xref: /freebsd/contrib/llvm-project/clang/lib/Serialization/ASTWriter.cpp (revision 924226fba12cc9a228c73b956e1b7fa24c60b055)
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<Module *> ProcessedModules;
168   SmallVector<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 
214   return ModuleMaps;
215 }
216 
217 class ASTTypeWriter {
218   ASTWriter &Writer;
219   ASTWriter::RecordData Record;
220   ASTRecordWriter BasicWriter;
221 
222 public:
223   ASTTypeWriter(ASTWriter &Writer)
224     : Writer(Writer), BasicWriter(Writer, Record) {}
225 
226   uint64_t write(QualType T) {
227     if (T.hasLocalNonFastQualifiers()) {
228       Qualifiers Qs = T.getLocalQualifiers();
229       BasicWriter.writeQualType(T.getLocalUnqualifiedType());
230       BasicWriter.writeQualifiers(Qs);
231       return BasicWriter.Emit(TYPE_EXT_QUAL, Writer.getTypeExtQualAbbrev());
232     }
233 
234     const Type *typePtr = T.getTypePtr();
235     serialization::AbstractTypeWriter<ASTRecordWriter> atw(BasicWriter);
236     atw.write(typePtr);
237     return BasicWriter.Emit(getTypeCodeForTypeClass(typePtr->getTypeClass()),
238                             /*abbrev*/ 0);
239   }
240 };
241 
242 class TypeLocWriter : public TypeLocVisitor<TypeLocWriter> {
243   ASTRecordWriter &Record;
244 
245 public:
246   TypeLocWriter(ASTRecordWriter &Record) : Record(Record) {}
247 
248 #define ABSTRACT_TYPELOC(CLASS, PARENT)
249 #define TYPELOC(CLASS, PARENT) \
250     void Visit##CLASS##TypeLoc(CLASS##TypeLoc TyLoc);
251 #include "clang/AST/TypeLocNodes.def"
252 
253   void VisitArrayTypeLoc(ArrayTypeLoc TyLoc);
254   void VisitFunctionTypeLoc(FunctionTypeLoc TyLoc);
255 };
256 
257 } // namespace
258 
259 void TypeLocWriter::VisitQualifiedTypeLoc(QualifiedTypeLoc TL) {
260   // nothing to do
261 }
262 
263 void TypeLocWriter::VisitBuiltinTypeLoc(BuiltinTypeLoc TL) {
264   Record.AddSourceLocation(TL.getBuiltinLoc());
265   if (TL.needsExtraLocalData()) {
266     Record.push_back(TL.getWrittenTypeSpec());
267     Record.push_back(static_cast<uint64_t>(TL.getWrittenSignSpec()));
268     Record.push_back(static_cast<uint64_t>(TL.getWrittenWidthSpec()));
269     Record.push_back(TL.hasModeAttr());
270   }
271 }
272 
273 void TypeLocWriter::VisitComplexTypeLoc(ComplexTypeLoc TL) {
274   Record.AddSourceLocation(TL.getNameLoc());
275 }
276 
277 void TypeLocWriter::VisitPointerTypeLoc(PointerTypeLoc TL) {
278   Record.AddSourceLocation(TL.getStarLoc());
279 }
280 
281 void TypeLocWriter::VisitDecayedTypeLoc(DecayedTypeLoc TL) {
282   // nothing to do
283 }
284 
285 void TypeLocWriter::VisitAdjustedTypeLoc(AdjustedTypeLoc TL) {
286   // nothing to do
287 }
288 
289 void TypeLocWriter::VisitBlockPointerTypeLoc(BlockPointerTypeLoc TL) {
290   Record.AddSourceLocation(TL.getCaretLoc());
291 }
292 
293 void TypeLocWriter::VisitLValueReferenceTypeLoc(LValueReferenceTypeLoc TL) {
294   Record.AddSourceLocation(TL.getAmpLoc());
295 }
296 
297 void TypeLocWriter::VisitRValueReferenceTypeLoc(RValueReferenceTypeLoc TL) {
298   Record.AddSourceLocation(TL.getAmpAmpLoc());
299 }
300 
301 void TypeLocWriter::VisitMemberPointerTypeLoc(MemberPointerTypeLoc TL) {
302   Record.AddSourceLocation(TL.getStarLoc());
303   Record.AddTypeSourceInfo(TL.getClassTInfo());
304 }
305 
306 void TypeLocWriter::VisitArrayTypeLoc(ArrayTypeLoc TL) {
307   Record.AddSourceLocation(TL.getLBracketLoc());
308   Record.AddSourceLocation(TL.getRBracketLoc());
309   Record.push_back(TL.getSizeExpr() ? 1 : 0);
310   if (TL.getSizeExpr())
311     Record.AddStmt(TL.getSizeExpr());
312 }
313 
314 void TypeLocWriter::VisitConstantArrayTypeLoc(ConstantArrayTypeLoc TL) {
315   VisitArrayTypeLoc(TL);
316 }
317 
318 void TypeLocWriter::VisitIncompleteArrayTypeLoc(IncompleteArrayTypeLoc TL) {
319   VisitArrayTypeLoc(TL);
320 }
321 
322 void TypeLocWriter::VisitVariableArrayTypeLoc(VariableArrayTypeLoc TL) {
323   VisitArrayTypeLoc(TL);
324 }
325 
326 void TypeLocWriter::VisitDependentSizedArrayTypeLoc(
327                                             DependentSizedArrayTypeLoc TL) {
328   VisitArrayTypeLoc(TL);
329 }
330 
331 void TypeLocWriter::VisitDependentAddressSpaceTypeLoc(
332     DependentAddressSpaceTypeLoc TL) {
333   Record.AddSourceLocation(TL.getAttrNameLoc());
334   SourceRange range = TL.getAttrOperandParensRange();
335   Record.AddSourceLocation(range.getBegin());
336   Record.AddSourceLocation(range.getEnd());
337   Record.AddStmt(TL.getAttrExprOperand());
338 }
339 
340 void TypeLocWriter::VisitDependentSizedExtVectorTypeLoc(
341                                         DependentSizedExtVectorTypeLoc TL) {
342   Record.AddSourceLocation(TL.getNameLoc());
343 }
344 
345 void TypeLocWriter::VisitVectorTypeLoc(VectorTypeLoc TL) {
346   Record.AddSourceLocation(TL.getNameLoc());
347 }
348 
349 void TypeLocWriter::VisitDependentVectorTypeLoc(
350     DependentVectorTypeLoc TL) {
351   Record.AddSourceLocation(TL.getNameLoc());
352 }
353 
354 void TypeLocWriter::VisitExtVectorTypeLoc(ExtVectorTypeLoc TL) {
355   Record.AddSourceLocation(TL.getNameLoc());
356 }
357 
358 void TypeLocWriter::VisitConstantMatrixTypeLoc(ConstantMatrixTypeLoc TL) {
359   Record.AddSourceLocation(TL.getAttrNameLoc());
360   SourceRange range = TL.getAttrOperandParensRange();
361   Record.AddSourceLocation(range.getBegin());
362   Record.AddSourceLocation(range.getEnd());
363   Record.AddStmt(TL.getAttrRowOperand());
364   Record.AddStmt(TL.getAttrColumnOperand());
365 }
366 
367 void TypeLocWriter::VisitDependentSizedMatrixTypeLoc(
368     DependentSizedMatrixTypeLoc TL) {
369   Record.AddSourceLocation(TL.getAttrNameLoc());
370   SourceRange range = TL.getAttrOperandParensRange();
371   Record.AddSourceLocation(range.getBegin());
372   Record.AddSourceLocation(range.getEnd());
373   Record.AddStmt(TL.getAttrRowOperand());
374   Record.AddStmt(TL.getAttrColumnOperand());
375 }
376 
377 void TypeLocWriter::VisitFunctionTypeLoc(FunctionTypeLoc TL) {
378   Record.AddSourceLocation(TL.getLocalRangeBegin());
379   Record.AddSourceLocation(TL.getLParenLoc());
380   Record.AddSourceLocation(TL.getRParenLoc());
381   Record.AddSourceRange(TL.getExceptionSpecRange());
382   Record.AddSourceLocation(TL.getLocalRangeEnd());
383   for (unsigned i = 0, e = TL.getNumParams(); i != e; ++i)
384     Record.AddDeclRef(TL.getParam(i));
385 }
386 
387 void TypeLocWriter::VisitFunctionProtoTypeLoc(FunctionProtoTypeLoc TL) {
388   VisitFunctionTypeLoc(TL);
389 }
390 
391 void TypeLocWriter::VisitFunctionNoProtoTypeLoc(FunctionNoProtoTypeLoc TL) {
392   VisitFunctionTypeLoc(TL);
393 }
394 
395 void TypeLocWriter::VisitUnresolvedUsingTypeLoc(UnresolvedUsingTypeLoc TL) {
396   Record.AddSourceLocation(TL.getNameLoc());
397 }
398 
399 void TypeLocWriter::VisitUsingTypeLoc(UsingTypeLoc TL) {
400   Record.AddSourceLocation(TL.getNameLoc());
401 }
402 
403 void TypeLocWriter::VisitTypedefTypeLoc(TypedefTypeLoc TL) {
404   Record.AddSourceLocation(TL.getNameLoc());
405 }
406 
407 void TypeLocWriter::VisitObjCTypeParamTypeLoc(ObjCTypeParamTypeLoc TL) {
408   if (TL.getNumProtocols()) {
409     Record.AddSourceLocation(TL.getProtocolLAngleLoc());
410     Record.AddSourceLocation(TL.getProtocolRAngleLoc());
411   }
412   for (unsigned i = 0, e = TL.getNumProtocols(); i != e; ++i)
413     Record.AddSourceLocation(TL.getProtocolLoc(i));
414 }
415 
416 void TypeLocWriter::VisitTypeOfExprTypeLoc(TypeOfExprTypeLoc TL) {
417   Record.AddSourceLocation(TL.getTypeofLoc());
418   Record.AddSourceLocation(TL.getLParenLoc());
419   Record.AddSourceLocation(TL.getRParenLoc());
420 }
421 
422 void TypeLocWriter::VisitTypeOfTypeLoc(TypeOfTypeLoc TL) {
423   Record.AddSourceLocation(TL.getTypeofLoc());
424   Record.AddSourceLocation(TL.getLParenLoc());
425   Record.AddSourceLocation(TL.getRParenLoc());
426   Record.AddTypeSourceInfo(TL.getUnderlyingTInfo());
427 }
428 
429 void TypeLocWriter::VisitDecltypeTypeLoc(DecltypeTypeLoc TL) {
430   Record.AddSourceLocation(TL.getDecltypeLoc());
431   Record.AddSourceLocation(TL.getRParenLoc());
432 }
433 
434 void TypeLocWriter::VisitUnaryTransformTypeLoc(UnaryTransformTypeLoc TL) {
435   Record.AddSourceLocation(TL.getKWLoc());
436   Record.AddSourceLocation(TL.getLParenLoc());
437   Record.AddSourceLocation(TL.getRParenLoc());
438   Record.AddTypeSourceInfo(TL.getUnderlyingTInfo());
439 }
440 
441 void TypeLocWriter::VisitAutoTypeLoc(AutoTypeLoc TL) {
442   Record.AddSourceLocation(TL.getNameLoc());
443   Record.push_back(TL.isConstrained());
444   if (TL.isConstrained()) {
445     Record.AddNestedNameSpecifierLoc(TL.getNestedNameSpecifierLoc());
446     Record.AddSourceLocation(TL.getTemplateKWLoc());
447     Record.AddSourceLocation(TL.getConceptNameLoc());
448     Record.AddDeclRef(TL.getFoundDecl());
449     Record.AddSourceLocation(TL.getLAngleLoc());
450     Record.AddSourceLocation(TL.getRAngleLoc());
451     for (unsigned I = 0; I < TL.getNumArgs(); ++I)
452       Record.AddTemplateArgumentLocInfo(TL.getTypePtr()->getArg(I).getKind(),
453                                         TL.getArgLocInfo(I));
454   }
455   Record.push_back(TL.isDecltypeAuto());
456   if (TL.isDecltypeAuto())
457     Record.AddSourceLocation(TL.getRParenLoc());
458 }
459 
460 void TypeLocWriter::VisitDeducedTemplateSpecializationTypeLoc(
461     DeducedTemplateSpecializationTypeLoc TL) {
462   Record.AddSourceLocation(TL.getTemplateNameLoc());
463 }
464 
465 void TypeLocWriter::VisitRecordTypeLoc(RecordTypeLoc TL) {
466   Record.AddSourceLocation(TL.getNameLoc());
467 }
468 
469 void TypeLocWriter::VisitEnumTypeLoc(EnumTypeLoc TL) {
470   Record.AddSourceLocation(TL.getNameLoc());
471 }
472 
473 void TypeLocWriter::VisitAttributedTypeLoc(AttributedTypeLoc TL) {
474   Record.AddAttr(TL.getAttr());
475 }
476 
477 void TypeLocWriter::VisitTemplateTypeParmTypeLoc(TemplateTypeParmTypeLoc TL) {
478   Record.AddSourceLocation(TL.getNameLoc());
479 }
480 
481 void TypeLocWriter::VisitSubstTemplateTypeParmTypeLoc(
482                                             SubstTemplateTypeParmTypeLoc TL) {
483   Record.AddSourceLocation(TL.getNameLoc());
484 }
485 
486 void TypeLocWriter::VisitSubstTemplateTypeParmPackTypeLoc(
487                                           SubstTemplateTypeParmPackTypeLoc TL) {
488   Record.AddSourceLocation(TL.getNameLoc());
489 }
490 
491 void TypeLocWriter::VisitTemplateSpecializationTypeLoc(
492                                            TemplateSpecializationTypeLoc TL) {
493   Record.AddSourceLocation(TL.getTemplateKeywordLoc());
494   Record.AddSourceLocation(TL.getTemplateNameLoc());
495   Record.AddSourceLocation(TL.getLAngleLoc());
496   Record.AddSourceLocation(TL.getRAngleLoc());
497   for (unsigned i = 0, e = TL.getNumArgs(); i != e; ++i)
498     Record.AddTemplateArgumentLocInfo(TL.getArgLoc(i).getArgument().getKind(),
499                                       TL.getArgLoc(i).getLocInfo());
500 }
501 
502 void TypeLocWriter::VisitParenTypeLoc(ParenTypeLoc TL) {
503   Record.AddSourceLocation(TL.getLParenLoc());
504   Record.AddSourceLocation(TL.getRParenLoc());
505 }
506 
507 void TypeLocWriter::VisitMacroQualifiedTypeLoc(MacroQualifiedTypeLoc TL) {
508   Record.AddSourceLocation(TL.getExpansionLoc());
509 }
510 
511 void TypeLocWriter::VisitElaboratedTypeLoc(ElaboratedTypeLoc TL) {
512   Record.AddSourceLocation(TL.getElaboratedKeywordLoc());
513   Record.AddNestedNameSpecifierLoc(TL.getQualifierLoc());
514 }
515 
516 void TypeLocWriter::VisitInjectedClassNameTypeLoc(InjectedClassNameTypeLoc TL) {
517   Record.AddSourceLocation(TL.getNameLoc());
518 }
519 
520 void TypeLocWriter::VisitDependentNameTypeLoc(DependentNameTypeLoc TL) {
521   Record.AddSourceLocation(TL.getElaboratedKeywordLoc());
522   Record.AddNestedNameSpecifierLoc(TL.getQualifierLoc());
523   Record.AddSourceLocation(TL.getNameLoc());
524 }
525 
526 void TypeLocWriter::VisitDependentTemplateSpecializationTypeLoc(
527        DependentTemplateSpecializationTypeLoc TL) {
528   Record.AddSourceLocation(TL.getElaboratedKeywordLoc());
529   Record.AddNestedNameSpecifierLoc(TL.getQualifierLoc());
530   Record.AddSourceLocation(TL.getTemplateKeywordLoc());
531   Record.AddSourceLocation(TL.getTemplateNameLoc());
532   Record.AddSourceLocation(TL.getLAngleLoc());
533   Record.AddSourceLocation(TL.getRAngleLoc());
534   for (unsigned I = 0, E = TL.getNumArgs(); I != E; ++I)
535     Record.AddTemplateArgumentLocInfo(TL.getArgLoc(I).getArgument().getKind(),
536                                       TL.getArgLoc(I).getLocInfo());
537 }
538 
539 void TypeLocWriter::VisitPackExpansionTypeLoc(PackExpansionTypeLoc TL) {
540   Record.AddSourceLocation(TL.getEllipsisLoc());
541 }
542 
543 void TypeLocWriter::VisitObjCInterfaceTypeLoc(ObjCInterfaceTypeLoc TL) {
544   Record.AddSourceLocation(TL.getNameLoc());
545 }
546 
547 void TypeLocWriter::VisitObjCObjectTypeLoc(ObjCObjectTypeLoc TL) {
548   Record.push_back(TL.hasBaseTypeAsWritten());
549   Record.AddSourceLocation(TL.getTypeArgsLAngleLoc());
550   Record.AddSourceLocation(TL.getTypeArgsRAngleLoc());
551   for (unsigned i = 0, e = TL.getNumTypeArgs(); i != e; ++i)
552     Record.AddTypeSourceInfo(TL.getTypeArgTInfo(i));
553   Record.AddSourceLocation(TL.getProtocolLAngleLoc());
554   Record.AddSourceLocation(TL.getProtocolRAngleLoc());
555   for (unsigned i = 0, e = TL.getNumProtocols(); i != e; ++i)
556     Record.AddSourceLocation(TL.getProtocolLoc(i));
557 }
558 
559 void TypeLocWriter::VisitObjCObjectPointerTypeLoc(ObjCObjectPointerTypeLoc TL) {
560   Record.AddSourceLocation(TL.getStarLoc());
561 }
562 
563 void TypeLocWriter::VisitAtomicTypeLoc(AtomicTypeLoc TL) {
564   Record.AddSourceLocation(TL.getKWLoc());
565   Record.AddSourceLocation(TL.getLParenLoc());
566   Record.AddSourceLocation(TL.getRParenLoc());
567 }
568 
569 void TypeLocWriter::VisitPipeTypeLoc(PipeTypeLoc TL) {
570   Record.AddSourceLocation(TL.getKWLoc());
571 }
572 
573 void TypeLocWriter::VisitBitIntTypeLoc(clang::BitIntTypeLoc TL) {
574   Record.AddSourceLocation(TL.getNameLoc());
575 }
576 void TypeLocWriter::VisitDependentBitIntTypeLoc(
577     clang::DependentBitIntTypeLoc TL) {
578   Record.AddSourceLocation(TL.getNameLoc());
579 }
580 
581 void ASTWriter::WriteTypeAbbrevs() {
582   using namespace llvm;
583 
584   std::shared_ptr<BitCodeAbbrev> Abv;
585 
586   // Abbreviation for TYPE_EXT_QUAL
587   Abv = std::make_shared<BitCodeAbbrev>();
588   Abv->Add(BitCodeAbbrevOp(serialization::TYPE_EXT_QUAL));
589   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // Type
590   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 3));   // Quals
591   TypeExtQualAbbrev = Stream.EmitAbbrev(std::move(Abv));
592 
593   // Abbreviation for TYPE_FUNCTION_PROTO
594   Abv = std::make_shared<BitCodeAbbrev>();
595   Abv->Add(BitCodeAbbrevOp(serialization::TYPE_FUNCTION_PROTO));
596   // FunctionType
597   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // ReturnType
598   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // NoReturn
599   Abv->Add(BitCodeAbbrevOp(0));                         // HasRegParm
600   Abv->Add(BitCodeAbbrevOp(0));                         // RegParm
601   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // CC
602   Abv->Add(BitCodeAbbrevOp(0));                         // ProducesResult
603   Abv->Add(BitCodeAbbrevOp(0));                         // NoCallerSavedRegs
604   Abv->Add(BitCodeAbbrevOp(0));                         // NoCfCheck
605   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // CmseNSCall
606   // FunctionProtoType
607   Abv->Add(BitCodeAbbrevOp(0));                         // IsVariadic
608   Abv->Add(BitCodeAbbrevOp(0));                         // HasTrailingReturn
609   Abv->Add(BitCodeAbbrevOp(0));                         // TypeQuals
610   Abv->Add(BitCodeAbbrevOp(0));                         // RefQualifier
611   Abv->Add(BitCodeAbbrevOp(EST_None));                  // ExceptionSpec
612   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // NumParams
613   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
614   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // Params
615   TypeFunctionProtoAbbrev = Stream.EmitAbbrev(std::move(Abv));
616 }
617 
618 //===----------------------------------------------------------------------===//
619 // ASTWriter Implementation
620 //===----------------------------------------------------------------------===//
621 
622 static void EmitBlockID(unsigned ID, const char *Name,
623                         llvm::BitstreamWriter &Stream,
624                         ASTWriter::RecordDataImpl &Record) {
625   Record.clear();
626   Record.push_back(ID);
627   Stream.EmitRecord(llvm::bitc::BLOCKINFO_CODE_SETBID, Record);
628 
629   // Emit the block name if present.
