionalModuleMapFiles(WritingModule)) {
1276       Record.push_back(AdditionalModMaps->size());
1277       for (const FileEntry *F : *AdditionalModMaps)
1278         AddPath(F->getName(), Record);
1279     } else {
1280       Record.push_back(0);
1281     }
1282 
1283     Stream.EmitRecord(MODULE_MAP_FILE, Record);
1284   }
1285 
1286   // Imports
1287   if (Chain) {
1288     serialization::ModuleManager &Mgr = Chain->getModuleManager();
1289     Record.clear();
1290 
1291     for (ModuleFile &M : Mgr) {
1292       // Skip modules that weren't directly imported.
1293       if (!M.isDirectlyImported())
1294         continue;
1295 
1296       Record.push_back((unsigned)M.Kind); // FIXME: Stable encoding
1297       AddSourceLocation(M.ImportLoc, Record);
1298 
1299       // If we have calculated signature, there is no need to store
1300       // the size or timestamp.
1301       Record.push_back(M.Signature ? 0 : M.File->getSize());
1302       Record.push_back(M.Signature ? 0 : getTimestampForOutput(M.File));
1303 
1304       llvm::append_range(Record, M.Signature);
1305 
1306       AddString(M.ModuleName, Record);
1307       AddPath(M.FileName, Record);
1308     }
1309     Stream.EmitRecord(IMPORTS, Record);
1310   }
1311 
1312   // Write the options block.
1313   Stream.EnterSubblock(OPTIONS_BLOCK_ID, 4);
1314 
1315   // Language options.
1316   Record.clear();
1317   const LangOptions &LangOpts = Context.getLangOpts();
1318 #define LANGOPT(Name, Bits, Default, Description) \
1319   Record.push_back(LangOpts.Name);
1320 #define ENUM_LANGOPT(Name, Type, Bits, Default, Description) \
1321   Record.push_back(static_cast<unsigned>(LangOpts.get##Name()));
1322 #include "clang/Basic/LangOptions.def"
1323 #define SANITIZER(NAME, ID)                                                    \
1324   Record.push_back(LangOpts.Sanitize.has(SanitizerKind::ID));
1325 #include "clang/Basic/Sanitizers.def"
1326 
1327   Record.push_back(LangOpts.ModuleFeatures.size());
1328   for (StringRef Feature : LangOpts.ModuleFeatures)
1329     AddString(Feature, Record);
1330 
1331   Record.push_back((unsigned) LangOpts.ObjCRuntime.getKind());
1332   AddVersionTuple(LangOpts.ObjCRuntime.getVersion(), Record);
1333 
1334   AddString(LangOpts.CurrentModule, Record);
1335 
1336   // Comment options.
1337   Record.push_back(LangOpts.CommentOpts.BlockCommandNames.size());
1338   for (const auto &I : LangOpts.CommentOpts.BlockCommandNames) {
1339     AddString(I, Record);
1340   }
1341   Record.push_back(LangOpts.CommentOpts.ParseAllComments);
1342 
1343   // OpenMP offloading options.
1344   Record.push_back(LangOpts.OMPTargetTriples.size());
1345   for (auto &T : LangOpts.OMPTargetTriples)
1346     AddString(T.getTriple(), Record);
1347 
1348   AddString(LangOpts.OMPHostIRFile, Record);
1349 
1350   Stream.EmitRecord(LANGUAGE_OPTIONS, Record);
1351 
1352   // Target options.
1353   Record.clear();
1354   const TargetInfo &Target = Context.getTargetInfo();
1355   const TargetOptions &TargetOpts = Target.getTargetOpts();
1356   AddString(TargetOpts.Triple, Record);
1357   AddString(TargetOpts.CPU, Record);
1358   AddString(TargetOpts.TuneCPU, Record);
1359   AddString(TargetOpts.ABI, Record);
1360   Record.push_back(TargetOpts.FeaturesAsWritten.size());
1361   for (unsigned I = 0, N = TargetOpts.FeaturesAsWritten.size(); I != N; ++I) {
1362     AddString(TargetOpts.FeaturesAsWritten[I], Record);
1363   }
1364   Record.push_back(TargetOpts.Features.size());
1365   for (unsigned I = 0, N = TargetOpts.Features.size(); I != N; ++I) {
1366     AddString(TargetOpts.Features[I], Record);
1367   }
1368   Stream.EmitRecord(TARGET_OPTIONS, Record);
1369 
1370   // File system options.
1371   Record.clear();
1372   const FileSystemOptions &FSOpts =
1373       Context.getSourceManager().getFileManager().getFileSystemOpts();
1374   AddString(FSOpts.WorkingDir, Record);
1375   Stream.EmitRecord(FILE_SYSTEM_OPTIONS, Record);
1376 
1377   // Header search options.
1378   Record.clear();
1379   const HeaderSearchOptions &HSOpts
1380     = PP.getHeaderSearchInfo().getHeaderSearchOpts();
1381   AddString(HSOpts.Sysroot, Record);
1382 
1383   // Include entries.
1384   Record.push_back(HSOpts.UserEntries.size());
1385   for (unsigned I = 0, N = HSOpts.UserEntries.size(); I != N; ++I) {
1386     const HeaderSearchOptions::Entry &Entry = HSOpts.UserEntries[I];
1387     AddString(Entry.Path, Record);
1388     Record.push_back(static_cast<unsigned>(Entry.Group));
1389     Record.push_back(Entry.IsFramework);
1390     Record.push_back(Entry.IgnoreSysRoot);
1391   }
1392 
1393   // System header prefixes.
1394   Record.push_back(HSOpts.SystemHeaderPrefixes.size());
1395   for (unsigned I = 0, N = HSOpts.SystemHeaderPrefixes.size(); I != N; ++I) {
1396     AddString(HSOpts.SystemHeaderPrefixes[I].Prefix, Record);
1397     Record.push_back(HSOpts.SystemHeaderPrefixes[I].IsSystemHeader);
1398   }
1399 
1400   AddString(HSOpts.ResourceDir, Record);
1401   AddString(HSOpts.ModuleCachePath, Record);
1402   AddString(HSOpts.ModuleUserBuildPath, Record);
1403   Record.push_back(HSOpts.DisableModuleHash);
1404   Record.push_back(HSOpts.ImplicitModuleMaps);
1405   Record.push_back(HSOpts.ModuleMapFileHomeIsCwd);
1406   Record.push_back(HSOpts.EnablePrebuiltImplicitModules);
1407   Record.push_back(HSOpts.UseBuiltinIncludes);
1408   Record.push_back(HSOpts.UseStandardSystemIncludes);
1409   Record.push_back(HSOpts.UseStandardCXXIncludes);
1410   Record.push_back(HSOpts.UseLibcxx);
1411   // Write out the specific module cache path that contains the module files.
1412   AddString(PP.getHeaderSearchInfo().getModuleCachePath(), Record);
1413   Stream.EmitRecord(HEADER_SEARCH_OPTIONS, Record);
1414 
1415   // Preprocessor options.
1416   Record.clear();
1417   const PreprocessorOptions &PPOpts = PP.getPreprocessorOpts();
1418 
1419   // Macro definitions.
1420   Record.push_back(PPOpts.Macros.size());
1421   for (unsigned I = 0, N = PPOpts.Macros.size(); I != N; ++I) {
1422     AddString(PPOpts.Macros[I].first, Record);
1423     Record.push_back(PPOpts.Macros[I].second);
1424   }
1425 
1426   // Includes
1427   Record.push_back(PPOpts.Includes.size());
1428   for (unsigned I = 0, N = PPOpts.Includes.size(); I != N; ++I)
1429     AddString(PPOpts.Includes[I], Record);
1430 
1431   // Macro includes
1432   Record.push_back(PPOpts.MacroIncludes.size());
1433   for (unsigned I = 0, N = PPOpts.MacroIncludes.size(); I != N; ++I)
1434     AddString(PPOpts.MacroIncludes[I], Record);
1435 
1436   Record.push_back(PPOpts.UsePredefines);
1437   // Detailed record is important since it is used for the module cache hash.
1438   Record.push_back(PPOpts.DetailedRecord);
1439   AddString(PPOpts.ImplicitPCHInclude, Record);
1440   Record.push_back(static_cast<unsigned>(PPOpts.ObjCXXARCStandardLibrary));
1441   Stream.EmitRecord(PREPROCESSOR_OPTIONS, Record);
1442 
1443   // Leave the options block.
1444   Stream.ExitBlock();
1445 
1446   // Original file name and file ID
1447   SourceManager &SM = Context.getSourceManager();
1448   if (const FileEntry *MainFile = SM.getFileEntryForID(SM.getMainFileID())) {
1449     auto FileAbbrev = std::make_shared<BitCodeAbbrev>();
1450     FileAbbrev->Add(BitCodeAbbrevOp(ORIGINAL_FILE));
1451     FileAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // File ID
1452     FileAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // File name
1453     unsigned FileAbbrevCode = Stream.EmitAbbrev(std::move(FileAbbrev));
1454 
1455     Record.clear();
1456     Record.push_back(ORIGINAL_FILE);
1457     Record.push_back(SM.getMainFileID().getOpaqueValue());
1458     EmitRecordWithPath(FileAbbrevCode, Record, MainFile->getName());
1459   }
1460 
1461   Record.clear();
1462   Record.push_back(SM.getMainFileID().getOpaqueValue());
1463   Stream.EmitRecord(ORIGINAL_FILE_ID, Record);
1464 
1465   // Original PCH directory
1466   if (!OutputFile.empty() && OutputFile != "-") {
1467     auto Abbrev = std::make_shared<BitCodeAbbrev>();
1468     Abbrev->Add(BitCodeAbbrevOp(ORIGINAL_PCH_DIR));
1469     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // File name
1470     unsigned AbbrevCode = Stream.EmitAbbrev(std::move(Abbrev));
1471 
1472     SmallString<128> OutputPath(OutputFile);
1473     PreparePathForOutput(OutputPath);
1474     StringRef origDir = llvm::sys::path::parent_path(OutputPath);
1475 
1476     RecordData::value_type Record[] = {ORIGINAL_PCH_DIR};
1477     Stream.EmitRecordWithBlob(AbbrevCode, Record, origDir);
1478   }
1479 
1480   std::set<const FileEntry *> AffectingModuleMaps;
1481   if (WritingModule) {
1482     AffectingModuleMaps =
1483         GetAllModuleMaps(PP.getHeaderSearchInfo(), WritingModule);
1484   }
1485 
1486   WriteInputFiles(Context.SourceMgr,
1487                   PP.getHeaderSearchInfo().getHeaderSearchOpts(),
1488                   AffectingModuleMaps);
1489   Stream.ExitBlock();
1490 }
1491 
1492 namespace  {
1493 
1494 /// An input file.
1495 struct InputFileEntry {
1496   const FileEntry *File;
1497   bool IsSystemFile;
1498   bool IsTransient;
1499   bool BufferOverridden;
1500   bool IsTopLevelModuleMap;
1501   uint32_t ContentHash[2];
1502 };
1503 
1504 } // namespace
1505 
1506 void ASTWriter::WriteInputFiles(
1507     SourceManager &SourceMgr, HeaderSearchOptions &HSOpts,
1508     std::set<const FileEntry *> &AffectingModuleMaps) {
1509   using namespace llvm;
1510 
1511   Stream.EnterSubblock(INPUT_FILES_BLOCK_ID, 4);
1512 
1513   // Create input-file abbreviation.
1514   auto IFAbbrev = std::make_shared<BitCodeAbbrev>();
1515   IFAbbrev->Add(BitCodeAbbrevOp(INPUT_FILE));
1516   IFAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ID
1517   IFAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 12)); // Size
1518   IFAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 32)); // Modification time
1519   IFAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Overridden
1520   IFAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Transient
1521   IFAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Module map
1522   IFAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // File name
1523   unsigned IFAbbrevCode = Stream.EmitAbbrev(std::move(IFAbbrev));
1524 
1525   // Create input file hash abbreviation.
1526   auto IFHAbbrev = std::make_shared<BitCodeAbbrev>();
1527   IFHAbbrev->Add(BitCodeAbbrevOp(INPUT_FILE_HASH));
1528   IFHAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
1529   IFHAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
1530   unsigned IFHAbbrevCode = Stream.EmitAbbrev(std::move(IFHAbbrev));
1531 
1532   // Get all ContentCache objects for files, sorted by whether the file is a
1533   // system one or not. System files go at the back, users files at the front.
1534   std::deque<InputFileEntry> SortedFiles;
1535   for (unsigned I = 1, N = SourceMgr.local_sloc_entry_size(); I != N; ++I) {
1536     // Get this source location entry.
1537     const SrcMgr::SLocEntry *SLoc = &SourceMgr.getLocalSLocEntry(I);
1538     assert(&SourceMgr.getSLocEntry(FileID::get(I)) == SLoc);
1539 
1540     // We only care about file entries that were not overridden.
1541     if (!SLoc->isFile())
1542       continue;
1543     const SrcMgr::FileInfo &File = SLoc->getFile();
1544     const SrcMgr::ContentCache *Cache = &File.getContentCache();
1545     if (!Cache->OrigEntry)
1546       continue;
1547 
1548     if (isModuleMap(File.getFileCharacteristic()) &&
1549         !isSystem(File.getFileCharacteristic()) &&
1550         !AffectingModuleMaps.empty() &&
1551         AffectingModuleMaps.find(Cache->OrigEntry) ==
1552             AffectingModuleMaps.end()) {
1553       SkippedModuleMaps.insert(Cache->OrigEntry);
1554       // Do not emit modulemaps that do not affect current module.
1555       continue;
1556     }
1557 
1558     InputFileEntry Entry;
1559     Entry.File = Cache->OrigEntry;
1560     Entry.IsSystemFile = isSystem(File.getFileCharacteristic());
1561     Entry.IsTransient = Cache->IsTransient;
1562     Entry.BufferOverridden = Cache->BufferOverridden;
1563     Entry.IsTopLevelModuleMap = isModuleMap(File.getFileCharacteristic()) &&
1564                                 File.getIncludeLoc().isInvalid();
1565 
1566     auto ContentHash = hash_code(-1);
1567     if (PP->getHeaderSearchInfo()
1568             .getHeaderSearchOpts()
1569             .ValidateASTInputFilesContent) {
1570       auto MemBuff = Cache->getBufferIfLoaded();
1571       if (MemBuff)
1572         ContentHash = hash_value(MemBuff->getBuffer());
1573       else
1574         // FIXME: The path should be taken from the FileEntryRef.
1575         PP->Diag(SourceLocation(), diag::err_module_unable_to_hash_content)
1576             << Entry.File->getName();
1577     }
1578     auto CH = llvm::APInt(64, ContentHash);
1579     Entry.ContentHash[0] =
1580         static_cast<uint32_t>(CH.getLoBits(32).getZExtValue());
1581     Entry.ContentHash[1] =
1582         static_cast<uint32_t>(CH.getHiBits(32).getZExtValue());
1583 
1584     if (Entry.IsSystemFile)
1585       SortedFiles.push_back(Entry);
1586     else
1587       SortedFiles.push_front(Entry);
1588   }
1589 
1590   unsigned UserFilesNum = 0;
1591   // Write out all of the input files.
1592   std::vector<uint64_t> InputFileOffsets;
1593   for (const auto &Entry : SortedFiles) {
1594     uint32_t &InputFileID = InputFileIDs[Entry.File];
1595     if (InputFileID != 0)
1596       continue; // already recorded this file.
1597 
1598     // Record this entry's offset.
1599     InputFileOffsets.push_back(Stream.GetCurrentBitNo());
1600 
1601     InputFileID = InputFileOffsets.size();
1602 
1603     if (!Entry.IsSystemFile)
1604       ++UserFilesNum;
1605 
1606     // Emit size/modification time for this file.
1607     // And whether this file was overridden.
1608     {
1609       RecordData::value_type Record[] = {
1610           INPUT_FILE,
1611           InputFileOffsets.size(),
1612           (uint64_t)Entry.File->getSize(),
1613           (uint64_t)getTimestampForOutput(Entry.File),
1614           Entry.BufferOverridden,
1615           Entry.IsTransient,
1616           Entry.IsTopLevelModuleMap};
1617 
1618       // FIXME: The path should be taken from the FileEntryRef.
1619       EmitRecordWithPath(IFAbbrevCode, Record, Entry.File->getName());
1620     }
1621 
1622     // Emit content hash for this file.
1623     {
1624       RecordData::value_type Record[] = {INPUT_FILE_HASH, Entry.ContentHash[0],
1625                                          Entry.ContentHash[1]};
1626       Stream.EmitRecordWithAbbrev(IFHAbbrevCode, Record);
1627     }
1628   }
1629 
1630   Stream.ExitBlock();
1631 
1632   // Create input file offsets abbreviation.
1633   auto OffsetsAbbrev = std::make_shared<BitCodeAbbrev>();
1634   OffsetsAbbrev->Add(BitCodeAbbrevOp(INPUT_FILE_OFFSETS));
1635   OffsetsAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // # input files
1636   OffsetsAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // # non-system
1637                                                                 //   input files
1638   OffsetsAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));   // Array
1639   unsigned OffsetsAbbrevCode = Stream.EmitAbbrev(std::move(OffsetsAbbrev));
1640 
1641   // Write input file offsets.
1642   RecordData::value_type Record[] = {INPUT_FILE_OFFSETS,
1643                                      InputFileOffsets.size(), UserFilesNum};
1644   Stream.EmitRecordWithBlob(OffsetsAbbrevCode, Record, bytes(InputFileOffsets));
1645 }
1646 
1647 //===----------------------------------------------------------------------===//
1648 // Source Manager Serialization
1649 //===----------------------------------------------------------------------===//
1650 
1651 /// Create an abbreviation for the SLocEntry that refers to a
1652 /// file.
1653 static unsigned CreateSLocFileAbbrev(llvm::BitstreamWriter &Stream) {
1654   using namespace llvm;
1655 
1656   auto Abbrev = std::make_shared<BitCodeAbbrev>();
1657   Abbrev->Add(BitCodeAbbrevOp(SM_SLOC_FILE_ENTRY));
1658   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Offset
1659   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Include location
1660   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // Characteristic
1661   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Line directives
1662   // FileEntry fields.
1663   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Input File ID
1664   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // NumCreatedFIDs
1665   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 24)); // FirstDeclIndex
1666   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // NumDecls
1667   return Stream.EmitAbbrev(std::move(Abbrev));
1668 }
1669 
1670 /// Create an abbreviation for the SLocEntry that refers to a
1671 /// buffer.
1672 static unsigned CreateSLocBufferAbbrev(llvm::BitstreamWriter &Stream) {
1673   using namespace llvm;
1674 
1675   auto Abbrev = std::make_shared<BitCodeAbbrev>();
1676   Abbrev->Add(BitCodeAbbrevOp(SM_SLOC_BUFFER_ENTRY));
1677   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Offset
1678   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Include location
1679   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // Characteristic
1680   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Line directives
1681   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Buffer name blob
1682   return Stream.EmitAbbrev(std::move(Abbrev));
1683 }
1684 
1685 /// Create an abbreviation for the SLocEntry that refers to a
1686 /// buffer's blob.
1687 static unsigned CreateSLocBufferBlobAbbrev(llvm::BitstreamWriter &Stream,
1688                                            bool Compressed) {
1689   using namespace llvm;
1690 
1691   auto Abbrev = std::make_shared<BitCodeAbbrev>();
1692   Abbrev->Add(BitCodeAbbrevOp(Compressed ? SM_SLOC_BUFFER_BLOB_COMPRESSED
1693                                          : SM_SLOC_BUFFER_BLOB));
1694   if (Compressed)
1695     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Uncompressed size
1696   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Blob
1697   return Stream.EmitAbbrev(std::move(Abbrev));
1698 }
1699 
1700 /// Create an abbreviation for the SLocEntry that refers to a macro
1701 /// expansion.
1702 static unsigned CreateSLocExpansionAbbrev(llvm::BitstreamWriter &Stream) {
1703   using namespace llvm;
1704 
1705   auto Abbrev = std::make_shared<BitCodeAbbrev>();
1706   Abbrev->Add(BitCodeAbbrevOp(SM_SLOC_EXPANSION_ENTRY));
1707   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Offset
1708   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Spelling location
1709   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Start location
1710   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // End location
1711   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Is token range
1712   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Token length
1713   return Stream.EmitAbbrev(std::move(Abbrev));
1714 }
1715 
1716 /// Emit key length and data length as ULEB-encoded data, and return them as a
1717 /// pair.
1718 static std::pair<unsigned, unsigned>
1719 emitULEBKeyDataLength(unsigned KeyLen, unsigned DataLen, raw_ostream &Out) {
1720   llvm::encodeULEB128(KeyLen, Out);
1721   llvm::encodeULEB128(DataLen, Out);
1722   return std::make_pair(KeyLen, DataLen);
1723 }
1724 
1725 namespace {
1726 
1727   // Trait used for the on-disk hash table of header search information.
1728   class HeaderFileInfoTrait {
1729     ASTWriter &Writer;
1730 
1731     // Keep track of the framework names we've used during serialization.
1732     SmallString<128> FrameworkStringData;
1733     llvm::StringMap<unsigned> FrameworkNameOffset;
1734 
1735   public:
1736     HeaderFileInfoTrait(ASTWriter &Writer) : Writer(Writer) {}
1737 
1738     struct key_type {
1739       StringRef Filename;
1740       off_t Size;
1741       time_t ModTime;
1742     };
1743     using key_type_ref = const key_type &;
1744 
1745     using UnresolvedModule =
1746         llvm::PointerIntPair<Module *, 2, ModuleMap::ModuleHeaderRole>;
1747 
1748     struct data_type {
1749       const HeaderFileInfo &HFI;
1750       ArrayRef<ModuleMap::KnownHeader> KnownHeaders;
1751       UnresolvedModule Unresolved;
1752     };
1753     using data_type_ref = const data_type &;
1754 
1755     using hash_value_type = unsigned;
1756     using offset_type = unsigned;
1757 
1758     hash_value_type ComputeHash(key_type_ref key) {
1759       // The hash is based only on size/time of the file, so that the reader can
1760       // match even when symlinking or excess path elements ("foo/../", "../")
1761       // change the form of the name. However, complete path is still the key.
1762       return llvm::hash_combine(key.Size, key.ModTime);
1763     }
1764 
1765     std::pair<unsigned, unsigned>
1766     EmitKeyDataLength(raw_ostream& Out, key_type_ref key, data_type_ref Data) {
1767       unsigned KeyLen = key.Filename.size() + 1 + 8 + 8;
1768       unsigned DataLen = 1 + 4 + 4;
1769       for (auto ModInfo : Data.KnownHeaders)
1770         if (Writer.getLocalOrImportedSubmoduleID(ModInfo.getModule()))
1771           DataLen += 4;
1772       if (Data.Unresolved.getPointer())
1773         DataLen += 4;
1774       return emitULEBKeyDataLength(KeyLen, DataLen, Out);
1775     }
1776 
1777     void EmitKey(raw_ostream& Out, key_type_ref key, unsigned KeyLen) {
1778       using namespace llvm::support;
1779 
1780       endian::Writer LE(Out, little);
1781       LE.write<uint64_t>(key.Size);
1782       KeyLen -= 8;
1783       LE.write<uint64_t>(key.ModTime);
1784       KeyLen -= 8;
1785       Out.write(key.Filename.data(), KeyLen);
1786     }
1787 
1788     void EmitData(raw_ostream &Out, key_type_ref key,
1789                   data_type_ref Data, unsigned DataLen) {
1790       using namespace llvm::support;
1791 
1792       endian::Writer LE(Out, little);
1793       uint64_t Start = Out.tell(); (void)Start;
1794 
1795       unsigned char Flags = (Data.HFI.isImport << 5)
1796                           | (Data.HFI.isPragmaOnce << 4)
1797                           | (Data.HFI.DirInfo << 1)
1798                           | Data.HFI.IndexHeaderMapHeader;
1799       LE.write<uint8_t>(Flags);
1800 
1801       if (!Data.HFI.ControllingMacro)
1802         LE.write<uint32_t>(Data.HFI.ControllingMacroID);
1803       else
1804         LE.write<uint32_t>(Writer.getIdentifierRef(Data.HFI.ControllingMacro));
1805 
1806       unsigned Offset = 0;
1807       if (!Data.HFI.Framework.empty()) {
1808         // If this header refers into a framework, save the framework name.
1809         llvm::StringMap<unsigned>::iterator Pos
1810           = FrameworkNameOffset.find(Data.HFI.Framework);
1811         if (Pos == FrameworkNameOffset.end()) {
1812           Offset = FrameworkStringData.size() + 1;
1813           FrameworkStringData.append(Data.HFI.Framework);
1814           FrameworkStringData.push_back(0);
1815 
1816           FrameworkNameOffset[Data.HFI.Framework] = Offset;
1817         } else
1818           Offset = Pos->second;
1819       }
1820       LE.write<uint32_t>(Offset);
1821 
1822       auto EmitModule = [&](Module *M, ModuleMap::ModuleHeaderRole Role) {
1823         if (uint32_t ModID = Writer.getLocalOrImportedSubmoduleID(M)) {
1824           uint32_t Value = (ModID << 2) | (unsigned)Role;
1825           assert((Value >> 2) == ModID && "overflow in header module info");
1826           LE.write<uint32_t>(Value);
1827         }
1828       };
1829 
1830       // FIXME: If the header is excluded, we should write out some
1831       // record of that fact.
1832       for (auto ModInfo : Data.KnownHeaders)
1833         EmitModule(ModInfo.getModule(), ModInfo.getRole());
1834       if (Data.Unresolved.getPointer())
1835         EmitModule(Data.Unresolved.getPointer(), Data.Unresolved.getInt());
1836 
1837       assert(Out.tell() - Start == DataLen && "Wrong data length");
1838     }
1839 
1840     const char *strings_begin() const { return FrameworkStringData.begin(); }
1841     const char *strings_end() const { return FrameworkStringData.end(); }
1842   };
1843 
1844 } // namespace
1845 
1846 /// Write the header search block for the list of files that
1847 ///
1848 /// \param HS The header search structure to save.
1849 void ASTWriter::WriteHeaderSearch(const HeaderSearch &HS) {
1850   HeaderFileInfoTrait GeneratorTrait(*this);
1851   llvm::OnDiskChainedHashTableGenerator<HeaderFileInfoTrait> Generator;
1852   SmallVector<const char *, 4> SavedStrings;
1853   unsigned NumHeaderSearchEntries = 0;
1854 
1855   // Find all unresolved headers for the current module. We generally will
1856   // have resolved them before we get here, but not necessarily: we might be
1857   // compiling a preprocessed module, where there is no requirement for the
1858   // original files to exist any more.
1859   const HeaderFileInfo Empty; // So we can take a reference.
1860   if (WritingModule) {
1861     llvm::SmallVector<Module *, 16> Worklist(1, WritingModule);
1862     while (!Worklist.empty()) {
1863       Module *M = Worklist.pop_back_val();
1864       // We don't care about headers in unimportable submodules.
1865       if (M->isUnimportable())
1866         continue;
1867 
1868       // Map to disk files where possible, to pick up any missing stat
1869       // information. This also means we don't need to check the unresolved
1870       // headers list when emitting resolved headers in the first loop below.
1871       // FIXME: It'd be preferable to avoid doing this if we were given
1872       // sufficient stat information in the module map.
1873       HS.getModuleMap().resolveHeaderDirectives(M, /*File=*/llvm::None);
1874 
1875       // If the file didn't exist, we can still create a module if we were given
1876       // enough information in the module map.
1877       for (auto U : M->MissingHeaders) {
1878         // Check that we were given enough information to build a module
1879         // without this file existing on disk.
1880         if (!U.Size || (!U.ModTime && IncludeTimestamps)) {
1881           PP->Diag(U.FileNameLoc, diag::err_module_no_size_mtime_for_header)
1882             << WritingModule->getFullModuleName() << U.Size.hasValue()
1883             << U.FileName;
1884           continue;
1885         }
1886 
1887         // Form the effective relative pathname for the file.
1888         SmallString<128> Filename(M->Directory->getName());
1889         llvm::sys::path::append(Filename, U.FileName);
1890         PreparePathForOutput(Filename);
1891 
1892         StringRef FilenameDup = strdup(Filename.c_str());
1893         SavedStrings.push_back(FilenameDup.data());
1894 
1895         HeaderFileInfoTrait::key_type Key = {
1896           FilenameDup, *U.Size, IncludeTimestamps ? *U.ModTime : 0
1897         };
1898         HeaderFileInfoTrait::data_type Data = {
1899           Empty, {}, {M, ModuleMap::headerKindToRole(U.Kind)}
1900         };
1901         // FIXME: Deal with cases where there are multiple unresolved header
1902         // directives in different submodules for the same header.
1903         Generator.insert(Key, Data, GeneratorTrait);
1904         ++NumHeaderSearchEntries;
1905       }
1906 
1907       Worklist.append(M->submodule_begin(), M->submodule_end());
1908     }
1909   }
1910 
1911   SmallVector<const FileEntry *, 16> FilesByUID;
1912   HS.getFileMgr().GetUniqueIDMapping(FilesByUID);
1913 
1914   if (FilesByUID.size() > HS.header_file_size())
1915     FilesByUID.resize(HS.header_file_size());
1916 
1917   for (unsigned UID = 0, LastUID = FilesByUID.size(); UID != LastUID; ++UID) {
1918     const FileEntry *File = FilesByUID[UID];
1919     if (!File)
1920       continue;
1921 
1922     // Get the file info. This will load info from the external source if
1923     // necessary. Skip emitting this file if we have no information on it
1924     // as a header file (in which case HFI will be null) or if it hasn't
1925     // changed since it was loaded. Also skip it if it's for a modular header
1926     // from a different module; in that case, we rely on the module(s)
1927     // containing the header to provide this information.
1928     const HeaderFileInfo *HFI =
1929         HS.getExistingFileInfo(File, /*WantExternal*/!Chain);
1930     if (!HFI || (HFI->isModuleHeader && !HFI->isCompilingModuleHeader))
1931       continue;
1932 
1933     // Massage the file path into an appropriate form.
1934     StringRef Filename = File->getName();
1935     SmallString<128> FilenameTmp(Filename);
1936     if (PreparePathForOutput(FilenameTmp)) {
1937       // If we performed any translation on the file name at all, we need to
1938       // save this string, since the generator will refer to it later.
1939       Filename = StringRef(strdup(FilenameTmp.c_str()));
1940       SavedStrings.push_back(Filename.data());
1941     }
1942 
1943     HeaderFileInfoTrait::key_type Key = {
1944       Filename, File->getSize(), getTimestampForOutput(File)
1945     };
1946     HeaderFileInfoTrait::data_type Data = {
1947       *HFI, HS.getModuleMap().findResolvedModulesForHeader(File), {}
1948     };
1949     Generator.insert(Key, Data, GeneratorTrait);
1950     ++NumHeaderSearchEntries;
1951   }
1952 
1953   // Create the on-disk hash table in a buffer.
1954   SmallString<4096> TableData;
1955   uint32_t BucketOffset;
1956   {
1957     using namespace llvm::support;
1958 
1959     llvm::raw_svector_ostream Out(TableData);
1960     // Make sure that no bucket is at offset 0
1961     endian::write<uint32_t>(Out, 0, little);
1962     BucketOffset = Generator.Emit(Out, GeneratorTrait);
1963   }
1964 
1965   // Create a blob abbreviation
1966   using namespace llvm;
1967 
1968   auto Abbrev = std::make_shared<BitCodeAbbrev>();
1969   Abbrev->Add(BitCodeAbbrevOp(HEADER_SEARCH_TABLE));
1970   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
1971   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
1972   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
1973   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
1974   unsigned TableAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
1975 
1976   // Write the header search table
1977   RecordData::value_type Record[] = {HEADER_SEARCH_TABLE, BucketOffset,
1978                                      NumHeaderSearchEntries, TableData.size()};
1979   TableData.append(GeneratorTrait.strings_begin(),GeneratorTrait.strings_end());
1980   Stream.EmitRecordWithBlob(TableAbbrev, Record, TableData);
1981 
1982   // Free all of the strings we had to duplicate.
1983   for (unsigned I = 0, N = SavedStrings.size(); I != N; ++I)
1984     free(const_cast<char *>(SavedStrings[I]));
1985 }
1986 
1987 static void emitBlob(llvm::BitstreamWriter &Stream, StringRef Blob,
1988                      unsigned SLocBufferBlobCompressedAbbrv,
1989                      unsigned SLocBufferBlobAbbrv) {
1990   using RecordDataType = ASTWriter::RecordData::value_type;
1991 
1992   // Compress the buffer if possible. We expect that almost all PCM
1993   // consumers will not want its contents.