630   if (!Name || Name[0] == 0)
631     return;
632   Record.clear();
633   while (*Name)
634     Record.push_back(*Name++);
635   Stream.EmitRecord(llvm::bitc::BLOCKINFO_CODE_BLOCKNAME, Record);
636 }
637 
638 static void EmitRecordID(unsigned ID, const char *Name,
639                          llvm::BitstreamWriter &Stream,
640                          ASTWriter::RecordDataImpl &Record) {
641   Record.clear();
642   Record.push_back(ID);
643   while (*Name)
644     Record.push_back(*Name++);
645   Stream.EmitRecord(llvm::bitc::BLOCKINFO_CODE_SETRECORDNAME, Record);
646 }
647 
648 static void AddStmtsExprs(llvm::BitstreamWriter &Stream,
649                           ASTWriter::RecordDataImpl &Record) {
650 #define RECORD(X) EmitRecordID(X, #X, Stream, Record)
651   RECORD(STMT_STOP);
652   RECORD(STMT_NULL_PTR);
653   RECORD(STMT_REF_PTR);
654   RECORD(STMT_NULL);
655   RECORD(STMT_COMPOUND);
656   RECORD(STMT_CASE);
657   RECORD(STMT_DEFAULT);
658   RECORD(STMT_LABEL);
659   RECORD(STMT_ATTRIBUTED);
660   RECORD(STMT_IF);
661   RECORD(STMT_SWITCH);
662   RECORD(STMT_WHILE);
663   RECORD(STMT_DO);
664   RECORD(STMT_FOR);
665   RECORD(STMT_GOTO);
666   RECORD(STMT_INDIRECT_GOTO);
667   RECORD(STMT_CONTINUE);
668   RECORD(STMT_BREAK);
669   RECORD(STMT_RETURN);
670   RECORD(STMT_DECL);
671   RECORD(STMT_GCCASM);
672   RECORD(STMT_MSASM);
673   RECORD(EXPR_PREDEFINED);
674   RECORD(EXPR_DECL_REF);
675   RECORD(EXPR_INTEGER_LITERAL);
676   RECORD(EXPR_FIXEDPOINT_LITERAL);
677   RECORD(EXPR_FLOATING_LITERAL);
678   RECORD(EXPR_IMAGINARY_LITERAL);
679   RECORD(EXPR_STRING_LITERAL);
680   RECORD(EXPR_CHARACTER_LITERAL);
681   RECORD(EXPR_PAREN);
682   RECORD(EXPR_PAREN_LIST);
683   RECORD(EXPR_UNARY_OPERATOR);
684   RECORD(EXPR_SIZEOF_ALIGN_OF);
685   RECORD(EXPR_ARRAY_SUBSCRIPT);
686   RECORD(EXPR_CALL);
687   RECORD(EXPR_MEMBER);
688   RECORD(EXPR_BINARY_OPERATOR);
689   RECORD(EXPR_COMPOUND_ASSIGN_OPERATOR);
690   RECORD(EXPR_CONDITIONAL_OPERATOR);
691   RECORD(EXPR_IMPLICIT_CAST);
692   RECORD(EXPR_CSTYLE_CAST);
693   RECORD(EXPR_COMPOUND_LITERAL);
694   RECORD(EXPR_EXT_VECTOR_ELEMENT);
695   RECORD(EXPR_INIT_LIST);
696   RECORD(EXPR_DESIGNATED_INIT);
697   RECORD(EXPR_DESIGNATED_INIT_UPDATE);
698   RECORD(EXPR_IMPLICIT_VALUE_INIT);
699   RECORD(EXPR_NO_INIT);
700   RECORD(EXPR_VA_ARG);
701   RECORD(EXPR_ADDR_LABEL);
702   RECORD(EXPR_STMT);
703   RECORD(EXPR_CHOOSE);
704   RECORD(EXPR_GNU_NULL);
705   RECORD(EXPR_SHUFFLE_VECTOR);
706   RECORD(EXPR_BLOCK);
707   RECORD(EXPR_GENERIC_SELECTION);
708   RECORD(EXPR_OBJC_STRING_LITERAL);
709   RECORD(EXPR_OBJC_BOXED_EXPRESSION);
710   RECORD(EXPR_OBJC_ARRAY_LITERAL);
711   RECORD(EXPR_OBJC_DICTIONARY_LITERAL);
712   RECORD(EXPR_OBJC_ENCODE);
713   RECORD(EXPR_OBJC_SELECTOR_EXPR);
714   RECORD(EXPR_OBJC_PROTOCOL_EXPR);
715   RECORD(EXPR_OBJC_IVAR_REF_EXPR);
716   RECORD(EXPR_OBJC_PROPERTY_REF_EXPR);
717   RECORD(EXPR_OBJC_KVC_REF_EXPR);
718   RECORD(EXPR_OBJC_MESSAGE_EXPR);
719   RECORD(STMT_OBJC_FOR_COLLECTION);
720   RECORD(STMT_OBJC_CATCH);
721   RECORD(STMT_OBJC_FINALLY);
722   RECORD(STMT_OBJC_AT_TRY);
723   RECORD(STMT_OBJC_AT_SYNCHRONIZED);
724   RECORD(STMT_OBJC_AT_THROW);
725   RECORD(EXPR_OBJC_BOOL_LITERAL);
726   RECORD(STMT_CXX_CATCH);
727   RECORD(STMT_CXX_TRY);
728   RECORD(STMT_CXX_FOR_RANGE);
729   RECORD(EXPR_CXX_OPERATOR_CALL);
730   RECORD(EXPR_CXX_MEMBER_CALL);
731   RECORD(EXPR_CXX_REWRITTEN_BINARY_OPERATOR);
732   RECORD(EXPR_CXX_CONSTRUCT);
733   RECORD(EXPR_CXX_TEMPORARY_OBJECT);
734   RECORD(EXPR_CXX_STATIC_CAST);
735   RECORD(EXPR_CXX_DYNAMIC_CAST);
736   RECORD(EXPR_CXX_REINTERPRET_CAST);
737   RECORD(EXPR_CXX_CONST_CAST);
738   RECORD(EXPR_CXX_ADDRSPACE_CAST);
739   RECORD(EXPR_CXX_FUNCTIONAL_CAST);
740   RECORD(EXPR_USER_DEFINED_LITERAL);
741   RECORD(EXPR_CXX_STD_INITIALIZER_LIST);
742   RECORD(EXPR_CXX_BOOL_LITERAL);
743   RECORD(EXPR_CXX_NULL_PTR_LITERAL);
744   RECORD(EXPR_CXX_TYPEID_EXPR);
745   RECORD(EXPR_CXX_TYPEID_TYPE);
746   RECORD(EXPR_CXX_THIS);
747   RECORD(EXPR_CXX_THROW);
748   RECORD(EXPR_CXX_DEFAULT_ARG);
749   RECORD(EXPR_CXX_DEFAULT_INIT);
750   RECORD(EXPR_CXX_BIND_TEMPORARY);
751   RECORD(EXPR_CXX_SCALAR_VALUE_INIT);
752   RECORD(EXPR_CXX_NEW);
753   RECORD(EXPR_CXX_DELETE);
754   RECORD(EXPR_CXX_PSEUDO_DESTRUCTOR);
755   RECORD(EXPR_EXPR_WITH_CLEANUPS);
756   RECORD(EXPR_CXX_DEPENDENT_SCOPE_MEMBER);
757   RECORD(EXPR_CXX_DEPENDENT_SCOPE_DECL_REF);
758   RECORD(EXPR_CXX_UNRESOLVED_CONSTRUCT);
759   RECORD(EXPR_CXX_UNRESOLVED_MEMBER);
760   RECORD(EXPR_CXX_UNRESOLVED_LOOKUP);
761   RECORD(EXPR_CXX_EXPRESSION_TRAIT);
762   RECORD(EXPR_CXX_NOEXCEPT);
763   RECORD(EXPR_OPAQUE_VALUE);
764   RECORD(EXPR_BINARY_CONDITIONAL_OPERATOR);
765   RECORD(EXPR_TYPE_TRAIT);
766   RECORD(EXPR_ARRAY_TYPE_TRAIT);
767   RECORD(EXPR_PACK_EXPANSION);
768   RECORD(EXPR_SIZEOF_PACK);
769   RECORD(EXPR_SUBST_NON_TYPE_TEMPLATE_PARM);
770   RECORD(EXPR_SUBST_NON_TYPE_TEMPLATE_PARM_PACK);
771   RECORD(EXPR_FUNCTION_PARM_PACK);
772   RECORD(EXPR_MATERIALIZE_TEMPORARY);
773   RECORD(EXPR_CUDA_KERNEL_CALL);
774   RECORD(EXPR_CXX_UUIDOF_EXPR);
775   RECORD(EXPR_CXX_UUIDOF_TYPE);
776   RECORD(EXPR_LAMBDA);
777 #undef RECORD
778 }
779 
780 void ASTWriter::WriteBlockInfoBlock() {
781   RecordData Record;
782   Stream.EnterBlockInfoBlock();
783 
784 #define BLOCK(X) EmitBlockID(X ## _ID, #X, Stream, Record)
785 #define RECORD(X) EmitRecordID(X, #X, Stream, Record)
786 
787   // Control Block.
788   BLOCK(CONTROL_BLOCK);
789   RECORD(METADATA);
790   RECORD(MODULE_NAME);
791   RECORD(MODULE_DIRECTORY);
792   RECORD(MODULE_MAP_FILE);
793   RECORD(IMPORTS);
794   RECORD(ORIGINAL_FILE);
795   RECORD(ORIGINAL_PCH_DIR);
796   RECORD(ORIGINAL_FILE_ID);
797   RECORD(INPUT_FILE_OFFSETS);
798 
799   BLOCK(OPTIONS_BLOCK);
800   RECORD(LANGUAGE_OPTIONS);
801   RECORD(TARGET_OPTIONS);
802   RECORD(FILE_SYSTEM_OPTIONS);
803   RECORD(HEADER_SEARCH_OPTIONS);
804   RECORD(PREPROCESSOR_OPTIONS);
805 
806   BLOCK(INPUT_FILES_BLOCK);
807   RECORD(INPUT_FILE);
808   RECORD(INPUT_FILE_HASH);
809 
810   // AST Top-Level Block.
811   BLOCK(AST_BLOCK);
812   RECORD(TYPE_OFFSET);
813   RECORD(DECL_OFFSET);
814   RECORD(IDENTIFIER_OFFSET);
815   RECORD(IDENTIFIER_TABLE);
816   RECORD(EAGERLY_DESERIALIZED_DECLS);
817   RECORD(MODULAR_CODEGEN_DECLS);
818   RECORD(SPECIAL_TYPES);
819   RECORD(STATISTICS);
820   RECORD(TENTATIVE_DEFINITIONS);
821   RECORD(SELECTOR_OFFSETS);
822   RECORD(METHOD_POOL);
823   RECORD(PP_COUNTER_VALUE);
824   RECORD(SOURCE_LOCATION_OFFSETS);
825   RECORD(SOURCE_LOCATION_PRELOADS);
826   RECORD(EXT_VECTOR_DECLS);
827   RECORD(UNUSED_FILESCOPED_DECLS);
828   RECORD(PPD_ENTITIES_OFFSETS);
829   RECORD(VTABLE_USES);
830   RECORD(PPD_SKIPPED_RANGES);
831   RECORD(REFERENCED_SELECTOR_POOL);
832   RECORD(TU_UPDATE_LEXICAL);
833   RECORD(SEMA_DECL_REFS);
834   RECORD(WEAK_UNDECLARED_IDENTIFIERS);
835   RECORD(PENDING_IMPLICIT_INSTANTIATIONS);
836   RECORD(UPDATE_VISIBLE);
837   RECORD(DECL_UPDATE_OFFSETS);
838   RECORD(DECL_UPDATES);
839   RECORD(CUDA_SPECIAL_DECL_REFS);
840   RECORD(HEADER_SEARCH_TABLE);
841   RECORD(FP_PRAGMA_OPTIONS);
842   RECORD(OPENCL_EXTENSIONS);
843   RECORD(OPENCL_EXTENSION_TYPES);
844   RECORD(OPENCL_EXTENSION_DECLS);
845   RECORD(DELEGATING_CTORS);
846   RECORD(KNOWN_NAMESPACES);
847   RECORD(MODULE_OFFSET_MAP);
848   RECORD(SOURCE_MANAGER_LINE_TABLE);
849   RECORD(OBJC_CATEGORIES_MAP);
850   RECORD(FILE_SORTED_DECLS);
851   RECORD(IMPORTED_MODULES);
852   RECORD(OBJC_CATEGORIES);
853   RECORD(MACRO_OFFSET);
854   RECORD(INTERESTING_IDENTIFIERS);
855   RECORD(UNDEFINED_BUT_USED);
856   RECORD(LATE_PARSED_TEMPLATE);
857   RECORD(OPTIMIZE_PRAGMA_OPTIONS);
858   RECORD(MSSTRUCT_PRAGMA_OPTIONS);
859   RECORD(POINTERS_TO_MEMBERS_PRAGMA_OPTIONS);
860   RECORD(UNUSED_LOCAL_TYPEDEF_NAME_CANDIDATES);
861   RECORD(DELETE_EXPRS_TO_ANALYZE);
862   RECORD(CUDA_PRAGMA_FORCE_HOST_DEVICE_DEPTH);
863   RECORD(PP_CONDITIONAL_STACK);
864   RECORD(DECLS_TO_CHECK_FOR_DEFERRED_DIAGS);
865   RECORD(PP_INCLUDED_FILES);
866 
867   // SourceManager Block.
868   BLOCK(SOURCE_MANAGER_BLOCK);
869   RECORD(SM_SLOC_FILE_ENTRY);
870   RECORD(SM_SLOC_BUFFER_ENTRY);
871   RECORD(SM_SLOC_BUFFER_BLOB);
872   RECORD(SM_SLOC_BUFFER_BLOB_COMPRESSED);
873   RECORD(SM_SLOC_EXPANSION_ENTRY);
874 
875   // Preprocessor Block.
876   BLOCK(PREPROCESSOR_BLOCK);
877   RECORD(PP_MACRO_DIRECTIVE_HISTORY);
878   RECORD(PP_MACRO_FUNCTION_LIKE);
879   RECORD(PP_MACRO_OBJECT_LIKE);
880   RECORD(PP_MODULE_MACRO);
881   RECORD(PP_TOKEN);
882 
883   // Submodule Block.
884   BLOCK(SUBMODULE_BLOCK);
885   RECORD(SUBMODULE_METADATA);
886   RECORD(SUBMODULE_DEFINITION);
887   RECORD(SUBMODULE_UMBRELLA_HEADER);
888   RECORD(SUBMODULE_HEADER);
889   RECORD(SUBMODULE_TOPHEADER);
890   RECORD(SUBMODULE_UMBRELLA_DIR);
891   RECORD(SUBMODULE_IMPORTS);
892   RECORD(SUBMODULE_EXPORTS);
893   RECORD(SUBMODULE_REQUIRES);
894   RECORD(SUBMODULE_EXCLUDED_HEADER);
895   RECORD(SUBMODULE_LINK_LIBRARY);
896   RECORD(SUBMODULE_CONFIG_MACRO);
897   RECORD(SUBMODULE_CONFLICT);
898   RECORD(SUBMODULE_PRIVATE_HEADER);
899   RECORD(SUBMODULE_TEXTUAL_HEADER);
900   RECORD(SUBMODULE_PRIVATE_TEXTUAL_HEADER);
901   RECORD(SUBMODULE_INITIALIZERS);
902   RECORD(SUBMODULE_EXPORT_AS);
903 
904   // Comments Block.
905   BLOCK(COMMENTS_BLOCK);
906   RECORD(COMMENTS_RAW_COMMENT);
907 
908   // Decls and Types block.
909   BLOCK(DECLTYPES_BLOCK);
910   RECORD(TYPE_EXT_QUAL);
911   RECORD(TYPE_COMPLEX);
912   RECORD(TYPE_POINTER);
913   RECORD(TYPE_BLOCK_POINTER);
914   RECORD(TYPE_LVALUE_REFERENCE);
915   RECORD(TYPE_RVALUE_REFERENCE);
916   RECORD(TYPE_MEMBER_POINTER);
917   RECORD(TYPE_CONSTANT_ARRAY);
918   RECORD(TYPE_INCOMPLETE_ARRAY);
919   RECORD(TYPE_VARIABLE_ARRAY);
920   RECORD(TYPE_VECTOR);
921   RECORD(TYPE_EXT_VECTOR);
922   RECORD(TYPE_FUNCTION_NO_PROTO);
923   RECORD(TYPE_FUNCTION_PROTO);
924   RECORD(TYPE_TYPEDEF);
925   RECORD(TYPE_TYPEOF_EXPR);
926   RECORD(TYPE_TYPEOF);
927   RECORD(TYPE_RECORD);
928   RECORD(TYPE_ENUM);
929   RECORD(TYPE_OBJC_INTERFACE);
930   RECORD(TYPE_OBJC_OBJECT_POINTER);
931   RECORD(TYPE_DECLTYPE);
932   RECORD(TYPE_ELABORATED);
933   RECORD(TYPE_SUBST_TEMPLATE_TYPE_PARM);
934   RECORD(TYPE_UNRESOLVED_USING);
935   RECORD(TYPE_INJECTED_CLASS_NAME);
936   RECORD(TYPE_OBJC_OBJECT);
937   RECORD(TYPE_TEMPLATE_TYPE_PARM);
938   RECORD(TYPE_TEMPLATE_SPECIALIZATION);
939   RECORD(TYPE_DEPENDENT_NAME);
940   RECORD(TYPE_DEPENDENT_TEMPLATE_SPECIALIZATION);
941   RECORD(TYPE_DEPENDENT_SIZED_ARRAY);
942   RECORD(TYPE_PAREN);
943   RECORD(TYPE_MACRO_QUALIFIED);
944   RECORD(TYPE_PACK_EXPANSION);
945   RECORD(TYPE_ATTRIBUTED);
946   RECORD(TYPE_SUBST_TEMPLATE_TYPE_PARM_PACK);
947   RECORD(TYPE_AUTO);
948   RECORD(TYPE_UNARY_TRANSFORM);
949   RECORD(TYPE_ATOMIC);
950   RECORD(TYPE_DECAYED);
951   RECORD(TYPE_ADJUSTED);
952   RECORD(TYPE_OBJC_TYPE_PARAM);
953   RECORD(LOCAL_REDECLARATIONS);
954   RECORD(DECL_TYPEDEF);
955   RECORD(DECL_TYPEALIAS);
956   RECORD(DECL_ENUM);
957   RECORD(DECL_RECORD);
958   RECORD(DECL_ENUM_CONSTANT);
959   RECORD(DECL_FUNCTION);
960   RECORD(DECL_OBJC_METHOD);
961   RECORD(DECL_OBJC_INTERFACE);
962   RECORD(DECL_OBJC_PROTOCOL);
963   RECORD(DECL_OBJC_IVAR);
964   RECORD(DECL_OBJC_AT_DEFS_FIELD);
965   RECORD(DECL_OBJC_CATEGORY);
966   RECORD(DECL_OBJC_CATEGORY_IMPL);
967   RECORD(DECL_OBJC_IMPLEMENTATION);
968   RECORD(DECL_OBJC_COMPATIBLE_ALIAS);
969   RECORD(DECL_OBJC_PROPERTY);
970   RECORD(DECL_OBJC_PROPERTY_IMPL);
971   RECORD(DECL_FIELD);
972   RECORD(DECL_MS_PROPERTY);
973   RECORD(DECL_VAR);
974   RECORD(DECL_IMPLICIT_PARAM);
975   RECORD(DECL_PARM_VAR);
976   RECORD(DECL_FILE_SCOPE_ASM);
977   RECORD(DECL_BLOCK);
978   RECORD(DECL_CONTEXT_LEXICAL);
979   RECORD(DECL_CONTEXT_VISIBLE);
980   RECORD(DECL_NAMESPACE);
981   RECORD(DECL_NAMESPACE_ALIAS);
982   RECORD(DECL_USING);
983   RECORD(DECL_USING_SHADOW);
984   RECORD(DECL_USING_DIRECTIVE);
985   RECORD(DECL_UNRESOLVED_USING_VALUE);
986   RECORD(DECL_UNRESOLVED_USING_TYPENAME);
987   RECORD(DECL_LINKAGE_SPEC);
988   RECORD(DECL_CXX_RECORD);
989   RECORD(DECL_CXX_METHOD);
990   RECORD(DECL_CXX_CONSTRUCTOR);
991   RECORD(DECL_CXX_DESTRUCTOR);
992   RECORD(DECL_CXX_CONVERSION);
993   RECORD(DECL_ACCESS_SPEC);
994   RECORD(DECL_FRIEND);
995   RECORD(DECL_FRIEND_TEMPLATE);
996   RECORD(DECL_CLASS_TEMPLATE);
997   RECORD(DECL_CLASS_TEMPLATE_SPECIALIZATION);
998   RECORD(DECL_CLASS_TEMPLATE_PARTIAL_SPECIALIZATION);
999   RECORD(DECL_VAR_TEMPLATE);
1000   RECORD(DECL_VAR_TEMPLATE_SPECIALIZATION);
1001   RECORD(DECL_VAR_TEMPLATE_PARTIAL_SPECIALIZATION);
1002   RECORD(DECL_FUNCTION_TEMPLATE);
1003   RECORD(DECL_TEMPLATE_TYPE_PARM);
1004   RECORD(DECL_NON_TYPE_TEMPLATE_PARM);
1005   RECORD(DECL_TEMPLATE_TEMPLATE_PARM);
1006   RECORD(DECL_CONCEPT);
1007   RECORD(DECL_REQUIRES_EXPR_BODY);
1008   RECORD(DECL_TYPE_ALIAS_TEMPLATE);
1009   RECORD(DECL_STATIC_ASSERT);
1010   RECORD(DECL_CXX_BASE_SPECIFIERS);
1011   RECORD(DECL_CXX_CTOR_INITIALIZERS);
1012   RECORD(DECL_INDIRECTFIELD);
1013   RECORD(DECL_EXPANDED_NON_TYPE_TEMPLATE_PARM_PACK);
1014   RECORD(DECL_EXPANDED_TEMPLATE_TEMPLATE_PARM_PACK);
1015   RECORD(DECL_CLASS_SCOPE_FUNCTION_SPECIALIZATION);
1016   RECORD(DECL_IMPORT);
1017   RECORD(DECL_OMP_THREADPRIVATE);
1018   RECORD(DECL_EMPTY);
1019   RECORD(DECL_OBJC_TYPE_PARAM);
1020   RECORD(DECL_OMP_CAPTUREDEXPR);
1021   RECORD(DECL_PRAGMA_COMMENT);
1022   RECORD(DECL_PRAGMA_DETECT_MISMATCH);
1023   RECORD(DECL_OMP_DECLARE_REDUCTION);
1024   RECORD(DECL_OMP_ALLOCATE);
1025 
1026   // Statements and Exprs can occur in the Decls and Types block.
1027   AddStmtsExprs(Stream, Record);
1028 
1029   BLOCK(PREPROCESSOR_DETAIL_BLOCK);
1030   RECORD(PPD_MACRO_EXPANSION);
1031   RECORD(PPD_MACRO_DEFINITION);
1032   RECORD(PPD_INCLUSION_DIRECTIVE);
1033 
1034   // Decls and Types block.
1035   BLOCK(EXTENSION_BLOCK);
1036   RECORD(EXTENSION_METADATA);
1037 
1038   BLOCK(UNHASHED_CONTROL_BLOCK);
1039   RECORD(SIGNATURE);
1040   RECORD(AST_BLOCK_HASH);
1041   RECORD(DIAGNOSTIC_OPTIONS);
1042   RECORD(DIAG_PRAGMA_MAPPINGS);
1043 
1044 #undef RECORD
1045 #undef BLOCK
1046   Stream.ExitBlock();
1047 }
1048 
1049 /// Prepares a path for being written to an AST file by converting it
1050 /// to an absolute path and removing nested './'s.
1051 ///
1052 /// \return \c true if the path was changed.
1053 static bool cleanPathForOutput(FileManager &FileMgr,
1054                                SmallVectorImpl<char> &Path) {
1055   bool Changed = FileMgr.makeAbsolutePath(Path);
1056   return Changed | llvm::sys::path::remove_dots(Path);
1057 }
1058 
1059 /// Adjusts the given filename to only write out the portion of the
1060 /// filename that is not part of the system root directory.
1061 ///
1062 /// \param Filename the file name to adjust.
1063 ///
1064 /// \param BaseDir When non-NULL, the PCH file is a relocatable AST file and
1065 /// the returned filename will be adjusted by this root directory.
1066 ///
1067 /// \returns either the original filename (if it needs no adjustment) or the
1068 /// adjusted filename (which points into the @p Filename parameter).
1069 static const char *
1070 adjustFilenameForRelocatableAST(const char *Filename, StringRef BaseDir) {
1071   assert(Filename && "No file name to adjust?");
1072 
1073   if (BaseDir.empty())
1074     return Filename;
1075 
1076   // Verify that the filename and the system root have the same prefix.
1077   unsigned Pos = 0;
1078   for (; Filename[Pos] && Pos < BaseDir.size(); ++Pos)
1079     if (Filename[Pos] != BaseDir[Pos])
1080       return Filename; // Prefixes don't match.
1081 
1082   // We hit the end of the filename before we hit the end of the system root.
1083   if (!Filename[Pos])
1084     return Filename;
1085 
1086   // If there's not a path separator at the end of the base directory nor
1087   // immediately after it, then this isn't within the base directory.
1088   if (!llvm::sys::path::is_separator(Filename[Pos])) {
1089     if (!llvm::sys::path::is_separator(BaseDir.back()))
1090       return Filename;
1091   } else {
1092     // If the file name has a '/' at the current position, skip over the '/'.
1093     // We distinguish relative paths from absolute paths by the
1094     // absence of '/' at the beginning of relative paths.
1095     //
1096     // FIXME: This is wrong. We distinguish them by asking if the path is
1097     // absolute, which isn't the same thing. And there might be multiple '/'s
1098     // in a row. Use a better mechanism to indicate whether we have emitted an
1099     // absolute or relative path.
1100     ++Pos;
1101   }
1102 
1103   return Filename + Pos;
1104 }
1105 
1106 std::pair<ASTFileSignature, ASTFileSignature>
1107 ASTWriter::createSignature(StringRef AllBytes, StringRef ASTBlockBytes) {
1108   llvm::SHA1 Hasher;
1109   Hasher.update(ASTBlockBytes);
1110   auto Hash = Hasher.result();
1111   ASTFileSignature ASTBlockHash = ASTFileSignature::create(Hash);
1112 
1113   // Add the remaining bytes (i.e. bytes before the unhashed control block that
1114   // are not part of the AST block).
1115   Hasher.update(
1116       AllBytes.take_front(ASTBlockBytes.bytes_end() - AllBytes.bytes_begin()));
1117   Hasher.update(
1118       AllBytes.take_back(AllBytes.bytes_end() - ASTBlockBytes.bytes_end()));
1119   Hash = Hasher.result();
1120   ASTFileSignature Signature = ASTFileSignature::create(Hash);
1121 
1122   return std::make_pair(ASTBlockHash, Signature);
1123 }
1124 
1125 ASTFileSignature ASTWriter::writeUnhashedControlBlock(Preprocessor &PP,
1126                                                       ASTContext &Context) {
1127   using namespace llvm;
1128 
1129   // Flush first to prepare the PCM hash (signature).
1130   Stream.FlushToWord();
1131   auto StartOfUnhashedControl = Stream.GetCurrentBitNo() >> 3;
1132 
1133   // Enter the block and prepare to write records.
1134   RecordData Record;
1135   Stream.EnterSubblock(UNHASHED_CONTROL_BLOCK_ID, 5);
1136 
1137   // For implicit modules, write the hash of the PCM as its signature.
1138   ASTFileSignature Signature;
1139   if (WritingModule &&
1140       PP.getHeaderSearchInfo().getHeaderSearchOpts().ModulesHashContent) {
1141     ASTFileSignature ASTBlockHash;
1142     auto ASTBlockStartByte = ASTBlockRange.first >> 3;
1143     auto ASTBlockByteLength = (ASTBlockRange.second >> 3) - ASTBlockStartByte;
1144     std::tie(ASTBlockHash, Signature) = createSignature(
1145         StringRef(Buffer.begin(), StartOfUnhashedControl),
1146         StringRef(Buffer.begin() + ASTBlockStartByte, ASTBlockByteLength));
1147 
1148     Record.append(ASTBlockHash.begin(), ASTBlockHash.end());
1149     Stream.EmitRecord(AST_BLOCK_HASH, Record);
1150     Record.clear();
1151     Record.append(Signature.begin(), Signature.end());
1152     Stream.EmitRecord(SIGNATURE, Record);
1153     Record.clear();
1154   }
1155 
1156   // Diagnostic options.
1157   const auto &Diags = Context.getDiagnostics();
1158   const DiagnosticOptions &DiagOpts = Diags.getDiagnosticOptions();
1159 #define DIAGOPT(Name, Bits, Default) Record.push_back(DiagOpts.Name);
1160 #define ENUM_DIAGOPT(Name, Type, Bits, Default)                                \
1161   Record.push_back(static_cast<unsigned>(DiagOpts.get##Name()));
1162 #include "clang/Basic/DiagnosticOptions.def"
1163   Record.push_back(DiagOpts.Warnings.size());
1164   for (unsigned I = 0, N = DiagOpts.Warnings.size(); I != N; ++I)
1165     AddString(DiagOpts.Warnings[I], Record);
1166   Record.push_back(DiagOpts.Remarks.size());
1167   for (unsigned I = 0, N = DiagOpts.Remarks.size(); I != N; ++I)
1168     AddString(DiagOpts.Remarks[I], Record);
1169   // Note: we don't serialize the log or serialization file names, because they
1170   // are generally transient files and will almost always be overridden.
1171   Stream.EmitRecord(DIAGNOSTIC_OPTIONS, Record);
1172   Record.clear();
1173 
1174   // Write out the diagnostic/pragma mappings.
1175   WritePragmaDiagnosticMappings(Diags, /* isModule = */ WritingModule);
1176 
1177   // Header search entry usage.
1178   auto HSEntryUsage = PP.getHeaderSearchInfo().computeUserEntryUsage();
1179   auto Abbrev = std::make_shared<BitCodeAbbrev>();
1180   Abbrev->Add(BitCodeAbbrevOp(HEADER_SEARCH_ENTRY_USAGE));
1181   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // Number of bits.
1182   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));      // Bit vector.
1183   unsigned HSUsageAbbrevCode = Stream.EmitAbbrev(std::move(Abbrev));
1184   {
1185     RecordData::value_type Record[] = {HEADER_SEARCH_ENTRY_USAGE,
1186                                        HSEntryUsage.size()};
1187     Stream.EmitRecordWithBlob(HSUsageAbbrevCode, Record, bytes(HSEntryUsage));
1188   }
1189 
1190   // Leave the options block.
1191   Stream.ExitBlock();
1192   return Signature;
1193 }
1194 
1195 /// Write the control block.
1196 void ASTWriter::WriteControlBlock(Preprocessor &PP, ASTContext &Context,
1197                                   StringRef isysroot,
1198                                   const std::string &OutputFile) {
1199   using namespace llvm;
1200 
1201   Stream.EnterSubblock(CONTROL_BLOCK_ID, 5);
1202   RecordData Record;
1203 
1204   // Metadata
1205   auto MetadataAbbrev = std::make_shared<BitCodeAbbrev>();
1206   MetadataAbbrev->Add(BitCodeAbbrevOp(METADATA));
1207   MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 16)); // Major
1208   MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 16)); // Minor
1209   MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 16)); // Clang maj.
1210   MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 16)); // Clang min.
1211   MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Relocatable
1212   MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Timestamps
1213   MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Errors
1214   MetadataAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // SVN branch/tag
1215   unsigned MetadataAbbrevCode = Stream.EmitAbbrev(std::move(MetadataAbbrev));
1216   assert((!WritingModule || isysroot.empty()) &&
1217          "writing module as a relocatable PCH?");
1218   {
1219     RecordData::value_type Record[] = {
1220         METADATA,
1221         VERSION_MAJOR,
1222         VERSION_MINOR,
1223         CLANG_VERSION_MAJOR,
1224         CLANG_VERSION_MINOR,
1225         !isysroot.empty(),
1226         IncludeTimestamps,
1227         ASTHasCompilerErrors};
1228     Stream.EmitRecordWithBlob(MetadataAbbrevCode, Record,
1229                               getClangFullRepositoryVersion());
1230   }
1231 
1232   if (WritingModule) {
1233     // Module name
1234     auto Abbrev = std::make_shared<BitCodeAbbrev>();
1235     Abbrev->Add(BitCodeAbbrevOp(MODULE_NAME));
1236     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
1237     unsigned AbbrevCode = Stream.EmitAbbrev(std::move(Abbrev));
1238     RecordData::value_type Record[] = {MODULE_NAME};
1239     Stream.EmitRecordWithBlob(AbbrevCode, Record, WritingModule->Name);
1240   }
1241 
1242   if (WritingModule && WritingModule->Directory) {
1243     SmallString<128> BaseDir(WritingModule->Directory->getName());
1244     cleanPathForOutput(Context.getSourceManager().getFileManager(), BaseDir);
1245 
1246     // If the home of the module is the current working directory, then we
1247     // want to pick up the cwd of the build process loading the module, not
1248     // our cwd, when we load this module.
1249     if (!PP.getHeaderSearchInfo()
1250              .getHeaderSearchOpts()
1251              .ModuleMapFileHomeIsCwd ||
1252         WritingModule->Directory->getName() != StringRef(".")) {
1253       // Module directory.
1254       auto Abbrev = std::make_shared<BitCodeAbbrev>();
1255       Abbrev->Add(BitCodeAbbrevOp(MODULE_DIRECTORY));
1256       Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Directory
1257       unsigned AbbrevCode = Stream.EmitAbbrev(std::move(Abbrev));
1258 
1259       RecordData::value_type Record[] = {MODULE_DIRECTORY};
1260       Stream.EmitRecordWithBlob(AbbrevCode, Record, BaseDir);
1261     }
1262 
1263     // Write out all other paths relative to the base directory if possible.
1264     BaseDirectory.assign(BaseDir.begin(), BaseDir.end());
1265   } else if (!isysroot.empty()) {
1266     // Write out paths relative to the sysroot if possible.
1267     BaseDirectory = std::string(isysroot);
1268   }
1269 
1270   // Module map file
1271   if (WritingModule && WritingModule->Kind == Module::ModuleMapModule) {
1272     Record.clear();
1273 
1274     auto &Map = PP.getHeaderSearchInfo().getModuleMap();
1275     AddPath(WritingModule->PresumedModuleMapFile.empty()
1276                 ? Map.getModuleMapFileForUniquing(WritingModule)->getName()
1277                 : StringRef(WritingModule->PresumedModuleMapFile),
1278             Record);
1279 
1280     // Additional module map files.
1281     if (auto *AdditionalModMaps =
1282             Map.getAdditionalModuleMapFiles(WritingModule)) {
1283       Record.push_back(AdditionalModMaps->size());
1284       for (const FileEntry *F : *AdditionalModMaps)
1285         AddPath(F->getName(), Record);
1286     } else {
1287       Record.push_back(0);
1288     }
1289 
1290     Stream.EmitRecord(MODULE_MAP_FILE, Record);
1291   }
1292 
1293   // Imports
1294   if (Chain) {
1295     serialization::ModuleManager &Mgr = Chain->getModuleManager();
1296     Record.clear();
1297 
1298     for (ModuleFile &M : Mgr) {
1299       // Skip modules that weren't directly imported.
1300       if (!M.isDirectlyImported())
1301         continue;
1302 
1303       Record.push_back((unsigned)M.Kind); // FIXME: Stable encoding
1304       AddSourceLocation(M.ImportLoc, Record);
1305 
1306       // If we have calculated signature, there is no need to store
1307       // the size or timestamp.
1308       Record.push_back(M.Signature ? 0 : M.File->getSize());
1309       Record.push_back(M.Signature ? 0 : getTimestampForOutput(M.File));
1310 
1311       for (auto I : M.Signature)
1312         Record.push_back(I);
1313 
1314       AddString(M.ModuleName, Record);
1315       AddPath(M.FileName, Record);
1316     }
1317     Stream.EmitRecord(IMPORTS, Record);
1318   }
1319 
1320   // Write the options block.
1321   Stream.EnterSubblock(OPTIONS_BLOCK_ID, 4);
1322 
1323   // Language options.
1324   Record.clear();
1325   const LangOptions &LangOpts = Context.getLangOpts();
1326 #define LANGOPT(Name, Bits, Default, Description) \
1327   Record.push_back(LangOpts.Name);
1328 #define ENUM_LANGOPT(Name, Type, Bits, Default, Description) \
1329   Record.push_back(static_cast<unsigned>(LangOpts.get##Name()));
1330 #include "clang/Basic/LangOptions.def"
1331 #define SANITIZER(NAME, ID)                                                    \
1332   Record.push_back(LangOpts.Sanitize.has(SanitizerKind::ID));
1333 #include "clang/Basic/Sanitizers.def"
1334 
1335   Record.push_back(LangOpts.ModuleFeatures.size());
1336   for (StringRef Feature : LangOpts.ModuleFeatures)
1337     AddString(Feature, Record);
1338 
1339   Record.push_back((unsigned) LangOpts.ObjCRuntime.getKind());
1340   AddVersionTuple(LangOpts.ObjCRuntime.getVersion(), Record);
1341 
1342   AddString(LangOpts.CurrentModule, Record);
1343 
1344   // Comment options.
1345   Record.push_back(LangOpts.CommentOpts.BlockCommandNames.size());
1346   for (const auto &I : LangOpts.CommentOpts.BlockCommandNames) {
1347     AddString(I, Record);
1348   }
1349   Record.push_back(LangOpts.CommentOpts.ParseAllComments);
1350 
1351   // OpenMP offloading options.
1352   Record.push_back(LangOpts.OMPTargetTriples.size());
1353   for (auto &T : LangOpts.OMPTargetTriples)
1354     AddString(T.getTriple(), Record);
1355 
1356   AddString(LangOpts.OMPHostIRFile, Record);
1357 
1358   Stream.EmitRecord(LANGUAGE_OPTIONS, Record);
1359 
1360   // Target options.
1361   Record.clear();
1362   const TargetInfo &Target = Context.getTargetInfo();
1363   const TargetOptions &TargetOpts = Target.getTargetOpts();
1364   AddString(TargetOpts.Triple, Record);
1365   AddString(TargetOpts.CPU, Record);
1366   AddString(TargetOpts.TuneCPU, Record);
1367   AddString(TargetOpts.ABI, Record);
1368   Record.push_back(TargetOpts.FeaturesAsWritten.size());
1369   for (unsigned I = 0, N = TargetOpts.FeaturesAsWritten.size(); I != N; ++I) {
1370     AddString(TargetOpts.FeaturesAsWritten[I], Record);
1371   }
1372   Record.push_back(TargetOpts.Features.size());
1373   for (unsigned I = 0, N = TargetOpts.Features.size(); I != N; ++I) {
1374     AddString(TargetOpts.Features[I], Record);
1375   }
1376   Stream.EmitRecord(TARGET_OPTIONS, Record);
1377 
1378   // File system options.
1379   Record.clear();
1380   const FileSystemOptions &FSOpts =
1381       Context.getSourceManager().getFileManager().getFileSystemOpts();
1382   AddString(FSOpts.WorkingDir, Record);
1383   Stream.EmitRecord(FILE_SYSTEM_OPTIONS, Record);
1384 
1385   // Header search options.
1386   Record.clear();
1387   const HeaderSearchOptions &HSOpts
1388     = PP.getHeaderSearchInfo().getHeaderSearchOpts();
1389   AddString(HSOpts.Sysroot, Record);
1390 
1391   // Include entries.
1392   Record.push_back(HSOpts.UserEntries.size());
1393   for (unsigned I = 0, N = HSOpts.UserEntries.size(); I != N; ++I) {
1394     const HeaderSearchOptions::Entry &Entry = HSOpts.UserEntries[I];
1395     AddString(Entry.Path, Record);
1396     Record.push_back(static_cast<unsigned>(Entry.Group));
1397     Record.push_back(Entry.IsFramework);
1398     Record.push_back(Entry.IgnoreSysRoot);
1399   }
1400 
1401   // System header prefixes.
1402   Record.push_back(HSOpts.SystemHeaderPrefixes.size());
1403   for (unsigned I = 0, N = HSOpts.SystemHeaderPrefixes.size(); I != N; ++I) {
1404     AddString(HSOpts.SystemHeaderPrefixes[I].Prefix, Record);
1405     Record.push_back(HSOpts.SystemHeaderPrefixes[I].IsSystemHeader);
1406   }
1407 
1408   AddString(HSOpts.ResourceDir, Record);
1409   AddString(HSOpts.ModuleCachePath, Record);
1410   AddString(HSOpts.ModuleUserBuildPath, Record);
1411   Record.push_back(HSOpts.DisableModuleHash);
1412   Record.push_back(HSOpts.ImplicitModuleMaps);
1413   Record.push_back(HSOpts.ModuleMapFileHomeIsCwd);
1414   Record.push_back(HSOpts.EnablePrebuiltImplicitModules);
1415   Record.push_back(HSOpts.UseBuiltinIncludes);
1416   Record.push_back(HSOpts.UseStandardSystemIncludes);
1417   Record.push_back(HSOpts.UseStandardCXXIncludes);
1418   Record.push_back(HSOpts.UseLibcxx);
1419   // Write out the specific module cache path that contains the module files.
1420   AddString(PP.getHeaderSearchInfo().getModuleCachePath(), Record);
1421   Stream.EmitRecord(HEADER_SEARCH_OPTIONS, Record);
1422 
1423   // Preprocessor options.
1424   Record.clear();
1425   const PreprocessorOptions &PPOpts = PP.getPreprocessorOpts();
1426 
1427   // Macro definitions.
1428   Record.push_back(PPOpts.Macros.size());
1429   for (unsigned I = 0, N = PPOpts.Macros.size(); I != N; ++I) {
1430     AddString(PPOpts.Macros[I].first, Record);
1431     Record.push_back(PPOpts.Macros[I].second);
1432   }
1433 
1434   // Includes
1435   Record.push_back(PPOpts.Includes.size());
1436   for (unsigned I = 0, N = PPOpts.Includes.size(); I != N; ++I)
1437     AddString(PPOpts.Includes[I], Record);
1438 
1439   // Macro includes
1440   Record.push_back(PPOpts.MacroIncludes.size());
1441   for (unsigned I = 0, N = PPOpts.MacroIncludes.size(); I != N; ++I)
1442     AddString(PPOpts.MacroIncludes[I], Record);
1443 
1444   Record.push_back(PPOpts.UsePredefines);
1445   // Detailed record is important since it is used for the module cache hash.
1446   Record.push_back(PPOpts.DetailedRecord);
1447   AddString(PPOpts.ImplicitPCHInclude, Record);
1448   Record.push_back(static_cast<unsigned>(PPOpts.ObjCXXARCStandardLibrary));
1449   Stream.EmitRecord(PREPROCESSOR_OPTIONS, Record);
1450 
1451   // Leave the options block.
1452   Stream.ExitBlock();
1453 
1454   // Original file name and file ID
1455   SourceManager &SM = Context.getSourceManager();
1456   if (const FileEntry *MainFile = SM.getFileEntryForID(SM.getMainFileID())) {
1457     auto FileAbbrev = std::make_shared<BitCodeAbbrev>();
1458     FileAbbrev->Add(BitCodeAbbrevOp(ORIGINAL_FILE));
1459     FileAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // File ID
1460     FileAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // File name
1461     unsigned FileAbbrevCode = Stream.EmitAbbrev(std::move(FileAbbrev));
1462 
1463     Record.clear();
1464     Record.push_back(ORIGINAL_FILE);
1465     Record.push_back(SM.getMainFileID().getOpaqueValue());
1466     EmitRecordWithPath(FileAbbrevCode, Record, MainFile->getName());
1467   }
1468 
1469   Record.clear();
1470   Record.push_back(SM.getMainFileID().getOpaqueValue());
1471   Stream.EmitRecord(ORIGINAL_FILE_ID, Record);
1472 
1473   // Original PCH directory
1474   if (!OutputFile.empty() && OutputFile != "-") {
1475     auto Abbrev = std::make_shared<BitCodeAbbrev>();
1476     Abbrev->Add(BitCodeAbbrevOp(ORIGINAL_PCH_DIR));
1477     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // File name
1478     unsigned AbbrevCode = Stream.EmitAbbrev(std::move(Abbrev));
1479 
1480     SmallString<128> OutputPath(OutputFile);
1481 
1482     SM.getFileManager().makeAbsolutePath(OutputPath);
1483     StringRef origDir = llvm::sys::path::parent_path(OutputPath);
1484 
1485     RecordData::value_type Record[] = {ORIGINAL_PCH_DIR};
1486     Stream.EmitRecordWithBlob(AbbrevCode, Record, origDir);
1487   }
1488 
1489   std::set<const FileEntry *> AffectingModuleMaps;
1490   if (WritingModule) {
1491     AffectingModuleMaps =
1492         GetAllModuleMaps(PP.getHeaderSearchInfo(), WritingModule);
1493   }
1494 
1495   WriteInputFiles(Context.SourceMgr,
1496                   PP.getHeaderSearchInfo().getHeaderSearchOpts(),
1497                   AffectingModuleMaps);
1498   Stream.ExitBlock();
1499 }
1500 
1501 namespace  {
1502 
1503 /// An input file.
1504 struct InputFileEntry {
1505   const FileEntry *File;
1506   bool IsSystemFile;
1507   bool IsTransient;
1508   bool BufferOverridden;
1509   bool IsTopLevelModuleMap;
1510   uint32_t ContentHash[2];
1511 };
1512 
1513 } // namespace
1514 
1515 void ASTWriter::WriteInputFiles(
1516     SourceManager &SourceMgr, HeaderSearchOptions &HSOpts,
1517     std::set<const FileEntry *> &AffectingModuleMaps) {
1518   using namespace llvm;
1519 
1520   Stream.EnterSubblock(INPUT_FILES_BLOCK_ID, 4);
1521 
1522   // Create input-file abbreviation.
1523   auto IFAbbrev = std::make_shared<BitCodeAbbrev>();
1524   IFAbbrev->Add(BitCodeAbbrevOp(INPUT_FILE));
1525   IFAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ID
1526   IFAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 12)); // Size
1527   IFAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 32)); // Modification time
1528   IFAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Overridden
1529   IFAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Transient
1530   IFAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Module map
1531   IFAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // File name
1532   unsigned IFAbbrevCode = Stream.EmitAbbrev(std::move(IFAbbrev));
1533 
1534   // Create input file hash abbreviation.
1535   auto IFHAbbrev = std::make_shared<BitCodeAbbrev>();
1536   IFHAbbrev->Add(BitCodeAbbrevOp(INPUT_FILE_HASH));
1537   IFHAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
1538   IFHAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
1539   unsigned IFHAbbrevCode = Stream.EmitAbbrev(std::move(IFHAbbrev));
1540 
1541   // Get all ContentCache objects for files, sorted by whether the file is a
1542   // system one or not. System files go at the back, users files at the front.
1543   std::deque<InputFileEntry> SortedFiles;
1544   for (unsigned I = 1, N = SourceMgr.local_sloc_entry_size(); I != N; ++I) {
1545     // Get this source location entry.
1546     const SrcMgr::SLocEntry *SLoc = &SourceMgr.getLocalSLocEntry(I);
1547     assert(&SourceMgr.getSLocEntry(FileID::get(I)) == SLoc);
1548 
1549     // We only care about file entries that were not overridden.
1550     if (!SLoc->isFile())
1551       continue;
1552     const SrcMgr::FileInfo &File = SLoc->getFile();
1553     const SrcMgr::ContentCache *Cache = &File.getContentCache();
1554     if (!Cache->OrigEntry)
1555       continue;
1556 
1557     if (isModuleMap(File.getFileCharacteristic()) &&
1558         !isSystem(File.getFileCharacteristic()) &&
1559         !AffectingModuleMaps.empty() &&
1560         AffectingModuleMaps.find(Cache->OrigEntry) ==
1561             AffectingModuleMaps.end()) {
1562       SkippedModuleMaps.insert(Cache->OrigEntry);
1563       // Do not emit modulemaps that do not affect current module.
1564       continue;
1565     }
1566 
1567     InputFileEntry Entry;
1568     Entry.File = Cache->OrigEntry;
1569     Entry.IsSystemFile = isSystem(File.getFileCharacteristic());
1570     Entry.IsTransient = Cache->IsTransient;
1571     Entry.BufferOverridden = Cache->BufferOverridden;
1572     Entry.IsTopLevelModuleMap = isModuleMap(File.getFileCharacteristic()) &&
1573                                 File.getIncludeLoc().isInvalid();
1574 
1575     auto ContentHash = hash_code(-1);
1576     if (PP->getHeaderSearchInfo()
1577             .getHeaderSearchOpts()
1578             .ValidateASTInputFilesContent) {
1579       auto MemBuff = Cache->getBufferIfLoaded();
1580       if (MemBuff)
1581         ContentHash = hash_value(MemBuff->getBuffer());
1582       else
1583         // FIXME: The path should be taken from the FileEntryRef.
1584         PP->Diag(SourceLocation(), diag::err_module_unable_to_hash_content)
1585             << Entry.File->getName();
1586     }
1587     auto CH = llvm::APInt(64, ContentHash);
1588     Entry.ContentHash[0] =
1589         static_cast<uint32_t>(CH.getLoBits(32).getZExtValue());
1590     Entry.ContentHash[1] =
1591         static_cast<uint32_t>(CH.getHiBits(32).getZExtValue());
1592 
1593     if (Entry.IsSystemFile)
1594       SortedFiles.push_back(Entry);
1595     else
1596       SortedFiles.push_front(Entry);
1597   }
1598 
1599   unsigned UserFilesNum = 0;
1600   // Write out all of the input files.