1994   SmallString<0> CompressedBuffer;
1995   if (llvm::zlib::isAvailable()) {
1996     llvm::zlib::compress(Blob.drop_back(1), CompressedBuffer);
1997     RecordDataType Record[] = {SM_SLOC_BUFFER_BLOB_COMPRESSED, Blob.size() - 1};
1998     Stream.EmitRecordWithBlob(SLocBufferBlobCompressedAbbrv, Record,
1999                               CompressedBuffer);
2000     return;
2001   }
2002 
2003   RecordDataType Record[] = {SM_SLOC_BUFFER_BLOB};
2004   Stream.EmitRecordWithBlob(SLocBufferBlobAbbrv, Record, Blob);
2005 }
2006 
2007 /// Writes the block containing the serialized form of the
2008 /// source manager.
2009 ///
2010 /// TODO: We should probably use an on-disk hash table (stored in a
2011 /// blob), indexed based on the file name, so that we only create
2012 /// entries for files that we actually need. In the common case (no
2013 /// errors), we probably won't have to create file entries for any of
2014 /// the files in the AST.
2015 void ASTWriter::WriteSourceManagerBlock(SourceManager &SourceMgr,
2016                                         const Preprocessor &PP) {
2017   RecordData Record;
2018 
2019   // Enter the source manager block.
2020   Stream.EnterSubblock(SOURCE_MANAGER_BLOCK_ID, 4);
2021   const uint64_t SourceManagerBlockOffset = Stream.GetCurrentBitNo();
2022 
2023   // Abbreviations for the various kinds of source-location entries.
2024   unsigned SLocFileAbbrv = CreateSLocFileAbbrev(Stream);
2025   unsigned SLocBufferAbbrv = CreateSLocBufferAbbrev(Stream);
2026   unsigned SLocBufferBlobAbbrv = CreateSLocBufferBlobAbbrev(Stream, false);
2027   unsigned SLocBufferBlobCompressedAbbrv =
2028       CreateSLocBufferBlobAbbrev(Stream, true);
2029   unsigned SLocExpansionAbbrv = CreateSLocExpansionAbbrev(Stream);
2030 
2031   // Write out the source location entry table. We skip the first
2032   // entry, which is always the same dummy entry.
2033   std::vector<uint32_t> SLocEntryOffsets;
2034   uint64_t SLocEntryOffsetsBase = Stream.GetCurrentBitNo();
2035   RecordData PreloadSLocs;
2036   SLocEntryOffsets.reserve(SourceMgr.local_sloc_entry_size() - 1);
2037   for (unsigned I = 1, N = SourceMgr.local_sloc_entry_size();
2038        I != N; ++I) {
2039     // Get this source location entry.
2040     const SrcMgr::SLocEntry *SLoc = &SourceMgr.getLocalSLocEntry(I);
2041     FileID FID = FileID::get(I);
2042     assert(&SourceMgr.getSLocEntry(FID) == SLoc);
2043 
2044     // Record the offset of this source-location entry.
2045     uint64_t Offset = Stream.GetCurrentBitNo() - SLocEntryOffsetsBase;
2046     assert((Offset >> 32) == 0 && "SLocEntry offset too large");
2047     SLocEntryOffsets.push_back(Offset);
2048 
2049     // Figure out which record code to use.
2050     unsigned Code;
2051     if (SLoc->isFile()) {
2052       const SrcMgr::ContentCache *Cache = &SLoc->getFile().getContentCache();
2053       if (Cache->OrigEntry) {
2054         Code = SM_SLOC_FILE_ENTRY;
2055       } else
2056         Code = SM_SLOC_BUFFER_ENTRY;
2057     } else
2058       Code = SM_SLOC_EXPANSION_ENTRY;
2059     Record.clear();
2060     Record.push_back(Code);
2061 
2062     // Starting offset of this entry within this module, so skip the dummy.
2063     Record.push_back(SLoc->getOffset() - 2);
2064     if (SLoc->isFile()) {
2065       const SrcMgr::FileInfo &File = SLoc->getFile();
2066       const SrcMgr::ContentCache *Content = &File.getContentCache();
2067       if (Content->OrigEntry && !SkippedModuleMaps.empty() &&
2068           SkippedModuleMaps.find(Content->OrigEntry) !=
2069               SkippedModuleMaps.end()) {
2070         // Do not emit files that were not listed as inputs.
2071         continue;
2072       }
2073       AddSourceLocation(File.getIncludeLoc(), Record);
2074       Record.push_back(File.getFileCharacteristic()); // FIXME: stable encoding
2075       Record.push_back(File.hasLineDirectives());
2076 
2077       bool EmitBlob = false;
2078       if (Content->OrigEntry) {
2079         assert(Content->OrigEntry == Content->ContentsEntry &&
2080                "Writing to AST an overridden file is not supported");
2081 
2082         // The source location entry is a file. Emit input file ID.
2083         assert(InputFileIDs[Content->OrigEntry] != 0 && "Missed file entry");
2084         Record.push_back(InputFileIDs[Content->OrigEntry]);
2085 
2086         Record.push_back(File.NumCreatedFIDs);
2087 
2088         FileDeclIDsTy::iterator FDI = FileDeclIDs.find(FID);
2089         if (FDI != FileDeclIDs.end()) {
2090           Record.push_back(FDI->second->FirstDeclIndex);
2091           Record.push_back(FDI->second->DeclIDs.size());
2092         } else {
2093           Record.push_back(0);
2094           Record.push_back(0);
2095         }
2096 
2097         Stream.EmitRecordWithAbbrev(SLocFileAbbrv, Record);
2098 
2099         if (Content->BufferOverridden || Content->IsTransient)
2100           EmitBlob = true;
2101       } else {
2102         // The source location entry is a buffer. The blob associated
2103         // with this entry contains the contents of the buffer.
2104 
2105         // We add one to the size so that we capture the trailing NULL
2106         // that is required by llvm::MemoryBuffer::getMemBuffer (on
2107         // the reader side).
2108         llvm::Optional<llvm::MemoryBufferRef> Buffer =
2109             Content->getBufferOrNone(PP.getDiagnostics(), PP.getFileManager());
2110         StringRef Name = Buffer ? Buffer->getBufferIdentifier() : "";
2111         Stream.EmitRecordWithBlob(SLocBufferAbbrv, Record,
2112                                   StringRef(Name.data(), Name.size() + 1));
2113         EmitBlob = true;
2114 
2115         if (Name == "<built-in>")
2116           PreloadSLocs.push_back(SLocEntryOffsets.size());
2117       }
2118 
2119       if (EmitBlob) {
2120         // Include the implicit terminating null character in the on-disk buffer
2121         // if we're writing it uncompressed.
2122         llvm::Optional<llvm::MemoryBufferRef> Buffer =
2123             Content->getBufferOrNone(PP.getDiagnostics(), PP.getFileManager());
2124         if (!Buffer)
2125           Buffer = llvm::MemoryBufferRef("<<<INVALID BUFFER>>>", "");
2126         StringRef Blob(Buffer->getBufferStart(), Buffer->getBufferSize() + 1);
2127         emitBlob(Stream, Blob, SLocBufferBlobCompressedAbbrv,
2128                  SLocBufferBlobAbbrv);
2129       }
2130     } else {
2131       // The source location entry is a macro expansion.
2132       const SrcMgr::ExpansionInfo &Expansion = SLoc->getExpansion();
2133       AddSourceLocation(Expansion.getSpellingLoc(), Record);
2134       AddSourceLocation(Expansion.getExpansionLocStart(), Record);
2135       AddSourceLocation(Expansion.isMacroArgExpansion()
2136                             ? SourceLocation()
2137                             : Expansion.getExpansionLocEnd(),
2138                         Record);
2139       Record.push_back(Expansion.isExpansionTokenRange());
2140 
2141       // Compute the token length for this macro expansion.
2142       SourceLocation::UIntTy NextOffset = SourceMgr.getNextLocalOffset();
2143       if (I + 1 != N)
2144         NextOffset = SourceMgr.getLocalSLocEntry(I + 1).getOffset();
2145       Record.push_back(NextOffset - SLoc->getOffset() - 1);
2146       Stream.EmitRecordWithAbbrev(SLocExpansionAbbrv, Record);
2147     }
2148   }
2149 
2150   Stream.ExitBlock();
2151 
2152   if (SLocEntryOffsets.empty())
2153     return;
2154 
2155   // Write the source-location offsets table into the AST block. This
2156   // table is used for lazily loading source-location information.
2157   using namespace llvm;
2158 
2159   auto Abbrev = std::make_shared<BitCodeAbbrev>();
2160   Abbrev->Add(BitCodeAbbrevOp(SOURCE_LOCATION_OFFSETS));
2161   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 16)); // # of slocs
2162   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 16)); // total size
2163   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 32)); // base offset
2164   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // offsets
2165   unsigned SLocOffsetsAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2166   {
2167     RecordData::value_type Record[] = {
2168         SOURCE_LOCATION_OFFSETS, SLocEntryOffsets.size(),
2169         SourceMgr.getNextLocalOffset() - 1 /* skip dummy */,
2170         SLocEntryOffsetsBase - SourceManagerBlockOffset};
2171     Stream.EmitRecordWithBlob(SLocOffsetsAbbrev, Record,
2172                               bytes(SLocEntryOffsets));
2173   }
2174   // Write the source location entry preloads array, telling the AST
2175   // reader which source locations entries it should load eagerly.
2176   Stream.EmitRecord(SOURCE_LOCATION_PRELOADS, PreloadSLocs);
2177 
2178   // Write the line table. It depends on remapping working, so it must come
2179   // after the source location offsets.
2180   if (SourceMgr.hasLineTable()) {
2181     LineTableInfo &LineTable = SourceMgr.getLineTable();
2182 
2183     Record.clear();
2184 
2185     // Emit the needed file names.
2186     llvm::DenseMap<int, int> FilenameMap;
2187     FilenameMap[-1] = -1; // For unspecified filenames.
2188     for (const auto &L : LineTable) {
2189       if (L.first.ID < 0)
2190         continue;
2191       for (auto &LE : L.second) {
2192         if (FilenameMap.insert(std::make_pair(LE.FilenameID,
2193                                               FilenameMap.size() - 1)).second)
2194           AddPath(LineTable.getFilename(LE.FilenameID), Record);
2195       }
2196     }
2197     Record.push_back(0);
2198 
2199     // Emit the line entries
2200     for (const auto &L : LineTable) {
2201       // Only emit entries for local files.
2202       if (L.first.ID < 0)
2203         continue;
2204 
2205       // Emit the file ID
2206       Record.push_back(L.first.ID);
2207 
2208       // Emit the line entries
2209       Record.push_back(L.second.size());
2210       for (const auto &LE : L.second) {
2211         Record.push_back(LE.FileOffset);
2212         Record.push_back(LE.LineNo);
2213         Record.push_back(FilenameMap[LE.FilenameID]);
2214         Record.push_back((unsigned)LE.FileKind);
2215         Record.push_back(LE.IncludeOffset);
2216       }
2217     }
2218 
2219     Stream.EmitRecord(SOURCE_MANAGER_LINE_TABLE, Record);
2220   }
2221 }
2222 
2223 //===----------------------------------------------------------------------===//
2224 // Preprocessor Serialization
2225 //===----------------------------------------------------------------------===//
2226 
2227 static bool shouldIgnoreMacro(MacroDirective *MD, bool IsModule,
2228                               const Preprocessor &PP) {
2229   if (MacroInfo *MI = MD->getMacroInfo())
2230     if (MI->isBuiltinMacro())
2231       return true;
2232 
2233   if (IsModule) {
2234     SourceLocation Loc = MD->getLocation();
2235     if (Loc.isInvalid())
2236       return true;
2237     if (PP.getSourceManager().getFileID(Loc) == PP.getPredefinesFileID())
2238       return true;
2239   }
2240 
2241   return false;
2242 }
2243 
2244 void ASTWriter::writeIncludedFiles(raw_ostream &Out, const Preprocessor &PP) {
2245   using namespace llvm::support;
2246 
2247   const Preprocessor::IncludedFilesSet &IncludedFiles = PP.getIncludedFiles();
2248 
2249   std::vector<uint32_t> IncludedInputFileIDs;
2250   IncludedInputFileIDs.reserve(IncludedFiles.size());
2251 
2252   for (const FileEntry *File : IncludedFiles) {
2253     auto InputFileIt = InputFileIDs.find(File);
2254     if (InputFileIt == InputFileIDs.end())
2255       continue;
2256     IncludedInputFileIDs.push_back(InputFileIt->second);
2257   }
2258 
2259   llvm::sort(IncludedInputFileIDs);
2260 
2261   endian::Writer LE(Out, little);
2262   LE.write<uint32_t>(IncludedInputFileIDs.size());
2263   for (uint32_t ID : IncludedInputFileIDs)
2264     LE.write<uint32_t>(ID);
2265 }
2266 
2267 /// Writes the block containing the serialized form of the
2268 /// preprocessor.
2269 void ASTWriter::WritePreprocessor(const Preprocessor &PP, bool IsModule) {
2270   uint64_t MacroOffsetsBase = Stream.GetCurrentBitNo();
2271 
2272   PreprocessingRecord *PPRec = PP.getPreprocessingRecord();
2273   if (PPRec)
2274     WritePreprocessorDetail(*PPRec, MacroOffsetsBase);
2275 
2276   RecordData Record;
2277   RecordData ModuleMacroRecord;
2278 
2279   // If the preprocessor __COUNTER__ value has been bumped, remember it.
2280   if (PP.getCounterValue() != 0) {
2281     RecordData::value_type Record[] = {PP.getCounterValue()};
2282     Stream.EmitRecord(PP_COUNTER_VALUE, Record);
2283   }
2284 
2285   // If we have a recorded #pragma assume_nonnull, remember it so it can be
2286   // replayed when the preamble terminates into the main file.
2287   SourceLocation AssumeNonNullLoc =
2288       PP.getPreambleRecordedPragmaAssumeNonNullLoc();
2289   if (AssumeNonNullLoc.isValid()) {
2290     assert(PP.isRecordingPreamble());
2291     AddSourceLocation(AssumeNonNullLoc, Record);
2292     Stream.EmitRecord(PP_ASSUME_NONNULL_LOC, Record);
2293     Record.clear();
2294   }
2295 
2296   if (PP.isRecordingPreamble() && PP.hasRecordedPreamble()) {
2297     assert(!IsModule);
2298     auto SkipInfo = PP.getPreambleSkipInfo();
2299     if (SkipInfo.hasValue()) {
2300       Record.push_back(true);
2301       AddSourceLocation(SkipInfo->HashTokenLoc, Record);
2302       AddSourceLocation(SkipInfo->IfTokenLoc, Record);
2303       Record.push_back(SkipInfo->FoundNonSkipPortion);
2304       Record.push_back(SkipInfo->FoundElse);
2305       AddSourceLocation(SkipInfo->ElseLoc, Record);
2306     } else {
2307       Record.push_back(false);
2308     }
2309     for (const auto &Cond : PP.getPreambleConditionalStack()) {
2310       AddSourceLocation(Cond.IfLoc, Record);
2311       Record.push_back(Cond.WasSkipping);
2312       Record.push_back(Cond.FoundNonSkip);
2313       Record.push_back(Cond.FoundElse);
2314     }
2315     Stream.EmitRecord(PP_CONDITIONAL_STACK, Record);
2316     Record.clear();
2317   }
2318 
2319   // Enter the preprocessor block.
2320   Stream.EnterSubblock(PREPROCESSOR_BLOCK_ID, 3);
2321 
2322   // If the AST file contains __DATE__ or __TIME__ emit a warning about this.
2323   // FIXME: Include a location for the use, and say which one was used.
2324   if (PP.SawDateOrTime())
2325     PP.Diag(SourceLocation(), diag::warn_module_uses_date_time) << IsModule;
2326 
2327   // Loop over all the macro directives that are live at the end of the file,
2328   // emitting each to the PP section.
2329 
2330   // Construct the list of identifiers with macro directives that need to be
2331   // serialized.
2332   SmallVector<const IdentifierInfo *, 128> MacroIdentifiers;
2333   for (auto &Id : PP.getIdentifierTable())
2334     if (Id.second->hadMacroDefinition() &&
2335         (!Id.second->isFromAST() ||
2336          Id.second->hasChangedSinceDeserialization()))
2337       MacroIdentifiers.push_back(Id.second);
2338   // Sort the set of macro definitions that need to be serialized by the
2339   // name of the macro, to provide a stable ordering.
2340   llvm::sort(MacroIdentifiers, llvm::deref<std::less<>>());
2341 
2342   // Emit the macro directives as a list and associate the offset with the
2343   // identifier they belong to.
2344   for (const IdentifierInfo *Name : MacroIdentifiers) {
2345     MacroDirective *MD = PP.getLocalMacroDirectiveHistory(Name);
2346     uint64_t StartOffset = Stream.GetCurrentBitNo() - MacroOffsetsBase;
2347     assert((StartOffset >> 32) == 0 && "Macro identifiers offset too large");
2348 
2349     // Write out any exported module macros.
2350     bool EmittedModuleMacros = false;
2351     // C+=20 Header Units are compiled module interfaces, but they preserve
2352     // macros that are live (i.e. have a defined value) at the end of the
2353     // compilation.  So when writing a header unit, we preserve only the final
2354     // value of each macro (and discard any that are undefined).  Header units
2355     // do not have sub-modules (although they might import other header units).
2356     // PCH files, conversely, retain the history of each macro's define/undef
2357     // and of leaf macros in sub modules.
2358     if (IsModule && WritingModule->isHeaderUnit()) {
2359       // This is for the main TU when it is a C++20 header unit.
2360       // We preserve the final state of defined macros, and we do not emit ones
2361       // that are undefined.
2362       if (!MD || shouldIgnoreMacro(MD, IsModule, PP) ||
2363           MD->getKind() == MacroDirective::MD_Undefine)
2364         continue;
2365       AddSourceLocation(MD->getLocation(), Record);
2366       Record.push_back(MD->getKind());
2367       if (auto *DefMD = dyn_cast<DefMacroDirective>(MD)) {
2368         Record.push_back(getMacroRef(DefMD->getInfo(), Name));
2369       } else if (auto *VisMD = dyn_cast<VisibilityMacroDirective>(MD)) {
2370         Record.push_back(VisMD->isPublic());
2371       }
2372       ModuleMacroRecord.push_back(getSubmoduleID(WritingModule));
2373       ModuleMacroRecord.push_back(getMacroRef(MD->getMacroInfo(), Name));
2374       Stream.EmitRecord(PP_MODULE_MACRO, ModuleMacroRecord);
2375       ModuleMacroRecord.clear();
2376       EmittedModuleMacros = true;
2377     } else {
2378       // Emit the macro directives in reverse source order.
2379       for (; MD; MD = MD->getPrevious()) {
2380         // Once we hit an ignored macro, we're done: the rest of the chain
2381         // will all be ignored macros.
2382         if (shouldIgnoreMacro(MD, IsModule, PP))
2383           break;
2384         AddSourceLocation(MD->getLocation(), Record);
2385         Record.push_back(MD->getKind());
2386         if (auto *DefMD = dyn_cast<DefMacroDirective>(MD)) {
2387           Record.push_back(getMacroRef(DefMD->getInfo(), Name));
2388         } else if (auto *VisMD = dyn_cast<VisibilityMacroDirective>(MD)) {
2389           Record.push_back(VisMD->isPublic());
2390         }
2391       }
2392 
2393       // We write out exported module macros for PCH as well.
2394       auto Leafs = PP.getLeafModuleMacros(Name);
2395       SmallVector<ModuleMacro *, 8> Worklist(Leafs.begin(), Leafs.end());
2396       llvm::DenseMap<ModuleMacro *, unsigned> Visits;
2397       while (!Worklist.empty()) {
2398         auto *Macro = Worklist.pop_back_val();
2399 
2400         // Emit a record indicating this submodule exports this macro.
2401         ModuleMacroRecord.push_back(getSubmoduleID(Macro->getOwningModule()));
2402         ModuleMacroRecord.push_back(getMacroRef(Macro->getMacroInfo(), Name));
2403         for (auto *M : Macro->overrides())
2404           ModuleMacroRecord.push_back(getSubmoduleID(M->getOwningModule()));
2405 
2406         Stream.EmitRecord(PP_MODULE_MACRO, ModuleMacroRecord);
2407         ModuleMacroRecord.clear();
2408 
2409         // Enqueue overridden macros once we've visited all their ancestors.
2410         for (auto *M : Macro->overrides())
2411           if (++Visits[M] == M->getNumOverridingMacros())
2412             Worklist.push_back(M);
2413 
2414         EmittedModuleMacros = true;
2415       }
2416     }
2417     if (Record.empty() && !EmittedModuleMacros)
2418       continue;
2419 
2420     IdentMacroDirectivesOffsetMap[Name] = StartOffset;
2421     Stream.EmitRecord(PP_MACRO_DIRECTIVE_HISTORY, Record);
2422     Record.clear();
2423   }
2424 
2425   /// Offsets of each of the macros into the bitstream, indexed by
2426   /// the local macro ID
2427   ///
2428   /// For each identifier that is associated with a macro, this map
2429   /// provides the offset into the bitstream where that macro is
2430   /// defined.
2431   std::vector<uint32_t> MacroOffsets;
2432 
2433   for (unsigned I = 0, N = MacroInfosToEmit.size(); I != N; ++I) {
2434     const IdentifierInfo *Name = MacroInfosToEmit[I].Name;
2435     MacroInfo *MI = MacroInfosToEmit[I].MI;
2436     MacroID ID = MacroInfosToEmit[I].ID;
2437 
2438     if (ID < FirstMacroID) {
2439       assert(0 && "Loaded MacroInfo entered MacroInfosToEmit ?");
2440       continue;
2441     }
2442 
2443     // Record the local offset of this macro.
2444     unsigned Index = ID - FirstMacroID;
2445     if (Index >= MacroOffsets.size())
2446       MacroOffsets.resize(Index + 1);
2447 
2448     uint64_t Offset = Stream.GetCurrentBitNo() - MacroOffsetsBase;
2449     assert((Offset >> 32) == 0 && "Macro offset too large");
2450     MacroOffsets[Index] = Offset;
2451 
2452     AddIdentifierRef(Name, Record);
2453     AddSourceLocation(MI->getDefinitionLoc(), Record);
2454     AddSourceLocation(MI->getDefinitionEndLoc(), Record);
2455     Record.push_back(MI->isUsed());
2456     Record.push_back(MI->isUsedForHeaderGuard());
2457     Record.push_back(MI->getNumTokens());
2458     unsigned Code;
2459     if (MI->isObjectLike()) {
2460       Code = PP_MACRO_OBJECT_LIKE;
2461     } else {
2462       Code = PP_MACRO_FUNCTION_LIKE;
2463 
2464       Record.push_back(MI->isC99Varargs());
2465       Record.push_back(MI->isGNUVarargs());
2466       Record.push_back(MI->hasCommaPasting());
2467       Record.push_back(MI->getNumParams());
2468       for (const IdentifierInfo *Param : MI->params())
2469         AddIdentifierRef(Param, Record);
2470     }
2471 
2472     // If we have a detailed preprocessing record, record the macro definition
2473     // ID that corresponds to this macro.
2474     if (PPRec)
2475       Record.push_back(MacroDefinitions[PPRec->findMacroDefinition(MI)]);
2476 
2477     Stream.EmitRecord(Code, Record);
2478     Record.clear();
2479 
2480     // Emit the tokens array.
2481     for (unsigned TokNo = 0, e = MI->getNumTokens(); TokNo != e; ++TokNo) {
2482       // Note that we know that the preprocessor does not have any annotation
2483       // tokens in it because they are created by the parser, and thus can't
2484       // be in a macro definition.
2485       const Token &Tok = MI->getReplacementToken(TokNo);
2486       AddToken(Tok, Record);
2487       Stream.EmitRecord(PP_TOKEN, Record);
2488       Record.clear();
2489     }
2490     ++NumMacros;
2491   }
2492 
2493   Stream.ExitBlock();
2494 
2495   // Write the offsets table for macro IDs.
2496   using namespace llvm;
2497 
2498   auto Abbrev = std::make_shared<BitCodeAbbrev>();
2499   Abbrev->Add(BitCodeAbbrevOp(MACRO_OFFSET));
2500   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // # of macros
2501   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // first ID
2502   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 32));   // base offset
2503   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2504 
2505   unsigned MacroOffsetAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2506   {
2507     RecordData::value_type Record[] = {MACRO_OFFSET, MacroOffsets.size(),
2508                                        FirstMacroID - NUM_PREDEF_MACRO_IDS,
2509                                        MacroOffsetsBase - ASTBlockStartOffset};
2510     Stream.EmitRecordWithBlob(MacroOffsetAbbrev, Record, bytes(MacroOffsets));
2511   }
2512 
2513   {
2514     auto Abbrev = std::make_shared<BitCodeAbbrev>();
2515     Abbrev->Add(BitCodeAbbrevOp(PP_INCLUDED_FILES));
2516     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2517     unsigned IncludedFilesAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2518 
2519     SmallString<2048> Buffer;
2520     raw_svector_ostream Out(Buffer);
2521     writeIncludedFiles(Out, PP);
2522     RecordData::value_type Record[] = {PP_INCLUDED_FILES};
2523     Stream.EmitRecordWithBlob(IncludedFilesAbbrev, Record, Buffer.data(),
2524                               Buffer.size());
2525   }
2526 }
2527 
2528 void ASTWriter::WritePreprocessorDetail(PreprocessingRecord &PPRec,
2529                                         uint64_t MacroOffsetsBase) {
2530   if (PPRec.local_begin() == PPRec.local_end())
2531     return;
2532 
2533   SmallVector<PPEntityOffset, 64> PreprocessedEntityOffsets;
2534 
2535   // Enter the preprocessor block.
2536   Stream.EnterSubblock(PREPROCESSOR_DETAIL_BLOCK_ID, 3);
2537 
2538   // If the preprocessor has a preprocessing record, emit it.
2539   unsigned NumPreprocessingRecords = 0;
2540   using namespace llvm;
2541 
2542   // Set up the abbreviation for
2543   unsigned InclusionAbbrev = 0;
2544   {
2545     auto Abbrev = std::make_shared<BitCodeAbbrev>();
2546     Abbrev->Add(BitCodeAbbrevOp(PPD_INCLUSION_DIRECTIVE));
2547     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // filename length
2548     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // in quotes
2549     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // kind
2550     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // imported module
2551     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2552     InclusionAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2553   }
2554 
2555   unsigned FirstPreprocessorEntityID
2556     = (Chain ? PPRec.getNumLoadedPreprocessedEntities() : 0)
2557     + NUM_PREDEF_PP_ENTITY_IDS;
2558   unsigned NextPreprocessorEntityID = FirstPreprocessorEntityID;
2559   RecordData Record;
2560   for (PreprocessingRecord::iterator E = PPRec.local_begin(),
2561                                   EEnd = PPRec.local_end();
2562        E != EEnd;
2563        (void)++E, ++NumPreprocessingRecords, ++NextPreprocessorEntityID) {
2564     Record.clear();
2565 
2566     uint64_t Offset = Stream.GetCurrentBitNo() - MacroOffsetsBase;
2567     assert((Offset >> 32) == 0 && "Preprocessed entity offset too large");
2568     PreprocessedEntityOffsets.push_back(
2569         PPEntityOffset((*E)->getSourceRange(), Offset));
2570 
2571     if (auto *MD = dyn_cast<MacroDefinitionRecord>(*E)) {
2572       // Record this macro definition's ID.
2573       MacroDefinitions[MD] = NextPreprocessorEntityID;
2574 
2575       AddIdentifierRef(MD->getName(), Record);
2576       Stream.EmitRecord(PPD_MACRO_DEFINITION, Record);
2577       continue;
2578     }
2579 
2580     if (auto *ME = dyn_cast<MacroExpansion>(*E)) {
2581       Record.push_back(ME->isBuiltinMacro());
2582       if (ME->isBuiltinMacro())
2583         AddIdentifierRef(ME->getName(), Record);
2584       else
2585         Record.push_back(MacroDefinitions[ME->getDefinition()]);
2586       Stream.EmitRecord(PPD_MACRO_EXPANSION, Record);
2587       continue;
2588     }
2589 
2590     if (auto *ID = dyn_cast<InclusionDirective>(*E)) {
2591       Record.push_back(PPD_INCLUSION_DIRECTIVE);
2592       Record.push_back(ID->getFileName().size());
2593       Record.push_back(ID->wasInQuotes());
2594       Record.push_back(static_cast<unsigned>(ID->getKind()));
2595       Record.push_back(ID->importedModule());
2596       SmallString<64> Buffer;
2597       Buffer += ID->getFileName();
2598       // Check that the FileEntry is not null because it was not resolved and
2599       // we create a PCH even with compiler errors.
2600       if (ID->getFile())
2601         Buffer += ID->getFile()->getName();
2602       Stream.EmitRecordWithBlob(InclusionAbbrev, Record, Buffer);
2603       continue;
2604     }
2605 
2606     llvm_unreachable("Unhandled PreprocessedEntity in ASTWriter");
2607   }
2608   Stream.ExitBlock();
2609 
2610   // Write the offsets table for the preprocessing record.
2611   if (NumPreprocessingRecords > 0) {
2612     assert(PreprocessedEntityOffsets.size() == NumPreprocessingRecords);
2613 
2614     // Write the offsets table for identifier IDs.
2615     using namespace llvm;
2616 
2617     auto Abbrev = std::make_shared<BitCodeAbbrev>();
2618     Abbrev->Add(BitCodeAbbrevOp(PPD_ENTITIES_OFFSETS));
2619     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // first pp entity
2620     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2621     unsigned PPEOffsetAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2622 
2623     RecordData::value_type Record[] = {PPD_ENTITIES_OFFSETS,
2624                                        FirstPreprocessorEntityID -
2625                                            NUM_PREDEF_PP_ENTITY_IDS};
2626     Stream.EmitRecordWithBlob(PPEOffsetAbbrev, Record,
2627                               bytes(PreprocessedEntityOffsets));
2628   }
2629 
2630   // Write the skipped region table for the preprocessing record.
2631   ArrayRef<SourceRange> SkippedRanges = PPRec.getSkippedRanges();
2632   if (SkippedRanges.size() > 0) {
2633     std::vector<PPSkippedRange> SerializedSkippedRanges;
2634     SerializedSkippedRanges.reserve(SkippedRanges.size());
2635     for (auto const& Range : SkippedRanges)
2636       SerializedSkippedRanges.emplace_back(Range);
2637 
2638     using namespace llvm;
2639     auto Abbrev = std::make_shared<BitCodeAbbrev>();
2640     Abbrev->Add(BitCodeAbbrevOp(PPD_SKIPPED_RANGES));
2641     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2642     unsigned PPESkippedRangeAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2643 
2644     Record.clear();
2645     Record.push_back(PPD_SKIPPED_RANGES);
2646     Stream.EmitRecordWithBlob(PPESkippedRangeAbbrev, Record,
2647                               bytes(SerializedSkippedRanges));
2648   }
2649 }
2650 
2651 unsigned ASTWriter::getLocalOrImportedSubmoduleID(const Module *Mod) {
2652   if (!Mod)
2653     return 0;
2654 
2655   auto Known = SubmoduleIDs.find(Mod);
2656   if (Known != SubmoduleIDs.end())
2657     return Known->second;
2658 
2659   auto *Top = Mod->getTopLevelModule();
2660   if (Top != WritingModule &&
2661       (getLangOpts().CompilingPCH ||
2662        !Top->fullModuleNameIs(StringRef(getLangOpts().CurrentModule))))
2663     return 0;
2664 
2665   return SubmoduleIDs[Mod] = NextSubmoduleID++;
2666 }
2667 
2668 unsigned ASTWriter::getSubmoduleID(Module *Mod) {
2669   // FIXME: This can easily happen, if we have a reference to a submodule that
2670   // did not result in us loading a module file for that submodule. For
2671   // instance, a cross-top-level-module 'conflict' declaration will hit this.
2672   unsigned ID = getLocalOrImportedSubmoduleID(Mod);
2673   assert((ID || !Mod) &&
2674          "asked for module ID for non-local, non-imported module");
2675   return ID;
2676 }
2677 
2678 /// Compute the number of modules within the given tree (including the
2679 /// given module).
2680 static unsigned getNumberOfModules(Module *Mod) {
2681   unsigned ChildModules = 0;
2682   for (auto Sub = Mod->submodule_begin(), SubEnd = Mod->submodule_end();
2683        Sub != SubEnd; ++Sub)
2684     ChildModules += getNumberOfModules(*Sub);
2685 
2686   return ChildModules + 1;
2687 }
2688 
2689 void ASTWriter::WriteSubmodules(Module *WritingModule) {
2690   // Enter the submodule description block.
2691   Stream.EnterSubblock(SUBMODULE_BLOCK_ID, /*bits for abbreviations*/5);
2692 
2693   // Write the abbreviations needed for the submodules block.
2694   using namespace llvm;
2695 
2696   auto Abbrev = std::make_shared<BitCodeAbbrev>();
2697   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_DEFINITION));
2698   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ID
2699   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Parent
2700   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // Kind
2701   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsFramework
2702   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsExplicit
2703   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsSystem
2704   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsExternC
2705   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // InferSubmodules...
2706   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // InferExplicit...
2707   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // InferExportWild...
2708   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // ConfigMacrosExh...
2709   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // ModuleMapIsPriv...
2710   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2711   unsigned DefinitionAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2712 
2713   Abbrev = std::make_shared<BitCodeAbbrev>();
2714   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_UMBRELLA_HEADER));
2715   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2716   unsigned UmbrellaAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2717 
2718   Abbrev = std::make_shared<BitCodeAbbrev>();
2719   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_HEADER));
2720   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2721   unsigned HeaderAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2722 
2723   Abbrev = std::make_shared<BitCodeAbbrev>();
2724   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_TOPHEADER));
2725   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2726   unsigned TopHeaderAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2727 
2728   Abbrev = std::make_shared<BitCodeAbbrev>();
2729   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_UMBRELLA_DIR));
2730   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2731   unsigned UmbrellaDirAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2732 
2733   Abbrev = std::make_shared<BitCodeAbbrev>();
2734   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_REQUIRES));
2735   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // State
2736   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));     // Feature
2737   unsigned RequiresAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2738 
2739   Abbrev = std::make_shared<BitCodeAbbrev>();
2740   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_EXCLUDED_HEADER));
2741   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2742   unsigned ExcludedHeaderAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2743 
2744   Abbrev = std::make_shared<BitCodeAbbrev>();
2745   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_TEXTUAL_HEADER));
2746   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2747   unsigned TextualHeaderAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2748 
2749   Abbrev = std::make_shared<BitCodeAbbrev>();
2750   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_PRIVATE_HEADER));
2751   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2752   unsigned PrivateHeaderAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2753 
2754   Abbrev = std::make_shared<BitCodeAbbrev>();
2755   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_PRIVATE_TEXTUAL_HEADER));
2756   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2757   unsigned PrivateTextualHeaderAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2758 
2759   Abbrev = std::make_shared<BitCodeAbbrev>();
2760   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_LINK_LIBRARY));
2761   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsFramework
2762   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));     // Name
2763   unsigned LinkLibraryAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2764 
2765   Abbrev = std::make_shared<BitCodeAbbrev>();
2766   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_CONFIG_MACRO));
2767   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));    // Macro name
2768   unsigned ConfigMacroAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2769 
2770   Abbrev = std::make_shared<BitCodeAbbrev>();
2771   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_CONFLICT));
2772   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));  // Other module
2773   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));    // Message
2774   unsigned ConflictAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2775 
2776   Abbrev = std::make_shared<BitCodeAbbrev>();
2777   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_EXPORT_AS));
2778   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));    // Macro name
2779   unsigned ExportAsAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2780 
2781   // Write the submodule metadata block.
2782   RecordData::value_type Record[] = {
2783       getNumberOfModules(WritingModule),
2784       FirstSubmoduleID - NUM_PREDEF_SUBMODULE_IDS};
2785   Stream.EmitRecord(SUBMODULE_METADATA, Record);
2786 
2787   // Write all of the submodules.
2788   std::queue<Module *> Q;
2789   Q.push(WritingModule);
2790   while (!Q.empty()) {
2791     Module *Mod = Q.front();
2792     Q.pop();
2793     unsigned ID = getSubmoduleID(Mod);
2794 
2795     uint64_t ParentID = 0;
2796     if (Mod->Parent) {
2797       assert(SubmoduleIDs[Mod->Parent] && "Submodule parent not written?");
2798       ParentID = SubmoduleIDs[Mod->Parent];
2799     }
2800 
2801     // Emit the definition of the block.
2802     {
2803       RecordData::value_type Record[] = {SUBMODULE_DEFINITION,
2804                                          ID,
2805                                          ParentID,
2806                                          (RecordData::value_type)Mod->Kind,
2807                                          Mod->IsFramework,
2808                                          Mod->IsExplicit,
2809                                          Mod->IsSystem,
2810                                          Mod->IsExternC,
2811                                          Mod->InferSubmodules,
2812                                          Mod->InferExplicitSubmodules,
2813                                          Mod->InferExportWildcard,
2814                                          Mod->ConfigMacrosExhaustive,
2815                                          Mod->ModuleMapIsPrivate};
2816       Stream.EmitRecordWithBlob(DefinitionAbbrev, Record, Mod->Name);
2817     }
2818 
2819     // Emit the requirements.
2820     for (const auto &R : Mod->Requirements) {
2821       RecordData::value_type Record[] = {SUBMODULE_REQUIRES, R.second};
2822       Stream.EmitRecordWithBlob(RequiresAbbrev, Record, R.first);
2823     }
2824 
2825     // Emit the umbrella header, if there is one.
2826     if (auto UmbrellaHeader = Mod->getUmbrellaHeader()) {
2827       RecordData::value_type Record[] = {SUBMODULE_UMBRELLA_HEADER};
2828       Stream.EmitRecordWithBlob(UmbrellaAbbrev, Record,
2829                                 UmbrellaHeader.NameAsWritten);
2830     } else if (auto UmbrellaDir = Mod->getUmbrellaDir()) {
2831       RecordData::value_type Record[] = {SUBMODULE_UMBRELLA_DIR};
2832       Stream.EmitRecordWithBlob(UmbrellaDirAbbrev, Record,
2833                                 UmbrellaDir.NameAsWritten);
2834     }
2835 
2836     // Emit the headers.
2837     struct {
2838       unsigned RecordKind;
2839       unsigned Abbrev;
2840       Module::HeaderKind HeaderKind;
2841     } HeaderLists[] = {
2842       {SUBMODULE_HEADER, HeaderAbbrev, Module::HK_Normal},
2843       {SUBMODULE_TEXTUAL_HEADER, TextualHeaderAbbrev, Module::HK_Textual},
2844       {SUBMODULE_PRIVATE_HEADER, PrivateHeaderAbbrev, Module::HK_Private},
2845       {SUBMODULE_PRIVATE_TEXTUAL_HEADER, PrivateTextualHeaderAbbrev,
2846         Module::HK_PrivateTextual},
2847       {SUBMODULE_EXCLUDED_HEADER, ExcludedHeaderAbbrev, Module::HK_Excluded}
2848     };
2849     for (auto &HL : HeaderLists) {
2850       RecordData::value_type Record[] = {HL.RecordKind};
2851       for (auto &H : Mod->Headers[HL.HeaderKind])
2852         Stream.EmitRecordWithBlob(HL.Abbrev, Record, H.NameAsWritten);
2853     }
2854 
2855     // Emit the top headers.
2856     {
2857       auto TopHeaders = Mod->getTopHeaders(PP->getFileManager());
2858       RecordData::value_type Record[] = {SUBMODULE_TOPHEADER};
2859       for (auto *H : TopHeaders) {
2860         SmallString<128> HeaderName(H->getName());
2861         PreparePathForOutput(HeaderName);
2862         Stream.EmitRecordWithBlob(TopHeaderAbbrev, Record, HeaderName);
2863       }
2864     }
2865 
2866     // Emit the imports.
2867     if (!Mod->Imports.empty()) {
2868       RecordData Record;
2869       for (auto *I : Mod->Imports)
2870         Record.push_back(getSubmoduleID(I));
2871       Stream.EmitRecord(SUBMODULE_IMPORTS, Record);
2872     }
2873 
2874     // Emit the exports.
2875     if (!Mod->Exports.empty()) {
2876       RecordData Record;
2877       for (const auto &E : Mod->Exports) {
2878         // FIXME: This may fail; we don't require that all exported modules
2879         // are local or imported.
2880         Record.push_back(getSubmoduleID(E.getPointer()));
2881         Record.push_back(E.getInt());
2882       }
2883       Stream.EmitRecord(SUBMODULE_EXPORTS, Record);
2884     }
2885 
2886     //FIXME: How do we emit the 'use'd modules?  They may not be submodules.
2887     // Might be unnecessary as use declarations are only used to build the
2888     // module itself.
2889 
2890     // TODO: Consider serializing undeclared uses of modules.
2891 
2892     // Emit the link libraries.
2893     for (const auto &LL : Mod->LinkLibraries) {
2894       RecordData::value_type Record[] = {SUBMODULE_LINK_LIBRARY,
2895                                          LL.IsFramework};
2896       Stream.EmitRecordWithBlob(LinkLibraryAbbrev, Record, LL.Library);
2897     }
2898 
2899     // Emit the conflicts.
2900     for (const auto &C : Mod->Conflicts) {
2901       // FIXME: This may fail; we don't require that all conflicting modules
2902       // are local or imported.
2903       RecordData::value_type Record[] = {SUBMODULE_CONFLICT,
2904                                          getSubmoduleID(C.Other)};
2905       Stream.EmitRecordWithBlob(ConflictAbbrev, Record, C.Message);
2906     }
2907 
2908     // Emit the configuration macros.
2909     for (const auto &CM : Mod->ConfigMacros) {
2910       RecordData::value_type Record[] = {SUBMODULE_CONFIG_MACRO};
2911       Stream.EmitRecordWithBlob(ConfigMacroAbbrev, Record, CM);
2912     }
2913 
2914     // Emit the initializers, if any.
2915     RecordData Inits;
2916     for (Decl *D : Context->getModuleInitializers(Mod))
2917       Inits.push_back(GetDeclRef(D));
2918     if (!Inits.empty())
2919       Stream.EmitRecord(SUBMODULE_INITIALIZERS, Inits);
2920 
2921     // Emit the name of the re-exported module, if any.
2922     if (!Mod->ExportAsModule.empty()) {
2923       RecordData::value_type Record[] = {SUBMODULE_EXPORT_AS};
2924       Stream.EmitRecordWithBlob(ExportAsAbbrev, Record, Mod->ExportAsModule);
2925     }
2926 
2927     // Queue up the submodules of this module.
2928     for (auto *M : Mod->submodules())
2929       Q.push(M);
2930   }
2931 
2932   Stream.ExitBlock();
2933 
2934   assert((NextSubmoduleID - FirstSubmoduleID ==
2935           getNumberOfModules(WritingModule)) &&
2936          "Wrong # of submodules; found a reference to a non-local, "
2937          "non-imported submodule?");
2938 }
2939 
2940 void ASTWriter::WritePragmaDiagnosticMappings(const DiagnosticsEngine &Diag,
2941                                               bool isModule) {
2942   llvm::SmallDenseMap<const DiagnosticsEngine::DiagState *, unsigned, 64>
2943       DiagStateIDMap;
2944   unsigned CurrID = 0;
2945   RecordData Record;
2946 
2947   auto EncodeDiagStateFlags =
2948       [](const DiagnosticsEngine::DiagState *DS) -> unsigned {
2949     unsigned Result = (unsigned)DS->ExtBehavior;
2950     for (unsigned Val :
2951          {(unsigned)DS->IgnoreAllWarnings, (unsigned)DS->EnableAllWarnings,
2952           (unsigned)DS->WarningsAsErrors, (unsigned)DS->ErrorsAsFatal,
2953           (unsigned)DS->SuppressSystemWarnings})
2954       Result = (Result << 1) | Val;
2955     return Result;
2956   };
2957 
2958   unsigned Flags = EncodeDiagStateFlags(Diag.DiagStatesByLoc.FirstDiagState);
2959   Record.push_back(Flags);
2960 
2961   auto AddDiagState = [&](const DiagnosticsEngine::DiagState *State,
2962                           bool IncludeNonPragmaStates) {
2963     // Ensure that the diagnostic state wasn't modified since it was created.
2964     // We will not correctly round-trip this information otherwise.
2965     assert(Flags == EncodeDiagStateFlags(State) &&
2966            "diag state flags vary in single AST file");
2967 
2968     unsigned &DiagStateID = DiagStateIDMap[State];
2969     Record.push_back(DiagStateID);
2970 
2971     if (DiagStateID == 0) {
2972       DiagStateID = ++CurrID;
2973 
2974       // Add a placeholder for the number of mappings.
2975       auto SizeIdx = Record.size();
2976       Record.emplace_back();
2977       for (const auto &I : *State) {
2978         if (I.second.isPragma() || IncludeNonPragmaStates) {
2979           Record.push_back(I.first);
2980           Record.push_back(I.second.serialize());
2981         }
2982       }
2983       // Update the placeholder.
2984       Record[SizeIdx] = (Record.size() - SizeIdx) / 2;
2985     }
2986   };
2987 
2988   AddDiagState(Diag.DiagStatesByLoc.FirstDiagState, isModule);
2989 
2990   // Reserve a spot for the number of locations with state transitions.
2991   auto NumLocationsIdx = Record.size();
2992   Record.emplace_back();
2993 
2994   // Emit the state transitions.
2995   unsigned NumLocations = 0;
2996   for (auto &FileIDAndFile : Diag.DiagStatesByLoc.Files) {
2997     if (!FileIDAndFile.first.isValid() ||
2998         !FileIDAndFile.second.HasLocalTransitions)
2999       continue;
3000     ++NumLocations;
3001 
3002     SourceLocation Loc = Diag.SourceMgr->getComposedLoc(FileIDAndFile.first, 0);
3003     assert(!Loc.isInvalid() && "start loc for valid FileID is invalid");
3004     AddSourceLocation(Loc, Record);
3005 
3006     Record.push_back(FileIDAndFile.second.StateTransitions.size());
3007     for (auto &StatePoint : FileIDAndFile.second.StateTransitions) {
3008       Record.push_back(StatePoint.Offset);
3009       AddDiagState(StatePoint.State, false);
3010     }
3011   }
3012 
3013   // Backpatch the number of locations.
3014   Record[NumLocationsIdx] = NumLocations;
3015 
3016   // Emit CurDiagStateLoc.  Do it last in order to match source order.
3017   //
3018   // This also protects against a hypothetical corner case with simulating
3019   // -Werror settings for implicit modules in the ASTReader, where reading
3020   // CurDiagState out of context could change whether warning pragmas are
3021   // treated as errors.
3022   AddSourceLocation(Diag.DiagStatesByLoc.CurDiagStateLoc, Record);
3023   AddDiagState(Diag.DiagStatesByLoc.CurDiagState, false);
3024 
3025   Stream.EmitRecord(DIAG_PRAGMA_MAPPINGS, Record);
3026 }
3027 
3028 //===----------------------------------------------------------------------===//
3029 // Type Serialization
3030 //===----------------------------------------------------------------------===//
3031 
3032 /// Write the representation of a type to the AST stream.
3033 void ASTWriter::WriteType(QualType T) {
3034   TypeIdx &IdxRef = TypeIdxs[T];
3035   if (IdxRef.getIndex() == 0) // we haven't seen this type before.
3036     IdxRef = TypeIdx(NextTypeID++);
3037   TypeIdx Idx = IdxRef;
3038 
3039   assert(Idx.getIndex() >= FirstTypeID && "Re-writing a type from a prior AST");
3040 
3041   // Emit the type's representation.
3042   uint64_t Offset = ASTTypeWriter(*this).write(T) - DeclTypesBlockStartOffset;
3043 
3044   // Record the offset for this type.
3045   unsigned Index = Idx.getIndex() - FirstTypeID;
3046   if (TypeOffsets.size() == Index)
3047     TypeOffsets.emplace_back(Offset);
3048   else if (TypeOffsets.size() < Index) {
3049     TypeOffsets.resize(Index + 1);
3050     TypeOffsets[Index].setBitOffset(Offset);
3051   } else {
3052     llvm_unreachable("Types emitted in wrong order");
3053   }
3054 }
3055 
3056 //===----------------------------------------------------------------------===//
3057 // Declaration Serialization
3058 //===----------------------------------------------------------------------===//
3059 
3060 /// Write the block containing all of the declaration IDs
3061 /// lexically declared within the given DeclContext.
3062 ///
3063 /// \returns the offset of the DECL_CONTEXT_LEXICAL block within the
3064 /// bitstream, or 0 if no block was written.
3065 uint64_t ASTWriter::WriteDeclContextLexicalBlock(ASTContext &Context,
3066                                                  DeclContext *DC) {
3067   if (DC->decls_empty())
3068     return 0;
3069 
3070   uint64_t Offset = Stream.GetCurrentBitNo();
3071   SmallVector<uint32_t, 128> KindDeclPairs;
3072   for (const auto *D : DC->decls()) {
3073     KindDeclPairs.push_back(D->getKind());
3074     KindDeclPairs.push_back(GetDeclRef(D));
3075   }
3076 
3077   ++NumLexicalDeclContexts;
3078   RecordData::value_type Record[] = {DECL_CONTEXT_LEXICAL};
3079   Stream.EmitRecordWithBlob(DeclContextLexicalAbbrev, Record,
3080                             bytes(KindDeclPairs));
3081   return Offset;
3082 }
3083 
3084 void ASTWriter::WriteTypeDeclOffsets() {
3085   using namespace llvm;
3086 
3087   // Write the type offsets array
3088   auto Abbrev = std::make_shared<BitCodeAbbrev>();
3089   Abbrev->Add(BitCodeAbbrevOp(TYPE_OFFSET));
3090   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // # of types
3091   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // base type index
3092   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // types block
3093   unsigned TypeOffsetAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
3094   {
3095     RecordData::value_type Record[] = {TYPE_OFFSET, TypeOffsets.size(),
3096                                        FirstTypeID - NUM_PREDEF_TYPE_IDS};
3097     Stream.EmitRecordWithBlob(TypeOffsetAbbrev, Record, bytes(TypeOffsets));
3098   }
3099 
3100   // Write the declaration offsets array
3101   Abbrev = std::make_shared<BitCodeAbbrev>();
3102   Abbrev->Add(BitCodeAbbrevOp(DECL_OFFSET));
3103   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // # of declarations
3104   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // base decl ID
3105   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // declarations block
3106   unsigned DeclOffsetAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
3107   {
3108     RecordData::value_type Record[] = {DECL_OFFSET, DeclOffsets.size(),
3109                                        FirstDeclID - NUM_PREDEF_DECL_IDS};
3110     Stream.EmitRecordWithBlob(DeclOffsetAbbrev, Record, bytes(DeclOffsets));
3111   }
3112 }
3113 
3114 void ASTWriter::WriteFileDeclIDsMap() {
3115   using namespace llvm;
3116 
3117   SmallVector<std::pair<FileID, DeclIDInFileInfo *>, 64> SortedFileDeclIDs;
3118   SortedFileDeclIDs.reserve(FileDeclIDs.size());
3119   for (const auto &P : FileDeclIDs)
3120     SortedFileDeclIDs.push_back(std::make_pair(P.first, P.second.get()));
3121   llvm::sort(SortedFileDeclIDs, llvm::less_first());
3122 
3123   // Join the vectors of DeclIDs from all files.
3124   SmallVector<DeclID, 256> FileGroupedDeclIDs;
3125   for (auto &FileDeclEntry : SortedFileDeclIDs) {
3126     DeclIDInFileInfo &Info = *FileDeclEntry.second;
3127     Info.FirstDeclIndex = FileGroupedDeclIDs.size();
3128     llvm::stable_sort(Info.DeclIDs);
3129     for (auto &LocDeclEntry : Info.DeclIDs)
3130       FileGroupedDeclIDs.push_back(LocDeclEntry.second);
3131   }
3132 
3133   auto Abbrev = std::make_shared<BitCodeAbbrev>();
3134   Abbrev->Add(BitCodeAbbrevOp(FILE_SORTED_DECLS));
3135   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
3136   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
3137   unsigned AbbrevCode = Stream.EmitAbbrev(std::move(Abbrev));
3138   RecordData::value_type Record[] = {FILE_SORTED_DECLS,
3139                                      FileGroupedDeclIDs.size()};
3140   Stream.EmitRecordWithBlob(AbbrevCode, Record, bytes(FileGroupedDeclIDs));
3141 }
3142 
3143 void ASTWriter::WriteComments() {
3144   Stream.EnterSubblock(COMMENTS_BLOCK_ID, 3);
3145   auto _ = llvm::make_scope_exit([this] { Stream.ExitBlock(); });
3146   if (!PP->getPreprocessorOpts().WriteCommentListToPCH)
3147     return;
3148   RecordData Record;
3149   for (const auto &FO : Context->Comments.OrderedComments) {
3150     for (const auto &OC : FO.second) {
3151       const RawComment *I = OC.second;
3152       Record.clear();
3153       AddSourceRange(I->getSourceRange(), Record);
3154       Record.push_back(I->getKind());
3155       Record.push_back(I->isTrailingComment());
3156       Record.push_back(I->isAlmostTrailingComment());
3157       Stream.EmitRecord(COMMENTS_RAW_COMMENT, Record);
3158     }
3159   }
3160 }
3161 
3162 //===----------------------------------------------------------------------===//
3163 // Global Method Pool and Selector Serialization
3164 //===----------------------------------------------------------------------===//
3165 
3166 namespace {
3167 
3168 // Trait used for the on-disk hash table used in the method pool.
3169 class ASTMethodPoolTrait {
3170   ASTWriter &Writer;
3171 
3172 public:
3173   using key_type = Selector;
3174   using key_type_ref = key_type;
3175 
3176   struct data_type {
3177     SelectorID ID;
3178     ObjCMethodList Instance, Factory;
3179   };
3180   using data_type_ref = const data_type &;
3181 
3182   using hash_value_type = unsigned;
3183   using offset_type = unsigned;
3184 
3185   explicit ASTMethodPoolTrait(ASTWriter &Writer) : Writer(Writer) {}
3186 
3187   static hash_value_type ComputeHash(Selector Sel) {
3188     return serialization::ComputeHash(Sel);
3189   }
3190 
3191   std::pair<unsigned, unsigned>
3192     EmitKeyDataLength(raw_ostream& Out, Selector Sel,
3193                       data_type_ref Methods) {
3194     unsigned KeyLen = 2 + (Sel.getNumArgs()? Sel.getNumArgs() * 4 : 4);
3195     unsigned DataLen = 4 + 2 + 2; // 2 bytes for each of the method counts
3196     for (const ObjCMethodList *Method = &Methods.Instance; Method;
3197          Method = Method->getNext())
3198       if (ShouldWriteMethodListNode(Method))
3199         DataLen += 4;
3200     for (const ObjCMethodList *Method = &Methods.Factory; Method;
3201          Method = Method->getNext())
3202       if (ShouldWriteMethodListNode(Method))
3203         DataLen += 4;
3204     return emitULEBKeyDataLength(KeyLen, DataLen, Out);
3205   }
3206 
3207   void EmitKey(raw_ostream& Out, Selector Sel, unsigned) {
3208     using namespace llvm::support;
3209 
3210     endian::Writer LE(Out, little);
3211     uint64_t Start = Out.tell();
3212     assert((Start >> 32) == 0 && "Selector key offset too large");
3213     Writer.SetSelectorOffset(Sel, Start);
3214     unsigned N = Sel.getNumArgs();
3215     LE.write<uint16_t>(N);
3216     if (N == 0)
3217       N = 1;
3218     for (unsigned I = 0; I != N; ++I)
3219       LE.write<uint32_t>(
3220           Writer.getIdentifierRef(Sel.getIdentifierInfoForSlot(I)));
3221   }
3222 
3223   void EmitData(raw_ostream& Out, key_type_ref,
3224                 data_type_ref Methods, unsigned DataLen) {
3225     using namespace llvm::support;
3226 
3227     endian::Writer LE(Out, little);
3228     uint64_t Start = Out.tell(); (void)Start;
3229     LE.write<uint32_t>(Methods.ID);
3230     unsigned NumInstanceMethods = 0;
3231     for (const ObjCMethodList *Method = &Methods.Instance; Method;
3232          Method = Method->getNext())
3233       if (ShouldWriteMethodListNode(Method))
3234         ++NumInstanceMethods;
3235 
3236     unsigned NumFactoryMethods = 0;
3237     for (const ObjCMethodList *Method = &Methods.Factory; Method;
3238          Method = Method->getNext())
3239       if (ShouldWriteMethodListNode(Method))
3240         ++NumFactoryMethods;
3241 
3242     unsigned InstanceBits = Methods.Instance.getBits();
3243     assert(InstanceBits < 4);
3244     unsigned InstanceHasMoreThanOneDeclBit =
3245         Methods.Instance.hasMoreThanOneDecl();
3246     unsigned FullInstanceBits = (NumInstanceMethods << 3) |
3247                                 (InstanceHasMoreThanOneDeclBit << 2) |
3248                                 InstanceBits;
3249     unsigned FactoryBits = Methods.Factory.getBits();
3250     assert(FactoryBits < 4);
3251     unsigned FactoryHasMoreThanOneDeclBit =
3252         Methods.Factory.hasMoreThanOneDecl();
3253     unsigned FullFactoryBits = (NumFactoryMethods << 3) |
3254                                (FactoryHasMoreThanOneDeclBit << 2) |
3255                                FactoryBits;
3256     LE.write<uint16_t>(FullInstanceBits);
3257     LE.write<uint16_t>(FullFactoryBits);
3258     for (const ObjCMethodList *Method = &Methods.Instance; Method;
3259          Method = Method->getNext())
3260       if (ShouldWriteMethodListNode(Method))
3261         LE.write<uint32_t>(Writer.getDeclID(Method->getMethod()));
3262     for (const ObjCMethodList *Method = &Methods.Factory; Method;
3263          Method = Method->getNext())
3264       if (ShouldWriteMethodListNode(Method))
3265         LE.write<uint32_t>(Writer.getDeclID(Method->getMethod()));
3266 
3267     assert(Out.tell() - Start == DataLen && "Data length is wrong");
3268   }
3269 
3270 private:
3271   static bool ShouldWriteMethodListNode(const ObjCMethodList *Node) {
3272     return (Node->getMethod() && !Node->getMethod()->isFromASTFile());
3273   }
3274 };
3275 
3276 } // namespace
3277 
3278 /// Write ObjC data: selectors and the method pool.
3279 ///
3280 /// The method pool contains both instance and factory methods, stored
3281 /// in an on-disk hash table indexed by the selector. The hash table also
3282 /// contains an empty entry for every other selector known to Sema.
3283 void ASTWriter::WriteSelectors(Sema &SemaRef) {
3284   using namespace llvm;
3285 
3286   // Do we have to do anything at all?
3287   if (SemaRef.MethodPool.empty() && SelectorIDs.empty())
3288     return;
3289   unsigned NumTableEntries = 0;
3290   // Create and write out the blob that contains selectors and the method pool.
3291   {
3292     llvm::OnDiskChainedHashTableGenerator<ASTMethodPoolTrait> Generator;
3293     ASTMethodPoolTrait Trait(*this);
3294 
3295     // Create the on-disk hash table representation. We walk through every
3296     // selector we've seen and look it up in the method pool.
3297     SelectorOffsets.resize(NextSelectorID - FirstSelectorID);
3298     for (auto &SelectorAndID : SelectorIDs) {
3299       Selector S = SelectorAndID.first;
3300       SelectorID ID = SelectorAndID.second;
3301       Sema::GlobalMethodPool::iterator F = SemaRef.MethodPool.find(S);
3302       ASTMethodPoolTrait::data_type Data = {
3303         ID,
3304         ObjCMethodList(),
3305         ObjCMethodList()
3306       };
3307       if (F != SemaRef.MethodPool.end()) {
3308         Data.Instance = F->second.first;
3309         Data.Factory = F->second.second;
3310       }
3311       // Only write this selector if it's not in an existing AST or something
3312       // changed.
3313       if (Chain && ID < FirstSelectorID) {
3314         // Selector already exists. Did it change?
3315         bool changed = false;
3316         for (ObjCMethodList *M = &Data.Instance; M && M->getMethod();
3317              M = M->getNext()) {
3318           if (!M->getMethod()->isFromASTFile()) {
3319             changed = true;
3320             Data.Instance = *M;
3321             break;
3322           }
3323         }
3324         for (ObjCMethodList *M = &Data.Factory; M && M->getMethod();
3325              M = M->getNext()) {
3326           if (!M->getMethod()->isFromASTFile()) {
3327             changed = true;
3328             Data.Factory = *M;
3329             break;
3330           }
3331         }
3332         if (!changed)
3333           continue;
3334       } else if (Data.Instance.getMethod() || Data.Factory.getMethod()) {
3335         // A new method pool entry.
3336         ++NumTableEntries;
3337       }
3338       Generator.insert(S, Data, Trait);
3339     }
3340 
3341     // Create the on-disk hash table in a buffer.
3342     SmallString<4096> MethodPool;
3343     uint32_t BucketOffset;
3344     {
3345       using namespace llvm::support;
3346 
3347       ASTMethodPoolTrait Trait(*this);
3348       llvm::raw_svector_ostream Out(MethodPool);
3349       // Make sure that no bucket is at offset 0
3350       endian::write<uint32_t>(Out, 0, little);
3351       BucketOffset = Generator.Emit(Out, Trait);
3352     }
3353 
3354     // Create a blob abbreviation
3355     auto Abbrev = std::make_shared<BitCodeAbbrev>();
3356     Abbrev->Add(BitCodeAbbrevOp(METHOD_POOL));
3357     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
3358     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
3359     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
3360     unsigned MethodPoolAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
3361 
3362     // Write the method pool
3363     {
3364       RecordData::value_type Record[] = {METHOD_POOL, BucketOffset,
3365                                          NumTableEntries};
3366       Stream.EmitRecordWithBlob(MethodPoolAbbrev, Record, MethodPool);
3367     }
3368 
3369     // Create a blob abbreviation for the selector table offsets.
3370     Abbrev = std::make_shared<BitCodeAbbrev>();
3371     Abbrev->Add(BitCodeAbbrevOp(SELECTOR_OFFSETS));
3372     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // size
3373     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // first ID
3374     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
3375     unsigned SelectorOffsetAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
3376 
3377     // Write the selector offsets table.
3378     {
3379       RecordData::value_type Record[] = {
3380           SELECTOR_OFFSETS, SelectorOffsets.size(),
3381           FirstSelectorID - NUM_PREDEF_SELECTOR_IDS};
3382       Stream.EmitRecordWithBlob(SelectorOffsetAbbrev, Record,
3383                                 bytes(SelectorOffsets));
3384     }
3385   }
3386 }
3387 
3388 /// Write the selectors referenced in @selector expression into AST file.
3389 void ASTWriter::WriteReferencedSelectorsPool(Sema &SemaRef) {
3390   using namespace llvm;
3391 
3392   if (SemaRef.ReferencedSelectors.empty())
3393     return;
3394 
3395   RecordData Record;
3396   ASTRecordWriter Writer(*this, Record);
3397 
3398   // Note: this writes out all references even for a dependent AST. But it is
3399   // very tricky to fix, and given that @selector shouldn't really appear in
3400   // headers, probably not worth it. It's not a correctness issue.
3401   for (auto &SelectorAndLocation : SemaRef.ReferencedSelectors) {
3402     Selector Sel = SelectorAndLocation.first;
3403     SourceLocation Loc = SelectorAndLocation.second;
3404     Writer.AddSelectorRef(Sel);
3405     Writer.AddSourceLocation(Loc);
3406   }
3407   Writer.Emit(REFERENCED_SELECTOR_POOL);
3408 }
3409 
3410 //===----------------------------------------------------------------------===//
3411 // Identifier Table Serialization
3412 //===----------------------------------------------------------------------===//
3413 
3414 /// Determine the declaration that should be put into the name lookup table to
3415 /// represent the given declaration in this module. This is usually D itself,
3416 /// but if D was imported and merged into a local declaration, we want the most
3417 /// recent local declaration instead. The chosen declaration will be the most
3418 /// recent declaration in any module that imports this one.
3419 static NamedDecl *getDeclForLocalLookup(const LangOptions &LangOpts,
3420                                         NamedDecl *D) {
3421   if (!LangOpts.Modules || !D->isFromASTFile())
3422     return D;
3423 
3424   if (Decl *Redecl = D->getPreviousDecl()) {
3425     // For Redeclarable decls, a prior declaration might be local.
3426     for (; Redecl; Redecl = Redecl->getPreviousDecl()) {
3427       // If we find a local decl, we're done.
3428       if (!Redecl->isFromASTFile()) {
3429         // Exception: in very rare cases (for injected-class-names), not all
3430         // redeclarations are in the same semantic context. Skip ones in a
3431         // different context. They don't go in this lookup table at all.
3432         if (!Redecl->getDeclContext()->getRedeclContext()->Equals(
3433                 D->getDeclContext()->getRedeclContext()))
3434           continue;
3435         return cast<NamedDecl>(Redecl);
3436       }
3437 
3438       // If we find a decl from a (chained-)PCH stop since we won't find a
3439       // local one.
3440       if (Redecl->getOwningModuleID() == 0)
3441         break;
3442     }
3443   } else if (Decl *First = D->getCanonicalDecl()) {
3444     // For Mergeable decls, the first decl might be local.
3445     if (!First->isFromASTFile())
3446       return cast<NamedDecl>(First);
3447   }
3448 
3449   // All declarations are imported. Our most recent declaration will also be
3450   // the most recent one in anyone who imports us.
3451   return D;
3452 }
3453 
3454 namespace {
3455 
3456 class ASTIdentifierTableTrait {
3457   ASTWriter &Writer;
3458   Preprocessor &PP;
3459   IdentifierResolver &IdResolver;
3460   bool IsModule;
3461   bool NeedDecls;
3462   ASTWriter::RecordData *InterestingIdentifierOffsets;
3463 
3464   /// Determines whether this is an "interesting" identifier that needs a
3465   /// full IdentifierInfo structure written into the hash table. Notably, this
3466   /// doesn't check whether the name has macros defined; use PublicMacroIterator
3467   /// to check that.