1601   std::vector<uint64_t> InputFileOffsets;
1602   for (const auto &Entry : SortedFiles) {
1603     uint32_t &InputFileID = InputFileIDs[Entry.File];
1604     if (InputFileID != 0)
1605       continue; // already recorded this file.
1606 
1607     // Record this entry's offset.
1608     InputFileOffsets.push_back(Stream.GetCurrentBitNo());
1609 
1610     InputFileID = InputFileOffsets.size();
1611 
1612     if (!Entry.IsSystemFile)
1613       ++UserFilesNum;
1614 
1615     // Emit size/modification time for this file.
1616     // And whether this file was overridden.
1617     {
1618       RecordData::value_type Record[] = {
1619           INPUT_FILE,
1620           InputFileOffsets.size(),
1621           (uint64_t)Entry.File->getSize(),
1622           (uint64_t)getTimestampForOutput(Entry.File),
1623           Entry.BufferOverridden,
1624           Entry.IsTransient,
1625           Entry.IsTopLevelModuleMap};
1626 
1627       // FIXME: The path should be taken from the FileEntryRef.
1628       EmitRecordWithPath(IFAbbrevCode, Record, Entry.File->getName());
1629     }
1630 
1631     // Emit content hash for this file.
1632     {
1633       RecordData::value_type Record[] = {INPUT_FILE_HASH, Entry.ContentHash[0],
1634                                          Entry.ContentHash[1]};
1635       Stream.EmitRecordWithAbbrev(IFHAbbrevCode, Record);
1636     }
1637   }
1638 
1639   Stream.ExitBlock();
1640 
1641   // Create input file offsets abbreviation.
1642   auto OffsetsAbbrev = std::make_shared<BitCodeAbbrev>();
1643   OffsetsAbbrev->Add(BitCodeAbbrevOp(INPUT_FILE_OFFSETS));
1644   OffsetsAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // # input files
1645   OffsetsAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // # non-system
1646                                                                 //   input files
1647   OffsetsAbbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));   // Array
1648   unsigned OffsetsAbbrevCode = Stream.EmitAbbrev(std::move(OffsetsAbbrev));
1649 
1650   // Write input file offsets.
1651   RecordData::value_type Record[] = {INPUT_FILE_OFFSETS,
1652                                      InputFileOffsets.size(), UserFilesNum};
1653   Stream.EmitRecordWithBlob(OffsetsAbbrevCode, Record, bytes(InputFileOffsets));
1654 }
1655 
1656 //===----------------------------------------------------------------------===//
1657 // Source Manager Serialization
1658 //===----------------------------------------------------------------------===//
1659 
1660 /// Create an abbreviation for the SLocEntry that refers to a
1661 /// file.
1662 static unsigned CreateSLocFileAbbrev(llvm::BitstreamWriter &Stream) {
1663   using namespace llvm;
1664 
1665   auto Abbrev = std::make_shared<BitCodeAbbrev>();
1666   Abbrev->Add(BitCodeAbbrevOp(SM_SLOC_FILE_ENTRY));
1667   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Offset
1668   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Include location
1669   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // Characteristic
1670   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Line directives
1671   // FileEntry fields.
1672   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Input File ID
1673   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // NumCreatedFIDs
1674   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 24)); // FirstDeclIndex
1675   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // NumDecls
1676   return Stream.EmitAbbrev(std::move(Abbrev));
1677 }
1678 
1679 /// Create an abbreviation for the SLocEntry that refers to a
1680 /// buffer.
1681 static unsigned CreateSLocBufferAbbrev(llvm::BitstreamWriter &Stream) {
1682   using namespace llvm;
1683 
1684   auto Abbrev = std::make_shared<BitCodeAbbrev>();
1685   Abbrev->Add(BitCodeAbbrevOp(SM_SLOC_BUFFER_ENTRY));
1686   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Offset
1687   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Include location
1688   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // Characteristic
1689   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Line directives
1690   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Buffer name blob
1691   return Stream.EmitAbbrev(std::move(Abbrev));
1692 }
1693 
1694 /// Create an abbreviation for the SLocEntry that refers to a
1695 /// buffer's blob.
1696 static unsigned CreateSLocBufferBlobAbbrev(llvm::BitstreamWriter &Stream,
1697                                            bool Compressed) {
1698   using namespace llvm;
1699 
1700   auto Abbrev = std::make_shared<BitCodeAbbrev>();
1701   Abbrev->Add(BitCodeAbbrevOp(Compressed ? SM_SLOC_BUFFER_BLOB_COMPRESSED
1702                                          : SM_SLOC_BUFFER_BLOB));
1703   if (Compressed)
1704     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Uncompressed size
1705   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Blob
1706   return Stream.EmitAbbrev(std::move(Abbrev));
1707 }
1708 
1709 /// Create an abbreviation for the SLocEntry that refers to a macro
1710 /// expansion.
1711 static unsigned CreateSLocExpansionAbbrev(llvm::BitstreamWriter &Stream) {
1712   using namespace llvm;
1713 
1714   auto Abbrev = std::make_shared<BitCodeAbbrev>();
1715   Abbrev->Add(BitCodeAbbrevOp(SM_SLOC_EXPANSION_ENTRY));
1716   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Offset
1717   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Spelling location
1718   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // Start location
1719   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // End location
1720   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Is token range
1721   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Token length
1722   return Stream.EmitAbbrev(std::move(Abbrev));
1723 }
1724 
1725 /// Emit key length and data length as ULEB-encoded data, and return them as a
1726 /// pair.
1727 static std::pair<unsigned, unsigned>
1728 emitULEBKeyDataLength(unsigned KeyLen, unsigned DataLen, raw_ostream &Out) {
1729   llvm::encodeULEB128(KeyLen, Out);
1730   llvm::encodeULEB128(DataLen, Out);
1731   return std::make_pair(KeyLen, DataLen);
1732 }
1733 
1734 namespace {
1735 
1736   // Trait used for the on-disk hash table of header search information.
1737   class HeaderFileInfoTrait {
1738     ASTWriter &Writer;
1739 
1740     // Keep track of the framework names we've used during serialization.
1741     SmallString<128> FrameworkStringData;
1742     llvm::StringMap<unsigned> FrameworkNameOffset;
1743 
1744   public:
1745     HeaderFileInfoTrait(ASTWriter &Writer) : Writer(Writer) {}
1746 
1747     struct key_type {
1748       StringRef Filename;
1749       off_t Size;
1750       time_t ModTime;
1751     };
1752     using key_type_ref = const key_type &;
1753 
1754     using UnresolvedModule =
1755         llvm::PointerIntPair<Module *, 2, ModuleMap::ModuleHeaderRole>;
1756 
1757     struct data_type {
1758       const HeaderFileInfo &HFI;
1759       ArrayRef<ModuleMap::KnownHeader> KnownHeaders;
1760       UnresolvedModule Unresolved;
1761     };
1762     using data_type_ref = const data_type &;
1763 
1764     using hash_value_type = unsigned;
1765     using offset_type = unsigned;
1766 
1767     hash_value_type ComputeHash(key_type_ref key) {
1768       // The hash is based only on size/time of the file, so that the reader can
1769       // match even when symlinking or excess path elements ("foo/../", "../")
1770       // change the form of the name. However, complete path is still the key.
1771       return llvm::hash_combine(key.Size, key.ModTime);
1772     }
1773 
1774     std::pair<unsigned, unsigned>
1775     EmitKeyDataLength(raw_ostream& Out, key_type_ref key, data_type_ref Data) {
1776       unsigned KeyLen = key.Filename.size() + 1 + 8 + 8;
1777       unsigned DataLen = 1 + 4 + 4;
1778       for (auto ModInfo : Data.KnownHeaders)
1779         if (Writer.getLocalOrImportedSubmoduleID(ModInfo.getModule()))
1780           DataLen += 4;
1781       if (Data.Unresolved.getPointer())
1782         DataLen += 4;
1783       return emitULEBKeyDataLength(KeyLen, DataLen, Out);
1784     }
1785 
1786     void EmitKey(raw_ostream& Out, key_type_ref key, unsigned KeyLen) {
1787       using namespace llvm::support;
1788 
1789       endian::Writer LE(Out, little);
1790       LE.write<uint64_t>(key.Size);
1791       KeyLen -= 8;
1792       LE.write<uint64_t>(key.ModTime);
1793       KeyLen -= 8;
1794       Out.write(key.Filename.data(), KeyLen);
1795     }
1796 
1797     void EmitData(raw_ostream &Out, key_type_ref key,
1798                   data_type_ref Data, unsigned DataLen) {
1799       using namespace llvm::support;
1800 
1801       endian::Writer LE(Out, little);
1802       uint64_t Start = Out.tell(); (void)Start;
1803 
1804       unsigned char Flags = (Data.HFI.isImport << 5)
1805                           | (Data.HFI.isPragmaOnce << 4)
1806                           | (Data.HFI.DirInfo << 1)
1807                           | Data.HFI.IndexHeaderMapHeader;
1808       LE.write<uint8_t>(Flags);
1809 
1810       if (!Data.HFI.ControllingMacro)
1811         LE.write<uint32_t>(Data.HFI.ControllingMacroID);
1812       else
1813         LE.write<uint32_t>(Writer.getIdentifierRef(Data.HFI.ControllingMacro));
1814 
1815       unsigned Offset = 0;
1816       if (!Data.HFI.Framework.empty()) {
1817         // If this header refers into a framework, save the framework name.
1818         llvm::StringMap<unsigned>::iterator Pos
1819           = FrameworkNameOffset.find(Data.HFI.Framework);
1820         if (Pos == FrameworkNameOffset.end()) {
1821           Offset = FrameworkStringData.size() + 1;
1822           FrameworkStringData.append(Data.HFI.Framework);
1823           FrameworkStringData.push_back(0);
1824 
1825           FrameworkNameOffset[Data.HFI.Framework] = Offset;
1826         } else
1827           Offset = Pos->second;
1828       }
1829       LE.write<uint32_t>(Offset);
1830 
1831       auto EmitModule = [&](Module *M, ModuleMap::ModuleHeaderRole Role) {
1832         if (uint32_t ModID = Writer.getLocalOrImportedSubmoduleID(M)) {
1833           uint32_t Value = (ModID << 2) | (unsigned)Role;
1834           assert((Value >> 2) == ModID && "overflow in header module info");
1835           LE.write<uint32_t>(Value);
1836         }
1837       };
1838 
1839       // FIXME: If the header is excluded, we should write out some
1840       // record of that fact.
1841       for (auto ModInfo : Data.KnownHeaders)
1842         EmitModule(ModInfo.getModule(), ModInfo.getRole());
1843       if (Data.Unresolved.getPointer())
1844         EmitModule(Data.Unresolved.getPointer(), Data.Unresolved.getInt());
1845 
1846       assert(Out.tell() - Start == DataLen && "Wrong data length");
1847     }
1848 
1849     const char *strings_begin() const { return FrameworkStringData.begin(); }
1850     const char *strings_end() const { return FrameworkStringData.end(); }
1851   };
1852 
1853 } // namespace
1854 
1855 /// Write the header search block for the list of files that
1856 ///
1857 /// \param HS The header search structure to save.
1858 void ASTWriter::WriteHeaderSearch(const HeaderSearch &HS) {
1859   HeaderFileInfoTrait GeneratorTrait(*this);
1860   llvm::OnDiskChainedHashTableGenerator<HeaderFileInfoTrait> Generator;
1861   SmallVector<const char *, 4> SavedStrings;
1862   unsigned NumHeaderSearchEntries = 0;
1863 
1864   // Find all unresolved headers for the current module. We generally will
1865   // have resolved them before we get here, but not necessarily: we might be
1866   // compiling a preprocessed module, where there is no requirement for the
1867   // original files to exist any more.
1868   const HeaderFileInfo Empty; // So we can take a reference.
1869   if (WritingModule) {
1870     llvm::SmallVector<Module *, 16> Worklist(1, WritingModule);
1871     while (!Worklist.empty()) {
1872       Module *M = Worklist.pop_back_val();
1873       // We don't care about headers in unimportable submodules.
1874       if (M->isUnimportable())
1875         continue;
1876 
1877       // Map to disk files where possible, to pick up any missing stat
1878       // information. This also means we don't need to check the unresolved
1879       // headers list when emitting resolved headers in the first loop below.
1880       // FIXME: It'd be preferable to avoid doing this if we were given
1881       // sufficient stat information in the module map.
1882       HS.getModuleMap().resolveHeaderDirectives(M);
1883 
1884       // If the file didn't exist, we can still create a module if we were given
1885       // enough information in the module map.
1886       for (auto U : M->MissingHeaders) {
1887         // Check that we were given enough information to build a module
1888         // without this file existing on disk.
1889         if (!U.Size || (!U.ModTime && IncludeTimestamps)) {
1890           PP->Diag(U.FileNameLoc, diag::err_module_no_size_mtime_for_header)
1891             << WritingModule->getFullModuleName() << U.Size.hasValue()
1892             << U.FileName;
1893           continue;
1894         }
1895 
1896         // Form the effective relative pathname for the file.
1897         SmallString<128> Filename(M->Directory->getName());
1898         llvm::sys::path::append(Filename, U.FileName);
1899         PreparePathForOutput(Filename);
1900 
1901         StringRef FilenameDup = strdup(Filename.c_str());
1902         SavedStrings.push_back(FilenameDup.data());
1903 
1904         HeaderFileInfoTrait::key_type Key = {
1905           FilenameDup, *U.Size, IncludeTimestamps ? *U.ModTime : 0
1906         };
1907         HeaderFileInfoTrait::data_type Data = {
1908           Empty, {}, {M, ModuleMap::headerKindToRole(U.Kind)}
1909         };
1910         // FIXME: Deal with cases where there are multiple unresolved header
1911         // directives in different submodules for the same header.
1912         Generator.insert(Key, Data, GeneratorTrait);
1913         ++NumHeaderSearchEntries;
1914       }
1915 
1916       Worklist.append(M->submodule_begin(), M->submodule_end());
1917     }
1918   }
1919 
1920   SmallVector<const FileEntry *, 16> FilesByUID;
1921   HS.getFileMgr().GetUniqueIDMapping(FilesByUID);
1922 
1923   if (FilesByUID.size() > HS.header_file_size())
1924     FilesByUID.resize(HS.header_file_size());
1925 
1926   for (unsigned UID = 0, LastUID = FilesByUID.size(); UID != LastUID; ++UID) {
1927     const FileEntry *File = FilesByUID[UID];
1928     if (!File)
1929       continue;
1930 
1931     // Get the file info. This will load info from the external source if
1932     // necessary. Skip emitting this file if we have no information on it
1933     // as a header file (in which case HFI will be null) or if it hasn't
1934     // changed since it was loaded. Also skip it if it's for a modular header
1935     // from a different module; in that case, we rely on the module(s)
1936     // containing the header to provide this information.
1937     const HeaderFileInfo *HFI =
1938         HS.getExistingFileInfo(File, /*WantExternal*/!Chain);
1939     if (!HFI || (HFI->isModuleHeader && !HFI->isCompilingModuleHeader))
1940       continue;
1941 
1942     // Massage the file path into an appropriate form.
1943     StringRef Filename = File->getName();
1944     SmallString<128> FilenameTmp(Filename);
1945     if (PreparePathForOutput(FilenameTmp)) {
1946       // If we performed any translation on the file name at all, we need to
1947       // save this string, since the generator will refer to it later.
1948       Filename = StringRef(strdup(FilenameTmp.c_str()));
1949       SavedStrings.push_back(Filename.data());
1950     }
1951 
1952     HeaderFileInfoTrait::key_type Key = {
1953       Filename, File->getSize(), getTimestampForOutput(File)
1954     };
1955     HeaderFileInfoTrait::data_type Data = {
1956       *HFI, HS.getModuleMap().findResolvedModulesForHeader(File), {}
1957     };
1958     Generator.insert(Key, Data, GeneratorTrait);
1959     ++NumHeaderSearchEntries;
1960   }
1961 
1962   // Create the on-disk hash table in a buffer.
1963   SmallString<4096> TableData;
1964   uint32_t BucketOffset;
1965   {
1966     using namespace llvm::support;
1967 
1968     llvm::raw_svector_ostream Out(TableData);
1969     // Make sure that no bucket is at offset 0
1970     endian::write<uint32_t>(Out, 0, little);
1971     BucketOffset = Generator.Emit(Out, GeneratorTrait);
1972   }
1973 
1974   // Create a blob abbreviation
1975   using namespace llvm;
1976 
1977   auto Abbrev = std::make_shared<BitCodeAbbrev>();
1978   Abbrev->Add(BitCodeAbbrevOp(HEADER_SEARCH_TABLE));
1979   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
1980   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
1981   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
1982   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
1983   unsigned TableAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
1984 
1985   // Write the header search table
1986   RecordData::value_type Record[] = {HEADER_SEARCH_TABLE, BucketOffset,
1987                                      NumHeaderSearchEntries, TableData.size()};
1988   TableData.append(GeneratorTrait.strings_begin(),GeneratorTrait.strings_end());
1989   Stream.EmitRecordWithBlob(TableAbbrev, Record, TableData);
1990 
1991   // Free all of the strings we had to duplicate.
1992   for (unsigned I = 0, N = SavedStrings.size(); I != N; ++I)
1993     free(const_cast<char *>(SavedStrings[I]));
1994 }
1995 
1996 static void emitBlob(llvm::BitstreamWriter &Stream, StringRef Blob,
1997                      unsigned SLocBufferBlobCompressedAbbrv,
1998                      unsigned SLocBufferBlobAbbrv) {
1999   using RecordDataType = ASTWriter::RecordData::value_type;
2000 
2001   // Compress the buffer if possible. We expect that almost all PCM
2002   // consumers will not want its contents.
2003   SmallString<0> CompressedBuffer;
2004   if (llvm::zlib::isAvailable()) {
2005     llvm::Error E = llvm::zlib::compress(Blob.drop_back(1), CompressedBuffer);
2006     if (!E) {
2007       RecordDataType Record[] = {SM_SLOC_BUFFER_BLOB_COMPRESSED,
2008                                  Blob.size() - 1};
2009       Stream.EmitRecordWithBlob(SLocBufferBlobCompressedAbbrv, Record,
2010                                 CompressedBuffer);
2011       return;
2012     }
2013     llvm::consumeError(std::move(E));
2014   }
2015 
2016   RecordDataType Record[] = {SM_SLOC_BUFFER_BLOB};
2017   Stream.EmitRecordWithBlob(SLocBufferBlobAbbrv, Record, Blob);
2018 }
2019 
2020 /// Writes the block containing the serialized form of the
2021 /// source manager.
2022 ///
2023 /// TODO: We should probably use an on-disk hash table (stored in a
2024 /// blob), indexed based on the file name, so that we only create
2025 /// entries for files that we actually need. In the common case (no
2026 /// errors), we probably won't have to create file entries for any of
2027 /// the files in the AST.
2028 void ASTWriter::WriteSourceManagerBlock(SourceManager &SourceMgr,
2029                                         const Preprocessor &PP) {
2030   RecordData Record;
2031 
2032   // Enter the source manager block.
2033   Stream.EnterSubblock(SOURCE_MANAGER_BLOCK_ID, 4);
2034   const uint64_t SourceManagerBlockOffset = Stream.GetCurrentBitNo();
2035 
2036   // Abbreviations for the various kinds of source-location entries.
2037   unsigned SLocFileAbbrv = CreateSLocFileAbbrev(Stream);
2038   unsigned SLocBufferAbbrv = CreateSLocBufferAbbrev(Stream);
2039   unsigned SLocBufferBlobAbbrv = CreateSLocBufferBlobAbbrev(Stream, false);
2040   unsigned SLocBufferBlobCompressedAbbrv =
2041       CreateSLocBufferBlobAbbrev(Stream, true);
2042   unsigned SLocExpansionAbbrv = CreateSLocExpansionAbbrev(Stream);
2043 
2044   // Write out the source location entry table. We skip the first
2045   // entry, which is always the same dummy entry.
2046   std::vector<uint32_t> SLocEntryOffsets;
2047   uint64_t SLocEntryOffsetsBase = Stream.GetCurrentBitNo();
2048   RecordData PreloadSLocs;
2049   SLocEntryOffsets.reserve(SourceMgr.local_sloc_entry_size() - 1);
2050   for (unsigned I = 1, N = SourceMgr.local_sloc_entry_size();
2051        I != N; ++I) {
2052     // Get this source location entry.
2053     const SrcMgr::SLocEntry *SLoc = &SourceMgr.getLocalSLocEntry(I);
2054     FileID FID = FileID::get(I);
2055     assert(&SourceMgr.getSLocEntry(FID) == SLoc);
2056 
2057     // Record the offset of this source-location entry.
2058     uint64_t Offset = Stream.GetCurrentBitNo() - SLocEntryOffsetsBase;
2059     assert((Offset >> 32) == 0 && "SLocEntry offset too large");
2060     SLocEntryOffsets.push_back(Offset);
2061 
2062     // Figure out which record code to use.
2063     unsigned Code;
2064     if (SLoc->isFile()) {
2065       const SrcMgr::ContentCache *Cache = &SLoc->getFile().getContentCache();
2066       if (Cache->OrigEntry) {
2067         Code = SM_SLOC_FILE_ENTRY;
2068       } else
2069         Code = SM_SLOC_BUFFER_ENTRY;
2070     } else
2071       Code = SM_SLOC_EXPANSION_ENTRY;
2072     Record.clear();
2073     Record.push_back(Code);
2074 
2075     // Starting offset of this entry within this module, so skip the dummy.
2076     Record.push_back(SLoc->getOffset() - 2);
2077     if (SLoc->isFile()) {
2078       const SrcMgr::FileInfo &File = SLoc->getFile();
2079       const SrcMgr::ContentCache *Content = &File.getContentCache();
2080       if (Content->OrigEntry && !SkippedModuleMaps.empty() &&
2081           SkippedModuleMaps.find(Content->OrigEntry) !=
2082               SkippedModuleMaps.end()) {
2083         // Do not emit files that were not listed as inputs.
2084         continue;
2085       }
2086       AddSourceLocation(File.getIncludeLoc(), Record);
2087       Record.push_back(File.getFileCharacteristic()); // FIXME: stable encoding
2088       Record.push_back(File.hasLineDirectives());
2089 
2090       bool EmitBlob = false;
2091       if (Content->OrigEntry) {
2092         assert(Content->OrigEntry == Content->ContentsEntry &&
2093                "Writing to AST an overridden file is not supported");
2094 
2095         // The source location entry is a file. Emit input file ID.
2096         assert(InputFileIDs[Content->OrigEntry] != 0 && "Missed file entry");
2097         Record.push_back(InputFileIDs[Content->OrigEntry]);
2098 
2099         Record.push_back(File.NumCreatedFIDs);
2100 
2101         FileDeclIDsTy::iterator FDI = FileDeclIDs.find(FID);
2102         if (FDI != FileDeclIDs.end()) {
2103           Record.push_back(FDI->second->FirstDeclIndex);
2104           Record.push_back(FDI->second->DeclIDs.size());
2105         } else {
2106           Record.push_back(0);
2107           Record.push_back(0);
2108         }
2109 
2110         Stream.EmitRecordWithAbbrev(SLocFileAbbrv, Record);
2111 
2112         if (Content->BufferOverridden || Content->IsTransient)
2113           EmitBlob = true;
2114       } else {
2115         // The source location entry is a buffer. The blob associated
2116         // with this entry contains the contents of the buffer.