3468   bool isInterestingIdentifier(const IdentifierInfo *II, uint64_t MacroOffset) {
3469     if (MacroOffset || II->isPoisoned() ||
3470         (!IsModule && II->getObjCOrBuiltinID()) ||
3471         II->hasRevertedTokenIDToIdentifier() ||
3472         (NeedDecls && II->getFETokenInfo()))
3473       return true;
3474 
3475     return false;
3476   }
3477 
3478 public:
3479   using key_type = IdentifierInfo *;
3480   using key_type_ref = key_type;
3481 
3482   using data_type = IdentID;
3483   using data_type_ref = data_type;
3484 
3485   using hash_value_type = unsigned;
3486   using offset_type = unsigned;
3487 
3488   ASTIdentifierTableTrait(ASTWriter &Writer, Preprocessor &PP,
3489                           IdentifierResolver &IdResolver, bool IsModule,
3490                           ASTWriter::RecordData *InterestingIdentifierOffsets)
3491       : Writer(Writer), PP(PP), IdResolver(IdResolver), IsModule(IsModule),
3492         NeedDecls(!IsModule || !Writer.getLangOpts().CPlusPlus),
3493         InterestingIdentifierOffsets(InterestingIdentifierOffsets) {}
3494 
3495   bool needDecls() const { return NeedDecls; }
3496 
3497   static hash_value_type ComputeHash(const IdentifierInfo* II) {
3498     return llvm::djbHash(II->getName());
3499   }
3500 
3501   bool isInterestingIdentifier(const IdentifierInfo *II) {
3502     auto MacroOffset = Writer.getMacroDirectivesOffset(II);
3503     return isInterestingIdentifier(II, MacroOffset);
3504   }
3505 
3506   bool isInterestingNonMacroIdentifier(const IdentifierInfo *II) {
3507     return isInterestingIdentifier(II, 0);
3508   }
3509 
3510   std::pair<unsigned, unsigned>
3511   EmitKeyDataLength(raw_ostream& Out, IdentifierInfo* II, IdentID ID) {
3512     // Record the location of the identifier data. This is used when generating
3513     // the mapping from persistent IDs to strings.
3514     Writer.SetIdentifierOffset(II, Out.tell());
3515 
3516     // Emit the offset of the key/data length information to the interesting
3517     // identifiers table if necessary.
3518     if (InterestingIdentifierOffsets && isInterestingIdentifier(II))
3519       InterestingIdentifierOffsets->push_back(Out.tell());
3520 
3521     unsigned KeyLen = II->getLength() + 1;
3522     unsigned DataLen = 4; // 4 bytes for the persistent ID << 1
3523     auto MacroOffset = Writer.getMacroDirectivesOffset(II);
3524     if (isInterestingIdentifier(II, MacroOffset)) {
3525       DataLen += 2; // 2 bytes for builtin ID
3526       DataLen += 2; // 2 bytes for flags
3527       if (MacroOffset)
3528         DataLen += 4; // MacroDirectives offset.
3529 
3530       if (NeedDecls) {
3531         for (IdentifierResolver::iterator D = IdResolver.begin(II),
3532                                        DEnd = IdResolver.end();
3533              D != DEnd; ++D)
3534           DataLen += 4;
3535       }
3536     }
3537     return emitULEBKeyDataLength(KeyLen, DataLen, Out);
3538   }
3539 
3540   void EmitKey(raw_ostream& Out, const IdentifierInfo* II,
3541                unsigned KeyLen) {
3542     Out.write(II->getNameStart(), KeyLen);
3543   }
3544 
3545   void EmitData(raw_ostream& Out, IdentifierInfo* II,
3546                 IdentID ID, unsigned) {
3547     using namespace llvm::support;
3548 
3549     endian::Writer LE(Out, little);
3550 
3551     auto MacroOffset = Writer.getMacroDirectivesOffset(II);
3552     if (!isInterestingIdentifier(II, MacroOffset)) {
3553       LE.write<uint32_t>(ID << 1);
3554       return;
3555     }
3556 
3557     LE.write<uint32_t>((ID << 1) | 0x01);
3558     uint32_t Bits = (uint32_t)II->getObjCOrBuiltinID();
3559     assert((Bits & 0xffff) == Bits && "ObjCOrBuiltinID too big for ASTReader.");
3560     LE.write<uint16_t>(Bits);
3561     Bits = 0;
3562     bool HadMacroDefinition = MacroOffset != 0;
3563     Bits = (Bits << 1) | unsigned(HadMacroDefinition);
3564     Bits = (Bits << 1) | unsigned(II->isExtensionToken());
3565     Bits = (Bits << 1) | unsigned(II->isPoisoned());
3566     Bits = (Bits << 1) | unsigned(II->hasRevertedTokenIDToIdentifier());
3567     Bits = (Bits << 1) | unsigned(II->isCPlusPlusOperatorKeyword());
3568     LE.write<uint16_t>(Bits);
3569 
3570     if (HadMacroDefinition)
3571       LE.write<uint32_t>(MacroOffset);
3572 
3573     if (NeedDecls) {
3574       // Emit the declaration IDs in reverse order, because the
3575       // IdentifierResolver provides the declarations as they would be
3576       // visible (e.g., the function "stat" would come before the struct
3577       // "stat"), but the ASTReader adds declarations to the end of the list
3578       // (so we need to see the struct "stat" before the function "stat").
3579       // Only emit declarations that aren't from a chained PCH, though.
3580       SmallVector<NamedDecl *, 16> Decls(IdResolver.begin(II),
3581                                          IdResolver.end());
3582       for (NamedDecl *D : llvm::reverse(Decls))
3583         LE.write<uint32_t>(
3584             Writer.getDeclID(getDeclForLocalLookup(PP.getLangOpts(), D)));
3585     }
3586   }
3587 };
3588 
3589 } // namespace
3590 
3591 /// Write the identifier table into the AST file.
3592 ///
3593 /// The identifier table consists of a blob containing string data
3594 /// (the actual identifiers themselves) and a separate "offsets" index
3595 /// that maps identifier IDs to locations within the blob.
3596 void ASTWriter::WriteIdentifierTable(Preprocessor &PP,
3597                                      IdentifierResolver &IdResolver,
3598                                      bool IsModule) {
3599   using namespace llvm;
3600 
3601   RecordData InterestingIdents;
3602 
3603   // Create and write out the blob that contains the identifier
3604   // strings.
3605   {
3606     llvm::OnDiskChainedHashTableGenerator<ASTIdentifierTableTrait> Generator;
3607     ASTIdentifierTableTrait Trait(
3608         *this, PP, IdResolver, IsModule,
3609         (getLangOpts().CPlusPlus && IsModule) ? &InterestingIdents : nullptr);
3610 
3611     // Look for any identifiers that were named while processing the
3612     // headers, but are otherwise not needed. We add these to the hash
3613     // table to enable checking of the predefines buffer in the case
3614     // where the user adds new macro definitions when building the AST
3615     // file.
3616     SmallVector<const IdentifierInfo *, 128> IIs;
3617     for (const auto &ID : PP.getIdentifierTable())
3618       IIs.push_back(ID.second);
3619     // Sort the identifiers lexicographically before getting them references so
3620     // that their order is stable.
3621     llvm::sort(IIs, llvm::deref<std::less<>>());
3622     for (const IdentifierInfo *II : IIs)
3623       if (Trait.isInterestingNonMacroIdentifier(II))
3624         getIdentifierRef(II);
3625 
3626     // Create the on-disk hash table representation. We only store offsets
3627     // for identifiers that appear here for the first time.
3628     IdentifierOffsets.resize(NextIdentID - FirstIdentID);
3629     for (auto IdentIDPair : IdentifierIDs) {
3630       auto *II = const_cast<IdentifierInfo *>(IdentIDPair.first);
3631       IdentID ID = IdentIDPair.second;
3632       assert(II && "NULL identifier in identifier table");
3633       // Write out identifiers if either the ID is local or the identifier has
3634       // changed since it was loaded.
3635       if (ID >= FirstIdentID || !Chain || !II->isFromAST()
3636           || II->hasChangedSinceDeserialization() ||
3637           (Trait.needDecls() &&
3638            II->hasFETokenInfoChangedSinceDeserialization()))
3639         Generator.insert(II, ID, Trait);
3640     }
3641 
3642     // Create the on-disk hash table in a buffer.
3643     SmallString<4096> IdentifierTable;
3644     uint32_t BucketOffset;
3645     {
3646       using namespace llvm::support;
3647 
3648       llvm::raw_svector_ostream Out(IdentifierTable);
3649       // Make sure that no bucket is at offset 0
3650       endian::write<uint32_t>(Out, 0, little);
3651       BucketOffset = Generator.Emit(Out, Trait);
3652     }
3653 
3654     // Create a blob abbreviation
3655     auto Abbrev = std::make_shared<BitCodeAbbrev>();
3656     Abbrev->Add(BitCodeAbbrevOp(IDENTIFIER_TABLE));
3657     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
3658     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
3659     unsigned IDTableAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
3660 
3661     // Write the identifier table
3662     RecordData::value_type Record[] = {IDENTIFIER_TABLE, BucketOffset};
3663     Stream.EmitRecordWithBlob(IDTableAbbrev, Record, IdentifierTable);
3664   }
3665 
3666   // Write the offsets table for identifier IDs.
3667   auto Abbrev = std::make_shared<BitCodeAbbrev>();
3668   Abbrev->Add(BitCodeAbbrevOp(IDENTIFIER_OFFSET));
3669   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // # of identifiers
3670   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // first ID
3671   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
3672   unsigned IdentifierOffsetAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
3673 
3674 #ifndef NDEBUG
3675   for (unsigned I = 0, N = IdentifierOffsets.size(); I != N; ++I)
3676     assert(IdentifierOffsets[I] && "Missing identifier offset?");
3677 #endif
3678 
3679   RecordData::value_type Record[] = {IDENTIFIER_OFFSET,
3680                                      IdentifierOffsets.size(),
3681                                      FirstIdentID - NUM_PREDEF_IDENT_IDS};
3682   Stream.EmitRecordWithBlob(IdentifierOffsetAbbrev, Record,
3683                             bytes(IdentifierOffsets));
3684 
3685   // In C++, write the list of interesting identifiers (those that are
3686   // defined as macros, poisoned, or similar unusual things).
3687   if (!InterestingIdents.empty())
3688     Stream.EmitRecord(INTERESTING_IDENTIFIERS, InterestingIdents);
3689 }
3690 
3691 //===----------------------------------------------------------------------===//
3692 // DeclContext's Name Lookup Table Serialization
3693 //===----------------------------------------------------------------------===//
3694 
3695 namespace {
3696 
3697 // Trait used for the on-disk hash table used in the method pool.
3698 class ASTDeclContextNameLookupTrait {
3699   ASTWriter &Writer;
3700   llvm::SmallVector<DeclID, 64> DeclIDs;
3701 
3702 public:
3703   using key_type = DeclarationNameKey;
3704   using key_type_ref = key_type;
3705 
3706   /// A start and end index into DeclIDs, representing a sequence of decls.
3707   using data_type = std::pair<unsigned, unsigned>;
3708   using data_type_ref = const data_type &;
3709 
3710   using hash_value_type = unsigned;
3711   using offset_type = unsigned;
3712 
3713   explicit ASTDeclContextNameLookupTrait(ASTWriter &Writer) : Writer(Writer) {}
3714 
3715   template<typename Coll>
3716   data_type getData(const Coll &Decls) {
3717     unsigned Start = DeclIDs.size();
3718     for (NamedDecl *D : Decls) {
3719       DeclIDs.push_back(
3720           Writer.GetDeclRef(getDeclForLocalLookup(Writer.getLangOpts(), D)));
3721     }
3722     return std::make_pair(Start, DeclIDs.size());
3723   }
3724 
3725   data_type ImportData(const reader::ASTDeclContextNameLookupTrait::data_type &FromReader) {
3726     unsigned Start = DeclIDs.size();
3727     llvm::append_range(DeclIDs, FromReader);
3728     return std::make_pair(Start, DeclIDs.size());
3729   }
3730 
3731   static bool EqualKey(key_type_ref a, key_type_ref b) {
3732     return a == b;
3733   }
3734 
3735   hash_value_type ComputeHash(DeclarationNameKey Name) {
3736     return Name.getHash();
3737   }
3738 
3739   void EmitFileRef(raw_ostream &Out, ModuleFile *F) const {
3740     assert(Writer.hasChain() &&
3741            "have reference to loaded module file but no chain?");
3742 
3743     using namespace llvm::support;
3744 
3745     endian::write<uint32_t>(Out, Writer.getChain()->getModuleFileID(F), little);
3746   }
3747 
3748   std::pair<unsigned, unsigned> EmitKeyDataLength(raw_ostream &Out,
3749                                                   DeclarationNameKey Name,
3750                                                   data_type_ref Lookup) {
3751     unsigned KeyLen = 1;
3752     switch (Name.getKind()) {
3753     case DeclarationName::Identifier:
3754     case DeclarationName::ObjCZeroArgSelector:
3755     case DeclarationName::ObjCOneArgSelector:
3756     case DeclarationName::ObjCMultiArgSelector:
3757     case DeclarationName::CXXLiteralOperatorName:
3758     case DeclarationName::CXXDeductionGuideName:
3759       KeyLen += 4;
3760       break;
3761     case DeclarationName::CXXOperatorName:
3762       KeyLen += 1;
3763       break;
3764     case DeclarationName::CXXConstructorName:
3765     case DeclarationName::CXXDestructorName:
3766     case DeclarationName::CXXConversionFunctionName:
3767     case DeclarationName::CXXUsingDirective:
3768       break;
3769     }
3770 
3771     // 4 bytes for each DeclID.
3772     unsigned DataLen = 4 * (Lookup.second - Lookup.first);
3773 
3774     return emitULEBKeyDataLength(KeyLen, DataLen, Out);
3775   }
3776 
3777   void EmitKey(raw_ostream &Out, DeclarationNameKey Name, unsigned) {
3778     using namespace llvm::support;
3779 
3780     endian::Writer LE(Out, little);
3781     LE.write<uint8_t>(Name.getKind());
3782     switch (Name.getKind()) {
3783     case DeclarationName::Identifier:
3784     case DeclarationName::CXXLiteralOperatorName:
3785     case DeclarationName::CXXDeductionGuideName:
3786       LE.write<uint32_t>(Writer.getIdentifierRef(Name.getIdentifier()));
3787       return;
3788     case DeclarationName::ObjCZeroArgSelector:
3789     case DeclarationName::ObjCOneArgSelector:
3790     case DeclarationName::ObjCMultiArgSelector:
3791       LE.write<uint32_t>(Writer.getSelectorRef(Name.getSelector()));
3792       return;
3793     case DeclarationName::CXXOperatorName:
3794       assert(Name.getOperatorKind() < NUM_OVERLOADED_OPERATORS &&
3795              "Invalid operator?");
3796       LE.write<uint8_t>(Name.getOperatorKind());
3797       return;
3798     case DeclarationName::CXXConstructorName:
3799     case DeclarationName::CXXDestructorName:
3800     case DeclarationName::CXXConversionFunctionName:
3801     case DeclarationName::CXXUsingDirective:
3802       return;
3803     }
3804 
3805     llvm_unreachable("Invalid name kind?");
3806   }
3807 
3808   void EmitData(raw_ostream &Out, key_type_ref, data_type Lookup,
3809                 unsigned DataLen) {
3810     using namespace llvm::support;
3811 
3812     endian::Writer LE(Out, little);
3813     uint64_t Start = Out.tell(); (void)Start;
3814     for (unsigned I = Lookup.first, N = Lookup.second; I != N; ++I)
3815       LE.write<uint32_t>(DeclIDs[I]);
3816     assert(Out.tell() - Start == DataLen && "Data length is wrong");
3817   }
3818 };
3819 
3820 } // namespace
3821 
3822 bool ASTWriter::isLookupResultExternal(StoredDeclsList &Result,
3823                                        DeclContext *DC) {
3824   return Result.hasExternalDecls() &&
3825          DC->hasNeedToReconcileExternalVisibleStorage();
3826 }
3827 
3828 bool ASTWriter::isLookupResultEntirelyExternal(StoredDeclsList &Result,
3829                                                DeclContext *DC) {
3830   for (auto *D : Result.getLookupResult())
3831     if (!getDeclForLocalLookup(getLangOpts(), D)->isFromASTFile())
3832       return false;
3833 
3834   return true;
3835 }
3836 
3837 void
3838 ASTWriter::GenerateNameLookupTable(const DeclContext *ConstDC,
3839                                    llvm::SmallVectorImpl<char> &LookupTable) {
3840   assert(!ConstDC->hasLazyLocalLexicalLookups() &&
3841          !ConstDC->hasLazyExternalLexicalLookups() &&
3842          "must call buildLookups first");
3843 
3844   // FIXME: We need to build the lookups table, which is logically const.
3845   auto *DC = const_cast<DeclContext*>(ConstDC);
3846   assert(DC == DC->getPrimaryContext() && "only primary DC has lookup table");
3847 
3848   // Create the on-disk hash table representation.
3849   MultiOnDiskHashTableGenerator<reader::ASTDeclContextNameLookupTrait,
3850                                 ASTDeclContextNameLookupTrait> Generator;
3851   ASTDeclContextNameLookupTrait Trait(*this);
3852 
3853   // The first step is to collect the declaration names which we need to
3854   // serialize into the name lookup table, and to collect them in a stable
3855   // order.
3856   SmallVector<DeclarationName, 16> Names;
3857 
3858   // We also build up small sets of the constructor and conversion function
3859   // names which are visible.
3860   llvm::SmallPtrSet<DeclarationName, 8> ConstructorNameSet, ConversionNameSet;
3861 
3862   for (auto &Lookup : *DC->buildLookup()) {
3863     auto &Name = Lookup.first;
3864     auto &Result = Lookup.second;
3865 
3866     // If there are no local declarations in our lookup result, we
3867     // don't need to write an entry for the name at all. If we can't
3868     // write out a lookup set without performing more deserialization,
3869     // just skip this entry.
3870     if (isLookupResultExternal(Result, DC) &&
3871         isLookupResultEntirelyExternal(Result, DC))
3872       continue;
3873 
3874     // We also skip empty results. If any of the results could be external and
3875     // the currently available results are empty, then all of the results are
3876     // external and we skip it above. So the only way we get here with an empty
3877     // results is when no results could have been external *and* we have
3878     // external results.
3879     //
3880     // FIXME: While we might want to start emitting on-disk entries for negative
3881     // lookups into a decl context as an optimization, today we *have* to skip
3882     // them because there are names with empty lookup results in decl contexts
3883     // which we can't emit in any stable ordering: we lookup constructors and
3884     // conversion functions in the enclosing namespace scope creating empty
3885     // results for them. This in almost certainly a bug in Clang's name lookup,
3886     // but that is likely to be hard or impossible to fix and so we tolerate it
3887     // here by omitting lookups with empty results.
3888     if (Lookup.second.getLookupResult().empty())
3889       continue;
3890 
3891     switch (Lookup.first.getNameKind()) {
3892     default:
3893       Names.push_back(Lookup.first);
3894       break;
3895 
3896     case DeclarationName::CXXConstructorName:
3897       assert(isa<CXXRecordDecl>(DC) &&
3898              "Cannot have a constructor name outside of a class!");
3899       ConstructorNameSet.insert(Name);
3900       break;
3901 
3902     case DeclarationName::CXXConversionFunctionName:
3903       assert(isa<CXXRecordDecl>(DC) &&
3904              "Cannot have a conversion function name outside of a class!");
3905       ConversionNameSet.insert(Name);
3906       break;
3907     }
3908   }
3909 
3910   // Sort the names into a stable order.
3911   llvm::sort(Names);
3912 
3913   if (auto *D = dyn_cast<CXXRecordDecl>(DC)) {
3914     // We need to establish an ordering of constructor and conversion function
3915     // names, and they don't have an intrinsic ordering.
3916 
3917     // First we try the easy case by forming the current context's constructor
3918     // name and adding that name first. This is a very useful optimization to
3919     // avoid walking the lexical declarations in many cases, and it also
3920     // handles the only case where a constructor name can come from some other
3921     // lexical context -- when that name is an implicit constructor merged from
3922     // another declaration in the redecl chain. Any non-implicit constructor or
3923     // conversion function which doesn't occur in all the lexical contexts
3924     // would be an ODR violation.
3925     auto ImplicitCtorName = Context->DeclarationNames.getCXXConstructorName(
3926         Context->getCanonicalType(Context->getRecordType(D)));
3927     if (ConstructorNameSet.erase(ImplicitCtorName))
3928       Names.push_back(ImplicitCtorName);
3929 
3930     // If we still have constructors or conversion functions, we walk all the
3931     // names in the decl and add the constructors and conversion functions
3932     // which are visible in the order they lexically occur within the context.
3933     if (!ConstructorNameSet.empty() || !ConversionNameSet.empty())
3934       for (Decl *ChildD : cast<CXXRecordDecl>(DC)->decls())
3935         if (auto *ChildND = dyn_cast<NamedDecl>(ChildD)) {
3936           auto Name = ChildND->getDeclName();
3937           switch (Name.getNameKind()) {
3938           default:
3939             continue;
3940 
3941           case DeclarationName::CXXConstructorName:
3942             if (ConstructorNameSet.erase(Name))
3943               Names.push_back(Name);
3944             break;
3945 
3946           case DeclarationName::CXXConversionFunctionName:
3947             if (ConversionNameSet.erase(Name))
3948               Names.push_back(Name);
3949             break;
3950           }
3951 
3952           if (ConstructorNameSet.empty() && ConversionNameSet.empty())
3953             break;
3954         }
3955 
3956     assert(ConstructorNameSet.empty() && "Failed to find all of the visible "
3957                                          "constructors by walking all the "
3958                                          "lexical members of the context.");
3959     assert(ConversionNameSet.empty() && "Failed to find all of the visible "
3960                                         "conversion functions by walking all "
3961                                         "the lexical members of the context.");
3962   }
3963 
3964   // Next we need to do a lookup with each name into this decl context to fully
3965   // populate any results from external sources. We don't actually use the
3966   // results of these lookups because we only want to use the results after all
3967   // results have been loaded and the pointers into them will be stable.
3968   for (auto &Name : Names)
3969     DC->lookup(Name);
3970 
3971   // Now we need to insert the results for each name into the hash table. For
3972   // constructor names and conversion function names, we actually need to merge
3973   // all of the results for them into one list of results each and insert
3974   // those.
3975   SmallVector<NamedDecl *, 8> ConstructorDecls;
3976   SmallVector<NamedDecl *, 8> ConversionDecls;
3977 
3978   // Now loop over the names, either inserting them or appending for the two
3979   // special cases.
3980   for (auto &Name : Names) {
3981     DeclContext::lookup_result Result = DC->noload_lookup(Name);
3982 
3983     switch (Name.getNameKind()) {
3984     default:
3985       Generator.insert(Name, Trait.getData(Result), Trait);
3986       break;
3987 
3988     case DeclarationName::CXXConstructorName:
3989       ConstructorDecls.append(Result.begin(), Result.end());
3990       break;
3991 
3992     case DeclarationName::CXXConversionFunctionName:
3993       ConversionDecls.append(Result.begin(), Result.end());
3994       break;
3995     }
3996   }
3997 
3998   // Handle our two special cases if we ended up having any. We arbitrarily use
3999   // the first declaration's name here because the name itself isn't part of
4000   // the key, only the kind of name is used.
4001   if (!ConstructorDecls.empty())
4002     Generator.insert(ConstructorDecls.front()->getDeclName(),
4003                      Trait.getData(ConstructorDecls), Trait);
4004   if (!ConversionDecls.empty())
4005     Generator.insert(ConversionDecls.front()->getDeclName(),
4006                      Trait.getData(ConversionDecls), Trait);
4007 
4008   // Create the on-disk hash table. Also emit the existing imported and
4009   // merged table if there is one.
4010   auto *Lookups = Chain ? Chain->getLoadedLookupTables(DC) : nullptr;
4011   Generator.emit(LookupTable, Trait, Lookups ? &Lookups->Table : nullptr);
4012 }
4013 
4014 /// Write the block containing all of the declaration IDs
4015 /// visible from the given DeclContext.
4016 ///
4017 /// \returns the offset of the DECL_CONTEXT_VISIBLE block within the
4018 /// bitstream, or 0 if no block was written.
4019 uint64_t ASTWriter::WriteDeclContextVisibleBlock(ASTContext &Context,
4020                                                  DeclContext *DC) {
4021   // If we imported a key declaration of this namespace, write the visible
4022   // lookup results as an update record for it rather than including them
4023   // on this declaration. We will only look at key declarations on reload.
4024   if (isa<NamespaceDecl>(DC) && Chain &&
4025       Chain->getKeyDeclaration(cast<Decl>(DC))->isFromASTFile()) {
4026     // Only do this once, for the first local declaration of the namespace.
4027     for (auto *Prev = cast<NamespaceDecl>(DC)->getPreviousDecl(); Prev;
4028          Prev = Prev->getPreviousDecl())
4029       if (!Prev->isFromASTFile())
4030         return 0;
4031 
4032     // Note that we need to emit an update record for the primary context.
4033     UpdatedDeclContexts.insert(DC->getPrimaryContext());
4034 
4035     // Make sure all visible decls are written. They will be recorded later. We
4036     // do this using a side data structure so we can sort the names into
4037     // a deterministic order.
4038     StoredDeclsMap *Map = DC->getPrimaryContext()->buildLookup();
4039     SmallVector<std::pair<DeclarationName, DeclContext::lookup_result>, 16>
4040         LookupResults;
4041     if (Map) {
4042       LookupResults.reserve(Map->size());
4043       for (auto &Entry : *Map)
4044         LookupResults.push_back(
4045             std::make_pair(Entry.first, Entry.second.getLookupResult()));
4046     }
4047 
4048     llvm::sort(LookupResults, llvm::less_first());
4049     for (auto &NameAndResult : LookupResults) {
4050       DeclarationName Name = NameAndResult.first;
4051       DeclContext::lookup_result Result = NameAndResult.second;
4052       if (Name.getNameKind() == DeclarationName::CXXConstructorName ||
4053           Name.getNameKind() == DeclarationName::CXXConversionFunctionName) {
4054         // We have to work around a name lookup bug here where negative lookup
4055         // results for these names get cached in namespace lookup tables (these
4056         // names should never be looked up in a namespace).
4057         assert(Result.empty() && "Cannot have a constructor or conversion "
4058                                  "function name in a namespace!");
4059         continue;
4060       }
4061 
4062       for (NamedDecl *ND : Result)
4063         if (!ND->isFromASTFile())
4064           GetDeclRef(ND);
4065     }
4066 
4067     return 0;
4068   }
4069 
4070   if (DC->getPrimaryContext() != DC)
4071     return 0;
4072 
4073   // Skip contexts which don't support name lookup.
4074   if (!DC->isLookupContext())
4075     return 0;
4076 
4077   // If not in C++, we perform name lookup for the translation unit via the
4078   // IdentifierInfo chains, don't bother to build a visible-declarations table.
4079   if (DC->isTranslationUnit() && !Context.getLangOpts().CPlusPlus)
4080     return 0;
4081 
4082   // Serialize the contents of the mapping used for lookup. Note that,
4083   // although we have two very different code paths, the serialized
4084   // representation is the same for both cases: a declaration name,
4085   // followed by a size, followed by references to the visible
4086   // declarations that have that name.
4087   uint64_t Offset = Stream.GetCurrentBitNo();
4088   StoredDeclsMap *Map = DC->buildLookup();
4089   if (!Map || Map->empty())
4090     return 0;
4091 
4092   // Create the on-disk hash table in a buffer.
4093   SmallString<4096> LookupTable;
4094   GenerateNameLookupTable(DC, LookupTable);
4095 
4096   // Write the lookup table
4097   RecordData::value_type Record[] = {DECL_CONTEXT_VISIBLE};
4098   Stream.EmitRecordWithBlob(DeclContextVisibleLookupAbbrev, Record,
4099                             LookupTable);
4100   ++NumVisibleDeclContexts;
4101   return Offset;
4102 }
4103 
4104 /// Write an UPDATE_VISIBLE block for the given context.
4105 ///
4106 /// UPDATE_VISIBLE blocks contain the declarations that are added to an existing
4107 /// DeclContext in a dependent AST file. As such, they only exist for the TU
4108 /// (in C++), for namespaces, and for classes with forward-declared unscoped
4109 /// enumeration members (in C++11).
4110 void ASTWriter::WriteDeclContextVisibleUpdate(const DeclContext *DC) {
4111   StoredDeclsMap *Map = DC->getLookupPtr();
4112   if (!Map || Map->empty())
4113     return;
4114 
4115   // Create the on-disk hash table in a buffer.
4116   SmallString<4096> LookupTable;
4117   GenerateNameLookupTable(DC, LookupTable);
4118 
4119   // If we're updating a namespace, select a key declaration as the key for the
4120   // update record; those are the only ones that will be checked on reload.
4121   if (isa<NamespaceDecl>(DC))
4122     DC = cast<DeclContext>(Chain->getKeyDeclaration(cast<Decl>(DC)));
4123 
4124   // Write the lookup table
4125   RecordData::value_type Record[] = {UPDATE_VISIBLE, getDeclID(cast<Decl>(DC))};
4126   Stream.EmitRecordWithBlob(UpdateVisibleAbbrev, Record, LookupTable);
4127 }
4128 
4129 /// Write an FP_PRAGMA_OPTIONS block for the given FPOptions.
4130 void ASTWriter::WriteFPPragmaOptions(const FPOptionsOverride &Opts) {
4131   RecordData::value_type Record[] = {Opts.getAsOpaqueInt()};
4132   Stream.EmitRecord(FP_PRAGMA_OPTIONS, Record);
4133 }
4134 
4135 /// Write an OPENCL_EXTENSIONS block for the given OpenCLOptions.
4136 void ASTWriter::WriteOpenCLExtensions(Sema &SemaRef) {
4137   if (!SemaRef.Context.getLangOpts().OpenCL)
4138     return;
4139 
4140   const OpenCLOptions &Opts = SemaRef.getOpenCLOptions();
4141   RecordData Record;
4142   for (const auto &I:Opts.OptMap) {
4143     AddString(I.getKey(), Record);
4144     auto V = I.getValue();
4145     Record.push_back(V.Supported ? 1 : 0);
4146     Record.push_back(V.Enabled ? 1 : 0);
4147     Record.push_back(V.WithPragma ? 1 : 0);
4148     Record.push_back(V.Avail);
4149     Record.push_back(V.Core);
4150     Record.push_back(V.Opt);
4151   }
4152   Stream.EmitRecord(OPENCL_EXTENSIONS, Record);
4153 }
4154 void ASTWriter::WriteCUDAPragmas(Sema &SemaRef) {
4155   if (SemaRef.ForceCUDAHostDeviceDepth > 0) {
4156     RecordData::value_type Record[] = {SemaRef.ForceCUDAHostDeviceDepth};
4157     Stream.EmitRecord(CUDA_PRAGMA_FORCE_HOST_DEVICE_DEPTH, Record);
4158   }
4159 }
4160 
4161 void ASTWriter::WriteObjCCategories() {
4162   SmallVector<ObjCCategoriesInfo, 2> CategoriesMap;
4163   RecordData Categories;
4164 
4165   for (unsigned I = 0, N = ObjCClassesWithCategories.size(); I != N; ++I) {
4166     unsigned Size = 0;
4167     unsigned StartIndex = Categories.size();
4168 
4169     ObjCInterfaceDecl *Class = ObjCClassesWithCategories[I];
4170 
4171     // Allocate space for the size.
4172     Categories.push_back(0);
4173 
4174     // Add the categories.
4175     for (ObjCInterfaceDecl::known_categories_iterator
4176            Cat = Class->known_categories_begin(),
4177            CatEnd = Class->known_categories_end();
4178          Cat != CatEnd; ++Cat, ++Size) {
4179       assert(getDeclID(*Cat) != 0 && "Bogus category");
4180       AddDeclRef(*Cat, Categories);
4181     }
4182 
4183     // Update the size.
4184     Categories[StartIndex] = Size;
4185 
4186     // Record this interface -> category map.
4187     ObjCCategoriesInfo CatInfo = { getDeclID(Class), StartIndex };
4188     CategoriesMap.push_back(CatInfo);
4189   }
4190 
4191   // Sort the categories map by the definition ID, since the reader will be
4192   // performing binary searches on this information.
4193   llvm::array_pod_sort(CategoriesMap.begin(), CategoriesMap.end());
4194 
4195   // Emit the categories map.
4196   using namespace llvm;
4197 
4198   auto Abbrev = std::make_shared<BitCodeAbbrev>();
4199   Abbrev->Add(BitCodeAbbrevOp(OBJC_CATEGORIES_MAP));
4200   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // # of entries
4201   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
4202   unsigned AbbrevID = Stream.EmitAbbrev(std::move(Abbrev));
4203 
4204   RecordData::value_type Record[] = {OBJC_CATEGORIES_MAP, CategoriesMap.size()};
4205   Stream.EmitRecordWithBlob(AbbrevID, Record,
4206                             reinterpret_cast<char *>(CategoriesMap.data()),
4207                             CategoriesMap.size() * sizeof(ObjCCategoriesInfo));
4208 
4209   // Emit the category lists.
4210   Stream.EmitRecord(OBJC_CATEGORIES, Categories);
4211 }
4212 
4213 void ASTWriter::WriteLateParsedTemplates(Sema &SemaRef) {
4214   Sema::LateParsedTemplateMapT &LPTMap = SemaRef.LateParsedTemplateMap;
4215 
4216   if (LPTMap.empty())
4217     return;
4218 
4219   RecordData Record;
4220   for (auto &LPTMapEntry : LPTMap) {
4221     const FunctionDecl *FD = LPTMapEntry.first;
4222     LateParsedTemplate &LPT = *LPTMapEntry.second;
4223     AddDeclRef(FD, Record);
4224     AddDeclRef(LPT.D, Record);
4225     Record.push_back(LPT.Toks.size());
4226 
4227     for (const auto &Tok : LPT.Toks) {
4228       AddToken(Tok, Record);
4229     }
4230   }
4231   Stream.EmitRecord(LATE_PARSED_TEMPLATE, Record);
4232 }
4233 
4234 /// Write the state of 'pragma clang optimize' at the end of the module.
4235 void ASTWriter::WriteOptimizePragmaOptions(Sema &SemaRef) {
4236   RecordData Record;
4237   SourceLocation PragmaLoc = SemaRef.getOptimizeOffPragmaLocation();
4238   AddSourceLocation(PragmaLoc, Record);
4239   Stream.EmitRecord(OPTIMIZE_PRAGMA_OPTIONS, Record);
4240 }
4241 
4242 /// Write the state of 'pragma ms_struct' at the end of the module.
4243 void ASTWriter::WriteMSStructPragmaOptions(Sema &SemaRef) {
4244   RecordData Record;
4245   Record.push_back(SemaRef.MSStructPragmaOn ? PMSST_ON : PMSST_OFF);
4246   Stream.EmitRecord(MSSTRUCT_PRAGMA_OPTIONS, Record);
4247 }
4248 
4249 /// Write the state of 'pragma pointers_to_members' at the end of the
4250 //module.
4251 void ASTWriter::WriteMSPointersToMembersPragmaOptions(Sema &SemaRef) {
4252   RecordData Record;
4253   Record.push_back(SemaRef.MSPointerToMemberRepresentationMethod);
4254   AddSourceLocation(SemaRef.ImplicitMSInheritanceAttrLoc, Record);
4255   Stream.EmitRecord(POINTERS_TO_MEMBERS_PRAGMA_OPTIONS, Record);
4256 }
4257 
4258 /// Write the state of 'pragma align/pack' at the end of the module.
4259 void ASTWriter::WritePackPragmaOptions(Sema &SemaRef) {
4260   // Don't serialize pragma align/pack state for modules, since it should only
4261   // take effect on a per-submodule basis.
4262   if (WritingModule)
4263     return;
4264 
4265   RecordData Record;
4266   AddAlignPackInfo(SemaRef.AlignPackStack.CurrentValue, Record);
4267   AddSourceLocation(SemaRef.AlignPackStack.CurrentPragmaLocation, Record);
4268   Record.push_back(SemaRef.AlignPackStack.Stack.size());
4269   for (const auto &StackEntry : SemaRef.AlignPackStack.Stack) {
4270     AddAlignPackInfo(StackEntry.Value, Record);
4271     AddSourceLocation(StackEntry.PragmaLocation, Record);
4272     AddSourceLocation(StackEntry.PragmaPushLocation, Record);
4273     AddString(StackEntry.StackSlotLabel, Record);
4274   }
4275   Stream.EmitRecord(ALIGN_PACK_PRAGMA_OPTIONS, Record);
4276 }
4277 
4278 /// Write the state of 'pragma float_control' at the end of the module.
4279 void ASTWriter::WriteFloatControlPragmaOptions(Sema &SemaRef) {
4280   // Don't serialize pragma float_control state for modules,
4281   // since it should only take effect on a per-submodule basis.
4282   if (WritingModule)
4283     return;
4284 
4285   RecordData Record;
4286   Record.push_back(SemaRef.FpPragmaStack.CurrentValue.getAsOpaqueInt());
4287   AddSourceLocation(SemaRef.FpPragmaStack.CurrentPragmaLocation, Record);
4288   Record.push_back(SemaRef.FpPragmaStack.Stack.size());
4289   for (const auto &StackEntry : SemaRef.FpPragmaStack.Stack) {
4290     Record.push_back(StackEntry.Value.getAsOpaqueInt());
4291     AddSourceLocation(StackEntry.PragmaLocation, Record);
4292     AddSourceLocation(StackEntry.PragmaPushLocation, Record);
4293     AddString(StackEntry.StackSlotLabel, Record);
4294   }
4295   Stream.EmitRecord(FLOAT_CONTROL_PRAGMA_OPTIONS, Record);
4296 }
4297 
4298 void ASTWriter::WriteModuleFileExtension(Sema &SemaRef,
4299                                          ModuleFileExtensionWriter &Writer) {
4300   // Enter the extension block.
4301   Stream.EnterSubblock(EXTENSION_BLOCK_ID, 4);
4302 
4303   // Emit the metadata record abbreviation.
4304   auto Abv = std::make_shared<llvm::BitCodeAbbrev>();
4305   Abv->Add(llvm::BitCodeAbbrevOp(EXTENSION_METADATA));
4306   Abv->Add(llvm::BitCodeAbbrevOp(llvm::BitCodeAbbrevOp::VBR, 6));
4307   Abv->Add(llvm::BitCodeAbbrevOp(llvm::BitCodeAbbrevOp::VBR, 6));
4308   Abv->Add(llvm::BitCodeAbbrevOp(llvm::BitCodeAbbrevOp::VBR, 6));
4309   Abv->Add(llvm::BitCodeAbbrevOp(llvm::BitCodeAbbrevOp::VBR, 6));
4310   Abv->Add(llvm::BitCodeAbbrevOp(llvm::BitCodeAbbrevOp::Blob));
4311   unsigned Abbrev = Stream.EmitAbbrev(std::move(Abv));
4312 
4313   // Emit the metadata record.
4314   RecordData Record;
4315   auto Metadata = Writer.getExtension()->getExtensionMetadata();
4316   Record.push_back(EXTENSION_METADATA);
4317   Record.push_back(Metadata.MajorVersion);
4318   Record.push_back(Metadata.MinorVersion);
4319   Record.push_back(Metadata.BlockName.size());
4320   Record.push_back(Metadata.UserInfo.size());
4321   SmallString<64> Buffer;
4322   Buffer += Metadata.BlockName;
4323   Buffer += Metadata.UserInfo;
4324   Stream.EmitRecordWithBlob(Abbrev, Record, Buffer);
4325 
4326   // Emit the contents of the extension block.
4327   Writer.writeExtensionContents(SemaRef, Stream);
4328 
4329   // Exit the extension block.
4330   Stream.ExitBlock();
4331 }
4332 
4333 //===----------------------------------------------------------------------===//
4334 // General Serialization Routines
4335 //===----------------------------------------------------------------------===//
4336 
4337 void ASTRecordWriter::AddAttr(const Attr *A) {
4338   auto &Record = *this;
4339   if (!A)
4340     return Record.push_back(0);
4341   Record.push_back(A->getKind() + 1); // FIXME: stable encoding, target attrs
4342 
4343   Record.AddIdentifierRef(A->getAttrName());
4344   Record.AddIdentifierRef(A->getScopeName());
4345   Record.AddSourceRange(A->getRange());
4346   Record.AddSourceLocation(A->getScopeLoc());
4347   Record.push_back(A->getParsedKind());
4348   Record.push_back(A->getSyntax());
4349   Record.push_back(A->getAttributeSpellingListIndexRaw());
4350 
4351 #include "clang/Serialization/AttrPCHWrite.inc"
4352 }
4353 
4354 /// Emit the list of attributes to the specified record.
4355 void ASTRecordWriter::AddAttributes(ArrayRef<const Attr *> Attrs) {
4356   push_back(Attrs.size());
4357   for (const auto *A : Attrs)
4358     AddAttr(A);
4359 }
4360 
4361 void ASTWriter::AddToken(const Token &Tok, RecordDataImpl &Record) {
4362   AddSourceLocation(Tok.getLocation(), Record);
4363   Record.push_back(Tok.getLength());
4364 
4365   // FIXME: When reading literal tokens, reconstruct the literal pointer
4366   // if it is needed.
4367   AddIdentifierRef(Tok.getIdentifierInfo(), Record);
4368   // FIXME: Should translate token kind to a stable encoding.
4369   Record.push_back(Tok.getKind());
4370   // FIXME: Should translate token flags to a stable encoding.
4371   Record.push_back(Tok.getFlags());
4372 }
4373 
4374 void ASTWriter::AddString(StringRef Str, RecordDataImpl &Record) {
4375   Record.push_back(Str.size());
4376   Record.insert(Record.end(), Str.begin(), Str.end());
4377 }
4378 
4379 bool ASTWriter::PreparePathForOutput(SmallVectorImpl<char> &Path) {
4380   assert(Context && "should have context when outputting path");
4381 
4382   bool Changed =
4383       cleanPathForOutput(Context->getSourceManager().getFileManager(), Path);
4384 
4385   // Remove a prefix to make the path relative, if relevant.
4386   const char *PathBegin = Path.data();
4387   const char *PathPtr =
4388       adjustFilenameForRelocatableAST(PathBegin, BaseDirectory);
4389   if (PathPtr != PathBegin) {
4390     Path.erase(Path.begin(), Path.begin() + (PathPtr - PathBegin));
4391     Changed = true;
4392   }
4393 
4394   return Changed;
4395 }
4396 
4397 void ASTWriter::AddPath(StringRef Path, RecordDataImpl &Record) {
4398   SmallString<128> FilePath(Path);
4399   PreparePathForOutput(FilePath);
4400   AddString(FilePath, Record);
4401 }
4402 
4403 void ASTWriter::EmitRecordWithPath(unsigned Abbrev, RecordDataRef Record,
4404                                    StringRef Path) {
4405   SmallString<128> FilePath(Path);
4406   PreparePathForOutput(FilePath);
4407   Stream.EmitRecordWithBlob(Abbrev, Record, FilePath);
4408 }
4409 
4410 void ASTWriter::AddVersionTuple(const VersionTuple &Version,
4411                                 RecordDataImpl &Record) {
4412   Record.push_back(Version.getMajor());
4413   if (Optional<unsigned> Minor = Version.getMinor())
4414     Record.push_back(*Minor + 1);
4415   else
4416     Record.push_back(0);
4417   if (Optional<unsigned> Subminor = Version.getSubminor())
4418     Record.push_back(*Subminor + 1);
4419   else
4420     Record.push_back(0);
4421 }
4422 
4423 /// Note that the identifier II occurs at the given offset
4424 /// within the identifier table.
4425 void ASTWriter::SetIdentifierOffset(const IdentifierInfo *II, uint32_t Offset) {
4426   IdentID ID = IdentifierIDs[II];
4427   // Only store offsets new to this AST file. Other identifier names are looked
4428   // up earlier in the chain and thus don't need an offset.
4429   if (ID >= FirstIdentID)
4430     IdentifierOffsets[ID - FirstIdentID] = Offset;
4431 }
4432 
4433 /// Note that the selector Sel occurs at the given offset
4434 /// within the method pool/selector table.
4435 void ASTWriter::SetSelectorOffset(Selector Sel, uint32_t Offset) {
4436   unsigned ID = SelectorIDs[Sel];
4437   assert(ID && "Unknown selector");
4438   // Don't record offsets for selectors that are also available in a different
4439   // file.
4440   if (ID < FirstSelectorID)
4441     return;
4442   SelectorOffsets[ID - FirstSelectorID] = Offset;
4443 }
4444 
4445 ASTWriter::ASTWriter(llvm::BitstreamWriter &Stream,
4446                      SmallVectorImpl<char> &Buffer,
4447                      InMemoryModuleCache &ModuleCache,
4448                      ArrayRef<std::shared_ptr<ModuleFileExtension>> Extensions,
4449                      bool IncludeTimestamps)
4450     : Stream(Stream), Buffer(Buffer), ModuleCache(ModuleCache),
4451       IncludeTimestamps(IncludeTimestamps) {
4452   for (const auto &Ext : Extensions) {
4453     if (auto Writer = Ext->createExtensionWriter(*this))
4454       ModuleFileExtensionWriters.push_back(std::move(Writer));
4455   }
4456 }
4457 
4458 ASTWriter::~ASTWriter() = default;
4459 
4460 const LangOptions &ASTWriter::getLangOpts() const {
4461   assert(WritingAST && "can't determine lang opts when not writing AST");
4462   return Context->getLangOpts();
4463 }
4464 
4465 time_t ASTWriter::getTimestampForOutput(const FileEntry *E) const {
4466   return IncludeTimestamps ? E->getModificationTime() : 0;
4467 }
4468 
4469 ASTFileSignature ASTWriter::WriteAST(Sema &SemaRef,
4470                                      const std::string &OutputFile,
4471                                      Module *WritingModule, StringRef isysroot,
4472                                      bool hasErrors,
4473                                      bool ShouldCacheASTInMemory) {
4474   WritingAST = true;
4475 
4476   ASTHasCompilerErrors = hasErrors;
4477 
4478   // Emit the file header.
4479   Stream.Emit((unsigned)'C', 8);
4480   Stream.Emit((unsigned)'P', 8);
4481   Stream.Emit((unsigned)'C', 8);
4482   Stream.Emit((unsigned)'H', 8);
4483 
4484   WriteBlockInfoBlock();
4485 
4486   Context = &SemaRef.Context;
4487   PP = &SemaRef.PP;
4488   this->WritingModule = WritingModule;
4489   ASTFileSignature Signature =
4490       WriteASTCore(SemaRef, isysroot, OutputFile, WritingModule);
4491   Context = nullptr;
4492   PP = nullptr;
4493   this->WritingModule = nullptr;
4494   this->BaseDirectory.clear();
4495 
4496   WritingAST = false;
4497   if (ShouldCacheASTInMemory) {
4498     // Construct MemoryBuffer and update buffer manager.
4499     ModuleCache.addBuiltPCM(OutputFile,
4500                             llvm::MemoryBuffer::getMemBufferCopy(
4501                                 StringRef(Buffer.begin(), Buffer.size())));
4502   }
4503   return Signature;
4504 }
4505 
4506 template<typename Vector>
4507 static void AddLazyVectorDecls(ASTWriter &Writer, Vector &Vec,
4508                                ASTWriter::RecordData &Record) {
4509   for (typename Vector::iterator I = Vec.begin(nullptr, true), E = Vec.end();
4510        I != E; ++I) {
4511     Writer.AddDeclRef(*I, Record);
4512   }
4513 }
4514 
4515 ASTFileSignature ASTWriter::WriteASTCore(Sema &SemaRef, StringRef isysroot,
4516                                          const std::string &OutputFile,
4517                                          Module *WritingModule) {
4518   using namespace llvm;
4519 
4520   bool isModule = WritingModule != nullptr;
4521 
4522   // Make sure that the AST reader knows to finalize itself.
4523   if (Chain)
4524     Chain->finalizeForWriting();
4525 
4526   ASTContext &Context = SemaRef.Context;
4527   Preprocessor &PP = SemaRef.PP;
4528 
4529   // Set up predefined declaration IDs.
4530   auto RegisterPredefDecl = [&] (Decl *D, PredefinedDeclIDs ID) {
4531     if (D) {
4532       assert(D->isCanonicalDecl() && "predefined decl is not canonical");
4533       DeclIDs[D] = ID;
4534     }
4535   };
4536   RegisterPredefDecl(Context.getTranslationUnitDecl(),
4537                      PREDEF_DECL_TRANSLATION_UNIT_ID);
4538   RegisterPredefDecl(Context.ObjCIdDecl, PREDEF_DECL_OBJC_ID_ID);
4539   RegisterPredefDecl(Context.ObjCSelDecl, PREDEF_DECL_OBJC_SEL_ID);
4540   RegisterPredefDecl(Context.ObjCClassDecl, PREDEF_DECL_OBJC_CLASS_ID);
4541   RegisterPredefDecl(Context.ObjCProtocolClassDecl,
4542                      PREDEF_DECL_OBJC_PROTOCOL_ID);
4543   RegisterPredefDecl(Context.Int128Decl, PREDEF_DECL_INT_128_ID);
4544   RegisterPredefDecl(Context.UInt128Decl, PREDEF_DECL_UNSIGNED_INT_128_ID);
4545   RegisterPredefDecl(Context.ObjCInstanceTypeDecl,
4546                      PREDEF_DECL_OBJC_INSTANCETYPE_ID);
4547   RegisterPredefDecl(Context.BuiltinVaListDecl, PREDEF_DECL_BUILTIN_VA_LIST_ID);
4548   RegisterPredefDecl(Context.VaListTagDecl, PREDEF_DECL_VA_LIST_TAG);
4549   RegisterPredefDecl(Context.BuiltinMSVaListDecl,
4550                      PREDEF_DECL_BUILTIN_MS_VA_LIST_ID);
4551   RegisterPredefDecl(Context.MSGuidTagDecl,
4552                      PREDEF_DECL_BUILTIN_MS_GUID_ID);
4553   RegisterPredefDecl(Context.ExternCContext, PREDEF_DECL_EXTERN_C_CONTEXT_ID);
4554   RegisterPredefDecl(Context.MakeIntegerSeqDecl,
4555                      PREDEF_DECL_MAKE_INTEGER_SEQ_ID);
4556   RegisterPredefDecl(Context.CFConstantStringTypeDecl,
4557                      PREDEF_DECL_CF_CONSTANT_STRING_ID);
4558   RegisterPredefDecl(Context.CFConstantStringTagDecl,
4559                      PREDEF_DECL_CF_CONSTANT_STRING_TAG_ID);
4560   RegisterPredefDecl(Context.TypePackElementDecl,
4561                      PREDEF_DECL_TYPE_PACK_ELEMENT_ID);
4562 
4563   // Build a record containing all of the tentative definitions in this file, in
4564   // TentativeDefinitions order.  Generally, this record will be empty for
4565   // headers.
4566   RecordData TentativeDefinitions;
4567   AddLazyVectorDecls(*this, SemaRef.TentativeDefinitions, TentativeDefinitions);
4568 
4569   // Build a record containing all of the file scoped decls in this file.
4570   RecordData UnusedFileScopedDecls;
4571   if (!isModule)
4572     AddLazyVectorDecls(*this, SemaRef.UnusedFileScopedDecls,
4573                        UnusedFileScopedDecls);
4574 
4575   // Build a record containing all of the delegating constructors we still need
4576   // to resolve.
4577   RecordData DelegatingCtorDecls;
4578   if (!isModule)
4579     AddLazyVectorDecls(*this, SemaRef.DelegatingCtorDecls, DelegatingCtorDecls);
4580 
4581   // Write the set of weak, undeclared identifiers. We always write the
4582   // entire table, since later PCH files in a PCH chain are only interested in
4583   // the results at the end of the chain.
4584   RecordData WeakUndeclaredIdentifiers;
4585   for (const auto &WeakUndeclaredIdentifierList :
4586        SemaRef.WeakUndeclaredIdentifiers) {
4587     const IdentifierInfo *const II = WeakUndeclaredIdentifierList.first;
4588     for (const auto &WI : WeakUndeclaredIdentifierList.second) {
4589       AddIdentifierRef(II, WeakUndeclaredIdentifiers);
4590       AddIdentifierRef(WI.getAlias(), WeakUndeclaredIdentifiers);
4591       AddSourceLocation(WI.getLocation(), WeakUndeclaredIdentifiers);
4592     }
4593   }
4594 
4595   // Build a record containing all of the ext_vector declarations.
4596   RecordData ExtVectorDecls;
4597   AddLazyVectorDecls(*this, SemaRef.ExtVectorDecls, ExtVectorDecls);
4598 
4599   // Build a record containing all of the VTable uses information.
4600   RecordData VTableUses;
4601   if (!SemaRef.VTableUses.empty()) {
4602     for (unsigned I = 0, N = SemaRef.VTableUses.size(); I != N; ++I) {
4603       AddDeclRef(SemaRef.VTableUses[I].first, VTableUses);
4604       AddSourceLocation(SemaRef.VTableUses[I].second, VTableUses);
4605       VTableUses.push_back(SemaRef.VTablesUsed[SemaRef.VTableUses[I].first]);
4606     }
4607   }
4608 
4609   // Build a record containing all of the UnusedLocalTypedefNameCandidates.
4610   RecordData UnusedLocalTypedefNameCandidates;
4611   for (const TypedefNameDecl *TD : SemaRef.UnusedLocalTypedefNameCandidates)
4612     AddDeclRef(TD, UnusedLocalTypedefNameCandidates);
4613 
4614   // Build a record containing all of pending implicit instantiations.
4615   RecordData PendingInstantiations;
4616   for (const auto &I : SemaRef.PendingInstantiations) {
4617     AddDeclRef(I.first, PendingInstantiations);
4618     AddSourceLocation(I.second, PendingInstantiations);
4619   }
4620   assert(SemaRef.PendingLocalImplicitInstantiations.empty() &&
4621          "There are local ones at end of translation unit!");
4622 
4623   // Build a record containing some declaration references.
4624   RecordData SemaDeclRefs;
4625   if (SemaRef.StdNamespace || SemaRef.StdBadAlloc || SemaRef.StdAlignValT) {
4626     AddDeclRef(SemaRef.getStdNamespace(), SemaDeclRefs);
4627     AddDeclRef(SemaRef.getStdBadAlloc(), SemaDeclRefs);
4628     AddDeclRef(SemaRef.getStdAlignValT(), SemaDeclRefs);
4629   }
4630 
4631   RecordData CUDASpecialDeclRefs;
4632   if (Context.getcudaConfigureCallDecl()) {
4633     AddDeclRef(Context.getcudaConfigureCallDecl(), CUDASpecialDeclRefs);
4634   }
4635 
4636   // Build a record containing all of the known namespaces.
4637   RecordData KnownNamespaces;
4638   for (const auto &I : SemaRef.KnownNamespaces) {
4639     if (!I.second)
4640       AddDeclRef(I.first, KnownNamespaces);
4641   }
4642 
4643   // Build a record of all used, undefined objects that require definitions.
4644   RecordData UndefinedButUsed;
4645 
4646   SmallVector<std::pair<NamedDecl *, SourceLocation>, 16> Undefined;
4647   SemaRef.getUndefinedButUsed(Undefined);
4648   for (const auto &I : Undefined) {
4649     AddDeclRef(I.first, UndefinedButUsed);
4650     AddSourceLocation(I.second, UndefinedButUsed);
4651   }
4652 
4653   // Build a record containing all delete-expressions that we would like to
4654   // analyze later in AST.
4655   RecordData DeleteExprsToAnalyze;
4656 
4657   if (!isModule) {
4658     for (const auto &DeleteExprsInfo :
4659          SemaRef.getMismatchingDeleteExpressions()) {
4660       AddDeclRef(DeleteExprsInfo.first, DeleteExprsToAnalyze);
4661       DeleteExprsToAnalyze.push_back(DeleteExprsInfo.second.size());
4662       for (const auto &DeleteLoc : DeleteExprsInfo.second) {
4663         AddSourceLocation(DeleteLoc.first, DeleteExprsToAnalyze);
4664         DeleteExprsToAnalyze.push_back(DeleteLoc.second);
4665       }
4666     }
4667   }
4668 
4669   // Write the control block
4670   WriteControlBlock(PP, Context, isysroot, OutputFile);
4671 
4672   // Write the remaining AST contents.
4673   Stream.FlushToWord();
4674   ASTBlockRange.first = Stream.GetCurrentBitNo();
4675   Stream.EnterSubblock(AST_BLOCK_ID, 5);
4676   ASTBlockStartOffset = Stream.GetCurrentBitNo();
4677 
4678   // This is so that older clang versions, before the introduction
4679   // of the control block, can read and reject the newer PCH format.
4680   {
4681     RecordData Record = {VERSION_MAJOR};
4682     Stream.EmitRecord(METADATA_OLD_FORMAT, Record);
4683   }
4684 
4685   // Create a lexical update block containing all of the declarations in the
4686   // translation unit that do not come from other AST files.
4687   const TranslationUnitDecl *TU = Context.getTranslationUnitDecl();
4688   SmallVector<uint32_t, 128> NewGlobalKindDeclPairs;
4689   for (const auto *D : TU->noload_decls()) {
4690     if (!D->isFromASTFile()) {
4691       NewGlobalKindDeclPairs.push_back(D->getKind());
4692       NewGlobalKindDeclPairs.push_back(GetDeclRef(D));
4693     }
4694   }
4695 
4696   auto Abv = std::make_shared<BitCodeAbbrev>();
4697   Abv->Add(llvm::BitCodeAbbrevOp(TU_UPDATE_LEXICAL));
4698   Abv->Add(llvm::BitCodeAbbrevOp(llvm::BitCodeAbbrevOp::Blob));
4699   unsigned TuUpdateLexicalAbbrev = Stream.EmitAbbrev(std::move(Abv));
4700   {
4701     RecordData::value_type Record[] = {TU_UPDATE_LEXICAL};
4702     Stream.EmitRecordWithBlob(TuUpdateLexicalAbbrev, Record,
4703                               bytes(NewGlobalKindDeclPairs));
4704   }
4705 
4706   // And a visible updates block for the translation unit.
4707   Abv = std::make_shared<BitCodeAbbrev>();
4708   Abv->Add(llvm::BitCodeAbbrevOp(UPDATE_VISIBLE));
4709   Abv->Add(llvm::BitCodeAbbrevOp(llvm::BitCodeAbbrevOp::VBR, 6));
4710   Abv->Add(llvm::BitCodeAbbrevOp(llvm::BitCodeAbbrevOp::Blob));
4711   UpdateVisibleAbbrev = Stream.EmitAbbrev(std::move(Abv));
4712   WriteDeclContextVisibleUpdate(TU);
4713 
4714   // If we have any extern "C" names, write out a visible update for them.
4715   if (Context.ExternCContext)
4716     WriteDeclContextVisibleUpdate(Context.ExternCContext);
4717 
4718   // If the translation unit has an anonymous namespace, and we don't already
4719   // have an update block for it, write it as an update block.
4720   // FIXME: Why do we not do this if there's already an update block?
4721   if (NamespaceDecl *NS = TU->getAnonymousNamespace()) {
4722     ASTWriter::UpdateRecord &Record = DeclUpdates[TU];
4723     if (Record.empty())
4724       Record.push_back(DeclUpdate(UPD_CXX_ADDED_ANONYMOUS_NAMESPACE, NS));
4725   }
4726 
4727   // Add update records for all mangling numbers and static local numbers.
4728   // These aren't really update records, but this is a convenient way of
4729   // tagging this rare extra data onto the declarations.
4730   for (const auto &Number : Context.MangleNumbers)
4731     if (!Number.first->isFromASTFile())
4732       DeclUpdates[Number.first].push_back(DeclUpdate(UPD_MANGLING_NUMBER,
4733                                                      Number.second));
4734   for (const auto &Number : Context.StaticLocalNumbers)
4735     if (!Number.first->isFromASTFile())
4736       DeclUpdates[Number.first].push_back(DeclUpdate(UPD_STATIC_LOCAL_NUMBER,
4737                                                      Number.second));
4738 
4739   // Make sure visible decls, added to DeclContexts previously loaded from
4740   // an AST file, are registered for serialization. Likewise for template
4741   // specializations added to imported templates.
4742   for (const auto *I : DeclsToEmitEvenIfUnreferenced) {
4743     GetDeclRef(I);
4744   }
4745 
4746   // Make sure all decls associated with an identifier are registered for
4747   // serialization, if we're storing decls with identifiers.
4748   if (!WritingModule || !getLangOpts().CPlusPlus) {
4749     llvm::SmallVector<const IdentifierInfo*, 256> IIs;
4750     for (const auto &ID : PP.getIdentifierTable()) {
4751       const IdentifierInfo *II = ID.second;
4752       if (!Chain || !II->isFromAST() || II->hasChangedSinceDeserialization())
4753         IIs.push_back(II);
4754     }
4755     // Sort the identifiers to visit based on their name.
4756     llvm::sort(IIs, llvm::deref<std::less<>>());
4757     for (const IdentifierInfo *II : IIs) {
4758       for (IdentifierResolver::iterator D = SemaRef.IdResolver.begin(II),
4759                                      DEnd = SemaRef.IdResolver.end();
4760            D != DEnd; ++D) {
4761         GetDeclRef(*D);
4762       }
4763     }
4764   }
4765 
4766   // For method pool in the module, if it contains an entry for a selector,
4767   // the entry should be complete, containing everything introduced by that
4768   // module and all modules it imports. It's possible that the entry is out of
4769   // date, so we need to pull in the new content here.
4770 
4771   // It's possible that updateOutOfDateSelector can update SelectorIDs. To be
4772   // safe, we copy all selectors out.
4773   llvm::SmallVector<Selector, 256> AllSelectors;
4774   for (auto &SelectorAndID : SelectorIDs)
4775     AllSelectors.push_back(SelectorAndID.first);
4776   for (auto &Selector : AllSelectors)
4777     SemaRef.updateOutOfDateSelector(Selector);
4778 
4779   // Form the record of special types.
4780   RecordData SpecialTypes;
4781   AddTypeRef(Context.getRawCFConstantStringType(), SpecialTypes);
4782   AddTypeRef(Context.getFILEType(), SpecialTypes);
4783   AddTypeRef(Context.getjmp_bufType(), SpecialTypes);
4784   AddTypeRef(Context.getsigjmp_bufType(), SpecialTypes);
4785   AddTypeRef(Context.ObjCIdRedefinitionType, SpecialTypes);
4786   AddTypeRef(Context.ObjCClassRedefinitionType, SpecialTypes);
4787   AddTypeRef(Context.ObjCSelRedefinitionType, SpecialTypes);
4788   AddTypeRef(Context.getucontext_tType(), SpecialTypes);
4789 
4790   if (Chain) {
4791     // Write the mapping information describing our module dependencies and how
4792     // each of those modules were mapped into our own offset/ID space, so that
4793     // the reader can build the appropriate mapping to its own offset/ID space.
4794     // The map consists solely of a blob with the following format:
4795     // *(module-kind:i8
4796     //   module-name-len:i16 module-name:len*i8
4797     //   source-location-offset:i32
4798     //   identifier-id:i32
4799     //   preprocessed-entity-id:i32
4800     //   macro-definition-id:i32
4801     //   submodule-id:i32
4802     //   selector-id:i32
4803     //   declaration-id:i32
4804     //   c++-base-specifiers-id:i32
4805     //   type-id:i32)
4806     //
4807     // module-kind is the ModuleKind enum value. If it is MK_PrebuiltModule,
4808     // MK_ExplicitModule or MK_ImplicitModule, then the module-name is the
4809     // module name. Otherwise, it is the module file name.
4810     auto Abbrev = std::make_shared<BitCodeAbbrev>();
4811     Abbrev->Add(BitCodeAbbrevOp(MODULE_OFFSET_MAP));
4812     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
4813     unsigned ModuleOffsetMapAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
4814     SmallString<2048> Buffer;
4815     {
4816       llvm::raw_svector_ostream Out(Buffer);
4817       for (ModuleFile &M : Chain->ModuleMgr) {
4818         using namespace llvm::support;
4819 
4820         endian::Writer LE(Out, little);
4821         LE.write<uint8_t>(static_cast<uint8_t>(M.Kind));
4822         StringRef Name = M.isModule() ? M.ModuleName : M.FileName;
4823         LE.write<uint16_t>(Name.size());
4824         Out.write(Name.data(), Name.size());
4825 
4826         // Note: if a base ID was uint max, it would not be possible to load
4827         // another module after it or have more than one entity inside it.
4828         uint32_t None = std::numeric_limits<uint32_t>::max();
4829 
4830         auto writeBaseIDOrNone = [&](auto BaseID, bool ShouldWrite) {
4831           assert(BaseID < std::numeric_limits<uint32_t>::max() && "base id too high");
4832           if (ShouldWrite)
4833             LE.write<uint32_t>(BaseID);
4834           else
4835             LE.write<uint32_t>(None);
4836         };
4837 
4838         // These values should be unique within a chain, since they will be read
4839         // as keys into ContinuousRangeMaps.