2117 
2118         // We add one to the size so that we capture the trailing NULL
2119         // that is required by llvm::MemoryBuffer::getMemBuffer (on
2120         // the reader side).
2121         llvm::Optional<llvm::MemoryBufferRef> Buffer =
2122             Content->getBufferOrNone(PP.getDiagnostics(), PP.getFileManager());
2123         StringRef Name = Buffer ? Buffer->getBufferIdentifier() : "";
2124         Stream.EmitRecordWithBlob(SLocBufferAbbrv, Record,
2125                                   StringRef(Name.data(), Name.size() + 1));
2126         EmitBlob = true;
2127 
2128         if (Name == "<built-in>")
2129           PreloadSLocs.push_back(SLocEntryOffsets.size());
2130       }
2131 
2132       if (EmitBlob) {
2133         // Include the implicit terminating null character in the on-disk buffer
2134         // if we're writing it uncompressed.
2135         llvm::Optional<llvm::MemoryBufferRef> Buffer =
2136             Content->getBufferOrNone(PP.getDiagnostics(), PP.getFileManager());
2137         if (!Buffer)
2138           Buffer = llvm::MemoryBufferRef("<<<INVALID BUFFER>>>", "");
2139         StringRef Blob(Buffer->getBufferStart(), Buffer->getBufferSize() + 1);
2140         emitBlob(Stream, Blob, SLocBufferBlobCompressedAbbrv,
2141                  SLocBufferBlobAbbrv);
2142       }
2143     } else {
2144       // The source location entry is a macro expansion.
2145       const SrcMgr::ExpansionInfo &Expansion = SLoc->getExpansion();
2146       AddSourceLocation(Expansion.getSpellingLoc(), Record);
2147       AddSourceLocation(Expansion.getExpansionLocStart(), Record);
2148       AddSourceLocation(Expansion.isMacroArgExpansion()
2149                             ? SourceLocation()
2150                             : Expansion.getExpansionLocEnd(),
2151                         Record);
2152       Record.push_back(Expansion.isExpansionTokenRange());
2153 
2154       // Compute the token length for this macro expansion.
2155       SourceLocation::UIntTy NextOffset = SourceMgr.getNextLocalOffset();
2156       if (I + 1 != N)
2157         NextOffset = SourceMgr.getLocalSLocEntry(I + 1).getOffset();
2158       Record.push_back(NextOffset - SLoc->getOffset() - 1);
2159       Stream.EmitRecordWithAbbrev(SLocExpansionAbbrv, Record);
2160     }
2161   }
2162 
2163   Stream.ExitBlock();
2164 
2165   if (SLocEntryOffsets.empty())
2166     return;
2167 
2168   // Write the source-location offsets table into the AST block. This
2169   // table is used for lazily loading source-location information.
2170   using namespace llvm;
2171 
2172   auto Abbrev = std::make_shared<BitCodeAbbrev>();
2173   Abbrev->Add(BitCodeAbbrevOp(SOURCE_LOCATION_OFFSETS));
2174   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 16)); // # of slocs
2175   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 16)); // total size
2176   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 32)); // base offset
2177   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // offsets
2178   unsigned SLocOffsetsAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2179   {
2180     RecordData::value_type Record[] = {
2181         SOURCE_LOCATION_OFFSETS, SLocEntryOffsets.size(),
2182         SourceMgr.getNextLocalOffset() - 1 /* skip dummy */,
2183         SLocEntryOffsetsBase - SourceManagerBlockOffset};
2184     Stream.EmitRecordWithBlob(SLocOffsetsAbbrev, Record,
2185                               bytes(SLocEntryOffsets));
2186   }
2187   // Write the source location entry preloads array, telling the AST
2188   // reader which source locations entries it should load eagerly.
2189   Stream.EmitRecord(SOURCE_LOCATION_PRELOADS, PreloadSLocs);
2190 
2191   // Write the line table. It depends on remapping working, so it must come
2192   // after the source location offsets.
2193   if (SourceMgr.hasLineTable()) {
2194     LineTableInfo &LineTable = SourceMgr.getLineTable();
2195 
2196     Record.clear();
2197 
2198     // Emit the needed file names.
2199     llvm::DenseMap<int, int> FilenameMap;
2200     FilenameMap[-1] = -1; // For unspecified filenames.
2201     for (const auto &L : LineTable) {
2202       if (L.first.ID < 0)
2203         continue;
2204       for (auto &LE : L.second) {
2205         if (FilenameMap.insert(std::make_pair(LE.FilenameID,
2206                                               FilenameMap.size() - 1)).second)
2207           AddPath(LineTable.getFilename(LE.FilenameID), Record);
2208       }
2209     }
2210     Record.push_back(0);
2211 
2212     // Emit the line entries
2213     for (const auto &L : LineTable) {
2214       // Only emit entries for local files.
2215       if (L.first.ID < 0)
2216         continue;
2217 
2218       // Emit the file ID
2219       Record.push_back(L.first.ID);
2220 
2221       // Emit the line entries
2222       Record.push_back(L.second.size());
2223       for (const auto &LE : L.second) {
2224         Record.push_back(LE.FileOffset);
2225         Record.push_back(LE.LineNo);
2226         Record.push_back(FilenameMap[LE.FilenameID]);
2227         Record.push_back((unsigned)LE.FileKind);
2228         Record.push_back(LE.IncludeOffset);
2229       }
2230     }
2231 
2232     Stream.EmitRecord(SOURCE_MANAGER_LINE_TABLE, Record);
2233   }
2234 }
2235 
2236 //===----------------------------------------------------------------------===//
2237 // Preprocessor Serialization
2238 //===----------------------------------------------------------------------===//
2239 
2240 static bool shouldIgnoreMacro(MacroDirective *MD, bool IsModule,
2241                               const Preprocessor &PP) {
2242   if (MacroInfo *MI = MD->getMacroInfo())
2243     if (MI->isBuiltinMacro())
2244       return true;
2245 
2246   if (IsModule) {
2247     SourceLocation Loc = MD->getLocation();
2248     if (Loc.isInvalid())
2249       return true;
2250     if (PP.getSourceManager().getFileID(Loc) == PP.getPredefinesFileID())
2251       return true;
2252   }
2253 
2254   return false;
2255 }
2256 
2257 void ASTWriter::writeIncludedFiles(raw_ostream &Out, const Preprocessor &PP) {
2258   using namespace llvm::support;
2259 
2260   const Preprocessor::IncludedFilesSet &IncludedFiles = PP.getIncludedFiles();
2261 
2262   std::vector<uint32_t> IncludedInputFileIDs;
2263   IncludedInputFileIDs.reserve(IncludedFiles.size());
2264 
2265   for (const FileEntry *File : IncludedFiles) {
2266     auto InputFileIt = InputFileIDs.find(File);
2267     if (InputFileIt == InputFileIDs.end())
2268       continue;
2269     IncludedInputFileIDs.push_back(InputFileIt->second);
2270   }
2271 
2272   llvm::sort(IncludedInputFileIDs);
2273 
2274   endian::Writer LE(Out, little);
2275   LE.write<uint32_t>(IncludedInputFileIDs.size());
2276   for (uint32_t ID : IncludedInputFileIDs)
2277     LE.write<uint32_t>(ID);
2278 }
2279 
2280 /// Writes the block containing the serialized form of the
2281 /// preprocessor.
2282 void ASTWriter::WritePreprocessor(const Preprocessor &PP, bool IsModule) {
2283   uint64_t MacroOffsetsBase = Stream.GetCurrentBitNo();
2284 
2285   PreprocessingRecord *PPRec = PP.getPreprocessingRecord();
2286   if (PPRec)
2287     WritePreprocessorDetail(*PPRec, MacroOffsetsBase);
2288 
2289   RecordData Record;
2290   RecordData ModuleMacroRecord;
2291 
2292   // If the preprocessor __COUNTER__ value has been bumped, remember it.
2293   if (PP.getCounterValue() != 0) {
2294     RecordData::value_type Record[] = {PP.getCounterValue()};
2295     Stream.EmitRecord(PP_COUNTER_VALUE, Record);
2296   }
2297 
2298   if (PP.isRecordingPreamble() && PP.hasRecordedPreamble()) {
2299     assert(!IsModule);
2300     auto SkipInfo = PP.getPreambleSkipInfo();
2301     if (SkipInfo.hasValue()) {
2302       Record.push_back(true);
2303       AddSourceLocation(SkipInfo->HashTokenLoc, Record);
2304       AddSourceLocation(SkipInfo->IfTokenLoc, Record);
2305       Record.push_back(SkipInfo->FoundNonSkipPortion);
2306       Record.push_back(SkipInfo->FoundElse);
2307       AddSourceLocation(SkipInfo->ElseLoc, Record);
2308     } else {
2309       Record.push_back(false);
2310     }
2311     for (const auto &Cond : PP.getPreambleConditionalStack()) {
2312       AddSourceLocation(Cond.IfLoc, Record);
2313       Record.push_back(Cond.WasSkipping);
2314       Record.push_back(Cond.FoundNonSkip);
2315       Record.push_back(Cond.FoundElse);
2316     }
2317     Stream.EmitRecord(PP_CONDITIONAL_STACK, Record);
2318     Record.clear();
2319   }
2320 
2321   // Enter the preprocessor block.
2322   Stream.EnterSubblock(PREPROCESSOR_BLOCK_ID, 3);
2323 
2324   // If the AST file contains __DATE__ or __TIME__ emit a warning about this.
2325   // FIXME: Include a location for the use, and say which one was used.
2326   if (PP.SawDateOrTime())
2327     PP.Diag(SourceLocation(), diag::warn_module_uses_date_time) << IsModule;
2328 
2329   // Loop over all the macro directives that are live at the end of the file,
2330   // emitting each to the PP section.
2331 
2332   // Construct the list of identifiers with macro directives that need to be
2333   // serialized.
2334   SmallVector<const IdentifierInfo *, 128> MacroIdentifiers;
2335   for (auto &Id : PP.getIdentifierTable())
2336     if (Id.second->hadMacroDefinition() &&
2337         (!Id.second->isFromAST() ||
2338          Id.second->hasChangedSinceDeserialization()))
2339       MacroIdentifiers.push_back(Id.second);
2340   // Sort the set of macro definitions that need to be serialized by the
2341   // name of the macro, to provide a stable ordering.
2342   llvm::sort(MacroIdentifiers, llvm::deref<std::less<>>());
2343 
2344   // Emit the macro directives as a list and associate the offset with the
2345   // identifier they belong to.
2346   for (const IdentifierInfo *Name : MacroIdentifiers) {
2347     MacroDirective *MD = PP.getLocalMacroDirectiveHistory(Name);
2348     uint64_t StartOffset = Stream.GetCurrentBitNo() - MacroOffsetsBase;
2349     assert((StartOffset >> 32) == 0 && "Macro identifiers offset too large");
2350 
2351     // Emit the macro directives in reverse source order.
2352     for (; MD; MD = MD->getPrevious()) {
2353       // Once we hit an ignored macro, we're done: the rest of the chain
2354       // will all be ignored macros.
2355       if (shouldIgnoreMacro(MD, IsModule, PP))
2356         break;
2357 
2358       AddSourceLocation(MD->getLocation(), Record);
2359       Record.push_back(MD->getKind());
2360       if (auto *DefMD = dyn_cast<DefMacroDirective>(MD)) {
2361         Record.push_back(getMacroRef(DefMD->getInfo(), Name));
2362       } else if (auto *VisMD = dyn_cast<VisibilityMacroDirective>(MD)) {
2363         Record.push_back(VisMD->isPublic());
2364       }
2365     }
2366 
2367     // Write out any exported module macros.
2368     bool EmittedModuleMacros = false;
2369     // We write out exported module macros for PCH as well.
2370     auto Leafs = PP.getLeafModuleMacros(Name);
2371     SmallVector<ModuleMacro*, 8> Worklist(Leafs.begin(), Leafs.end());
2372     llvm::DenseMap<ModuleMacro*, unsigned> Visits;
2373     while (!Worklist.empty()) {
2374       auto *Macro = Worklist.pop_back_val();
2375 
2376       // Emit a record indicating this submodule exports this macro.
2377       ModuleMacroRecord.push_back(
2378           getSubmoduleID(Macro->getOwningModule()));
2379       ModuleMacroRecord.push_back(getMacroRef(Macro->getMacroInfo(), Name));
2380       for (auto *M : Macro->overrides())
2381         ModuleMacroRecord.push_back(getSubmoduleID(M->getOwningModule()));
2382 
2383       Stream.EmitRecord(PP_MODULE_MACRO, ModuleMacroRecord);
2384       ModuleMacroRecord.clear();
2385 
2386       // Enqueue overridden macros once we've visited all their ancestors.
2387       for (auto *M : Macro->overrides())
2388         if (++Visits[M] == M->getNumOverridingMacros())
2389           Worklist.push_back(M);
2390 
2391       EmittedModuleMacros = true;
2392     }
2393 
2394     if (Record.empty() && !EmittedModuleMacros)
2395       continue;
2396 
2397     IdentMacroDirectivesOffsetMap[Name] = StartOffset;
2398     Stream.EmitRecord(PP_MACRO_DIRECTIVE_HISTORY, Record);
2399     Record.clear();
2400   }
2401 
2402   /// Offsets of each of the macros into the bitstream, indexed by
2403   /// the local macro ID
2404   ///
2405   /// For each identifier that is associated with a macro, this map
2406   /// provides the offset into the bitstream where that macro is
2407   /// defined.
2408   std::vector<uint32_t> MacroOffsets;
2409 
2410   for (unsigned I = 0, N = MacroInfosToEmit.size(); I != N; ++I) {
2411     const IdentifierInfo *Name = MacroInfosToEmit[I].Name;
2412     MacroInfo *MI = MacroInfosToEmit[I].MI;
2413     MacroID ID = MacroInfosToEmit[I].ID;
2414 
2415     if (ID < FirstMacroID) {
2416       assert(0 && "Loaded MacroInfo entered MacroInfosToEmit ?");
2417       continue;
2418     }
2419 
2420     // Record the local offset of this macro.
2421     unsigned Index = ID - FirstMacroID;
2422     if (Index >= MacroOffsets.size())
2423       MacroOffsets.resize(Index + 1);
2424 
2425     uint64_t Offset = Stream.GetCurrentBitNo() - MacroOffsetsBase;
2426     assert((Offset >> 32) == 0 && "Macro offset too large");
2427     MacroOffsets[Index] = Offset;
2428 
2429     AddIdentifierRef(Name, Record);
2430     AddSourceLocation(MI->getDefinitionLoc(), Record);
2431     AddSourceLocation(MI->getDefinitionEndLoc(), Record);
2432     Record.push_back(MI->isUsed());
2433     Record.push_back(MI->isUsedForHeaderGuard());
2434     unsigned Code;
2435     if (MI->isObjectLike()) {
2436       Code = PP_MACRO_OBJECT_LIKE;
2437     } else {
2438       Code = PP_MACRO_FUNCTION_LIKE;
2439 
2440       Record.push_back(MI->isC99Varargs());
2441       Record.push_back(MI->isGNUVarargs());
2442       Record.push_back(MI->hasCommaPasting());
2443       Record.push_back(MI->getNumParams());
2444       for (const IdentifierInfo *Param : MI->params())
2445         AddIdentifierRef(Param, Record);
2446     }
2447 
2448     // If we have a detailed preprocessing record, record the macro definition
2449     // ID that corresponds to this macro.
2450     if (PPRec)
2451       Record.push_back(MacroDefinitions[PPRec->findMacroDefinition(MI)]);
2452 
2453     Stream.EmitRecord(Code, Record);
2454     Record.clear();
2455 
2456     // Emit the tokens array.
2457     for (unsigned TokNo = 0, e = MI->getNumTokens(); TokNo != e; ++TokNo) {
2458       // Note that we know that the preprocessor does not have any annotation
2459       // tokens in it because they are created by the parser, and thus can't
2460       // be in a macro definition.
2461       const Token &Tok = MI->getReplacementToken(TokNo);
2462       AddToken(Tok, Record);
2463       Stream.EmitRecord(PP_TOKEN, Record);
2464       Record.clear();
2465     }
2466     ++NumMacros;
2467   }
2468 
2469   Stream.ExitBlock();
2470 
2471   // Write the offsets table for macro IDs.
2472   using namespace llvm;
2473 
2474   auto Abbrev = std::make_shared<BitCodeAbbrev>();
2475   Abbrev->Add(BitCodeAbbrevOp(MACRO_OFFSET));
2476   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // # of macros
2477   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // first ID
2478   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 32));   // base offset
2479   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2480 
2481   unsigned MacroOffsetAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2482   {
2483     RecordData::value_type Record[] = {MACRO_OFFSET, MacroOffsets.size(),
2484                                        FirstMacroID - NUM_PREDEF_MACRO_IDS,
2485                                        MacroOffsetsBase - ASTBlockStartOffset};
2486     Stream.EmitRecordWithBlob(MacroOffsetAbbrev, Record, bytes(MacroOffsets));
2487   }
2488 
2489   {
2490     auto Abbrev = std::make_shared<BitCodeAbbrev>();
2491     Abbrev->Add(BitCodeAbbrevOp(PP_INCLUDED_FILES));
2492     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2493     unsigned IncludedFilesAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2494 
2495     SmallString<2048> Buffer;
2496     raw_svector_ostream Out(Buffer);
2497     writeIncludedFiles(Out, PP);
2498     RecordData::value_type Record[] = {PP_INCLUDED_FILES};
2499     Stream.EmitRecordWithBlob(IncludedFilesAbbrev, Record, Buffer.data(),
2500                               Buffer.size());
2501   }
2502 }
2503 
2504 void ASTWriter::WritePreprocessorDetail(PreprocessingRecord &PPRec,
2505                                         uint64_t MacroOffsetsBase) {
2506   if (PPRec.local_begin() == PPRec.local_end())
2507     return;
2508 
2509   SmallVector<PPEntityOffset, 64> PreprocessedEntityOffsets;
2510 
2511   // Enter the preprocessor block.
2512   Stream.EnterSubblock(PREPROCESSOR_DETAIL_BLOCK_ID, 3);
2513 
2514   // If the preprocessor has a preprocessing record, emit it.
2515   unsigned NumPreprocessingRecords = 0;
2516   using namespace llvm;
2517 
2518   // Set up the abbreviation for
2519   unsigned InclusionAbbrev = 0;
2520   {
2521     auto Abbrev = std::make_shared<BitCodeAbbrev>();
2522     Abbrev->Add(BitCodeAbbrevOp(PPD_INCLUSION_DIRECTIVE));
2523     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // filename length
2524     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // in quotes
2525     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // kind
2526     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // imported module
2527     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2528     InclusionAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2529   }
2530 
2531   unsigned FirstPreprocessorEntityID
2532     = (Chain ? PPRec.getNumLoadedPreprocessedEntities() : 0)
2533     + NUM_PREDEF_PP_ENTITY_IDS;
2534   unsigned NextPreprocessorEntityID = FirstPreprocessorEntityID;
2535   RecordData Record;
2536   for (PreprocessingRecord::iterator E = PPRec.local_begin(),
2537                                   EEnd = PPRec.local_end();
2538        E != EEnd;
2539        (void)++E, ++NumPreprocessingRecords, ++NextPreprocessorEntityID) {
2540     Record.clear();
2541 
2542     uint64_t Offset = Stream.GetCurrentBitNo() - MacroOffsetsBase;
2543     assert((Offset >> 32) == 0 && "Preprocessed entity offset too large");
2544     PreprocessedEntityOffsets.push_back(
2545         PPEntityOffset((*E)->getSourceRange(), Offset));
2546 
2547     if (auto *MD = dyn_cast<MacroDefinitionRecord>(*E)) {
2548       // Record this macro definition's ID.
2549       MacroDefinitions[MD] = NextPreprocessorEntityID;
2550 
2551       AddIdentifierRef(MD->getName(), Record);
2552       Stream.EmitRecord(PPD_MACRO_DEFINITION, Record);
2553       continue;
2554     }
2555 
2556     if (auto *ME = dyn_cast<MacroExpansion>(*E)) {
2557       Record.push_back(ME->isBuiltinMacro());
2558       if (ME->isBuiltinMacro())
2559         AddIdentifierRef(ME->getName(), Record);
2560       else
2561         Record.push_back(MacroDefinitions[ME->getDefinition()]);
2562       Stream.EmitRecord(PPD_MACRO_EXPANSION, Record);
2563       continue;
2564     }
2565 
2566     if (auto *ID = dyn_cast<InclusionDirective>(*E)) {
2567       Record.push_back(PPD_INCLUSION_DIRECTIVE);
2568       Record.push_back(ID->getFileName().size());
2569       Record.push_back(ID->wasInQuotes());
2570       Record.push_back(static_cast<unsigned>(ID->getKind()));
2571       Record.push_back(ID->importedModule());
2572       SmallString<64> Buffer;
2573       Buffer += ID->getFileName();
2574       // Check that the FileEntry is not null because it was not resolved and
2575       // we create a PCH even with compiler errors.
2576       if (ID->getFile())
2577         Buffer += ID->getFile()->getName();
2578       Stream.EmitRecordWithBlob(InclusionAbbrev, Record, Buffer);
2579       continue;
2580     }
2581 
2582     llvm_unreachable("Unhandled PreprocessedEntity in ASTWriter");
2583   }
2584   Stream.ExitBlock();
2585 
2586   // Write the offsets table for the preprocessing record.
2587   if (NumPreprocessingRecords > 0) {
2588     assert(PreprocessedEntityOffsets.size() == NumPreprocessingRecords);
2589 
2590     // Write the offsets table for identifier IDs.
2591     using namespace llvm;
2592 
2593     auto Abbrev = std::make_shared<BitCodeAbbrev>();
2594     Abbrev->Add(BitCodeAbbrevOp(PPD_ENTITIES_OFFSETS));
2595     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // first pp entity
2596     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2597     unsigned PPEOffsetAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2598 
2599     RecordData::value_type Record[] = {PPD_ENTITIES_OFFSETS,
2600                                        FirstPreprocessorEntityID -
2601                                            NUM_PREDEF_PP_ENTITY_IDS};
2602     Stream.EmitRecordWithBlob(PPEOffsetAbbrev, Record,
2603                               bytes(PreprocessedEntityOffsets));
2604   }
2605 
2606   // Write the skipped region table for the preprocessing record.
2607   ArrayRef<SourceRange> SkippedRanges = PPRec.getSkippedRanges();
2608   if (SkippedRanges.size() > 0) {
2609     std::vector<PPSkippedRange> SerializedSkippedRanges;
2610     SerializedSkippedRanges.reserve(SkippedRanges.size());
2611     for (auto const& Range : SkippedRanges)
2612       SerializedSkippedRanges.emplace_back(Range);
2613 
2614     using namespace llvm;
2615     auto Abbrev = std::make_shared<BitCodeAbbrev>();
2616     Abbrev->Add(BitCodeAbbrevOp(PPD_SKIPPED_RANGES));
2617     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2618     unsigned PPESkippedRangeAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2619 
2620     Record.clear();
2621     Record.push_back(PPD_SKIPPED_RANGES);
2622     Stream.EmitRecordWithBlob(PPESkippedRangeAbbrev, Record,
2623                               bytes(SerializedSkippedRanges));
2624   }
2625 }
2626 
2627 unsigned ASTWriter::getLocalOrImportedSubmoduleID(const Module *Mod) {
2628   if (!Mod)
2629     return 0;
2630 
2631   auto Known = SubmoduleIDs.find(Mod);
2632   if (Known != SubmoduleIDs.end())
2633     return Known->second;
2634 
2635   auto *Top = Mod->getTopLevelModule();
2636   if (Top != WritingModule &&
2637       (getLangOpts().CompilingPCH ||
2638        !Top->fullModuleNameIs(StringRef(getLangOpts().CurrentModule))))
2639     return 0;
2640 
2641   return SubmoduleIDs[Mod] = NextSubmoduleID++;
2642 }
2643 
2644 unsigned ASTWriter::getSubmoduleID(Module *Mod) {
2645   // FIXME: This can easily happen, if we have a reference to a submodule that
2646   // did not result in us loading a module file for that submodule. For
2647   // instance, a cross-top-level-module 'conflict' declaration will hit this.