4840         writeBaseIDOrNone(M.SLocEntryBaseOffset, M.LocalNumSLocEntries);
4841         writeBaseIDOrNone(M.BaseIdentifierID, M.LocalNumIdentifiers);
4842         writeBaseIDOrNone(M.BaseMacroID, M.LocalNumMacros);
4843         writeBaseIDOrNone(M.BasePreprocessedEntityID,
4844                           M.NumPreprocessedEntities);
4845         writeBaseIDOrNone(M.BaseSubmoduleID, M.LocalNumSubmodules);
4846         writeBaseIDOrNone(M.BaseSelectorID, M.LocalNumSelectors);
4847         writeBaseIDOrNone(M.BaseDeclID, M.LocalNumDecls);
4848         writeBaseIDOrNone(M.BaseTypeIndex, M.LocalNumTypes);
4849       }
4850     }
4851     RecordData::value_type Record[] = {MODULE_OFFSET_MAP};
4852     Stream.EmitRecordWithBlob(ModuleOffsetMapAbbrev, Record,
4853                               Buffer.data(), Buffer.size());
4854   }
4855 
4856   // Build a record containing all of the DeclsToCheckForDeferredDiags.
4857   SmallVector<serialization::DeclID, 64> DeclsToCheckForDeferredDiags;
4858   for (auto *D : SemaRef.DeclsToCheckForDeferredDiags)
4859     DeclsToCheckForDeferredDiags.push_back(GetDeclRef(D));
4860 
4861   RecordData DeclUpdatesOffsetsRecord;
4862 
4863   // Keep writing types, declarations, and declaration update records
4864   // until we've emitted all of them.
4865   Stream.EnterSubblock(DECLTYPES_BLOCK_ID, /*bits for abbreviations*/5);
4866   DeclTypesBlockStartOffset = Stream.GetCurrentBitNo();
4867   WriteTypeAbbrevs();
4868   WriteDeclAbbrevs();
4869   do {
4870     WriteDeclUpdatesBlocks(DeclUpdatesOffsetsRecord);
4871     while (!DeclTypesToEmit.empty()) {
4872       DeclOrType DOT = DeclTypesToEmit.front();
4873       DeclTypesToEmit.pop();
4874       if (DOT.isType())
4875         WriteType(DOT.getType());
4876       else
4877         WriteDecl(Context, DOT.getDecl());
4878     }
4879   } while (!DeclUpdates.empty());
4880   Stream.ExitBlock();
4881 
4882   DoneWritingDeclsAndTypes = true;
4883 
4884   // These things can only be done once we've written out decls and types.
4885   WriteTypeDeclOffsets();
4886   if (!DeclUpdatesOffsetsRecord.empty())
4887     Stream.EmitRecord(DECL_UPDATE_OFFSETS, DeclUpdatesOffsetsRecord);
4888   WriteFileDeclIDsMap();
4889   WriteSourceManagerBlock(Context.getSourceManager(), PP);
4890   WriteComments();
4891   WritePreprocessor(PP, isModule);
4892   WriteHeaderSearch(PP.getHeaderSearchInfo());
4893   WriteSelectors(SemaRef);
4894   WriteReferencedSelectorsPool(SemaRef);
4895   WriteLateParsedTemplates(SemaRef);
4896   WriteIdentifierTable(PP, SemaRef.IdResolver, isModule);
4897   WriteFPPragmaOptions(SemaRef.CurFPFeatureOverrides());
4898   WriteOpenCLExtensions(SemaRef);
4899   WriteCUDAPragmas(SemaRef);
4900 
4901   // If we're emitting a module, write out the submodule information.
4902   if (WritingModule)
4903     WriteSubmodules(WritingModule);
4904 
4905   Stream.EmitRecord(SPECIAL_TYPES, SpecialTypes);
4906 
4907   // Write the record containing external, unnamed definitions.
4908   if (!EagerlyDeserializedDecls.empty())
4909     Stream.EmitRecord(EAGERLY_DESERIALIZED_DECLS, EagerlyDeserializedDecls);
4910 
4911   if (!ModularCodegenDecls.empty())
4912     Stream.EmitRecord(MODULAR_CODEGEN_DECLS, ModularCodegenDecls);
4913 
4914   // Write the record containing tentative definitions.
4915   if (!TentativeDefinitions.empty())
4916     Stream.EmitRecord(TENTATIVE_DEFINITIONS, TentativeDefinitions);
4917 
4918   // Write the record containing unused file scoped decls.
4919   if (!UnusedFileScopedDecls.empty())
4920     Stream.EmitRecord(UNUSED_FILESCOPED_DECLS, UnusedFileScopedDecls);
4921 
4922   // Write the record containing weak undeclared identifiers.
4923   if (!WeakUndeclaredIdentifiers.empty())
4924     Stream.EmitRecord(WEAK_UNDECLARED_IDENTIFIERS,
4925                       WeakUndeclaredIdentifiers);
4926 
4927   // Write the record containing ext_vector type names.
4928   if (!ExtVectorDecls.empty())
4929     Stream.EmitRecord(EXT_VECTOR_DECLS, ExtVectorDecls);
4930 
4931   // Write the record containing VTable uses information.
4932   if (!VTableUses.empty())
4933     Stream.EmitRecord(VTABLE_USES, VTableUses);
4934 
4935   // Write the record containing potentially unused local typedefs.
4936   if (!UnusedLocalTypedefNameCandidates.empty())
4937     Stream.EmitRecord(UNUSED_LOCAL_TYPEDEF_NAME_CANDIDATES,
4938                       UnusedLocalTypedefNameCandidates);
4939 
4940   // Write the record containing pending implicit instantiations.
4941   if (!PendingInstantiations.empty())
4942     Stream.EmitRecord(PENDING_IMPLICIT_INSTANTIATIONS, PendingInstantiations);
4943 
4944   // Write the record containing declaration references of Sema.
4945   if (!SemaDeclRefs.empty())
4946     Stream.EmitRecord(SEMA_DECL_REFS, SemaDeclRefs);
4947 
4948   // Write the record containing decls to be checked for deferred diags.
4949   if (!DeclsToCheckForDeferredDiags.empty())
4950     Stream.EmitRecord(DECLS_TO_CHECK_FOR_DEFERRED_DIAGS,
4951         DeclsToCheckForDeferredDiags);
4952 
4953   // Write the record containing CUDA-specific declaration references.
4954   if (!CUDASpecialDeclRefs.empty())
4955     Stream.EmitRecord(CUDA_SPECIAL_DECL_REFS, CUDASpecialDeclRefs);
4956 
4957   // Write the delegating constructors.
4958   if (!DelegatingCtorDecls.empty())
4959     Stream.EmitRecord(DELEGATING_CTORS, DelegatingCtorDecls);
4960 
4961   // Write the known namespaces.
4962   if (!KnownNamespaces.empty())
4963     Stream.EmitRecord(KNOWN_NAMESPACES, KnownNamespaces);
4964 
4965   // Write the undefined internal functions and variables, and inline functions.
4966   if (!UndefinedButUsed.empty())
4967     Stream.EmitRecord(UNDEFINED_BUT_USED, UndefinedButUsed);
4968 
4969   if (!DeleteExprsToAnalyze.empty())
4970     Stream.EmitRecord(DELETE_EXPRS_TO_ANALYZE, DeleteExprsToAnalyze);
4971 
4972   // Write the visible updates to DeclContexts.
4973   for (auto *DC : UpdatedDeclContexts)
4974     WriteDeclContextVisibleUpdate(DC);
4975 
4976   if (!WritingModule) {
4977     // Write the submodules that were imported, if any.
4978     struct ModuleInfo {
4979       uint64_t ID;
4980       Module *M;
4981       ModuleInfo(uint64_t ID, Module *M) : ID(ID), M(M) {}
4982     };
4983     llvm::SmallVector<ModuleInfo, 64> Imports;
4984     for (const auto *I : Context.local_imports()) {
4985       assert(SubmoduleIDs.find(I->getImportedModule()) != SubmoduleIDs.end());
4986       Imports.push_back(ModuleInfo(SubmoduleIDs[I->getImportedModule()],
4987                          I->getImportedModule()));
4988     }
4989 
4990     if (!Imports.empty()) {
4991       auto Cmp = [](const ModuleInfo &A, const ModuleInfo &B) {
4992         return A.ID < B.ID;
4993       };
4994       auto Eq = [](const ModuleInfo &A, const ModuleInfo &B) {
4995         return A.ID == B.ID;
4996       };
4997 
4998       // Sort and deduplicate module IDs.
4999       llvm::sort(Imports, Cmp);
5000       Imports.erase(std::unique(Imports.begin(), Imports.end(), Eq),
5001                     Imports.end());
5002 
5003       RecordData ImportedModules;
5004       for (const auto &Import : Imports) {
5005         ImportedModules.push_back(Import.ID);
5006         // FIXME: If the module has macros imported then later has declarations
5007         // imported, this location won't be the right one as a location for the
5008         // declaration imports.
5009         AddSourceLocation(PP.getModuleImportLoc(Import.M), ImportedModules);
5010       }
5011 
5012       Stream.EmitRecord(IMPORTED_MODULES, ImportedModules);
5013     }
5014   }
5015 
5016   WriteObjCCategories();
5017   if(!WritingModule) {
5018     WriteOptimizePragmaOptions(SemaRef);
5019     WriteMSStructPragmaOptions(SemaRef);
5020     WriteMSPointersToMembersPragmaOptions(SemaRef);
5021   }
5022   WritePackPragmaOptions(SemaRef);
5023   WriteFloatControlPragmaOptions(SemaRef);
5024 
5025   // Some simple statistics
5026   RecordData::value_type Record[] = {
5027       NumStatements, NumMacros, NumLexicalDeclContexts, NumVisibleDeclContexts};
5028   Stream.EmitRecord(STATISTICS, Record);
5029   Stream.ExitBlock();
5030   Stream.FlushToWord();
5031   ASTBlockRange.second = Stream.GetCurrentBitNo();
5032 
5033   // Write the module file extension blocks.
5034   for (const auto &ExtWriter : ModuleFileExtensionWriters)
5035     WriteModuleFileExtension(SemaRef, *ExtWriter);
5036 
5037   return writeUnhashedControlBlock(PP, Context);
5038 }
5039 
5040 void ASTWriter::WriteDeclUpdatesBlocks(RecordDataImpl &OffsetsRecord) {
5041   if (DeclUpdates.empty())
5042     return;
5043 
5044   DeclUpdateMap LocalUpdates;
5045   LocalUpdates.swap(DeclUpdates);
5046 
5047   for (auto &DeclUpdate : LocalUpdates) {
5048     const Decl *D = DeclUpdate.first;
5049 
5050     bool HasUpdatedBody = false;
5051     RecordData RecordData;
5052     ASTRecordWriter Record(*this, RecordData);
5053     for (auto &Update : DeclUpdate.second) {
5054       DeclUpdateKind Kind = (DeclUpdateKind)Update.getKind();
5055 
5056       // An updated body is emitted last, so that the reader doesn't need
5057       // to skip over the lazy body to reach statements for other records.
5058       if (Kind == UPD_CXX_ADDED_FUNCTION_DEFINITION)
5059         HasUpdatedBody = true;
5060       else
5061         Record.push_back(Kind);
5062 
5063       switch (Kind) {
5064       case UPD_CXX_ADDED_IMPLICIT_MEMBER:
5065       case UPD_CXX_ADDED_TEMPLATE_SPECIALIZATION:
5066       case UPD_CXX_ADDED_ANONYMOUS_NAMESPACE:
5067         assert(Update.getDecl() && "no decl to add?");
5068         Record.push_back(GetDeclRef(Update.getDecl()));
5069         break;
5070 
5071       case UPD_CXX_ADDED_FUNCTION_DEFINITION:
5072         break;
5073 
5074       case UPD_CXX_POINT_OF_INSTANTIATION:
5075         // FIXME: Do we need to also save the template specialization kind here?
5076         Record.AddSourceLocation(Update.getLoc());
5077         break;
5078 
5079       case UPD_CXX_ADDED_VAR_DEFINITION: {
5080         const VarDecl *VD = cast<VarDecl>(D);
5081         Record.push_back(VD->isInline());
5082         Record.push_back(VD->isInlineSpecified());
5083         Record.AddVarDeclInit(VD);
5084         break;
5085       }
5086 
5087       case UPD_CXX_INSTANTIATED_DEFAULT_ARGUMENT:
5088         Record.AddStmt(const_cast<Expr *>(
5089             cast<ParmVarDecl>(Update.getDecl())->getDefaultArg()));
5090         break;
5091 
5092       case UPD_CXX_INSTANTIATED_DEFAULT_MEMBER_INITIALIZER:
5093         Record.AddStmt(
5094             cast<FieldDecl>(Update.getDecl())->getInClassInitializer());
5095         break;
5096 
5097       case UPD_CXX_INSTANTIATED_CLASS_DEFINITION: {
5098         auto *RD = cast<CXXRecordDecl>(D);
5099         UpdatedDeclContexts.insert(RD->getPrimaryContext());
5100         Record.push_back(RD->isParamDestroyedInCallee());
5101         Record.push_back(RD->getArgPassingRestrictions());
5102         Record.AddCXXDefinitionData(RD);
5103         Record.AddOffset(WriteDeclContextLexicalBlock(
5104             *Context, const_cast<CXXRecordDecl *>(RD)));
5105 
5106         // This state is sometimes updated by template instantiation, when we
5107         // switch from the specialization referring to the template declaration
5108         // to it referring to the template definition.
5109         if (auto *MSInfo = RD->getMemberSpecializationInfo()) {
5110           Record.push_back(MSInfo->getTemplateSpecializationKind());
5111           Record.AddSourceLocation(MSInfo->getPointOfInstantiation());
5112         } else {
5113           auto *Spec = cast<ClassTemplateSpecializationDecl>(RD);
5114           Record.push_back(Spec->getTemplateSpecializationKind());
5115           Record.AddSourceLocation(Spec->getPointOfInstantiation());
5116 
5117           // The instantiation might have been resolved to a partial
5118           // specialization. If so, record which one.
5119           auto From = Spec->getInstantiatedFrom();
5120           if (auto PartialSpec =
5121                 From.dyn_cast<ClassTemplatePartialSpecializationDecl*>()) {
5122             Record.push_back(true);
5123             Record.AddDeclRef(PartialSpec);
5124             Record.AddTemplateArgumentList(
5125                 &Spec->getTemplateInstantiationArgs());
5126           } else {
5127             Record.push_back(false);
5128           }
5129         }
5130         Record.push_back(RD->getTagKind());
5131         Record.AddSourceLocation(RD->getLocation());
5132         Record.AddSourceLocation(RD->getBeginLoc());
5133         Record.AddSourceRange(RD->getBraceRange());
5134 
5135         // Instantiation may change attributes; write them all out afresh.
5136         Record.push_back(D->hasAttrs());
5137         if (D->hasAttrs())
5138           Record.AddAttributes(D->getAttrs());
5139 
5140         // FIXME: Ensure we don't get here for explicit instantiations.
5141         break;
5142       }
5143 
5144       case UPD_CXX_RESOLVED_DTOR_DELETE:
5145         Record.AddDeclRef(Update.getDecl());
5146         Record.AddStmt(cast<CXXDestructorDecl>(D)->getOperatorDeleteThisArg());
5147         break;
5148 
5149       case UPD_CXX_RESOLVED_EXCEPTION_SPEC: {
5150         auto prototype =
5151           cast<FunctionDecl>(D)->getType()->castAs<FunctionProtoType>();
5152         Record.writeExceptionSpecInfo(prototype->getExceptionSpecInfo());
5153         break;
5154       }
5155 
5156       case UPD_CXX_DEDUCED_RETURN_TYPE:
5157         Record.push_back(GetOrCreateTypeID(Update.getType()));
5158         break;
5159 
5160       case UPD_DECL_MARKED_USED:
5161         break;
5162 
5163       case UPD_MANGLING_NUMBER:
5164       case UPD_STATIC_LOCAL_NUMBER:
5165         Record.push_back(Update.getNumber());
5166         break;
5167 
5168       case UPD_DECL_MARKED_OPENMP_THREADPRIVATE:
5169         Record.AddSourceRange(
5170             D->getAttr<OMPThreadPrivateDeclAttr>()->getRange());
5171         break;
5172 
5173       case UPD_DECL_MARKED_OPENMP_ALLOCATE: {
5174         auto *A = D->getAttr<OMPAllocateDeclAttr>();
5175         Record.push_back(A->getAllocatorType());
5176         Record.AddStmt(A->getAllocator());
5177         Record.AddStmt(A->getAlignment());
5178         Record.AddSourceRange(A->getRange());
5179         break;
5180       }
5181 
5182       case UPD_DECL_MARKED_OPENMP_DECLARETARGET:
5183         Record.push_back(D->getAttr<OMPDeclareTargetDeclAttr>()->getMapType());
5184         Record.AddSourceRange(
5185             D->getAttr<OMPDeclareTargetDeclAttr>()->getRange());
5186         break;
5187 
5188       case UPD_DECL_EXPORTED:
5189         Record.push_back(getSubmoduleID(Update.getModule()));
5190         break;
5191 
5192       case UPD_ADDED_ATTR_TO_RECORD:
5193         Record.AddAttributes(llvm::makeArrayRef(Update.getAttr()));
5194         break;
5195       }
5196     }
5197 
5198     if (HasUpdatedBody) {
5199       const auto *Def = cast<FunctionDecl>(D);
5200       Record.push_back(UPD_CXX_ADDED_FUNCTION_DEFINITION);
5201       Record.push_back(Def->isInlined());
5202       Record.AddSourceLocation(Def->getInnerLocStart());
5203       Record.AddFunctionDefinition(Def);
5204     }
5205 
5206     OffsetsRecord.push_back(GetDeclRef(D));
5207     OffsetsRecord.push_back(Record.Emit(DECL_UPDATES));
5208   }
5209 }
5210 
5211 void ASTWriter::AddAlignPackInfo(const Sema::AlignPackInfo &Info,
5212                                  RecordDataImpl &Record) {
5213   uint32_t Raw = Sema::AlignPackInfo::getRawEncoding(Info);
5214   Record.push_back(Raw);
5215 }
5216 
5217 void ASTWriter::AddSourceLocation(SourceLocation Loc, RecordDataImpl &Record) {
5218   SourceLocation::UIntTy Raw = Loc.getRawEncoding();
5219   Record.push_back((Raw << 1) | (Raw >> (8 * sizeof(Raw) - 1)));
5220 }
5221 
5222 void ASTWriter::AddSourceRange(SourceRange Range, RecordDataImpl &Record) {
5223   AddSourceLocation(Range.getBegin(), Record);
5224   AddSourceLocation(Range.getEnd(), Record);
5225 }
5226 
5227 void ASTRecordWriter::AddAPFloat(const llvm::APFloat &Value) {
5228   AddAPInt(Value.bitcastToAPInt());
5229 }
5230 
5231 void ASTWriter::AddIdentifierRef(const IdentifierInfo *II, RecordDataImpl &Record) {
5232   Record.push_back(getIdentifierRef(II));
5233 }
5234 
5235 IdentID ASTWriter::getIdentifierRef(const IdentifierInfo *II) {
5236   if (!II)
5237     return 0;
5238 
5239   IdentID &ID = IdentifierIDs[II];
5240   if (ID == 0)
5241     ID = NextIdentID++;
5242   return ID;
5243 }
5244 
5245 MacroID ASTWriter::getMacroRef(MacroInfo *MI, const IdentifierInfo *Name) {
5246   // Don't emit builtin macros like __LINE__ to the AST file unless they
5247   // have been redefined by the header (in which case they are not
5248   // isBuiltinMacro).
5249   if (!MI || MI->isBuiltinMacro())
5250     return 0;
5251 
5252   MacroID &ID = MacroIDs[MI];
5253   if (ID == 0) {
5254     ID = NextMacroID++;
5255     MacroInfoToEmitData Info = { Name, MI, ID };
5256     MacroInfosToEmit.push_back(Info);
5257   }
5258   return ID;
5259 }
5260 
5261 MacroID ASTWriter::getMacroID(MacroInfo *MI) {
5262   if (!MI || MI->isBuiltinMacro())
5263     return 0;
5264 
5265   assert(MacroIDs.find(MI) != MacroIDs.end() && "Macro not emitted!");
5266   return MacroIDs[MI];
5267 }
5268 
5269 uint32_t ASTWriter::getMacroDirectivesOffset(const IdentifierInfo *Name) {
5270   return IdentMacroDirectivesOffsetMap.lookup(Name);
5271 }
5272 
5273 void ASTRecordWriter::AddSelectorRef(const Selector SelRef) {
5274   Record->push_back(Writer->getSelectorRef(SelRef));
5275 }
5276 
5277 SelectorID ASTWriter::getSelectorRef(Selector Sel) {
5278   if (Sel.getAsOpaquePtr() == nullptr) {
5279     return 0;
5280   }
5281 
5282   SelectorID SID = SelectorIDs[Sel];
5283   if (SID == 0 && Chain) {
5284     // This might trigger a ReadSelector callback, which will set the ID for
5285     // this selector.
5286     Chain->LoadSelector(Sel);
5287     SID = SelectorIDs[Sel];
5288   }
5289   if (SID == 0) {
5290     SID = NextSelectorID++;
5291     SelectorIDs[Sel] = SID;
5292   }
5293   return SID;
5294 }
5295 
5296 void ASTRecordWriter::AddCXXTemporary(const CXXTemporary *Temp) {
5297   AddDeclRef(Temp->getDestructor());
5298 }
5299 
5300 void ASTRecordWriter::AddTemplateArgumentLocInfo(
5301     TemplateArgument::ArgKind Kind, const TemplateArgumentLocInfo &Arg) {
5302   switch (Kind) {
5303   case TemplateArgument::Expression:
5304     AddStmt(Arg.getAsExpr());
5305     break;
5306   case TemplateArgument::Type:
5307     AddTypeSourceInfo(Arg.getAsTypeSourceInfo());
5308     break;
5309   case TemplateArgument::Template:
5310     AddNestedNameSpecifierLoc(Arg.getTemplateQualifierLoc());
5311     AddSourceLocation(Arg.getTemplateNameLoc());
5312     break;
5313   case TemplateArgument::TemplateExpansion:
5314     AddNestedNameSpecifierLoc(Arg.getTemplateQualifierLoc());
5315     AddSourceLocation(Arg.getTemplateNameLoc());
5316     AddSourceLocation(Arg.getTemplateEllipsisLoc());
5317     break;
5318   case TemplateArgument::Null:
5319   case TemplateArgument::Integral:
5320   case TemplateArgument::Declaration:
5321   case TemplateArgument::NullPtr:
5322   case TemplateArgument::Pack:
5323     // FIXME: Is this right?
5324     break;
5325   }
5326 }
5327 
5328 void ASTRecordWriter::AddTemplateArgumentLoc(const TemplateArgumentLoc &Arg) {
5329   AddTemplateArgument(Arg.getArgument());
5330 
5331   if (Arg.getArgument().getKind() == TemplateArgument::Expression) {
5332     bool InfoHasSameExpr
5333       = Arg.getArgument().getAsExpr() == Arg.getLocInfo().getAsExpr();
5334     Record->push_back(InfoHasSameExpr);
5335     if (InfoHasSameExpr)
5336       return; // Avoid storing the same expr twice.
5337   }
5338   AddTemplateArgumentLocInfo(Arg.getArgument().getKind(), Arg.getLocInfo());
5339 }
5340 
5341 void ASTRecordWriter::AddTypeSourceInfo(TypeSourceInfo *TInfo) {
5342   if (!TInfo) {
5343     AddTypeRef(QualType());
5344     return;
5345   }
5346 
5347   AddTypeRef(TInfo->getType());
5348   AddTypeLoc(TInfo->getTypeLoc());
5349 }
5350 
5351 void ASTRecordWriter::AddTypeLoc(TypeLoc TL) {
5352   TypeLocWriter TLW(*this);
5353   for (; !TL.isNull(); TL = TL.getNextTypeLoc())
5354     TLW.Visit(TL);
5355 }
5356 
5357 void ASTWriter::AddTypeRef(QualType T, RecordDataImpl &Record) {
5358   Record.push_back(GetOrCreateTypeID(T));
5359 }
5360 
5361 TypeID ASTWriter::GetOrCreateTypeID(QualType T) {
5362   assert(Context);
5363   return MakeTypeID(*Context, T, [&](QualType T) -> TypeIdx {
5364     if (T.isNull())
5365       return TypeIdx();
5366     assert(!T.getLocalFastQualifiers());
5367 
5368     TypeIdx &Idx = TypeIdxs[T];
5369     if (Idx.getIndex() == 0) {
5370       if (DoneWritingDeclsAndTypes) {
5371         assert(0 && "New type seen after serializing all the types to emit!");
5372         return TypeIdx();
5373       }
5374 
5375       // We haven't seen this type before. Assign it a new ID and put it
5376       // into the queue of types to emit.
5377       Idx = TypeIdx(NextTypeID++);
5378       DeclTypesToEmit.push(T);
5379     }
5380     return Idx;
5381   });
5382 }
5383 
5384 TypeID ASTWriter::getTypeID(QualType T) const {
5385   assert(Context);
5386   return MakeTypeID(*Context, T, [&](QualType T) -> TypeIdx {
5387     if (T.isNull())
5388       return TypeIdx();
5389     assert(!T.getLocalFastQualifiers());
5390 
5391     TypeIdxMap::const_iterator I = TypeIdxs.find(T);
5392     assert(I != TypeIdxs.end() && "Type not emitted!");
5393     return I->second;
5394   });
5395 }
5396 
5397 void ASTWriter::AddDeclRef(const Decl *D, RecordDataImpl &Record) {
5398   Record.push_back(GetDeclRef(D));
5399 }
5400 
5401 DeclID ASTWriter::GetDeclRef(const Decl *D) {
5402   assert(WritingAST && "Cannot request a declaration ID before AST writing");
5403 
5404   if (!D) {
5405     return 0;
5406   }
5407 
5408   // If D comes from an AST file, its declaration ID is already known and
5409   // fixed.
5410   if (D->isFromASTFile())
5411     return D->getGlobalID();
5412 
5413   assert(!(reinterpret_cast<uintptr_t>(D) & 0x01) && "Invalid decl pointer");
5414   DeclID &ID = DeclIDs[D];
5415   if (ID == 0) {
5416     if (DoneWritingDeclsAndTypes) {
5417       assert(0 && "New decl seen after serializing all the decls to emit!");
5418       return 0;
5419     }
5420 
5421     // We haven't seen this declaration before. Give it a new ID and
5422     // enqueue it in the list of declarations to emit.
5423     ID = NextDeclID++;
5424     DeclTypesToEmit.push(const_cast<Decl *>(D));
5425   }
5426 
5427   return ID;
5428 }
5429 
5430 DeclID ASTWriter::getDeclID(const Decl *D) {
5431   if (!D)
5432     return 0;
5433 
5434   // If D comes from an AST file, its declaration ID is already known and
5435   // fixed.
5436   if (D->isFromASTFile())
5437     return D->getGlobalID();
5438 
5439   assert(DeclIDs.find(D) != DeclIDs.end() && "Declaration not emitted!");
5440   return DeclIDs[D];
5441 }
5442 
5443 void ASTWriter::associateDeclWithFile(const Decl *D, DeclID ID) {
5444   assert(ID);
5445   assert(D);
5446 
5447   SourceLocation Loc = D->getLocation();
5448   if (Loc.isInvalid())
5449     return;
5450 
5451   // We only keep track of the file-level declarations of each file.
5452   if (!D->getLexicalDeclContext()->isFileContext())
5453     return;
5454   // FIXME: ParmVarDecls that are part of a function type of a parameter of
5455   // a function/objc method, should not have TU as lexical context.
5456   // TemplateTemplateParmDecls that are part of an alias template, should not
5457   // have TU as lexical context.
5458   if (isa<ParmVarDecl>(D) || isa<TemplateTemplateParmDecl>(D))
5459     return;
5460 
5461   SourceManager &SM = Context->getSourceManager();
5462   SourceLocation FileLoc = SM.getFileLoc(Loc);
5463   assert(SM.isLocalSourceLocation(FileLoc));
5464   FileID FID;
5465   unsigned Offset;
5466   std::tie(FID, Offset) = SM.getDecomposedLoc(FileLoc);
5467   if (FID.isInvalid())
5468     return;
5469   assert(SM.getSLocEntry(FID).isFile());
5470 
5471   std::unique_ptr<DeclIDInFileInfo> &Info = FileDeclIDs[FID];
5472   if (!Info)
5473     Info = std::make_unique<DeclIDInFileInfo>();
5474 
5475   std::pair<unsigned, serialization::DeclID> LocDecl(Offset, ID);
5476   LocDeclIDsTy &Decls = Info->DeclIDs;
5477   Decls.push_back(LocDecl);
5478 }
5479 
5480 unsigned ASTWriter::getAnonymousDeclarationNumber(const NamedDecl *D) {
5481   assert(needsAnonymousDeclarationNumber(D) &&
5482          "expected an anonymous declaration");
5483 
5484   // Number the anonymous declarations within this context, if we've not
5485   // already done so.
5486   auto It = AnonymousDeclarationNumbers.find(D);
5487   if (It == AnonymousDeclarationNumbers.end()) {
5488     auto *DC = D->getLexicalDeclContext();
5489     numberAnonymousDeclsWithin(DC, [&](const NamedDecl *ND, unsigned Number) {
5490       AnonymousDeclarationNumbers[ND] = Number;
5491     });
5492 
5493     It = AnonymousDeclarationNumbers.find(D);
5494     assert(It != AnonymousDeclarationNumbers.end() &&
5495            "declaration not found within its lexical context");
5496   }
5497 
5498   return It->second;
5499 }
5500 
5501 void ASTRecordWriter::AddDeclarationNameLoc(const DeclarationNameLoc &DNLoc,
5502                                             DeclarationName Name) {
5503   switch (Name.getNameKind()) {
5504   case DeclarationName::CXXConstructorName:
5505   case DeclarationName::CXXDestructorName:
5506   case DeclarationName::CXXConversionFunctionName:
5507     AddTypeSourceInfo(DNLoc.getNamedTypeInfo());
5508     break;
5509 
5510   case DeclarationName::CXXOperatorName:
5511     AddSourceRange(DNLoc.getCXXOperatorNameRange());
5512     break;
5513 
5514   case DeclarationName::CXXLiteralOperatorName:
5515     AddSourceLocation(DNLoc.getCXXLiteralOperatorNameLoc());
5516     break;
5517 
5518   case DeclarationName::Identifier:
5519   case DeclarationName::ObjCZeroArgSelector:
5520   case DeclarationName::ObjCOneArgSelector:
5521   case DeclarationName::ObjCMultiArgSelector:
5522   case DeclarationName::CXXUsingDirective:
5523   case DeclarationName::CXXDeductionGuideName:
5524     break;
5525   }
5526 }
5527 
5528 void ASTRecordWriter::AddDeclarationNameInfo(
5529     const DeclarationNameInfo &NameInfo) {
5530   AddDeclarationName(NameInfo.getName());
5531   AddSourceLocation(NameInfo.getLoc());
5532   AddDeclarationNameLoc(NameInfo.getInfo(), NameInfo.getName());
5533 }
5534 
5535 void ASTRecordWriter::AddQualifierInfo(const QualifierInfo &Info) {
5536   AddNestedNameSpecifierLoc(Info.QualifierLoc);
5537   Record->push_back(Info.NumTemplParamLists);
5538   for (unsigned i = 0, e = Info.NumTemplParamLists; i != e; ++i)
5539     AddTemplateParameterList(Info.TemplParamLists[i]);
5540 }
5541 
5542 void ASTRecordWriter::AddNestedNameSpecifierLoc(NestedNameSpecifierLoc NNS) {
5543   // Nested name specifiers usually aren't too long. I think that 8 would
5544   // typically accommodate the vast majority.
5545   SmallVector<NestedNameSpecifierLoc , 8> NestedNames;
5546 
5547   // Push each of the nested-name-specifiers's onto a stack for
5548   // serialization in reverse order.