2648   unsigned ID = getLocalOrImportedSubmoduleID(Mod);
2649   assert((ID || !Mod) &&
2650          "asked for module ID for non-local, non-imported module");
2651   return ID;
2652 }
2653 
2654 /// Compute the number of modules within the given tree (including the
2655 /// given module).
2656 static unsigned getNumberOfModules(Module *Mod) {
2657   unsigned ChildModules = 0;
2658   for (auto Sub = Mod->submodule_begin(), SubEnd = Mod->submodule_end();
2659        Sub != SubEnd; ++Sub)
2660     ChildModules += getNumberOfModules(*Sub);
2661 
2662   return ChildModules + 1;
2663 }
2664 
2665 void ASTWriter::WriteSubmodules(Module *WritingModule) {
2666   // Enter the submodule description block.
2667   Stream.EnterSubblock(SUBMODULE_BLOCK_ID, /*bits for abbreviations*/5);
2668 
2669   // Write the abbreviations needed for the submodules block.
2670   using namespace llvm;
2671 
2672   auto Abbrev = std::make_shared<BitCodeAbbrev>();
2673   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_DEFINITION));
2674   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ID
2675   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Parent
2676   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // Kind
2677   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsFramework
2678   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsExplicit
2679   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsSystem
2680   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsExternC
2681   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // InferSubmodules...
2682   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // InferExplicit...
2683   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // InferExportWild...
2684   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // ConfigMacrosExh...
2685   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // ModuleMapIsPriv...
2686   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2687   unsigned DefinitionAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2688 
2689   Abbrev = std::make_shared<BitCodeAbbrev>();
2690   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_UMBRELLA_HEADER));
2691   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2692   unsigned UmbrellaAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2693 
2694   Abbrev = std::make_shared<BitCodeAbbrev>();
2695   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_HEADER));
2696   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2697   unsigned HeaderAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2698 
2699   Abbrev = std::make_shared<BitCodeAbbrev>();
2700   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_TOPHEADER));
2701   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2702   unsigned TopHeaderAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2703 
2704   Abbrev = std::make_shared<BitCodeAbbrev>();
2705   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_UMBRELLA_DIR));
2706   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2707   unsigned UmbrellaDirAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2708 
2709   Abbrev = std::make_shared<BitCodeAbbrev>();
2710   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_REQUIRES));
2711   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // State
2712   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));     // Feature
2713   unsigned RequiresAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2714 
2715   Abbrev = std::make_shared<BitCodeAbbrev>();
2716   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_EXCLUDED_HEADER));
2717   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2718   unsigned ExcludedHeaderAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2719 
2720   Abbrev = std::make_shared<BitCodeAbbrev>();
2721   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_TEXTUAL_HEADER));
2722   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2723   unsigned TextualHeaderAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2724 
2725   Abbrev = std::make_shared<BitCodeAbbrev>();
2726   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_PRIVATE_HEADER));
2727   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2728   unsigned PrivateHeaderAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2729 
2730   Abbrev = std::make_shared<BitCodeAbbrev>();
2731   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_PRIVATE_TEXTUAL_HEADER));
2732   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // Name
2733   unsigned PrivateTextualHeaderAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2734 
2735   Abbrev = std::make_shared<BitCodeAbbrev>();
2736   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_LINK_LIBRARY));
2737   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsFramework
2738   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));     // Name
2739   unsigned LinkLibraryAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2740 
2741   Abbrev = std::make_shared<BitCodeAbbrev>();
2742   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_CONFIG_MACRO));
2743   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));    // Macro name
2744   unsigned ConfigMacroAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2745 
2746   Abbrev = std::make_shared<BitCodeAbbrev>();
2747   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_CONFLICT));
2748   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));  // Other module
2749   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));    // Message
2750   unsigned ConflictAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2751 
2752   Abbrev = std::make_shared<BitCodeAbbrev>();
2753   Abbrev->Add(BitCodeAbbrevOp(SUBMODULE_EXPORT_AS));
2754   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));    // Macro name
2755   unsigned ExportAsAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
2756 
2757   // Write the submodule metadata block.
2758   RecordData::value_type Record[] = {
2759       getNumberOfModules(WritingModule),
2760       FirstSubmoduleID - NUM_PREDEF_SUBMODULE_IDS};
2761   Stream.EmitRecord(SUBMODULE_METADATA, Record);
2762 
2763   // Write all of the submodules.
2764   std::queue<Module *> Q;
2765   Q.push(WritingModule);
2766   while (!Q.empty()) {
2767     Module *Mod = Q.front();
2768     Q.pop();
2769     unsigned ID = getSubmoduleID(Mod);
2770 
2771     uint64_t ParentID = 0;
2772     if (Mod->Parent) {
2773       assert(SubmoduleIDs[Mod->Parent] && "Submodule parent not written?");
2774       ParentID = SubmoduleIDs[Mod->Parent];
2775     }
2776 
2777     // Emit the definition of the block.
2778     {
2779       RecordData::value_type Record[] = {SUBMODULE_DEFINITION,
2780                                          ID,
2781                                          ParentID,
2782                                          (RecordData::value_type)Mod->Kind,
2783                                          Mod->IsFramework,
2784                                          Mod->IsExplicit,
2785                                          Mod->IsSystem,
2786                                          Mod->IsExternC,
2787                                          Mod->InferSubmodules,
2788                                          Mod->InferExplicitSubmodules,
2789                                          Mod->InferExportWildcard,
2790                                          Mod->ConfigMacrosExhaustive,
2791                                          Mod->ModuleMapIsPrivate};
2792       Stream.EmitRecordWithBlob(DefinitionAbbrev, Record, Mod->Name);
2793     }
2794 
2795     // Emit the requirements.
2796     for (const auto &R : Mod->Requirements) {
2797       RecordData::value_type Record[] = {SUBMODULE_REQUIRES, R.second};
2798       Stream.EmitRecordWithBlob(RequiresAbbrev, Record, R.first);
2799     }
2800 
2801     // Emit the umbrella header, if there is one.
2802     if (auto UmbrellaHeader = Mod->getUmbrellaHeader()) {
2803       RecordData::value_type Record[] = {SUBMODULE_UMBRELLA_HEADER};
2804       Stream.EmitRecordWithBlob(UmbrellaAbbrev, Record,
2805                                 UmbrellaHeader.NameAsWritten);
2806     } else if (auto UmbrellaDir = Mod->getUmbrellaDir()) {
2807       RecordData::value_type Record[] = {SUBMODULE_UMBRELLA_DIR};
2808       Stream.EmitRecordWithBlob(UmbrellaDirAbbrev, Record,
2809                                 UmbrellaDir.NameAsWritten);
2810     }
2811 
2812     // Emit the headers.
2813     struct {
2814       unsigned RecordKind;
2815       unsigned Abbrev;
2816       Module::HeaderKind HeaderKind;
2817     } HeaderLists[] = {
2818       {SUBMODULE_HEADER, HeaderAbbrev, Module::HK_Normal},
2819       {SUBMODULE_TEXTUAL_HEADER, TextualHeaderAbbrev, Module::HK_Textual},
2820       {SUBMODULE_PRIVATE_HEADER, PrivateHeaderAbbrev, Module::HK_Private},
2821       {SUBMODULE_PRIVATE_TEXTUAL_HEADER, PrivateTextualHeaderAbbrev,
2822         Module::HK_PrivateTextual},
2823       {SUBMODULE_EXCLUDED_HEADER, ExcludedHeaderAbbrev, Module::HK_Excluded}
2824     };
2825     for (auto &HL : HeaderLists) {
2826       RecordData::value_type Record[] = {HL.RecordKind};
2827       for (auto &H : Mod->Headers[HL.HeaderKind])
2828         Stream.EmitRecordWithBlob(HL.Abbrev, Record, H.NameAsWritten);
2829     }
2830 
2831     // Emit the top headers.
2832     {
2833       auto TopHeaders = Mod->getTopHeaders(PP->getFileManager());
2834       RecordData::value_type Record[] = {SUBMODULE_TOPHEADER};
2835       for (auto *H : TopHeaders)
2836         Stream.EmitRecordWithBlob(TopHeaderAbbrev, Record, H->getName());
2837     }
2838 
2839     // Emit the imports.
2840     if (!Mod->Imports.empty()) {
2841       RecordData Record;
2842       for (auto *I : Mod->Imports)
2843         Record.push_back(getSubmoduleID(I));
2844       Stream.EmitRecord(SUBMODULE_IMPORTS, Record);
2845     }
2846 
2847     // Emit the exports.
2848     if (!Mod->Exports.empty()) {
2849       RecordData Record;
2850       for (const auto &E : Mod->Exports) {
2851         // FIXME: This may fail; we don't require that all exported modules
2852         // are local or imported.
2853         Record.push_back(getSubmoduleID(E.getPointer()));
2854         Record.push_back(E.getInt());
2855       }
2856       Stream.EmitRecord(SUBMODULE_EXPORTS, Record);
2857     }
2858 
2859     //FIXME: How do we emit the 'use'd modules?  They may not be submodules.
2860     // Might be unnecessary as use declarations are only used to build the
2861     // module itself.
2862 
2863     // Emit the link libraries.
2864     for (const auto &LL : Mod->LinkLibraries) {
2865       RecordData::value_type Record[] = {SUBMODULE_LINK_LIBRARY,
2866                                          LL.IsFramework};
2867       Stream.EmitRecordWithBlob(LinkLibraryAbbrev, Record, LL.Library);
2868     }
2869 
2870     // Emit the conflicts.
2871     for (const auto &C : Mod->Conflicts) {
2872       // FIXME: This may fail; we don't require that all conflicting modules
2873       // are local or imported.
2874       RecordData::value_type Record[] = {SUBMODULE_CONFLICT,
2875                                          getSubmoduleID(C.Other)};
2876       Stream.EmitRecordWithBlob(ConflictAbbrev, Record, C.Message);
2877     }
2878 
2879     // Emit the configuration macros.
2880     for (const auto &CM : Mod->ConfigMacros) {
2881       RecordData::value_type Record[] = {SUBMODULE_CONFIG_MACRO};
2882       Stream.EmitRecordWithBlob(ConfigMacroAbbrev, Record, CM);
2883     }
2884 
2885     // Emit the initializers, if any.
2886     RecordData Inits;
2887     for (Decl *D : Context->getModuleInitializers(Mod))
2888       Inits.push_back(GetDeclRef(D));
2889     if (!Inits.empty())
2890       Stream.EmitRecord(SUBMODULE_INITIALIZERS, Inits);
2891 
2892     // Emit the name of the re-exported module, if any.
2893     if (!Mod->ExportAsModule.empty()) {
2894       RecordData::value_type Record[] = {SUBMODULE_EXPORT_AS};
2895       Stream.EmitRecordWithBlob(ExportAsAbbrev, Record, Mod->ExportAsModule);
2896     }
2897 
2898     // Queue up the submodules of this module.
2899     for (auto *M : Mod->submodules())
2900       Q.push(M);
2901   }
2902 
2903   Stream.ExitBlock();
2904 
2905   assert((NextSubmoduleID - FirstSubmoduleID ==
2906           getNumberOfModules(WritingModule)) &&
2907          "Wrong # of submodules; found a reference to a non-local, "
2908          "non-imported submodule?");
2909 }
2910 
2911 void ASTWriter::WritePragmaDiagnosticMappings(const DiagnosticsEngine &Diag,
2912                                               bool isModule) {
2913   llvm::SmallDenseMap<const DiagnosticsEngine::DiagState *, unsigned, 64>
2914       DiagStateIDMap;
2915   unsigned CurrID = 0;
2916   RecordData Record;
2917 
2918   auto EncodeDiagStateFlags =
2919       [](const DiagnosticsEngine::DiagState *DS) -> unsigned {
2920     unsigned Result = (unsigned)DS->ExtBehavior;
2921     for (unsigned Val :
2922          {(unsigned)DS->IgnoreAllWarnings, (unsigned)DS->EnableAllWarnings,
2923           (unsigned)DS->WarningsAsErrors, (unsigned)DS->ErrorsAsFatal,
2924           (unsigned)DS->SuppressSystemWarnings})
2925       Result = (Result << 1) | Val;
2926     return Result;
2927   };
2928 
2929   unsigned Flags = EncodeDiagStateFlags(Diag.DiagStatesByLoc.FirstDiagState);
2930   Record.push_back(Flags);
2931 
2932   auto AddDiagState = [&](const DiagnosticsEngine::DiagState *State,
2933                           bool IncludeNonPragmaStates) {
2934     // Ensure that the diagnostic state wasn't modified since it was created.
2935     // We will not correctly round-trip this information otherwise.
2936     assert(Flags == EncodeDiagStateFlags(State) &&
2937            "diag state flags vary in single AST file");
2938 
2939     unsigned &DiagStateID = DiagStateIDMap[State];
2940     Record.push_back(DiagStateID);
2941 
2942     if (DiagStateID == 0) {
2943       DiagStateID = ++CurrID;
2944 
2945       // Add a placeholder for the number of mappings.
2946       auto SizeIdx = Record.size();
2947       Record.emplace_back();
2948       for (const auto &I : *State) {
2949         if (I.second.isPragma() || IncludeNonPragmaStates) {
2950           Record.push_back(I.first);
2951           Record.push_back(I.second.serialize());
2952         }
2953       }
2954       // Update the placeholder.
2955       Record[SizeIdx] = (Record.size() - SizeIdx) / 2;
2956     }
2957   };
2958 
2959   AddDiagState(Diag.DiagStatesByLoc.FirstDiagState, isModule);
2960 
2961   // Reserve a spot for the number of locations with state transitions.
2962   auto NumLocationsIdx = Record.size();
2963   Record.emplace_back();
2964 
2965   // Emit the state transitions.
2966   unsigned NumLocations = 0;
2967   for (auto &FileIDAndFile : Diag.DiagStatesByLoc.Files) {
2968     if (!FileIDAndFile.first.isValid() ||
2969         !FileIDAndFile.second.HasLocalTransitions)
2970       continue;
2971     ++NumLocations;
2972 
2973     SourceLocation Loc = Diag.SourceMgr->getComposedLoc(FileIDAndFile.first, 0);
2974     assert(!Loc.isInvalid() && "start loc for valid FileID is invalid");
2975     AddSourceLocation(Loc, Record);
2976 
2977     Record.push_back(FileIDAndFile.second.StateTransitions.size());
2978     for (auto &StatePoint : FileIDAndFile.second.StateTransitions) {
2979       Record.push_back(StatePoint.Offset);
2980       AddDiagState(StatePoint.State, false);
2981     }
2982   }
2983 
2984   // Backpatch the number of locations.
2985   Record[NumLocationsIdx] = NumLocations;
2986 
2987   // Emit CurDiagStateLoc.  Do it last in order to match source order.
2988   //
2989   // This also protects against a hypothetical corner case with simulating
2990   // -Werror settings for implicit modules in the ASTReader, where reading
2991   // CurDiagState out of context could change whether warning pragmas are
2992   // treated as errors.
2993   AddSourceLocation(Diag.DiagStatesByLoc.CurDiagStateLoc, Record);
2994   AddDiagState(Diag.DiagStatesByLoc.CurDiagState, false);
2995 
2996   Stream.EmitRecord(DIAG_PRAGMA_MAPPINGS, Record);
2997 }
2998 
2999 //===----------------------------------------------------------------------===//
3000 // Type Serialization
3001 //===----------------------------------------------------------------------===//
3002 
3003 /// Write the representation of a type to the AST stream.
3004 void ASTWriter::WriteType(QualType T) {
3005   TypeIdx &IdxRef = TypeIdxs[T];
3006   if (IdxRef.getIndex() == 0) // we haven't seen this type before.
3007     IdxRef = TypeIdx(NextTypeID++);
3008   TypeIdx Idx = IdxRef;
3009 
3010   assert(Idx.getIndex() >= FirstTypeID && "Re-writing a type from a prior AST");
3011 
3012   // Emit the type's representation.
3013   uint64_t Offset = ASTTypeWriter(*this).write(T) - DeclTypesBlockStartOffset;
3014 
3015   // Record the offset for this type.
3016   unsigned Index = Idx.getIndex() - FirstTypeID;
3017   if (TypeOffsets.size() == Index)
3018     TypeOffsets.emplace_back(Offset);
3019   else if (TypeOffsets.size() < Index) {
3020     TypeOffsets.resize(Index + 1);
3021     TypeOffsets[Index].setBitOffset(Offset);
3022   } else {
3023     llvm_unreachable("Types emitted in wrong order");
3024   }
3025 }
3026 
3027 //===----------------------------------------------------------------------===//
3028 // Declaration Serialization
3029 //===----------------------------------------------------------------------===//
3030 
3031 /// Write the block containing all of the declaration IDs
3032 /// lexically declared within the given DeclContext.
3033 ///
3034 /// \returns the offset of the DECL_CONTEXT_LEXICAL block within the
3035 /// bitstream, or 0 if no block was written.
3036 uint64_t ASTWriter::WriteDeclContextLexicalBlock(ASTContext &Context,
3037                                                  DeclContext *DC) {
3038   if (DC->decls_empty())
3039     return 0;
3040 
3041   uint64_t Offset = Stream.GetCurrentBitNo();
3042   SmallVector<uint32_t, 128> KindDeclPairs;
3043   for (const auto *D : DC->decls()) {
3044     KindDeclPairs.push_back(D->getKind());
3045     KindDeclPairs.push_back(GetDeclRef(D));
3046   }
3047 
3048   ++NumLexicalDeclContexts;
3049   RecordData::value_type Record[] = {DECL_CONTEXT_LEXICAL};
3050   Stream.EmitRecordWithBlob(DeclContextLexicalAbbrev, Record,
3051                             bytes(KindDeclPairs));
3052   return Offset;
3053 }
3054 
3055 void ASTWriter::WriteTypeDeclOffsets() {
3056   using namespace llvm;
3057 
3058   // Write the type offsets array
3059   auto Abbrev = std::make_shared<BitCodeAbbrev>();
3060   Abbrev->Add(BitCodeAbbrevOp(TYPE_OFFSET));
3061   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // # of types
3062   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // base type index
3063   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // types block
3064   unsigned TypeOffsetAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
3065   {
3066     RecordData::value_type Record[] = {TYPE_OFFSET, TypeOffsets.size(),
3067                                        FirstTypeID - NUM_PREDEF_TYPE_IDS};
3068     Stream.EmitRecordWithBlob(TypeOffsetAbbrev, Record, bytes(TypeOffsets));
3069   }
3070 
3071   // Write the declaration offsets array
3072   Abbrev = std::make_shared<BitCodeAbbrev>();
3073   Abbrev->Add(BitCodeAbbrevOp(DECL_OFFSET));
3074   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // # of declarations
3075   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // base decl ID
3076   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob)); // declarations block
3077   unsigned DeclOffsetAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
3078   {
3079     RecordData::value_type Record[] = {DECL_OFFSET, DeclOffsets.size(),
3080                                        FirstDeclID - NUM_PREDEF_DECL_IDS};
3081     Stream.EmitRecordWithBlob(DeclOffsetAbbrev, Record, bytes(DeclOffsets));
3082   }
3083 }
3084 
3085 void ASTWriter::WriteFileDeclIDsMap() {
3086   using namespace llvm;
3087 
3088   SmallVector<std::pair<FileID, DeclIDInFileInfo *>, 64> SortedFileDeclIDs;
3089   SortedFileDeclIDs.reserve(FileDeclIDs.size());
3090   for (const auto &P : FileDeclIDs)
3091     SortedFileDeclIDs.push_back(std::make_pair(P.first, P.second.get()));
3092   llvm::sort(SortedFileDeclIDs, llvm::less_first());
3093 
3094   // Join the vectors of DeclIDs from all files.
3095   SmallVector<DeclID, 256> FileGroupedDeclIDs;
3096   for (auto &FileDeclEntry : SortedFileDeclIDs) {
3097     DeclIDInFileInfo &Info = *FileDeclEntry.second;
3098     Info.FirstDeclIndex = FileGroupedDeclIDs.size();
3099     for (auto &LocDeclEntry : Info.DeclIDs)
3100       FileGroupedDeclIDs.push_back(LocDeclEntry.second);
3101   }
3102 
3103   auto Abbrev = std::make_shared<BitCodeAbbrev>();
3104   Abbrev->Add(BitCodeAbbrevOp(FILE_SORTED_DECLS));
3105   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
3106   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
3107   unsigned AbbrevCode = Stream.EmitAbbrev(std::move(Abbrev));
3108   RecordData::value_type Record[] = {FILE_SORTED_DECLS,
3109                                      FileGroupedDeclIDs.size()};
3110   Stream.EmitRecordWithBlob(AbbrevCode, Record, bytes(FileGroupedDeclIDs));
3111 }
3112 
3113 void ASTWriter::WriteComments() {
3114   Stream.EnterSubblock(COMMENTS_BLOCK_ID, 3);
3115   auto _ = llvm::make_scope_exit([this] { Stream.ExitBlock(); });
3116   if (!PP->getPreprocessorOpts().WriteCommentListToPCH)
3117     return;
3118   RecordData Record;
3119   for (const auto &FO : Context->Comments.OrderedComments) {
3120     for (const auto &OC : FO.second) {
3121       const RawComment *I = OC.second;
3122       Record.clear();
3123       AddSourceRange(I->getSourceRange(), Record);
3124       Record.push_back(I->getKind());
3125       Record.push_back(I->isTrailingComment());
3126       Record.push_back(I->isAlmostTrailingComment());
3127       Stream.EmitRecord(COMMENTS_RAW_COMMENT, Record);
3128     }
3129   }
3130 }
3131 
3132 //===----------------------------------------------------------------------===//
3133 // Global Method Pool and Selector Serialization
3134 //===----------------------------------------------------------------------===//
3135 
3136 namespace {
3137 
3138 // Trait used for the on-disk hash table used in the method pool.
3139 class ASTMethodPoolTrait {
3140   ASTWriter &Writer;
3141 
3142 public:
3143   using key_type = Selector;
3144   using key_type_ref = key_type;
3145 
3146   struct data_type {
3147     SelectorID ID;
3148     ObjCMethodList Instance, Factory;
3149   };
3150   using data_type_ref = const data_type &;
3151 
3152   using hash_value_type = unsigned;
3153   using offset_type = unsigned;
3154 
3155   explicit ASTMethodPoolTrait(ASTWriter &Writer) : Writer(Writer) {}
3156 
3157   static hash_value_type ComputeHash(Selector Sel) {
3158     return serialization::ComputeHash(Sel);
3159   }
3160 
3161   std::pair<unsigned, unsigned>
3162     EmitKeyDataLength(raw_ostream& Out, Selector Sel,
3163                       data_type_ref Methods) {
3164     unsigned KeyLen = 2 + (Sel.getNumArgs()? Sel.getNumArgs() * 4 : 4);
3165     unsigned DataLen = 4 + 2 + 2; // 2 bytes for each of the method counts
3166     for (const ObjCMethodList *Method = &Methods.Instance; Method;
3167          Method = Method->getNext())
3168       if (ShouldWriteMethodListNode(Method))
3169         DataLen += 4;
3170     for (const ObjCMethodList *Method = &Methods.Factory; Method;
3171          Method = Method->getNext())
3172       if (ShouldWriteMethodListNode(Method))
3173         DataLen += 4;
3174     return emitULEBKeyDataLength(KeyLen, DataLen, Out);
3175   }
3176 
3177   void EmitKey(raw_ostream& Out, Selector Sel, unsigned) {
3178     using namespace llvm::support;
3179 
3180     endian::Writer LE(Out, little);
3181     uint64_t Start = Out.tell();
3182     assert((Start >> 32) == 0 && "Selector key offset too large");
3183     Writer.SetSelectorOffset(Sel, Start);
3184     unsigned N = Sel.getNumArgs();
3185     LE.write<uint16_t>(N);
3186     if (N == 0)
3187       N = 1;
3188     for (unsigned I = 0; I != N; ++I)
3189       LE.write<uint32_t>(
3190           Writer.getIdentifierRef(Sel.getIdentifierInfoForSlot(I)));
3191   }
3192 
3193   void EmitData(raw_ostream& Out, key_type_ref,
3194                 data_type_ref Methods, unsigned DataLen) {
3195     using namespace llvm::support;
3196 
3197     endian::Writer LE(Out, little);
3198     uint64_t Start = Out.tell(); (void)Start;
3199     LE.write<uint32_t>(Methods.ID);
3200     unsigned NumInstanceMethods = 0;
3201     for (const ObjCMethodList *Method = &Methods.Instance; Method;
3202          Method = Method->getNext())
3203       if (ShouldWriteMethodListNode(Method))
3204         ++NumInstanceMethods;
3205 
3206     unsigned NumFactoryMethods = 0;
3207     for (const ObjCMethodList *Method = &Methods.Factory; Method;
3208          Method = Method->getNext())
3209       if (ShouldWriteMethodListNode(Method))
3210         ++NumFactoryMethods;
3211 
3212     unsigned InstanceBits = Methods.Instance.getBits();
3213     assert(InstanceBits < 4);
3214     unsigned InstanceHasMoreThanOneDeclBit =
3215         Methods.Instance.hasMoreThanOneDecl();
3216     unsigned FullInstanceBits = (NumInstanceMethods << 3) |
3217                                 (InstanceHasMoreThanOneDeclBit << 2) |
3218                                 InstanceBits;
3219     unsigned FactoryBits = Methods.Factory.getBits();
3220     assert(FactoryBits < 4);
3221     unsigned FactoryHasMoreThanOneDeclBit =
3222         Methods.Factory.hasMoreThanOneDecl();
3223     unsigned FullFactoryBits = (NumFactoryMethods << 3) |
3224                                (FactoryHasMoreThanOneDeclBit << 2) |
3225                                FactoryBits;
3226     LE.write<uint16_t>(FullInstanceBits);
3227     LE.write<uint16_t>(FullFactoryBits);
3228     for (const ObjCMethodList *Method = &Methods.Instance; Method;
3229          Method = Method->getNext())
3230       if (ShouldWriteMethodListNode(Method))
3231         LE.write<uint32_t>(Writer.getDeclID(Method->getMethod()));
3232     for (const ObjCMethodList *Method = &Methods.Factory; Method;
3233          Method = Method->getNext())
3234       if (ShouldWriteMethodListNode(Method))
3235         LE.write<uint32_t>(Writer.getDeclID(Method->getMethod()));
3236 
3237     assert(Out.tell() - Start == DataLen && "Data length is wrong");
3238   }
3239 
3240 private:
3241   static bool ShouldWriteMethodListNode(const ObjCMethodList *Node) {
3242     return (Node->getMethod() && !Node->getMethod()->isFromASTFile());
3243   }
3244 };
3245 
3246 } // namespace
3247 
3248 /// Write ObjC data: selectors and the method pool.
3249 ///
3250 /// The method pool contains both instance and factory methods, stored
3251 /// in an on-disk hash table indexed by the selector. The hash table also
3252 /// contains an empty entry for every other selector known to Sema.
3253 void ASTWriter::WriteSelectors(Sema &SemaRef) {
3254   using namespace llvm;
3255 
3256   // Do we have to do anything at all?
3257   if (SemaRef.MethodPool.empty() && SelectorIDs.empty())
3258     return;
3259   unsigned NumTableEntries = 0;
3260   // Create and write out the blob that contains selectors and the method pool.
3261   {
3262     llvm::OnDiskChainedHashTableGenerator<ASTMethodPoolTrait> Generator;
3263     ASTMethodPoolTrait Trait(*this);
3264 
3265     // Create the on-disk hash table representation. We walk through every
3266     // selector we've seen and look it up in the method pool.
3267     SelectorOffsets.resize(NextSelectorID - FirstSelectorID);
3268     for (auto &SelectorAndID : SelectorIDs) {
3269       Selector S = SelectorAndID.first;
3270       SelectorID ID = SelectorAndID.second;
3271       Sema::GlobalMethodPool::iterator F = SemaRef.MethodPool.find(S);
3272       ASTMethodPoolTrait::data_type Data = {
3273         ID,
3274         ObjCMethodList(),
3275         ObjCMethodList()
3276       };
3277       if (F != SemaRef.MethodPool.end()) {
3278         Data.Instance = F->second.first;
3279         Data.Factory = F->second.second;
3280       }
3281       // Only write this selector if it's not in an existing AST or something
3282       // changed.
3283       if (Chain && ID < FirstSelectorID) {
3284         // Selector already exists. Did it change?
3285         bool changed = false;
3286         for (ObjCMethodList *M = &Data.Instance; M && M->getMethod();
3287              M = M->getNext()) {
3288           if (!M->getMethod()->isFromASTFile()) {
3289             changed = true;
3290             Data.Instance = *M;
3291             break;
3292           }
3293         }
3294         for (ObjCMethodList *M = &Data.Factory; M && M->getMethod();
3295              M = M->getNext()) {
3296           if (!M->getMethod()->isFromASTFile()) {
3297             changed = true;
3298             Data.Factory = *M;
3299             break;
3300           }
3301         }
3302         if (!changed)
3303           continue;
3304       } else if (Data.Instance.getMethod() || Data.Factory.getMethod()) {
3305         // A new method pool entry.
3306         ++NumTableEntries;
3307       }
3308       Generator.insert(S, Data, Trait);
3309     }
3310 
3311     // Create the on-disk hash table in a buffer.
3312     SmallString<4096> MethodPool;
3313     uint32_t BucketOffset;
3314     {
3315       using namespace llvm::support;
3316 
3317       ASTMethodPoolTrait Trait(*this);
3318       llvm::raw_svector_ostream Out(MethodPool);
3319       // Make sure that no bucket is at offset 0
3320       endian::write<uint32_t>(Out, 0, little);
3321       BucketOffset = Generator.Emit(Out, Trait);
3322     }
3323 
3324     // Create a blob abbreviation
3325     auto Abbrev = std::make_shared<BitCodeAbbrev>();
3326     Abbrev->Add(BitCodeAbbrevOp(METHOD_POOL));
3327     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
3328     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
3329     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
3330     unsigned MethodPoolAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
3331 
3332     // Write the method pool
3333     {
3334       RecordData::value_type Record[] = {METHOD_POOL, BucketOffset,
3335                                          NumTableEntries};
3336       Stream.EmitRecordWithBlob(MethodPoolAbbrev, Record, MethodPool);
3337     }
3338 
3339     // Create a blob abbreviation for the selector table offsets.
3340     Abbrev = std::make_shared<BitCodeAbbrev>();
3341     Abbrev->Add(BitCodeAbbrevOp(SELECTOR_OFFSETS));
3342     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // size
3343     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // first ID
3344     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
3345     unsigned SelectorOffsetAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
3346 
3347     // Write the selector offsets table.
3348     {
3349       RecordData::value_type Record[] = {
3350           SELECTOR_OFFSETS, SelectorOffsets.size(),
3351           FirstSelectorID - NUM_PREDEF_SELECTOR_IDS};
3352       Stream.EmitRecordWithBlob(SelectorOffsetAbbrev, Record,
3353                                 bytes(SelectorOffsets));
3354     }
3355   }
3356 }
3357 
3358 /// Write the selectors referenced in @selector expression into AST file.
3359 void ASTWriter::WriteReferencedSelectorsPool(Sema &SemaRef) {
3360   using namespace llvm;
3361 
3362   if (SemaRef.ReferencedSelectors.empty())
3363     return;
3364 
3365   RecordData Record;
3366   ASTRecordWriter Writer(*this, Record);
3367 
3368   // Note: this writes out all references even for a dependent AST. But it is
3369   // very tricky to fix, and given that @selector shouldn't really appear in
3370   // headers, probably not worth it. It's not a correctness issue.
3371   for (auto &SelectorAndLocation : SemaRef.ReferencedSelectors) {
3372     Selector Sel = SelectorAndLocation.first;
3373     SourceLocation Loc = SelectorAndLocation.second;
3374     Writer.AddSelectorRef(Sel);
3375     Writer.AddSourceLocation(Loc);
3376   }
3377   Writer.Emit(REFERENCED_SELECTOR_POOL);
3378 }
3379 
3380 //===----------------------------------------------------------------------===//
3381 // Identifier Table Serialization
3382 //===----------------------------------------------------------------------===//
3383 
3384 /// Determine the declaration that should be put into the name lookup table to
3385 /// represent the given declaration in this module. This is usually D itself,
3386 /// but if D was imported and merged into a local declaration, we want the most
3387 /// recent local declaration instead. The chosen declaration will be the most
3388 /// recent declaration in any module that imports this one.
3389 static NamedDecl *getDeclForLocalLookup(const LangOptions &LangOpts,
3390                                         NamedDecl *D) {
3391   if (!LangOpts.Modules || !D->isFromASTFile())
3392     return D;
3393 
3394   if (Decl *Redecl = D->getPreviousDecl()) {
3395     // For Redeclarable decls, a prior declaration might be local.
3396     for (; Redecl; Redecl = Redecl->getPreviousDecl()) {
3397       // If we find a local decl, we're done.
3398       if (!Redecl->isFromASTFile()) {
3399         // Exception: in very rare cases (for injected-class-names), not all
3400         // redeclarations are in the same semantic context. Skip ones in a
3401         // different context. They don't go in this lookup table at all.
3402         if (!Redecl->getDeclContext()->getRedeclContext()->Equals(
3403                 D->getDeclContext()->getRedeclContext()))
3404           continue;
3405         return cast<NamedDecl>(Redecl);
3406       }
3407 
3408       // If we find a decl from a (chained-)PCH stop since we won't find a
3409       // local one.
3410       if (Redecl->getOwningModuleID() == 0)
3411         break;
3412     }
3413   } else if (Decl *First = D->getCanonicalDecl()) {
3414     // For Mergeable decls, the first decl might be local.
3415     if (!First->isFromASTFile())
3416       return cast<NamedDecl>(First);
3417   }
3418 
3419   // All declarations are imported. Our most recent declaration will also be
3420   // the most recent one in anyone who imports us.
3421   return D;
3422 }
3423 
3424 namespace {
3425 
3426 class ASTIdentifierTableTrait {
3427   ASTWriter &Writer;
3428   Preprocessor &PP;
3429   IdentifierResolver &IdResolver;
3430   bool IsModule;
3431   bool NeedDecls;
3432   ASTWriter::RecordData *InterestingIdentifierOffsets;
3433 
3434   /// Determines whether this is an "interesting" identifier that needs a
3435   /// full IdentifierInfo structure written into the hash table. Notably, this
3436   /// doesn't check whether the name has macros defined; use PublicMacroIterator
3437   /// to check that.
3438   bool isInterestingIdentifier(const IdentifierInfo *II, uint64_t MacroOffset) {
3439     if (MacroOffset || II->isPoisoned() ||
3440         (!IsModule && II->getObjCOrBuiltinID()) ||
3441         II->hasRevertedTokenIDToIdentifier() ||
3442         (NeedDecls && II->getFETokenInfo()))
3443       return true;
3444 
3445     return false;
3446   }
3447 
3448 public:
3449   using key_type = IdentifierInfo *;
3450   using key_type_ref = key_type;
3451 
3452   using data_type = IdentID;
3453   using data_type_ref = data_type;
3454 
3455   using hash_value_type = unsigned;
3456   using offset_type = unsigned;
3457 
3458   ASTIdentifierTableTrait(ASTWriter &Writer, Preprocessor &PP,
3459                           IdentifierResolver &IdResolver, bool IsModule,
3460                           ASTWriter::RecordData *InterestingIdentifierOffsets)
3461       : Writer(Writer), PP(PP), IdResolver(IdResolver), IsModule(IsModule),
3462         NeedDecls(!IsModule || !Writer.getLangOpts().CPlusPlus),
3463         InterestingIdentifierOffsets(InterestingIdentifierOffsets) {}
3464 
3465   bool needDecls() const { return NeedDecls; }
3466 
3467   static hash_value_type ComputeHash(const IdentifierInfo* II) {
3468     return llvm::djbHash(II->getName());
3469   }
3470 
3471   bool isInterestingIdentifier(const IdentifierInfo *II) {
3472     auto MacroOffset = Writer.getMacroDirectivesOffset(II);
3473     return isInterestingIdentifier(II, MacroOffset);
3474   }
3475 
3476   bool isInterestingNonMacroIdentifier(const IdentifierInfo *II) {
3477     return isInterestingIdentifier(II, 0);
3478   }
3479 
3480   std::pair<unsigned, unsigned>
3481   EmitKeyDataLength(raw_ostream& Out, IdentifierInfo* II, IdentID ID) {
3482     // Record the location of the identifier data. This is used when generating
3483     // the mapping from persistent IDs to strings.
3484     Writer.SetIdentifierOffset(II, Out.tell());
3485 
3486     // Emit the offset of the key/data length information to the interesting
3487     // identifiers table if necessary.
3488     if (InterestingIdentifierOffsets && isInterestingIdentifier(II))
3489       InterestingIdentifierOffsets->push_back(Out.tell());
3490 
3491     unsigned KeyLen = II->getLength() + 1;
3492     unsigned DataLen = 4; // 4 bytes for the persistent ID << 1
3493     auto MacroOffset = Writer.getMacroDirectivesOffset(II);
3494     if (isInterestingIdentifier(II, MacroOffset)) {
3495       DataLen += 2; // 2 bytes for builtin ID
3496       DataLen += 2; // 2 bytes for flags
3497       if (MacroOffset)
3498         DataLen += 4; // MacroDirectives offset.
3499 
3500       if (NeedDecls) {
3501         for (IdentifierResolver::iterator D = IdResolver.begin(II),
3502                                        DEnd = IdResolver.end();
3503              D != DEnd; ++D)
3504           DataLen += 4;
3505       }
3506     }
3507     return emitULEBKeyDataLength(KeyLen, DataLen, Out);
3508   }
3509 
3510   void EmitKey(raw_ostream& Out, const IdentifierInfo* II,
3511                unsigned KeyLen) {
3512     Out.write(II->getNameStart(), KeyLen);
3513   }
3514 
3515   void EmitData(raw_ostream& Out, IdentifierInfo* II,
3516                 IdentID ID, unsigned) {
3517     using namespace llvm::support;
3518 
3519     endian::Writer LE(Out, little);
3520 
3521     auto MacroOffset = Writer.getMacroDirectivesOffset(II);
3522     if (!isInterestingIdentifier(II, MacroOffset)) {
3523       LE.write<uint32_t>(ID << 1);
3524       return;
3525     }
3526 
3527     LE.write<uint32_t>((ID << 1) | 0x01);
3528     uint32_t Bits = (uint32_t)II->getObjCOrBuiltinID();
3529     assert((Bits & 0xffff) == Bits && "ObjCOrBuiltinID too big for ASTReader.");
3530     LE.write<uint16_t>(Bits);
3531     Bits = 0;
3532     bool HadMacroDefinition = MacroOffset != 0;
3533     Bits = (Bits << 1) | unsigned(HadMacroDefinition);
3534     Bits = (Bits << 1) | unsigned(II->isExtensionToken());
3535     Bits = (Bits << 1) | unsigned(II->isPoisoned());
3536     Bits = (Bits << 1) | unsigned(II->hasRevertedTokenIDToIdentifier());
3537     Bits = (Bits << 1) | unsigned(II->isCPlusPlusOperatorKeyword());
3538     LE.write<uint16_t>(Bits);
3539 
3540     if (HadMacroDefinition)
3541       LE.write<uint32_t>(MacroOffset);
3542 
3543     if (NeedDecls) {
3544       // Emit the declaration IDs in reverse order, because the
3545       // IdentifierResolver provides the declarations as they would be
3546       // visible (e.g., the function "stat" would come before the struct
3547       // "stat"), but the ASTReader adds declarations to the end of the list
3548       // (so we need to see the struct "stat" before the function "stat").
3549       // Only emit declarations that aren't from a chained PCH, though.
3550       SmallVector<NamedDecl *, 16> Decls(IdResolver.begin(II),
3551                                          IdResolver.end());
3552       for (NamedDecl *D : llvm::reverse(Decls))
3553         LE.write<uint32_t>(
3554             Writer.getDeclID(getDeclForLocalLookup(PP.getLangOpts(), D)));
3555     }
3556   }
3557 };
3558 
3559 } // namespace
3560 
3561 /// Write the identifier table into the AST file.
3562 ///
3563 /// The identifier table consists of a blob containing string data
3564 /// (the actual identifiers themselves) and a separate "offsets" index
3565 /// that maps identifier IDs to locations within the blob.
3566 void ASTWriter::WriteIdentifierTable(Preprocessor &PP,
3567                                      IdentifierResolver &IdResolver,
3568                                      bool IsModule) {
3569   using namespace llvm;
3570 
3571   RecordData InterestingIdents;
3572 
3573   // Create and write out the blob that contains the identifier
3574   // strings.
3575   {
3576     llvm::OnDiskChainedHashTableGenerator<ASTIdentifierTableTrait> Generator;
3577     ASTIdentifierTableTrait Trait(
3578         *this, PP, IdResolver, IsModule,
3579         (getLangOpts().CPlusPlus && IsModule) ? &InterestingIdents : nullptr);
3580 
3581     // Look for any identifiers that were named while processing the
3582     // headers, but are otherwise not needed. We add these to the hash
3583     // table to enable checking of the predefines buffer in the case
3584     // where the user adds new macro definitions when building the AST
3585     // file.
3586     SmallVector<const IdentifierInfo *, 128> IIs;
3587     for (const auto &ID : PP.getIdentifierTable())
3588       IIs.push_back(ID.second);
3589     // Sort the identifiers lexicographically before getting them references so
3590     // that their order is stable.
3591     llvm::sort(IIs, llvm::deref<std::less<>>());
3592     for (const IdentifierInfo *II : IIs)
3593       if (Trait.isInterestingNonMacroIdentifier(II))
3594         getIdentifierRef(II);
3595 
3596     // Create the on-disk hash table representation. We only store offsets
3597     // for identifiers that appear here for the first time.
3598     IdentifierOffsets.resize(NextIdentID - FirstIdentID);
3599     for (auto IdentIDPair : IdentifierIDs) {
3600       auto *II = const_cast<IdentifierInfo *>(IdentIDPair.first);
3601       IdentID ID = IdentIDPair.second;
3602       assert(II && "NULL identifier in identifier table");
3603       // Write out identifiers if either the ID is local or the identifier has
3604       // changed since it was loaded.
3605       if (ID >= FirstIdentID || !Chain || !II->isFromAST()
3606           || II->hasChangedSinceDeserialization() ||
3607           (Trait.needDecls() &&
3608            II->hasFETokenInfoChangedSinceDeserialization()))
3609         Generator.insert(II, ID, Trait);
3610     }
3611 
3612     // Create the on-disk hash table in a buffer.
3613     SmallString<4096> IdentifierTable;
3614     uint32_t BucketOffset;
3615     {
3616       using namespace llvm::support;
3617 
3618       llvm::raw_svector_ostream Out(IdentifierTable);
3619       // Make sure that no bucket is at offset 0
3620       endian::write<uint32_t>(Out, 0, little);
3621       BucketOffset = Generator.Emit(Out, Trait);
3622     }
3623 
3624     // Create a blob abbreviation
3625     auto Abbrev = std::make_shared<BitCodeAbbrev>();
3626     Abbrev->Add(BitCodeAbbrevOp(IDENTIFIER_TABLE));
3627     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
3628     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
3629     unsigned IDTableAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
3630 
3631     // Write the identifier table
3632     RecordData::value_type Record[] = {IDENTIFIER_TABLE, BucketOffset};
3633     Stream.EmitRecordWithBlob(IDTableAbbrev, Record, IdentifierTable);
3634   }
3635 
3636   // Write the offsets table for identifier IDs.
3637   auto Abbrev = std::make_shared<BitCodeAbbrev>();
3638   Abbrev->Add(BitCodeAbbrevOp(IDENTIFIER_OFFSET));
3639   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // # of identifiers
3640   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // first ID
3641   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
3642   unsigned IdentifierOffsetAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
3643 
3644 #ifndef NDEBUG
3645   for (unsigned I = 0, N = IdentifierOffsets.size(); I != N; ++I)
3646     assert(IdentifierOffsets[I] && "Missing identifier offset?");
3647 #endif
3648 
3649   RecordData::value_type Record[] = {IDENTIFIER_OFFSET,
3650                                      IdentifierOffsets.size(),
3651                                      FirstIdentID - NUM_PREDEF_IDENT_IDS};
3652   Stream.EmitRecordWithBlob(IdentifierOffsetAbbrev, Record,
3653                             bytes(IdentifierOffsets));
3654 
3655   // In C++, write the list of interesting identifiers (those that are
3656   // defined as macros, poisoned, or similar unusual things).
3657   if (!InterestingIdents.empty())
3658     Stream.EmitRecord(INTERESTING_IDENTIFIERS, InterestingIdents);
3659 }
3660 
3661 //===----------------------------------------------------------------------===//
3662 // DeclContext's Name Lookup Table Serialization
3663 //===----------------------------------------------------------------------===//
3664 
3665 namespace {
3666 
3667 // Trait used for the on-disk hash table used in the method pool.
3668 class ASTDeclContextNameLookupTrait {
3669   ASTWriter &Writer;
3670   llvm::SmallVector<DeclID, 64> DeclIDs;
3671 
3672 public:
3673   using key_type = DeclarationNameKey;
3674   using key_type_ref = key_type;
3675 
3676   /// A start and end index into DeclIDs, representing a sequence of decls.
3677   using data_type = std::pair<unsigned, unsigned>;
3678   using data_type_ref = const data_type &;
3679 
3680   using hash_value_type = unsigned;
3681   using offset_type = unsigned;
3682 
3683   explicit ASTDeclContextNameLookupTrait(ASTWriter &Writer) : Writer(Writer) {}
3684 
3685   template<typename Coll>
3686   data_type getData(const Coll &Decls) {
3687     unsigned Start = DeclIDs.size();
3688     for (NamedDecl *D : Decls) {
3689       DeclIDs.push_back(
3690           Writer.GetDeclRef(getDeclForLocalLookup(Writer.getLangOpts(), D)));
3691     }
3692     return std::make_pair(Start, DeclIDs.size());
3693   }
3694 
3695   data_type ImportData(const reader::ASTDeclContextNameLookupTrait::data_type &FromReader) {
3696     unsigned Start = DeclIDs.size();
3697     for (auto ID : FromReader)
3698       DeclIDs.push_back(ID);
3699     return std::make_pair(Start, DeclIDs.size());
3700   }
3701 
3702   static bool EqualKey(key_type_ref a, key_type_ref b) {
3703     return a == b;
3704   }
3705 
3706   hash_value_type ComputeHash(DeclarationNameKey Name) {
3707     return Name.getHash();
3708   }
3709 
3710   void EmitFileRef(raw_ostream &Out, ModuleFile *F) const {
3711     assert(Writer.hasChain() &&
3712            "have reference to loaded module file but no chain?");
3713 
3714     using namespace llvm::support;
3715 
3716     endian::write<uint32_t>(Out, Writer.getChain()->getModuleFileID(F), little);
3717   }
3718 
3719   std::pair<unsigned, unsigned> EmitKeyDataLength(raw_ostream &Out,
3720                                                   DeclarationNameKey Name,
3721                                                   data_type_ref Lookup) {
3722     unsigned KeyLen = 1;
3723     switch (Name.getKind()) {
3724     case DeclarationName::Identifier:
3725     case DeclarationName::ObjCZeroArgSelector:
3726     case DeclarationName::ObjCOneArgSelector:
3727     case DeclarationName::ObjCMultiArgSelector:
3728     case DeclarationName::CXXLiteralOperatorName:
3729     case DeclarationName::CXXDeductionGuideName:
3730       KeyLen += 4;
3731       break;
3732     case DeclarationName::CXXOperatorName:
3733       KeyLen += 1;
3734       break;
3735     case DeclarationName::CXXConstructorName:
3736     case DeclarationName::CXXDestructorName:
3737     case DeclarationName::CXXConversionFunctionName:
3738     case DeclarationName::CXXUsingDirective:
3739       break;
3740     }
3741 
3742     // 4 bytes for each DeclID.