5549   while (NNS) {
5550     NestedNames.push_back(NNS);
5551     NNS = NNS.getPrefix();
5552   }
5553 
5554   Record->push_back(NestedNames.size());
5555   while(!NestedNames.empty()) {
5556     NNS = NestedNames.pop_back_val();
5557     NestedNameSpecifier::SpecifierKind Kind
5558       = NNS.getNestedNameSpecifier()->getKind();
5559     Record->push_back(Kind);
5560     switch (Kind) {
5561     case NestedNameSpecifier::Identifier:
5562       AddIdentifierRef(NNS.getNestedNameSpecifier()->getAsIdentifier());
5563       AddSourceRange(NNS.getLocalSourceRange());
5564       break;
5565 
5566     case NestedNameSpecifier::Namespace:
5567       AddDeclRef(NNS.getNestedNameSpecifier()->getAsNamespace());
5568       AddSourceRange(NNS.getLocalSourceRange());
5569       break;
5570 
5571     case NestedNameSpecifier::NamespaceAlias:
5572       AddDeclRef(NNS.getNestedNameSpecifier()->getAsNamespaceAlias());
5573       AddSourceRange(NNS.getLocalSourceRange());
5574       break;
5575 
5576     case NestedNameSpecifier::TypeSpec:
5577     case NestedNameSpecifier::TypeSpecWithTemplate:
5578       Record->push_back(Kind == NestedNameSpecifier::TypeSpecWithTemplate);
5579       AddTypeRef(NNS.getTypeLoc().getType());
5580       AddTypeLoc(NNS.getTypeLoc());
5581       AddSourceLocation(NNS.getLocalSourceRange().getEnd());
5582       break;
5583 
5584     case NestedNameSpecifier::Global:
5585       AddSourceLocation(NNS.getLocalSourceRange().getEnd());
5586       break;
5587 
5588     case NestedNameSpecifier::Super:
5589       AddDeclRef(NNS.getNestedNameSpecifier()->getAsRecordDecl());
5590       AddSourceRange(NNS.getLocalSourceRange());
5591       break;
5592     }
5593   }
5594 }
5595 
5596 void ASTRecordWriter::AddTemplateParameterList(
5597     const TemplateParameterList *TemplateParams) {
5598   assert(TemplateParams && "No TemplateParams!");
5599   AddSourceLocation(TemplateParams->getTemplateLoc());
5600   AddSourceLocation(TemplateParams->getLAngleLoc());
5601   AddSourceLocation(TemplateParams->getRAngleLoc());
5602 
5603   Record->push_back(TemplateParams->size());
5604   for (const auto &P : *TemplateParams)
5605     AddDeclRef(P);
5606   if (const Expr *RequiresClause = TemplateParams->getRequiresClause()) {
5607     Record->push_back(true);
5608     AddStmt(const_cast<Expr*>(RequiresClause));
5609   } else {
5610     Record->push_back(false);
5611   }
5612 }
5613 
5614 /// Emit a template argument list.
5615 void ASTRecordWriter::AddTemplateArgumentList(
5616     const TemplateArgumentList *TemplateArgs) {
5617   assert(TemplateArgs && "No TemplateArgs!");
5618   Record->push_back(TemplateArgs->size());
5619   for (int i = 0, e = TemplateArgs->size(); i != e; ++i)
5620     AddTemplateArgument(TemplateArgs->get(i));
5621 }
5622 
5623 void ASTRecordWriter::AddASTTemplateArgumentListInfo(
5624     const ASTTemplateArgumentListInfo *ASTTemplArgList) {
5625   assert(ASTTemplArgList && "No ASTTemplArgList!");
5626   AddSourceLocation(ASTTemplArgList->LAngleLoc);
5627   AddSourceLocation(ASTTemplArgList->RAngleLoc);
5628   Record->push_back(ASTTemplArgList->NumTemplateArgs);
5629   const TemplateArgumentLoc *TemplArgs = ASTTemplArgList->getTemplateArgs();
5630   for (int i = 0, e = ASTTemplArgList->NumTemplateArgs; i != e; ++i)
5631     AddTemplateArgumentLoc(TemplArgs[i]);
5632 }
5633 
5634 void ASTRecordWriter::AddUnresolvedSet(const ASTUnresolvedSet &Set) {
5635   Record->push_back(Set.size());
5636   for (ASTUnresolvedSet::const_iterator
5637          I = Set.begin(), E = Set.end(); I != E; ++I) {
5638     AddDeclRef(I.getDecl());
5639     Record->push_back(I.getAccess());
5640   }
5641 }
5642 
5643 // FIXME: Move this out of the main ASTRecordWriter interface.
5644 void ASTRecordWriter::AddCXXBaseSpecifier(const CXXBaseSpecifier &Base) {
5645   Record->push_back(Base.isVirtual());
5646   Record->push_back(Base.isBaseOfClass());
5647   Record->push_back(Base.getAccessSpecifierAsWritten());
5648   Record->push_back(Base.getInheritConstructors());
5649   AddTypeSourceInfo(Base.getTypeSourceInfo());
5650   AddSourceRange(Base.getSourceRange());
5651   AddSourceLocation(Base.isPackExpansion()? Base.getEllipsisLoc()
5652                                           : SourceLocation());
5653 }
5654 
5655 static uint64_t EmitCXXBaseSpecifiers(ASTWriter &W,
5656                                       ArrayRef<CXXBaseSpecifier> Bases) {
5657   ASTWriter::RecordData Record;
5658   ASTRecordWriter Writer(W, Record);
5659   Writer.push_back(Bases.size());
5660 
5661   for (auto &Base : Bases)
5662     Writer.AddCXXBaseSpecifier(Base);
5663 
5664   return Writer.Emit(serialization::DECL_CXX_BASE_SPECIFIERS);
5665 }
5666 
5667 // FIXME: Move this out of the main ASTRecordWriter interface.
5668 void ASTRecordWriter::AddCXXBaseSpecifiers(ArrayRef<CXXBaseSpecifier> Bases) {
5669   AddOffset(EmitCXXBaseSpecifiers(*Writer, Bases));
5670 }
5671 
5672 static uint64_t
5673 EmitCXXCtorInitializers(ASTWriter &W,
5674                         ArrayRef<CXXCtorInitializer *> CtorInits) {
5675   ASTWriter::RecordData Record;
5676   ASTRecordWriter Writer(W, Record);
5677   Writer.push_back(CtorInits.size());
5678 
5679   for (auto *Init : CtorInits) {
5680     if (Init->isBaseInitializer()) {
5681       Writer.push_back(CTOR_INITIALIZER_BASE);
5682       Writer.AddTypeSourceInfo(Init->getTypeSourceInfo());
5683       Writer.push_back(Init->isBaseVirtual());
5684     } else if (Init->isDelegatingInitializer()) {
5685       Writer.push_back(CTOR_INITIALIZER_DELEGATING);
5686       Writer.AddTypeSourceInfo(Init->getTypeSourceInfo());
5687     } else if (Init->isMemberInitializer()){
5688       Writer.push_back(CTOR_INITIALIZER_MEMBER);
5689       Writer.AddDeclRef(Init->getMember());
5690     } else {
5691       Writer.push_back(CTOR_INITIALIZER_INDIRECT_MEMBER);
5692       Writer.AddDeclRef(Init->getIndirectMember());
5693     }
5694 
5695     Writer.AddSourceLocation(Init->getMemberLocation());
5696     Writer.AddStmt(Init->getInit());
5697     Writer.AddSourceLocation(Init->getLParenLoc());
5698     Writer.AddSourceLocation(Init->getRParenLoc());
5699     Writer.push_back(Init->isWritten());
5700     if (Init->isWritten())
5701       Writer.push_back(Init->getSourceOrder());
5702   }
5703 
5704   return Writer.Emit(serialization::DECL_CXX_CTOR_INITIALIZERS);
5705 }
5706 
5707 // FIXME: Move this out of the main ASTRecordWriter interface.
5708 void ASTRecordWriter::AddCXXCtorInitializers(
5709     ArrayRef<CXXCtorInitializer *> CtorInits) {
5710   AddOffset(EmitCXXCtorInitializers(*Writer, CtorInits));
5711 }
5712 
5713 void ASTRecordWriter::AddCXXDefinitionData(const CXXRecordDecl *D) {
5714   auto &Data = D->data();
5715   Record->push_back(Data.IsLambda);
5716 
5717   #define FIELD(Name, Width, Merge) \
5718   Record->push_back(Data.Name);
5719   #include "clang/AST/CXXRecordDeclDefinitionBits.def"
5720 
5721   // getODRHash will compute the ODRHash if it has not been previously computed.
5722   Record->push_back(D->getODRHash());
5723   bool ModulesDebugInfo =
5724       Writer->Context->getLangOpts().ModulesDebugInfo && !D->isDependentType();
5725   Record->push_back(ModulesDebugInfo);
5726   if (ModulesDebugInfo)
5727     Writer->ModularCodegenDecls.push_back(Writer->GetDeclRef(D));
5728 
5729   // IsLambda bit is already saved.
5730 
5731   Record->push_back(Data.NumBases);
5732   if (Data.NumBases > 0)
5733     AddCXXBaseSpecifiers(Data.bases());
5734 
5735   // FIXME: Make VBases lazily computed when needed to avoid storing them.
5736   Record->push_back(Data.NumVBases);
5737   if (Data.NumVBases > 0)
5738     AddCXXBaseSpecifiers(Data.vbases());
5739 
5740   AddUnresolvedSet(Data.Conversions.get(*Writer->Context));
5741   Record->push_back(Data.ComputedVisibleConversions);
5742   if (Data.ComputedVisibleConversions)
5743     AddUnresolvedSet(Data.VisibleConversions.get(*Writer->Context));
5744   // Data.Definition is the owning decl, no need to write it.
5745   AddDeclRef(D->getFirstFriend());
5746 
5747   // Add lambda-specific data.
5748   if (Data.IsLambda) {
5749     auto &Lambda = D->getLambdaData();
5750     Record->push_back(Lambda.DependencyKind);
5751     Record->push_back(Lambda.IsGenericLambda);
5752     Record->push_back(Lambda.CaptureDefault);
5753     Record->push_back(Lambda.NumCaptures);
5754     Record->push_back(Lambda.NumExplicitCaptures);
5755     Record->push_back(Lambda.HasKnownInternalLinkage);
5756     Record->push_back(Lambda.ManglingNumber);
5757     Record->push_back(D->getDeviceLambdaManglingNumber());
5758     AddDeclRef(D->getLambdaContextDecl());
5759     AddTypeSourceInfo(Lambda.MethodTyInfo);
5760     for (unsigned I = 0, N = Lambda.NumCaptures; I != N; ++I) {
5761       const LambdaCapture &Capture = Lambda.Captures[I];
5762       AddSourceLocation(Capture.getLocation());
5763       Record->push_back(Capture.isImplicit());
5764       Record->push_back(Capture.getCaptureKind());
5765       switch (Capture.getCaptureKind()) {
5766       case LCK_StarThis:
5767       case LCK_This:
5768       case LCK_VLAType:
5769         break;
5770       case LCK_ByCopy:
5771       case LCK_ByRef:
5772         VarDecl *Var =
5773             Capture.capturesVariable() ? Capture.getCapturedVar() : nullptr;
5774         AddDeclRef(Var);
5775         AddSourceLocation(Capture.isPackExpansion() ? Capture.getEllipsisLoc()
5776                                                     : SourceLocation());
5777         break;
5778       }
5779     }
5780   }
5781 }
5782 
5783 void ASTRecordWriter::AddVarDeclInit(const VarDecl *VD) {
5784   const Expr *Init = VD->getInit();
5785   if (!Init) {
5786     push_back(0);
5787     return;
5788   }
5789 
5790   unsigned Val = 1;
5791   if (EvaluatedStmt *ES = VD->getEvaluatedStmt()) {
5792     Val |= (ES->HasConstantInitialization ? 2 : 0);
5793     Val |= (ES->HasConstantDestruction ? 4 : 0);
5794     // FIXME: Also emit the constant initializer value.
5795   }
5796   push_back(Val);
5797   writeStmtRef(Init);
5798 }
5799 
5800 void ASTWriter::ReaderInitialized(ASTReader *Reader) {
5801   assert(Reader && "Cannot remove chain");
5802   assert((!Chain || Chain == Reader) && "Cannot replace chain");
5803   assert(FirstDeclID == NextDeclID &&
5804          FirstTypeID == NextTypeID &&
5805          FirstIdentID == NextIdentID &&
5806          FirstMacroID == NextMacroID &&
5807          FirstSubmoduleID == NextSubmoduleID &&
5808          FirstSelectorID == NextSelectorID &&
5809          "Setting chain after writing has started.");
5810 
5811   Chain = Reader;
5812 
5813   // Note, this will get called multiple times, once one the reader starts up
5814   // and again each time it's done reading a PCH or module.
5815   FirstDeclID = NUM_PREDEF_DECL_IDS + Chain->getTotalNumDecls();
5816   FirstTypeID = NUM_PREDEF_TYPE_IDS + Chain->getTotalNumTypes();
5817   FirstIdentID = NUM_PREDEF_IDENT_IDS + Chain->getTotalNumIdentifiers();
5818   FirstMacroID = NUM_PREDEF_MACRO_IDS + Chain->getTotalNumMacros();
5819   FirstSubmoduleID = NUM_PREDEF_SUBMODULE_IDS + Chain->getTotalNumSubmodules();
5820   FirstSelectorID = NUM_PREDEF_SELECTOR_IDS + Chain->getTotalNumSelectors();
5821   NextDeclID = FirstDeclID;
5822   NextTypeID = FirstTypeID;
5823   NextIdentID = FirstIdentID;
5824   NextMacroID = FirstMacroID;
5825   NextSelectorID = FirstSelectorID;
5826   NextSubmoduleID = FirstSubmoduleID;
5827 }
5828 
5829 void ASTWriter::IdentifierRead(IdentID ID, IdentifierInfo *II) {
5830   // Always keep the highest ID. See \p TypeRead() for more information.
5831   IdentID &StoredID = IdentifierIDs[II];
5832   if (ID > StoredID)
5833     StoredID = ID;
5834 }
5835 
5836 void ASTWriter::MacroRead(serialization::MacroID ID, MacroInfo *MI) {
5837   // Always keep the highest ID. See \p TypeRead() for more information.
5838   MacroID &StoredID = MacroIDs[MI];
5839   if (ID > StoredID)
5840     StoredID = ID;
5841 }
5842 
5843 void ASTWriter::TypeRead(TypeIdx Idx, QualType T) {
5844   // Always take the highest-numbered type index. This copes with an interesting
5845   // case for chained AST writing where we schedule writing the type and then,
5846   // later, deserialize the type from another AST. In this case, we want to
5847   // keep the higher-numbered entry so that we can properly write it out to
5848   // the AST file.
5849   TypeIdx &StoredIdx = TypeIdxs[T];
5850   if (Idx.getIndex() >= StoredIdx.getIndex())
5851     StoredIdx = Idx;
5852 }
5853 
5854 void ASTWriter::SelectorRead(SelectorID ID, Selector S) {
5855   // Always keep the highest ID. See \p TypeRead() for more information.
5856   SelectorID &StoredID = SelectorIDs[S];
5857   if (ID > StoredID)
5858     StoredID = ID;
5859 }
5860 
5861 void ASTWriter::MacroDefinitionRead(serialization::PreprocessedEntityID ID,
5862                                     MacroDefinitionRecord *MD) {
5863   assert(MacroDefinitions.find(MD) == MacroDefinitions.end());
5864   MacroDefinitions[MD] = ID;
5865 }
5866 
5867 void ASTWriter::ModuleRead(serialization::SubmoduleID ID, Module *Mod) {
5868   assert(SubmoduleIDs.find(Mod) == SubmoduleIDs.end());
5869   SubmoduleIDs[Mod] = ID;
5870 }
5871 
5872 void ASTWriter::CompletedTagDefinition(const TagDecl *D) {
5873   if (Chain && Chain->isProcessingUpdateRecords()) return;
5874   assert(D->isCompleteDefinition());
5875   assert(!WritingAST && "Already writing the AST!");
5876   if (auto *RD = dyn_cast<CXXRecordDecl>(D)) {
5877     // We are interested when a PCH decl is modified.
5878     if (RD->isFromASTFile()) {
5879       // A forward reference was mutated into a definition. Rewrite it.
5880       // FIXME: This happens during template instantiation, should we
5881       // have created a new definition decl instead ?
5882       assert(isTemplateInstantiation(RD->getTemplateSpecializationKind()) &&
5883              "completed a tag from another module but not by instantiation?");
5884       DeclUpdates[RD].push_back(
5885           DeclUpdate(UPD_CXX_INSTANTIATED_CLASS_DEFINITION));
5886     }
5887   }
5888 }
5889 
5890 static bool isImportedDeclContext(ASTReader *Chain, const Decl *D) {
5891   if (D->isFromASTFile())
5892     return true;
5893 
5894   // The predefined __va_list_tag struct is imported if we imported any decls.
5895   // FIXME: This is a gross hack.
5896   return D == D->getASTContext().getVaListTagDecl();
5897 }
5898 
5899 void ASTWriter::AddedVisibleDecl(const DeclContext *DC, const Decl *D) {
5900   if (Chain && Chain->isProcessingUpdateRecords()) return;
5901   assert(DC->isLookupContext() &&
5902           "Should not add lookup results to non-lookup contexts!");
5903 
5904   // TU is handled elsewhere.
5905   if (isa<TranslationUnitDecl>(DC))
5906     return;
5907 
5908   // Namespaces are handled elsewhere, except for template instantiations of
5909   // FunctionTemplateDecls in namespaces. We are interested in cases where the
5910   // local instantiations are added to an imported context. Only happens when
5911   // adding ADL lookup candidates, for example templated friends.
5912   if (isa<NamespaceDecl>(DC) && D->getFriendObjectKind() == Decl::FOK_None &&
5913       !isa<FunctionTemplateDecl>(D))
5914     return;
5915 
5916   // We're only interested in cases where a local declaration is added to an
5917   // imported context.
5918   if (D->isFromASTFile() || !isImportedDeclContext(Chain, cast<Decl>(DC)))
5919     return;
5920 
5921   assert(DC == DC->getPrimaryContext() && "added to non-primary context");
5922   assert(!getDefinitiveDeclContext(DC) && "DeclContext not definitive!");
5923   assert(!WritingAST && "Already writing the AST!");
5924   if (UpdatedDeclContexts.insert(DC) && !cast<Decl>(DC)->isFromASTFile()) {
5925     // We're adding a visible declaration to a predefined decl context. Ensure
5926     // that we write out all of its lookup results so we don't get a nasty
5927     // surprise when we try to emit its lookup table.
5928     llvm::append_range(DeclsToEmitEvenIfUnreferenced, DC->decls());
5929   }
5930   DeclsToEmitEvenIfUnreferenced.push_back(D);
5931 }
5932 
5933 void ASTWriter::AddedCXXImplicitMember(const CXXRecordDecl *RD, const Decl *D) {
5934   if (Chain && Chain->isProcessingUpdateRecords()) return;
5935   assert(D->isImplicit());
5936 
5937   // We're only interested in cases where a local declaration is added to an
5938   // imported context.
5939   if (D->isFromASTFile() || !isImportedDeclContext(Chain, RD))
5940     return;
5941 
5942   if (!isa<CXXMethodDecl>(D))
5943     return;
5944 
5945   // A decl coming from PCH was modified.
5946   assert(RD->isCompleteDefinition());
5947   assert(!WritingAST && "Already writing the AST!");
5948   DeclUpdates[RD].push_back(DeclUpdate(UPD_CXX_ADDED_IMPLICIT_MEMBER, D));
5949 }
5950 
5951 void ASTWriter::ResolvedExceptionSpec(const FunctionDecl *FD) {
5952   if (Chain && Chain->isProcessingUpdateRecords()) return;
5953   assert(!DoneWritingDeclsAndTypes && "Already done writing updates!");
5954   if (!Chain) return;
5955   Chain->forEachImportedKeyDecl(FD, [&](const Decl *D) {
5956     // If we don't already know the exception specification for this redecl
5957     // chain, add an update record for it.
5958     if (isUnresolvedExceptionSpec(cast<FunctionDecl>(D)
5959                                       ->getType()
5960                                       ->castAs<FunctionProtoType>()
5961                                       ->getExceptionSpecType()))
5962       DeclUpdates[D].push_back(UPD_CXX_RESOLVED_EXCEPTION_SPEC);
5963   });
5964 }
5965 
5966 void ASTWriter::DeducedReturnType(const FunctionDecl *FD, QualType ReturnType) {
5967   if (Chain && Chain->isProcessingUpdateRecords()) return;
5968   assert(!WritingAST && "Already writing the AST!");
5969   if (!Chain) return;
5970   Chain->forEachImportedKeyDecl(FD, [&](const Decl *D) {
5971     DeclUpdates[D].push_back(
5972         DeclUpdate(UPD_CXX_DEDUCED_RETURN_TYPE, ReturnType));
5973   });
5974 }
5975 
5976 void ASTWriter::ResolvedOperatorDelete(const CXXDestructorDecl *DD,
5977                                        const FunctionDecl *Delete,
5978                                        Expr *ThisArg) {
5979   if (Chain && Chain->isProcessingUpdateRecords()) return;
5980   assert(!WritingAST && "Already writing the AST!");
5981   assert(Delete && "Not given an operator delete");
5982   if (!Chain) return;
5983   Chain->forEachImportedKeyDecl(DD, [&](const Decl *D) {
5984     DeclUpdates[D].push_back(DeclUpdate(UPD_CXX_RESOLVED_DTOR_DELETE, Delete));
5985   });
5986 }
5987 
5988 void ASTWriter::CompletedImplicitDefinition(const FunctionDecl *D) {
5989   if (Chain && Chain->isProcessingUpdateRecords()) return;
5990   assert(!WritingAST && "Already writing the AST!");
5991   if (!D->isFromASTFile())
5992     return; // Declaration not imported from PCH.
5993 
5994   // Implicit function decl from a PCH was defined.
5995   DeclUpdates[D].push_back(DeclUpdate(UPD_CXX_ADDED_FUNCTION_DEFINITION));
5996 }
5997 
5998 void ASTWriter::VariableDefinitionInstantiated(const VarDecl *D) {
5999   if (Chain && Chain->isProcessingUpdateRecords()) return;
6000   assert(!WritingAST && "Already writing the AST!");
6001   if (!D->isFromASTFile())
6002     return;
6003 
6004   DeclUpdates[D].push_back(DeclUpdate(UPD_CXX_ADDED_VAR_DEFINITION));
6005 }
6006 
6007 void ASTWriter::FunctionDefinitionInstantiated(const FunctionDecl *D) {
6008   if (Chain && Chain->isProcessingUpdateRecords()) return;
6009   assert(!WritingAST && "Already writing the AST!");
6010   if (!D->isFromASTFile())
6011     return;
6012 
6013   DeclUpdates[D].push_back(DeclUpdate(UPD_CXX_ADDED_FUNCTION_DEFINITION));
6014 }
6015 
6016 void ASTWriter::InstantiationRequested(const ValueDecl *D) {
6017   if (Chain && Chain->isProcessingUpdateRecords()) return;
6018   assert(!WritingAST && "Already writing the AST!");
6019   if (!D->isFromASTFile())
6020     return;
6021 
6022   // Since the actual instantiation is delayed, this really means that we need
6023   // to update the instantiation location.
6024   SourceLocation POI;
6025   if (auto *VD = dyn_cast<VarDecl>(D))
6026     POI = VD->getPointOfInstantiation();
6027   else
6028     POI = cast<FunctionDecl>(D)->getPointOfInstantiation();
6029   DeclUpdates[D].push_back(DeclUpdate(UPD_CXX_POINT_OF_INSTANTIATION, POI));
6030 }
6031 
6032 void ASTWriter::DefaultArgumentInstantiated(const ParmVarDecl *D) {
6033   if (Chain && Chain->isProcessingUpdateRecords()) return;
6034   assert(!WritingAST && "Already writing the AST!");
6035   if (!D->isFromASTFile())
6036     return;
6037 
6038   DeclUpdates[D].push_back(
6039       DeclUpdate(UPD_CXX_INSTANTIATED_DEFAULT_ARGUMENT, D));
6040 }
6041 
6042 void ASTWriter::DefaultMemberInitializerInstantiated(const FieldDecl *D) {
6043   assert(!WritingAST && "Already writing the AST!");
6044   if (!D->isFromASTFile())
6045     return;
6046 
6047   DeclUpdates[D].push_back(
6048       DeclUpdate(UPD_CXX_INSTANTIATED_DEFAULT_MEMBER_INITIALIZER, D));
6049 }
6050 
6051 void ASTWriter::AddedObjCCategoryToInterface(const ObjCCategoryDecl *CatD,
6052                                              const ObjCInterfaceDecl *IFD) {
6053   if (Chain && Chain->isProcessingUpdateRecords()) return;
6054   assert(!WritingAST && "Already writing the AST!");
6055   if (!IFD->isFromASTFile())
6056     return; // Declaration not imported from PCH.
6057 
6058   assert(IFD->getDefinition() && "Category on a class without a definition?");
6059   ObjCClassesWithCategories.insert(
6060     const_cast<ObjCInterfaceDecl *>(IFD->getDefinition()));
6061 }
6062 
6063 void ASTWriter::DeclarationMarkedUsed(const Decl *D) {
6064   if (Chain && Chain->isProcessingUpdateRecords()) return;
6065   assert(!WritingAST && "Already writing the AST!");
6066 
6067   // If there is *any* declaration of the entity that's not from an AST file,
6068   // we can skip writing the update record. We make sure that isUsed() triggers
6069   // completion of the redeclaration chain of the entity.
6070   for (auto Prev = D->getMostRecentDecl(); Prev; Prev = Prev->getPreviousDecl())
6071     if (IsLocalDecl(Prev))
6072       return;
6073 
6074   DeclUpdates[D].push_back(DeclUpdate(UPD_DECL_MARKED_USED));
6075 }
6076 
6077 void ASTWriter::DeclarationMarkedOpenMPThreadPrivate(const Decl *D) {
6078   if (Chain && Chain->isProcessingUpdateRecords()) return;
6079   assert(!WritingAST && "Already writing the AST!");
6080   if (!D->isFromASTFile())
6081     return;
6082 
6083   DeclUpdates[D].push_back(DeclUpdate(UPD_DECL_MARKED_OPENMP_THREADPRIVATE));
6084 }
6085 
6086 void ASTWriter::DeclarationMarkedOpenMPAllocate(const Decl *D, const Attr *A) {
6087   if (Chain && Chain->isProcessingUpdateRecords()) return;
6088   assert(!WritingAST && "Already writing the AST!");
6089   if (!D->isFromASTFile())
6090     return;
6091 
6092   DeclUpdates[D].push_back(DeclUpdate(UPD_DECL_MARKED_OPENMP_ALLOCATE, A));
6093 }
6094 
6095 void ASTWriter::DeclarationMarkedOpenMPDeclareTarget(const Decl *D,
6096                                                      const Attr *Attr) {
6097   if (Chain && Chain->isProcessingUpdateRecords()) return;
6098   assert(!WritingAST && "Already writing the AST!");
6099   if (!D->isFromASTFile())
6100     return;
6101 
6102   DeclUpdates[D].push_back(
6103       DeclUpdate(UPD_DECL_MARKED_OPENMP_DECLARETARGET, Attr));
6104 }
6105 
6106 void ASTWriter::RedefinedHiddenDefinition(const NamedDecl *D, Module *M) {
6107   if (Chain && Chain->isProcessingUpdateRecords()) return;
6108   assert(!WritingAST && "Already writing the AST!");
6109   assert(!D->isUnconditionallyVisible() && "expected a hidden declaration");
6110   DeclUpdates[D].push_back(DeclUpdate(UPD_DECL_EXPORTED, M));
6111 }
6112 
6113 void ASTWriter::AddedAttributeToRecord(const Attr *Attr,
6114                                        const RecordDecl *Record) {
6115   if (Chain && Chain->isProcessingUpdateRecords()) return;
6116   assert(!WritingAST && "Already writing the AST!");
6117   if (!Record->isFromASTFile())
6118     return;
6119   DeclUpdates[Record].push_back(DeclUpdate(UPD_ADDED_ATTR_TO_RECORD, Attr));
6120 }
6121 
6122 void ASTWriter::AddedCXXTemplateSpecialization(
6123     const ClassTemplateDecl *TD, const ClassTemplateSpecializationDecl *D) {
6124   assert(!WritingAST && "Already writing the AST!");
6125 
6126   if (!TD->getFirstDecl()->isFromASTFile())
6127     return;
6128   if (Chain && Chain->isProcessingUpdateRecords())
6129     return;
6130 
6131   DeclsToEmitEvenIfUnreferenced.push_back(D);
6132 }
6133 
6134 void ASTWriter::AddedCXXTemplateSpecialization(
6135     const VarTemplateDecl *TD, const VarTemplateSpecializationDecl *D) {
6136   assert(!WritingAST && "Already writing the AST!");
6137 
6138   if (!TD->getFirstDecl()->isFromASTFile())
6139     return;
6140   if (Chain && Chain->isProcessingUpdateRecords())
6141     return;
6142 
6143   DeclsToEmitEvenIfUnreferenced.push_back(D);
6144 }
6145 
6146 void ASTWriter::AddedCXXTemplateSpecialization(const FunctionTemplateDecl *TD,
6147                                                const FunctionDecl *D) {
6148   assert(!WritingAST && "Already writing the AST!");
6149 
6150   if (!TD->getFirstDecl()->isFromASTFile())
6151     return;
6152   if (Chain && Chain->isProcessingUpdateRecords())
6153     return;
6154 
6155   DeclsToEmitEvenIfUnreferenced.push_back(D);
6156 }
6157 
6158 //===----------------------------------------------------------------------===//
6159 //// OMPClause Serialization
6160 ////===----------------------------------------------------------------------===//
6161 
6162 namespace {
6163 
6164 class OMPClauseWriter : public OMPClauseVisitor<OMPClauseWriter> {
6165   ASTRecordWriter &Record;
6166 
6167 public:
6168   OMPClauseWriter(ASTRecordWriter &Record) : Record(Record) {}
6169 #define GEN_CLANG_CLAUSE_CLASS
6170 #define CLAUSE_CLASS(Enum, Str, Class) void Visit##Class(Class *S);
6171 #include "llvm/Frontend/OpenMP/OMP.inc"
6172   void writeClause(OMPClause *C);
6173   void VisitOMPClauseWithPreInit(OMPClauseWithPreInit *C);
6174   void VisitOMPClauseWithPostUpdate(OMPClauseWithPostUpdate *C);
6175 };
6176 
6177 }
6178 
6179 void ASTRecordWriter::writeOMPClause(OMPClause *C) {
6180   OMPClauseWriter(*this).writeClause(C);
6181 }
6182 
6183 void OMPClauseWriter::writeClause(OMPClause *C) {
6184   Record.push_back(unsigned(C->getClauseKind()));
6185   Visit(C);
6186   Record.AddSourceLocation(C->getBeginLoc());
6187   Record.AddSourceLocation(C->getEndLoc());
6188 }
6189 
6190 void OMPClauseWriter::VisitOMPClauseWithPreInit(OMPClauseWithPreInit *C) {
6191   Record.push_back(uint64_t(C->getCaptureRegion()));
6192   Record.AddStmt(C->getPreInitStmt());
6193 }
6194 
6195 void OMPClauseWriter::VisitOMPClauseWithPostUpdate(OMPClauseWithPostUpdate *C) {
6196   VisitOMPClauseWithPreInit(C);
6197   Record.AddStmt(C->getPostUpdateExpr());
6198 }
6199 
6200 void OMPClauseWriter::VisitOMPIfClause(OMPIfClause *C) {
6201   VisitOMPClauseWithPreInit(C);
6202   Record.push_back(uint64_t(C->getNameModifier()));
6203   Record.AddSourceLocation(C->getNameModifierLoc());
6204   Record.AddSourceLocation(C->getColonLoc());
6205   Record.AddStmt(C->getCondition());
6206   Record.AddSourceLocation(C->getLParenLoc());
6207 }
6208 
6209 void OMPClauseWriter::VisitOMPFinalClause(OMPFinalClause *C) {
6210   VisitOMPClauseWithPreInit(C);
6211   Record.AddStmt(C->getCondition());
6212   Record.AddSourceLocation(C->getLParenLoc());
6213 }
6214 
6215 void OMPClauseWriter::VisitOMPNumThreadsClause(OMPNumThreadsClause *C) {
6216   VisitOMPClauseWithPreInit(C);
6217   Record.AddStmt(C->getNumThreads());
6218   Record.AddSourceLocation(C->getLParenLoc());
6219 }
6220 
6221 void OMPClauseWriter::VisitOMPSafelenClause(OMPSafelenClause *C) {
6222   Record.AddStmt(C->getSafelen());
6223   Record.AddSourceLocation(C->getLParenLoc());
6224 }
6225 
6226 void OMPClauseWriter::VisitOMPSimdlenClause(OMPSimdlenClause *C) {
6227   Record.AddStmt(C->getSimdlen());
6228   Record.AddSourceLocation(C->getLParenLoc());
6229 }
6230 
6231 void OMPClauseWriter::VisitOMPSizesClause(OMPSizesClause *C) {
6232   Record.push_back(C->getNumSizes());
6233   for (Expr *Size : C->getSizesRefs())
6234     Record.AddStmt(Size);
6235   Record.AddSourceLocation(C->getLParenLoc());
6236 }
6237 
6238 void OMPClauseWriter::VisitOMPFullClause(OMPFullClause *C) {}
6239 
6240 void OMPClauseWriter::VisitOMPPartialClause(OMPPartialClause *C) {
6241   Record.AddStmt(C->getFactor());
6242   Record.AddSourceLocation(C->getLParenLoc());
6243 }
6244 
6245 void OMPClauseWriter::VisitOMPAllocatorClause(OMPAllocatorClause *C) {
6246   Record.AddStmt(C->getAllocator());
6247   Record.AddSourceLocation(C->getLParenLoc());
6248 }
6249 
6250 void OMPClauseWriter::VisitOMPCollapseClause(OMPCollapseClause *C) {
6251   Record.AddStmt(C->getNumForLoops());
6252   Record.AddSourceLocation(C->getLParenLoc());
6253 }
6254 
6255 void OMPClauseWriter::VisitOMPDetachClause(OMPDetachClause *C) {
6256   Record.AddStmt(C->getEventHandler());
6257   Record.AddSourceLocation(C->getLParenLoc());
6258 }
6259 
6260 void OMPClauseWriter::VisitOMPDefaultClause(OMPDefaultClause *C) {
6261   Record.push_back(unsigned(C->getDefaultKind()));
6262   Record.AddSourceLocation(C->getLParenLoc());
6263   Record.AddSourceLocation(C->getDefaultKindKwLoc());
6264 }
6265 
6266 void OMPClauseWriter::VisitOMPProcBindClause(OMPProcBindClause *C) {
6267   Record.push_back(unsigned(C->getProcBindKind()));
6268   Record.AddSourceLocation(C->getLParenLoc());
6269   Record.AddSourceLocation(C->getProcBindKindKwLoc());
6270 }
6271 
6272 void OMPClauseWriter::VisitOMPScheduleClause(OMPScheduleClause *C) {
6273   VisitOMPClauseWithPreInit(C);
6274   Record.push_back(C->getScheduleKind());
6275   Record.push_back(C->getFirstScheduleModifier());
6276   Record.push_back(C->getSecondScheduleModifier());
6277   Record.AddStmt(C->getChunkSize());
6278   Record.AddSourceLocation(C->getLParenLoc());
6279   Record.AddSourceLocation(C->getFirstScheduleModifierLoc());
6280   Record.AddSourceLocation(C->getSecondScheduleModifierLoc());
6281   Record.AddSourceLocation(C->getScheduleKindLoc());
6282   Record.AddSourceLocation(C->getCommaLoc());
6283 }
6284 
6285 void OMPClauseWriter::VisitOMPOrderedClause(OMPOrderedClause *C) {
6286   Record.push_back(C->getLoopNumIterations().size());
6287   Record.AddStmt(C->getNumForLoops());
6288   for (Expr *NumIter : C->getLoopNumIterations())
6289     Record.AddStmt(NumIter);
6290   for (unsigned I = 0, E = C->getLoopNumIterations().size(); I <E; ++I)
6291     Record.AddStmt(C->getLoopCounter(I));
6292   Record.AddSourceLocation(C->getLParenLoc());
6293 }
6294 
6295 void OMPClauseWriter::VisitOMPNowaitClause(OMPNowaitClause *) {}
6296 
6297 void OMPClauseWriter::VisitOMPUntiedClause(OMPUntiedClause *) {}
6298 
6299 void OMPClauseWriter::VisitOMPMergeableClause(OMPMergeableClause *) {}
6300 
6301 void OMPClauseWriter::VisitOMPReadClause(OMPReadClause *) {}
6302 
6303 void OMPClauseWriter::VisitOMPWriteClause(OMPWriteClause *) {}
6304 
6305 void OMPClauseWriter::VisitOMPUpdateClause(OMPUpdateClause *C) {
6306   Record.push_back(C->isExtended() ? 1 : 0);
6307   if (C->isExtended()) {
6308     Record.AddSourceLocation(C->getLParenLoc());
6309     Record.AddSourceLocation(C->getArgumentLoc());
6310     Record.writeEnum(C->getDependencyKind());
6311   }
6312 }
6313 
6314 void OMPClauseWriter::VisitOMPCaptureClause(OMPCaptureClause *) {}
6315 
6316 void OMPClauseWriter::VisitOMPCompareClause(OMPCompareClause *) {}
6317 
6318 void OMPClauseWriter::VisitOMPSeqCstClause(OMPSeqCstClause *) {}
6319 
6320 void OMPClauseWriter::VisitOMPAcqRelClause(OMPAcqRelClause *) {}
6321 
6322 void OMPClauseWriter::VisitOMPAcquireClause(OMPAcquireClause *) {}
6323 
6324 void OMPClauseWriter::VisitOMPReleaseClause(OMPReleaseClause *) {}
6325 
6326 void OMPClauseWriter::VisitOMPRelaxedClause(OMPRelaxedClause *) {}
6327 
6328 void OMPClauseWriter::VisitOMPThreadsClause(OMPThreadsClause *) {}
6329 
6330 void OMPClauseWriter::VisitOMPSIMDClause(OMPSIMDClause *) {}
6331 
6332 void OMPClauseWriter::VisitOMPNogroupClause(OMPNogroupClause *) {}
6333 
6334 void OMPClauseWriter::VisitOMPInitClause(OMPInitClause *C) {
6335   Record.push_back(C->varlist_size());
6336   for (Expr *VE : C->varlists())
6337     Record.AddStmt(VE);
6338   Record.writeBool(C->getIsTarget());
6339   Record.writeBool(C->getIsTargetSync());
6340   Record.AddSourceLocation(C->getLParenLoc());
6341   Record.AddSourceLocation(C->getVarLoc());
6342 }
6343 
6344 void OMPClauseWriter::VisitOMPUseClause(OMPUseClause *C) {
6345   Record.AddStmt(C->getInteropVar());
6346   Record.AddSourceLocation(C->getLParenLoc());
6347   Record.AddSourceLocation(C->getVarLoc());
6348 }
6349 
6350 void OMPClauseWriter::VisitOMPDestroyClause(OMPDestroyClause *C) {
6351   Record.AddStmt(C->getInteropVar());
6352   Record.AddSourceLocation(C->getLParenLoc());
6353   Record.AddSourceLocation(C->getVarLoc());
6354 }
6355 
6356 void OMPClauseWriter::VisitOMPNovariantsClause(OMPNovariantsClause *C) {
6357   VisitOMPClauseWithPreInit(C);
6358   Record.AddStmt(C->getCondition());
6359   Record.AddSourceLocation(C->getLParenLoc());
6360 }
6361 
6362 void OMPClauseWriter::VisitOMPNocontextClause(OMPNocontextClause *C) {
6363   VisitOMPClauseWithPreInit(C);
6364   Record.AddStmt(C->getCondition());
6365   Record.AddSourceLocation(C->getLParenLoc());
6366 }
6367 
6368 void OMPClauseWriter::VisitOMPFilterClause(OMPFilterClause *C) {
6369   VisitOMPClauseWithPreInit(C);
6370   Record.AddStmt(C->getThreadID());
6371   Record.AddSourceLocation(C->getLParenLoc());
6372 }
6373 
6374 void OMPClauseWriter::VisitOMPAlignClause(OMPAlignClause *C) {
6375   Record.AddStmt(C->getAlignment());
6376   Record.AddSourceLocation(C->getLParenLoc());
6377 }
6378 
6379 void OMPClauseWriter::VisitOMPPrivateClause(OMPPrivateClause *C) {
6380   Record.push_back(C->varlist_size());
6381   Record.AddSourceLocation(C->getLParenLoc());
6382   for (auto *VE : C->varlists()) {
6383     Record.AddStmt(VE);
6384   }
6385   for (auto *VE : C->private_copies()) {
6386     Record.AddStmt(VE);
6387   }
6388 }
6389 
6390 void OMPClauseWriter::VisitOMPFirstprivateClause(OMPFirstprivateClause *C) {
6391   Record.push_back(C->varlist_size());
6392   VisitOMPClauseWithPreInit(C);
6393   Record.AddSourceLocation(C->getLParenLoc());
6394   for (auto *VE : C->varlists()) {
6395     Record.AddStmt(VE);
6396   }
6397   for (auto *VE : C->private_copies()) {
6398     Record.AddStmt(VE);
6399   }
6400   for (auto *VE : C->inits()) {
6401     Record.AddStmt(VE);
6402   }
6403 }
6404 
6405 void OMPClauseWriter::VisitOMPLastprivateClause(OMPLastprivateClause *C) {
6406   Record.push_back(C->varlist_size());
6407   VisitOMPClauseWithPostUpdate(C);
6408   Record.AddSourceLocation(C->getLParenLoc());
6409   Record.writeEnum(C->getKind());
6410   Record.AddSourceLocation(C->getKindLoc());
6411   Record.AddSourceLocation(C->getColonLoc());
6412   for (auto *VE : C->varlists())
6413     Record.AddStmt(VE);
6414   for (auto *E : C->private_copies())
6415     Record.AddStmt(E);
6416   for (auto *E : C->source_exprs())
6417     Record.AddStmt(E);
6418   for (auto *E : C->destination_exprs())
6419     Record.AddStmt(E);
6420   for (auto *E : C->assignment_ops())
6421     Record.AddStmt(E);
6422 }
6423 
6424 void OMPClauseWriter::VisitOMPSharedClause(OMPSharedClause *C) {
6425   Record.push_back(C->varlist_size());
6426   Record.AddSourceLocation(C->getLParenLoc());
6427   for (auto *VE : C->varlists())
6428     Record.AddStmt(VE);
6429 }
6430 
6431 void OMPClauseWriter::VisitOMPReductionClause(OMPReductionClause *C) {
6432   Record.push_back(C->varlist_size());
6433   Record.writeEnum(C->getModifier());
6434   VisitOMPClauseWithPostUpdate(C);
6435   Record.AddSourceLocation(C->getLParenLoc());
6436   Record.AddSourceLocation(C->getModifierLoc());
6437   Record.AddSourceLocation(C->getColonLoc());
6438   Record.AddNestedNameSpecifierLoc(C->getQualifierLoc());
6439   Record.AddDeclarationNameInfo(C->getNameInfo());
6440   for (auto *VE : C->varlists())
6441     Record.AddStmt(VE);
6442   for (auto *VE : C->privates())
6443     Record.AddStmt(VE);
6444   for (auto *E : C->lhs_exprs())
6445     Record.AddStmt(E);
6446   for (auto *E : C->rhs_exprs())
6447     Record.AddStmt(E);
6448   for (auto *E : C->reduction_ops())
6449     Record.AddStmt(E);
6450   if (C->getModifier() == clang::OMPC_REDUCTION_inscan) {
6451     for (auto *E : C->copy_ops())
6452       Record.AddStmt(E);
6453     for (auto *E : C->copy_array_temps())
6454       Record.AddStmt(E);
6455     for (auto *E : C->copy_array_elems())
6456       Record.AddStmt(E);
6457   }
6458 }
6459 
6460 void OMPClauseWriter::VisitOMPTaskReductionClause(OMPTaskReductionClause *C) {
6461   Record.push_back(C->varlist_size());
6462   VisitOMPClauseWithPostUpdate(C);
6463   Record.AddSourceLocation(C->getLParenLoc());
6464   Record.AddSourceLocation(C->getColonLoc());
6465   Record.AddNestedNameSpecifierLoc(C->getQualifierLoc());
6466   Record.AddDeclarationNameInfo(C->getNameInfo());
6467   for (auto *VE : C->varlists())
6468     Record.AddStmt(VE);
6469   for (auto *VE : C->privates())
6470     Record.AddStmt(VE);
6471   for (auto *E : C->lhs_exprs())
6472     Record.AddStmt(E);
6473   for (auto *E : C->rhs_exprs())
6474     Record.AddStmt(E);
6475   for (auto *E : C->reduction_ops())
6476     Record.AddStmt(E);
6477 }
6478 
6479 void OMPClauseWriter::VisitOMPInReductionClause(OMPInReductionClause *C) {
6480   Record.push_back(C->varlist_size());
6481   VisitOMPClauseWithPostUpdate(C);
6482   Record.AddSourceLocation(C->getLParenLoc());
6483   Record.AddSourceLocation(C->getColonLoc());
6484   Record.AddNestedNameSpecifierLoc(C->getQualifierLoc());
6485   Record.AddDeclarationNameInfo(C->getNameInfo());
6486   for (auto *VE : C->varlists())
6487     Record.AddStmt(VE);
6488   for (auto *VE : C->privates())
6489     Record.AddStmt(VE);
6490   for (auto *E : C->lhs_exprs())
6491     Record.AddStmt(E);
6492   for (auto *E : C->rhs_exprs())
6493     Record.AddStmt(E);
6494   for (auto *E : C->reduction_ops())
6495     Record.AddStmt(E);
6496   for (auto *E : C->taskgroup_descriptors())
6497     Record.AddStmt(E);
6498 }
6499 
6500 void OMPClauseWriter::VisitOMPLinearClause(OMPLinearClause *C) {
6501   Record.push_back(C->varlist_size());
6502   VisitOMPClauseWithPostUpdate(C);
6503   Record.AddSourceLocation(C->getLParenLoc());
6504   Record.AddSourceLocation(C->getColonLoc());
6505   Record.push_back(C->getModifier());
6506   Record.AddSourceLocation(C->getModifierLoc());
6507   for (auto *VE : C->varlists()) {
6508     Record.AddStmt(VE);
6509   }
6510   for (auto *VE : C->privates()) {
6511     Record.AddStmt(VE);
6512   }
6513   for (auto *VE : C->inits()) {
6514     Record.AddStmt(VE);
6515   }
6516   for (auto *VE : C->updates()) {
6517     Record.AddStmt(VE);
6518   }
6519   for (auto *VE : C->finals()) {
6520     Record.AddStmt(VE);
6521   }
6522   Record.AddStmt(C->getStep());
6523   Record.AddStmt(C->getCalcStep());
6524   for (auto *VE : C->used_expressions())
6525     Record.AddStmt(VE);
6526 }
6527 
6528 void OMPClauseWriter::VisitOMPAlignedClause(OMPAlignedClause *C) {
6529   Record.push_back(C->varlist_size());
6530   Record.AddSourceLocation(C->getLParenLoc());
6531   Record.AddSourceLocation(C->getColonLoc());
6532   for (auto *VE : C->varlists())
6533     Record.AddStmt(VE);
6534   Record.AddStmt(C->getAlignment());
6535 }
6536 
6537 void OMPClauseWriter::VisitOMPCopyinClause(OMPCopyinClause *C) {
6538   Record.push_back(C->varlist_size());
6539   Record.AddSourceLocation(C->getLParenLoc());
6540   for (auto *VE : C->varlists())
6541     Record.AddStmt(VE);
6542   for (auto *E : C->source_exprs())
6543     Record.AddStmt(E);
6544   for (auto *E : C->destination_exprs())
6545     Record.AddStmt(E);
6546   for (auto *E : C->assignment_ops())
6547     Record.AddStmt(E);
6548 }
6549 
6550 void OMPClauseWriter::VisitOMPCopyprivateClause(OMPCopyprivateClause *C) {
6551   Record.push_back(C->varlist_size());
6552   Record.AddSourceLocation(C->getLParenLoc());
6553   for (auto *VE : C->varlists())
6554     Record.AddStmt(VE);
6555   for (auto *E : C->source_exprs())
6556     Record.AddStmt(E);
6557   for (auto *E : C->destination_exprs())
6558     Record.AddStmt(E);
6559   for (auto *E : C->assignment_ops())
6560     Record.AddStmt(E);
6561 }
6562 
6563 void OMPClauseWriter::VisitOMPFlushClause(OMPFlushClause *C) {
6564   Record.push_back(C->varlist_size());
6565   Record.AddSourceLocation(C->getLParenLoc());
6566   for (auto *VE : C->varlists())
6567     Record.AddStmt(VE);
6568 }
6569 
6570 void OMPClauseWriter::VisitOMPDepobjClause(OMPDepobjClause *C) {
6571   Record.AddStmt(C->getDepobj());
6572   Record.AddSourceLocation(C->getLParenLoc());
6573 }
6574 
6575 void OMPClauseWriter::VisitOMPDependClause(OMPDependClause *C) {
6576   Record.push_back(C->varlist_size());
6577   Record.push_back(C->getNumLoops());
6578   Record.AddSourceLocation(C->getLParenLoc());
6579   Record.AddStmt(C->getModifier());
6580   Record.push_back(C->getDependencyKind());
6581   Record.AddSourceLocation(C->getDependencyLoc());
6582   Record.AddSourceLocation(C->getColonLoc());
6583   for (auto *VE : C->varlists())
6584     Record.AddStmt(VE);
6585   for (unsigned I = 0, E = C->getNumLoops(); I < E; ++I)
6586     Record.AddStmt(C->getLoopData(I));
6587 }
6588 
6589 void OMPClauseWriter::VisitOMPDeviceClause(OMPDeviceClause *C) {
6590   VisitOMPClauseWithPreInit(C);
6591   Record.writeEnum(C->getModifier());
6592   Record.AddStmt(C->getDevice());
6593   Record.AddSourceLocation(C->getModifierLoc());
6594   Record.AddSourceLocation(C->getLParenLoc());
6595 }
6596 
6597 void OMPClauseWriter::VisitOMPMapClause(OMPMapClause *C) {
6598   Record.push_back(C->varlist_size());
6599   Record.push_back(C->getUniqueDeclarationsNum());
6600   Record.push_back(C->getTotalComponentListNum());
6601   Record.push_back(C->getTotalComponentsNum());
6602   Record.AddSourceLocation(C->getLParenLoc());
6603   for (unsigned I = 0; I < NumberOfOMPMapClauseModifiers; ++I) {
6604     Record.push_back(C->getMapTypeModifier(I));
6605     Record.AddSourceLocation(C->getMapTypeModifierLoc(I));
6606   }
6607   Record.AddNestedNameSpecifierLoc(C->getMapperQualifierLoc());
6608   Record.AddDeclarationNameInfo(C->getMapperIdInfo());
6609   Record.push_back(C->getMapType());
6610   Record.AddSourceLocation(C->getMapLoc());
6611   Record.AddSourceLocation(C->getColonLoc());
6612   for (auto *E : C->varlists())
6613     Record.AddStmt(E);
6614   for (auto *E : C->mapperlists())
6615     Record.AddStmt(E);
6616   for (auto *D : C->all_decls())
6617     Record.AddDeclRef(D);
6618   for (auto N : C->all_num_lists())
6619     Record.push_back(N);
6620   for (auto N : C->all_lists_sizes())
6621     Record.push_back(N);
6622   for (auto &M : C->all_components()) {
6623     Record.AddStmt(M.getAssociatedExpression());
6624     Record.AddDeclRef(M.getAssociatedDeclaration());
6625   }
6626 }
6627 
6628 void OMPClauseWriter::VisitOMPAllocateClause(OMPAllocateClause *C) {
6629   Record.push_back(C->varlist_size());
6630   Record.AddSourceLocation(C->getLParenLoc());
6631   Record.AddSourceLocation(C->getColonLoc());
6632   Record.AddStmt(C->getAllocator());
6633   for (auto *VE : C->varlists())
6634     Record.AddStmt(VE);
6635 }
6636 
6637 void OMPClauseWriter::VisitOMPNumTeamsClause(OMPNumTeamsClause *C) {
6638   VisitOMPClauseWithPreInit(C);
6639   Record.AddStmt(C->getNumTeams());
6640   Record.AddSourceLocation(C->getLParenLoc());
6641 }
6642 
6643 void OMPClauseWriter::VisitOMPThreadLimitClause(OMPThreadLimitClause *C) {
6644   VisitOMPClauseWithPreInit(C);
6645   Record.AddStmt(C->getThreadLimit());
6646   Record.AddSourceLocation(C->getLParenLoc());
6647 }
6648 
6649 void OMPClauseWriter::VisitOMPPriorityClause(OMPPriorityClause *C) {
6650   VisitOMPClauseWithPreInit(C);
6651   Record.AddStmt(C->getPriority());
6652   Record.AddSourceLocation(C->getLParenLoc());
6653 }
6654 
6655 void OMPClauseWriter::VisitOMPGrainsizeClause(OMPGrainsizeClause *C) {
6656   VisitOMPClauseWithPreInit(C);
6657   Record.AddStmt(C->getGrainsize());
6658   Record.AddSourceLocation(C->getLParenLoc());
6659 }
6660 
6661 void OMPClauseWriter::VisitOMPNumTasksClause(OMPNumTasksClause *C) {
6662   VisitOMPClauseWithPreInit(C);
6663   Record.AddStmt(C->getNumTasks());
6664   Record.AddSourceLocation(C->getLParenLoc());
6665 }
6666 
6667 void OMPClauseWriter::VisitOMPHintClause(OMPHintClause *C) {
6668   Record.AddStmt(C->getHint());
6669   Record.AddSourceLocation(C->getLParenLoc());
6670 }
6671 
6672 void OMPClauseWriter::VisitOMPDistScheduleClause(OMPDistScheduleClause *C) {
6673   VisitOMPClauseWithPreInit(C);
6674   Record.push_back(C->getDistScheduleKind());
6675   Record.AddStmt(C->getChunkSize());
6676   Record.AddSourceLocation(C->getLParenLoc());
6677   Record.AddSourceLocation(C->getDistScheduleKindLoc());
6678   Record.AddSourceLocation(C->getCommaLoc());
6679 }
6680 
6681 void OMPClauseWriter::VisitOMPDefaultmapClause(OMPDefaultmapClause *C) {
6682   Record.push_back(C->getDefaultmapKind());
6683   Record.push_back(C->getDefaultmapModifier());
6684   Record.AddSourceLocation(C->getLParenLoc());
6685   Record.AddSourceLocation(C->getDefaultmapModifierLoc());
6686   Record.AddSourceLocation(C->getDefaultmapKindLoc());
6687 }
6688 
6689 void OMPClauseWriter::VisitOMPToClause(OMPToClause *C) {
6690   Record.push_back(C->varlist_size());
6691   Record.push_back(C->getUniqueDeclarationsNum());
6692   Record.push_back(C->getTotalComponentListNum());
6693   Record.push_back(C->getTotalComponentsNum());
6694   Record.AddSourceLocation(C->getLParenLoc());
6695   for (unsigned I = 0; I < NumberOfOMPMotionModifiers; ++I) {
6696     Record.push_back(C->getMotionModifier(I));
6697     Record.AddSourceLocation(C->getMotionModifierLoc(I));
6698   }
6699   Record.AddNestedNameSpecifierLoc(C->getMapperQualifierLoc());
6700   Record.AddDeclarationNameInfo(C->getMapperIdInfo());
6701   Record.AddSourceLocation(C->getColonLoc());
6702   for (auto *E : C->varlists())
6703     Record.AddStmt(E);
6704   for (auto *E : C->mapperlists())
6705     Record.AddStmt(E);
6706   for (auto *D : C->all_decls())
6707     Record.AddDeclRef(D);
6708   for (auto N : C->all_num_lists())
6709     Record.push_back(N);
6710   for (auto N : C->all_lists_sizes())
6711     Record.push_back(N);
6712   for (auto &M : C->all_components()) {
6713     Record.AddStmt(M.getAssociatedExpression());
6714     Record.writeBool(M.isNonContiguous());
6715     Record.AddDeclRef(M.getAssociatedDeclaration());
6716   }
6717 }
6718 
6719 void OMPClauseWriter::VisitOMPFromClause(OMPFromClause *C) {
6720   Record.push_back(C->varlist_size());
6721   Record.push_back(C->getUniqueDeclarationsNum());
6722   Record.push_back(C->getTotalComponentListNum());
6723   Record.push_back(C->getTotalComponentsNum());
6724   Record.AddSourceLocation(C->getLParenLoc());
6725   for (unsigned I = 0; I < NumberOfOMPMotionModifiers; ++I) {
6726     Record.push_back(C->getMotionModifier(I));
6727     Record.AddSourceLocation(C->getMotionModifierLoc(I));
6728   }
6729   Record.AddNestedNameSpecifierLoc(C->getMapperQualifierLoc());
6730   Record.AddDeclarationNameInfo(C->getMapperIdInfo());
6731   Record.AddSourceLocation(C->getColonLoc());
6732   for (auto *E : C->varlists())
6733     Record.AddStmt(E);
6734   for (auto *E : C->mapperlists())
6735     Record.AddStmt(E);
6736   for (auto *D : C->all_decls())
6737     Record.AddDeclRef(D);
6738   for (auto N : C->all_num_lists())
6739     Record.push_back(N);
6740   for (auto N : C->all_lists_sizes())
6741     Record.push_back(N);
6742   for (auto &M : C->all_components()) {
6743     Record.AddStmt(M.getAssociatedExpression());
6744     Record.writeBool(M.isNonContiguous());
6745     Record.AddDeclRef(M.getAssociatedDeclaration());
6746   }
6747 }
6748 
6749 void OMPClauseWriter::VisitOMPUseDevicePtrClause(OMPUseDevicePtrClause *C) {
6750   Record.push_back(C->varlist_size());
6751   Record.push_back(C->getUniqueDeclarationsNum());
6752   Record.push_back(C->getTotalComponentListNum());
6753   Record.push_back(C->getTotalComponentsNum());
6754   Record.AddSourceLocation(C->getLParenLoc());
6755   for (auto *E : C->varlists())
6756     Record.AddStmt(E);
6757   for (auto *VE : C->private_copies())
6758     Record.AddStmt(VE);
6759   for (auto *VE : C->inits())
6760     Record.AddStmt(VE);
6761   for (auto *D : C->all_decls())
6762     Record.AddDeclRef(D);
6763   for (auto N : C->all_num_lists())
6764     Record.push_back(N);
6765   for (auto N : C->all_lists_sizes())
6766     Record.push_back(N);
6767   for (auto &M : C->all_components()) {
6768     Record.AddStmt(M.getAssociatedExpression());
6769     Record.AddDeclRef(M.getAssociatedDeclaration());
6770   }
6771 }
6772 
6773 void OMPClauseWriter::VisitOMPUseDeviceAddrClause(OMPUseDeviceAddrClause *C) {
6774   Record.push_back(C->varlist_size());
6775   Record.push_back(C->getUniqueDeclarationsNum());
6776   Record.push_back(C->getTotalComponentListNum());
6777   Record.push_back(C->getTotalComponentsNum());
6778   Record.AddSourceLocation(C->getLParenLoc());
6779   for (auto *E : C->varlists())
6780     Record.AddStmt(E);
6781   for (auto *D : C->all_decls())
6782     Record.AddDeclRef(D);
6783   for (auto N : C->all_num_lists())
6784     Record.push_back(N);
6785   for (auto N : C->all_lists_sizes())
6786     Record.push_back(N);
6787   for (auto &M : C->all_components()) {
6788     Record.AddStmt(M.getAssociatedExpression());
6789     Record.AddDeclRef(M.getAssociatedDeclaration());
6790   }
6791 }
6792 
6793 void OMPClauseWriter::VisitOMPIsDevicePtrClause(OMPIsDevicePtrClause *C) {
6794   Record.push_back(C->varlist_size());
6795   Record.push_back(C->getUniqueDeclarationsNum());
6796   Record.push_back(C->getTotalComponentListNum());
6797   Record.push_back(C->getTotalComponentsNum());
6798   Record.AddSourceLocation(C->getLParenLoc());
6799   for (auto *E : C->varlists())
6800     Record.AddStmt(E);
6801   for (auto *D : C->all_decls())
6802     Record.AddDeclRef(D);
6803   for (auto N : C->all_num_lists())
6804     Record.push_back(N);
6805   for (auto N : C->all_lists_sizes())
6806     Record.push_back(N);
6807   for (auto &M : C->all_components()) {
6808     Record.AddStmt(M.getAssociatedExpression());
6809     Record.AddDeclRef(M.getAssociatedDeclaration());
6810   }
6811 }
6812 
6813 void OMPClauseWriter::VisitOMPHasDeviceAddrClause(OMPHasDeviceAddrClause *C) {
6814   Record.push_back(C->varlist_size());
6815   Record.push_back(C->getUniqueDeclarationsNum());
6816   Record.push_back(C->getTotalComponentListNum());
6817   Record.push_back(C->getTotalComponentsNum());
6818   Record.AddSourceLocation(C->getLParenLoc());
6819   for (auto *E : C->varlists())
6820     Record.AddStmt(E);
6821   for (auto *D : C->all_decls())
6822     Record.AddDeclRef(D);
6823   for (auto N : C->all_num_lists())
6824     Record.push_back(N);
6825   for (auto N : C->all_lists_sizes())
6826     Record.push_back(N);
6827   for (auto &M : C->all_components()) {
6828     Record.AddStmt(M.getAssociatedExpression());
6829     Record.AddDeclRef(M.getAssociatedDeclaration());
6830   }
6831 }
6832 
6833 void OMPClauseWriter::VisitOMPUnifiedAddressClause(OMPUnifiedAddressClause *) {}
6834 
6835 void OMPClauseWriter::VisitOMPUnifiedSharedMemoryClause(
6836     OMPUnifiedSharedMemoryClause *) {}
6837 
6838 void OMPClauseWriter::VisitOMPReverseOffloadClause(OMPReverseOffloadClause *) {}
6839 
6840 void
6841 OMPClauseWriter::VisitOMPDynamicAllocatorsClause(OMPDynamicAllocatorsClause *) {
6842 }
6843 
6844 void OMPClauseWriter::VisitOMPAtomicDefaultMemOrderClause(
6845     OMPAtomicDefaultMemOrderClause *C) {
6846   Record.push_back(C->getAtomicDefaultMemOrderKind());
6847   Record.AddSourceLocation(C->getLParenLoc());
6848   Record.AddSourceLocation(C->getAtomicDefaultMemOrderKindKwLoc());
6849 }
6850 
6851 void OMPClauseWriter::VisitOMPNontemporalClause(OMPNontemporalClause *C) {
6852   Record.push_back(C->varlist_size());
6853   Record.AddSourceLocation(C->getLParenLoc());
6854   for (auto *VE : C->varlists())
6855     Record.AddStmt(VE);
6856   for (auto *E : C->private_refs())
6857     Record.AddStmt(E);
6858 }
6859 
6860 void OMPClauseWriter::VisitOMPInclusiveClause(OMPInclusiveClause *C) {
6861   Record.push_back(C->varlist_size());
6862   Record.AddSourceLocation(C->getLParenLoc());
6863   for (auto *VE : C->varlists())
6864     Record.AddStmt(VE);
6865 }
6866 
6867 void OMPClauseWriter::VisitOMPExclusiveClause(OMPExclusiveClause *C) {
6868   Record.push_back(C->varlist_size());
6869   Record.AddSourceLocation(C->getLParenLoc());
6870   for (auto *VE : C->varlists())
6871     Record.AddStmt(VE);
6872 }
6873 
6874 void OMPClauseWriter::VisitOMPOrderClause(OMPOrderClause *C) {
6875   Record.writeEnum(C->getKind());
6876   Record.AddSourceLocation(C->getLParenLoc());
6877   Record.AddSourceLocation(C->getKindKwLoc());
6878 }
6879 
6880 void OMPClauseWriter::VisitOMPUsesAllocatorsClause(OMPUsesAllocatorsClause *C) {
6881   Record.push_back(C->getNumberOfAllocators());
6882   Record.AddSourceLocation(C->getLParenLoc());
6883   for (unsigned I = 0, E = C->getNumberOfAllocators(); I < E; ++I) {
6884     OMPUsesAllocatorsClause::Data Data = C->getAllocatorData(I);
6885     Record.AddStmt(Data.Allocator);
6886     Record.AddStmt(Data.AllocatorTraits);
6887     Record.AddSourceLocation(Data.LParenLoc);
6888     Record.AddSourceLocation(Data.RParenLoc);
6889   }
6890 }
6891 
6892 void OMPClauseWriter::VisitOMPAffinityClause(OMPAffinityClause *C) {
6893   Record.push_back(C->varlist_size());
6894   Record.AddSourceLocation(C->getLParenLoc());
6895   Record.AddStmt(C->getModifier());
6896   Record.AddSourceLocation(C->getColonLoc());
6897   for (Expr *E : C->varlists())
6898     Record.AddStmt(E);
6899 }
6900 
6901 void OMPClauseWriter::VisitOMPBindClause(OMPBindClause *C) {
6902   Record.writeEnum(C->getBindKind());
6903   Record.AddSourceLocation(C->getLParenLoc());
6904   Record.AddSourceLocation(C->getBindKindLoc());
6905 }
6906 
6907 void ASTRecordWriter::writeOMPTraitInfo(const OMPTraitInfo *TI) {
6908   writeUInt32(TI->Sets.size());
6909   for (const auto &Set : TI->Sets) {
6910     writeEnum(Set.Kind);
6911     writeUInt32(Set.Selectors.size());
6912     for (const auto &Selector : Set.Selectors) {
6913       writeEnum(Selector.Kind);
6914       writeBool(Selector.ScoreOrCondition);
6915       if (Selector.ScoreOrCondition)
6916         writeExprRef(Selector.ScoreOrCondition);
6917       writeUInt32(Selector.Properties.size());
6918       for (const auto &Property : Selector.Properties)
6919         writeEnum(Property.Kind);
6920     }
6921   }
6922 }
6923 
6924 void ASTRecordWriter::writeOMPChildren(OMPChildren *Data) {
6925   if (!Data)
6926     return;
6927   writeUInt32(Data->getNumClauses());
6928   writeUInt32(Data->getNumChildren());
6929   writeBool(Data->hasAssociatedStmt());
6930   for (unsigned I = 0, E = Data->getNumClauses(); I < E; ++I)
6931     writeOMPClause(Data->getClauses()[I]);
6932   if (Data->hasAssociatedStmt())
6933     AddStmt(Data->getAssociatedStmt());
6934   for (unsigned I = 0, E = Data->getNumChildren(); I < E; ++I)
6935     AddStmt(Data->getChildren()[I]);
6936 }
6937