3743     unsigned DataLen = 4 * (Lookup.second - Lookup.first);
3744 
3745     return emitULEBKeyDataLength(KeyLen, DataLen, Out);
3746   }
3747 
3748   void EmitKey(raw_ostream &Out, DeclarationNameKey Name, unsigned) {
3749     using namespace llvm::support;
3750 
3751     endian::Writer LE(Out, little);
3752     LE.write<uint8_t>(Name.getKind());
3753     switch (Name.getKind()) {
3754     case DeclarationName::Identifier:
3755     case DeclarationName::CXXLiteralOperatorName:
3756     case DeclarationName::CXXDeductionGuideName:
3757       LE.write<uint32_t>(Writer.getIdentifierRef(Name.getIdentifier()));
3758       return;
3759     case DeclarationName::ObjCZeroArgSelector:
3760     case DeclarationName::ObjCOneArgSelector:
3761     case DeclarationName::ObjCMultiArgSelector:
3762       LE.write<uint32_t>(Writer.getSelectorRef(Name.getSelector()));
3763       return;
3764     case DeclarationName::CXXOperatorName:
3765       assert(Name.getOperatorKind() < NUM_OVERLOADED_OPERATORS &&
3766              "Invalid operator?");
3767       LE.write<uint8_t>(Name.getOperatorKind());
3768       return;
3769     case DeclarationName::CXXConstructorName:
3770     case DeclarationName::CXXDestructorName:
3771     case DeclarationName::CXXConversionFunctionName:
3772     case DeclarationName::CXXUsingDirective:
3773       return;
3774     }
3775 
3776     llvm_unreachable("Invalid name kind?");
3777   }
3778 
3779   void EmitData(raw_ostream &Out, key_type_ref, data_type Lookup,
3780                 unsigned DataLen) {
3781     using namespace llvm::support;
3782 
3783     endian::Writer LE(Out, little);
3784     uint64_t Start = Out.tell(); (void)Start;
3785     for (unsigned I = Lookup.first, N = Lookup.second; I != N; ++I)
3786       LE.write<uint32_t>(DeclIDs[I]);
3787     assert(Out.tell() - Start == DataLen && "Data length is wrong");
3788   }
3789 };
3790 
3791 } // namespace
3792 
3793 bool ASTWriter::isLookupResultExternal(StoredDeclsList &Result,
3794                                        DeclContext *DC) {
3795   return Result.hasExternalDecls() &&
3796          DC->hasNeedToReconcileExternalVisibleStorage();
3797 }
3798 
3799 bool ASTWriter::isLookupResultEntirelyExternal(StoredDeclsList &Result,
3800                                                DeclContext *DC) {
3801   for (auto *D : Result.getLookupResult())
3802     if (!getDeclForLocalLookup(getLangOpts(), D)->isFromASTFile())
3803       return false;
3804 
3805   return true;
3806 }
3807 
3808 void
3809 ASTWriter::GenerateNameLookupTable(const DeclContext *ConstDC,
3810                                    llvm::SmallVectorImpl<char> &LookupTable) {
3811   assert(!ConstDC->hasLazyLocalLexicalLookups() &&
3812          !ConstDC->hasLazyExternalLexicalLookups() &&
3813          "must call buildLookups first");
3814 
3815   // FIXME: We need to build the lookups table, which is logically const.
3816   auto *DC = const_cast<DeclContext*>(ConstDC);
3817   assert(DC == DC->getPrimaryContext() && "only primary DC has lookup table");
3818 
3819   // Create the on-disk hash table representation.
3820   MultiOnDiskHashTableGenerator<reader::ASTDeclContextNameLookupTrait,
3821                                 ASTDeclContextNameLookupTrait> Generator;
3822   ASTDeclContextNameLookupTrait Trait(*this);
3823 
3824   // The first step is to collect the declaration names which we need to
3825   // serialize into the name lookup table, and to collect them in a stable
3826   // order.
3827   SmallVector<DeclarationName, 16> Names;
3828 
3829   // We also build up small sets of the constructor and conversion function
3830   // names which are visible.
3831   llvm::SmallPtrSet<DeclarationName, 8> ConstructorNameSet, ConversionNameSet;
3832 
3833   for (auto &Lookup : *DC->buildLookup()) {
3834     auto &Name = Lookup.first;
3835     auto &Result = Lookup.second;
3836 
3837     // If there are no local declarations in our lookup result, we
3838     // don't need to write an entry for the name at all. If we can't
3839     // write out a lookup set without performing more deserialization,
3840     // just skip this entry.
3841     if (isLookupResultExternal(Result, DC) &&
3842         isLookupResultEntirelyExternal(Result, DC))
3843       continue;
3844 
3845     // We also skip empty results. If any of the results could be external and
3846     // the currently available results are empty, then all of the results are
3847     // external and we skip it above. So the only way we get here with an empty
3848     // results is when no results could have been external *and* we have
3849     // external results.
3850     //
3851     // FIXME: While we might want to start emitting on-disk entries for negative
3852     // lookups into a decl context as an optimization, today we *have* to skip
3853     // them because there are names with empty lookup results in decl contexts
3854     // which we can't emit in any stable ordering: we lookup constructors and
3855     // conversion functions in the enclosing namespace scope creating empty
3856     // results for them. This in almost certainly a bug in Clang's name lookup,
3857     // but that is likely to be hard or impossible to fix and so we tolerate it
3858     // here by omitting lookups with empty results.
3859     if (Lookup.second.getLookupResult().empty())
3860       continue;
3861 
3862     switch (Lookup.first.getNameKind()) {
3863     default:
3864       Names.push_back(Lookup.first);
3865       break;
3866 
3867     case DeclarationName::CXXConstructorName:
3868       assert(isa<CXXRecordDecl>(DC) &&
3869              "Cannot have a constructor name outside of a class!");
3870       ConstructorNameSet.insert(Name);
3871       break;
3872 
3873     case DeclarationName::CXXConversionFunctionName:
3874       assert(isa<CXXRecordDecl>(DC) &&
3875              "Cannot have a conversion function name outside of a class!");
3876       ConversionNameSet.insert(Name);
3877       break;
3878     }
3879   }
3880 
3881   // Sort the names into a stable order.
3882   llvm::sort(Names);
3883 
3884   if (auto *D = dyn_cast<CXXRecordDecl>(DC)) {
3885     // We need to establish an ordering of constructor and conversion function
3886     // names, and they don't have an intrinsic ordering.
3887 
3888     // First we try the easy case by forming the current context's constructor
3889     // name and adding that name first. This is a very useful optimization to
3890     // avoid walking the lexical declarations in many cases, and it also
3891     // handles the only case where a constructor name can come from some other
3892     // lexical context -- when that name is an implicit constructor merged from
3893     // another declaration in the redecl chain. Any non-implicit constructor or
3894     // conversion function which doesn't occur in all the lexical contexts
3895     // would be an ODR violation.
3896     auto ImplicitCtorName = Context->DeclarationNames.getCXXConstructorName(
3897         Context->getCanonicalType(Context->getRecordType(D)));
3898     if (ConstructorNameSet.erase(ImplicitCtorName))
3899       Names.push_back(ImplicitCtorName);
3900 
3901     // If we still have constructors or conversion functions, we walk all the
3902     // names in the decl and add the constructors and conversion functions
3903     // which are visible in the order they lexically occur within the context.
3904     if (!ConstructorNameSet.empty() || !ConversionNameSet.empty())
3905       for (Decl *ChildD : cast<CXXRecordDecl>(DC)->decls())
3906         if (auto *ChildND = dyn_cast<NamedDecl>(ChildD)) {
3907           auto Name = ChildND->getDeclName();
3908           switch (Name.getNameKind()) {
3909           default:
3910             continue;
3911 
3912           case DeclarationName::CXXConstructorName:
3913             if (ConstructorNameSet.erase(Name))
3914               Names.push_back(Name);
3915             break;
3916 
3917           case DeclarationName::CXXConversionFunctionName:
3918             if (ConversionNameSet.erase(Name))
3919               Names.push_back(Name);
3920             break;
3921           }
3922 
3923           if (ConstructorNameSet.empty() && ConversionNameSet.empty())
3924             break;
3925         }
3926 
3927     assert(ConstructorNameSet.empty() && "Failed to find all of the visible "
3928                                          "constructors by walking all the "
3929                                          "lexical members of the context.");
3930     assert(ConversionNameSet.empty() && "Failed to find all of the visible "
3931                                         "conversion functions by walking all "
3932                                         "the lexical members of the context.");
3933   }
3934 
3935   // Next we need to do a lookup with each name into this decl context to fully
3936   // populate any results from external sources. We don't actually use the
3937   // results of these lookups because we only want to use the results after all
3938   // results have been loaded and the pointers into them will be stable.
3939   for (auto &Name : Names)
3940     DC->lookup(Name);
3941 
3942   // Now we need to insert the results for each name into the hash table. For
3943   // constructor names and conversion function names, we actually need to merge
3944   // all of the results for them into one list of results each and insert
3945   // those.
3946   SmallVector<NamedDecl *, 8> ConstructorDecls;
3947   SmallVector<NamedDecl *, 8> ConversionDecls;
3948 
3949   // Now loop over the names, either inserting them or appending for the two
3950   // special cases.
3951   for (auto &Name : Names) {
3952     DeclContext::lookup_result Result = DC->noload_lookup(Name);
3953 
3954     switch (Name.getNameKind()) {
3955     default:
3956       Generator.insert(Name, Trait.getData(Result), Trait);
3957       break;
3958 
3959     case DeclarationName::CXXConstructorName:
3960       ConstructorDecls.append(Result.begin(), Result.end());
3961       break;
3962 
3963     case DeclarationName::CXXConversionFunctionName:
3964       ConversionDecls.append(Result.begin(), Result.end());
3965       break;
3966     }
3967   }
3968 
3969   // Handle our two special cases if we ended up having any. We arbitrarily use
3970   // the first declaration's name here because the name itself isn't part of
3971   // the key, only the kind of name is used.
3972   if (!ConstructorDecls.empty())
3973     Generator.insert(ConstructorDecls.front()->getDeclName(),
3974                      Trait.getData(ConstructorDecls), Trait);
3975   if (!ConversionDecls.empty())
3976     Generator.insert(ConversionDecls.front()->getDeclName(),
3977                      Trait.getData(ConversionDecls), Trait);
3978 
3979   // Create the on-disk hash table. Also emit the existing imported and
3980   // merged table if there is one.
3981   auto *Lookups = Chain ? Chain->getLoadedLookupTables(DC) : nullptr;
3982   Generator.emit(LookupTable, Trait, Lookups ? &Lookups->Table : nullptr);
3983 }
3984 
3985 /// Write the block containing all of the declaration IDs
3986 /// visible from the given DeclContext.
3987 ///
3988 /// \returns the offset of the DECL_CONTEXT_VISIBLE block within the
3989 /// bitstream, or 0 if no block was written.
3990 uint64_t ASTWriter::WriteDeclContextVisibleBlock(ASTContext &Context,
3991                                                  DeclContext *DC) {
3992   // If we imported a key declaration of this namespace, write the visible
3993   // lookup results as an update record for it rather than including them
3994   // on this declaration. We will only look at key declarations on reload.
3995   if (isa<NamespaceDecl>(DC) && Chain &&
3996       Chain->getKeyDeclaration(cast<Decl>(DC))->isFromASTFile()) {
3997     // Only do this once, for the first local declaration of the namespace.
3998     for (auto *Prev = cast<NamespaceDecl>(DC)->getPreviousDecl(); Prev;
3999          Prev = Prev->getPreviousDecl())
4000       if (!Prev->isFromASTFile())
4001         return 0;
4002 
4003     // Note that we need to emit an update record for the primary context.
4004     UpdatedDeclContexts.insert(DC->getPrimaryContext());
4005 
4006     // Make sure all visible decls are written. They will be recorded later. We
4007     // do this using a side data structure so we can sort the names into
4008     // a deterministic order.
4009     StoredDeclsMap *Map = DC->getPrimaryContext()->buildLookup();
4010     SmallVector<std::pair<DeclarationName, DeclContext::lookup_result>, 16>
4011         LookupResults;
4012     if (Map) {
4013       LookupResults.reserve(Map->size());
4014       for (auto &Entry : *Map)
4015         LookupResults.push_back(
4016             std::make_pair(Entry.first, Entry.second.getLookupResult()));
4017     }
4018 
4019     llvm::sort(LookupResults, llvm::less_first());
4020     for (auto &NameAndResult : LookupResults) {
4021       DeclarationName Name = NameAndResult.first;
4022       DeclContext::lookup_result Result = NameAndResult.second;
4023       if (Name.getNameKind() == DeclarationName::CXXConstructorName ||
4024           Name.getNameKind() == DeclarationName::CXXConversionFunctionName) {
4025         // We have to work around a name lookup bug here where negative lookup
4026         // results for these names get cached in namespace lookup tables (these
4027         // names should never be looked up in a namespace).
4028         assert(Result.empty() && "Cannot have a constructor or conversion "
4029                                  "function name in a namespace!");
4030         continue;
4031       }
4032 
4033       for (NamedDecl *ND : Result)
4034         if (!ND->isFromASTFile())
4035           GetDeclRef(ND);
4036     }
4037 
4038     return 0;
4039   }
4040 
4041   if (DC->getPrimaryContext() != DC)
4042     return 0;
4043 
4044   // Skip contexts which don't support name lookup.
4045   if (!DC->isLookupContext())
4046     return 0;
4047 
4048   // If not in C++, we perform name lookup for the translation unit via the
4049   // IdentifierInfo chains, don't bother to build a visible-declarations table.
4050   if (DC->isTranslationUnit() && !Context.getLangOpts().CPlusPlus)
4051     return 0;
4052 
4053   // Serialize the contents of the mapping used for lookup. Note that,
4054   // although we have two very different code paths, the serialized
4055   // representation is the same for both cases: a declaration name,
4056   // followed by a size, followed by references to the visible
4057   // declarations that have that name.
4058   uint64_t Offset = Stream.GetCurrentBitNo();
4059   StoredDeclsMap *Map = DC->buildLookup();
4060   if (!Map || Map->empty())
4061     return 0;
4062 
4063   // Create the on-disk hash table in a buffer.
4064   SmallString<4096> LookupTable;
4065   GenerateNameLookupTable(DC, LookupTable);
4066 
4067   // Write the lookup table
4068   RecordData::value_type Record[] = {DECL_CONTEXT_VISIBLE};
4069   Stream.EmitRecordWithBlob(DeclContextVisibleLookupAbbrev, Record,
4070                             LookupTable);
4071   ++NumVisibleDeclContexts;
4072   return Offset;
4073 }
4074 
4075 /// Write an UPDATE_VISIBLE block for the given context.
4076 ///
4077 /// UPDATE_VISIBLE blocks contain the declarations that are added to an existing
4078 /// DeclContext in a dependent AST file. As such, they only exist for the TU
4079 /// (in C++), for namespaces, and for classes with forward-declared unscoped
4080 /// enumeration members (in C++11).
4081 void ASTWriter::WriteDeclContextVisibleUpdate(const DeclContext *DC) {
4082   StoredDeclsMap *Map = DC->getLookupPtr();
4083   if (!Map || Map->empty())
4084     return;
4085 
4086   // Create the on-disk hash table in a buffer.
4087   SmallString<4096> LookupTable;
4088   GenerateNameLookupTable(DC, LookupTable);
4089 
4090   // If we're updating a namespace, select a key declaration as the key for the
4091   // update record; those are the only ones that will be checked on reload.
4092   if (isa<NamespaceDecl>(DC))
4093     DC = cast<DeclContext>(Chain->getKeyDeclaration(cast<Decl>(DC)));
4094 
4095   // Write the lookup table
4096   RecordData::value_type Record[] = {UPDATE_VISIBLE, getDeclID(cast<Decl>(DC))};
4097   Stream.EmitRecordWithBlob(UpdateVisibleAbbrev, Record, LookupTable);
4098 }
4099 
4100 /// Write an FP_PRAGMA_OPTIONS block for the given FPOptions.
4101 void ASTWriter::WriteFPPragmaOptions(const FPOptionsOverride &Opts) {
4102   RecordData::value_type Record[] = {Opts.getAsOpaqueInt()};
4103   Stream.EmitRecord(FP_PRAGMA_OPTIONS, Record);
4104 }
4105 
4106 /// Write an OPENCL_EXTENSIONS block for the given OpenCLOptions.
4107 void ASTWriter::WriteOpenCLExtensions(Sema &SemaRef) {
4108   if (!SemaRef.Context.getLangOpts().OpenCL)
4109     return;
4110 
4111   const OpenCLOptions &Opts = SemaRef.getOpenCLOptions();
4112   RecordData Record;
4113   for (const auto &I:Opts.OptMap) {
4114     AddString(I.getKey(), Record);
4115     auto V = I.getValue();
4116     Record.push_back(V.Supported ? 1 : 0);
4117     Record.push_back(V.Enabled ? 1 : 0);
4118     Record.push_back(V.WithPragma ? 1 : 0);
4119     Record.push_back(V.Avail);
4120     Record.push_back(V.Core);
4121     Record.push_back(V.Opt);
4122   }
4123   Stream.EmitRecord(OPENCL_EXTENSIONS, Record);
4124 }
4125 void ASTWriter::WriteCUDAPragmas(Sema &SemaRef) {
4126   if (SemaRef.ForceCUDAHostDeviceDepth > 0) {
4127     RecordData::value_type Record[] = {SemaRef.ForceCUDAHostDeviceDepth};
4128     Stream.EmitRecord(CUDA_PRAGMA_FORCE_HOST_DEVICE_DEPTH, Record);
4129   }
4130 }
4131 
4132 void ASTWriter::WriteObjCCategories() {
4133   SmallVector<ObjCCategoriesInfo, 2> CategoriesMap;
4134   RecordData Categories;
4135 
4136   for (unsigned I = 0, N = ObjCClassesWithCategories.size(); I != N; ++I) {
4137     unsigned Size = 0;
4138     unsigned StartIndex = Categories.size();
4139 
4140     ObjCInterfaceDecl *Class = ObjCClassesWithCategories[I];
4141 
4142     // Allocate space for the size.
4143     Categories.push_back(0);
4144 
4145     // Add the categories.
4146     for (ObjCInterfaceDecl::known_categories_iterator
4147            Cat = Class->known_categories_begin(),
4148            CatEnd = Class->known_categories_end();
4149          Cat != CatEnd; ++Cat, ++Size) {
4150       assert(getDeclID(*Cat) != 0 && "Bogus category");
4151       AddDeclRef(*Cat, Categories);
4152     }
4153 
4154     // Update the size.
4155     Categories[StartIndex] = Size;
4156 
4157     // Record this interface -> category map.
4158     ObjCCategoriesInfo CatInfo = { getDeclID(Class), StartIndex };
4159     CategoriesMap.push_back(CatInfo);
4160   }
4161 
4162   // Sort the categories map by the definition ID, since the reader will be
4163   // performing binary searches on this information.
4164   llvm::array_pod_sort(CategoriesMap.begin(), CategoriesMap.end());
4165 
4166   // Emit the categories map.
4167   using namespace llvm;
4168 
4169   auto Abbrev = std::make_shared<BitCodeAbbrev>();
4170   Abbrev->Add(BitCodeAbbrevOp(OBJC_CATEGORIES_MAP));
4171   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // # of entries
4172   Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
4173   unsigned AbbrevID = Stream.EmitAbbrev(std::move(Abbrev));
4174 
4175   RecordData::value_type Record[] = {OBJC_CATEGORIES_MAP, CategoriesMap.size()};
4176   Stream.EmitRecordWithBlob(AbbrevID, Record,
4177                             reinterpret_cast<char *>(CategoriesMap.data()),
4178                             CategoriesMap.size() * sizeof(ObjCCategoriesInfo));
4179 
4180   // Emit the category lists.
4181   Stream.EmitRecord(OBJC_CATEGORIES, Categories);
4182 }
4183 
4184 void ASTWriter::WriteLateParsedTemplates(Sema &SemaRef) {
4185   Sema::LateParsedTemplateMapT &LPTMap = SemaRef.LateParsedTemplateMap;
4186 
4187   if (LPTMap.empty())
4188     return;
4189 
4190   RecordData Record;
4191   for (auto &LPTMapEntry : LPTMap) {
4192     const FunctionDecl *FD = LPTMapEntry.first;
4193     LateParsedTemplate &LPT = *LPTMapEntry.second;
4194     AddDeclRef(FD, Record);
4195     AddDeclRef(LPT.D, Record);
4196     Record.push_back(LPT.Toks.size());
4197 
4198     for (const auto &Tok : LPT.Toks) {
4199       AddToken(Tok, Record);
4200     }
4201   }
4202   Stream.EmitRecord(LATE_PARSED_TEMPLATE, Record);
4203 }
4204 
4205 /// Write the state of 'pragma clang optimize' at the end of the module.
4206 void ASTWriter::WriteOptimizePragmaOptions(Sema &SemaRef) {
4207   RecordData Record;
4208   SourceLocation PragmaLoc = SemaRef.getOptimizeOffPragmaLocation();
4209   AddSourceLocation(PragmaLoc, Record);
4210   Stream.EmitRecord(OPTIMIZE_PRAGMA_OPTIONS, Record);
4211 }
4212 
4213 /// Write the state of 'pragma ms_struct' at the end of the module.
4214 void ASTWriter::WriteMSStructPragmaOptions(Sema &SemaRef) {
4215   RecordData Record;
4216   Record.push_back(SemaRef.MSStructPragmaOn ? PMSST_ON : PMSST_OFF);
4217   Stream.EmitRecord(MSSTRUCT_PRAGMA_OPTIONS, Record);
4218 }
4219 
4220 /// Write the state of 'pragma pointers_to_members' at the end of the
4221 //module.
4222 void ASTWriter::WriteMSPointersToMembersPragmaOptions(Sema &SemaRef) {
4223   RecordData Record;
4224   Record.push_back(SemaRef.MSPointerToMemberRepresentationMethod);
4225   AddSourceLocation(SemaRef.ImplicitMSInheritanceAttrLoc, Record);
4226   Stream.EmitRecord(POINTERS_TO_MEMBERS_PRAGMA_OPTIONS, Record);
4227 }
4228 
4229 /// Write the state of 'pragma align/pack' at the end of the module.
4230 void ASTWriter::WritePackPragmaOptions(Sema &SemaRef) {
4231   // Don't serialize pragma align/pack state for modules, since it should only
4232   // take effect on a per-submodule basis.
4233   if (WritingModule)
4234     return;
4235 
4236   RecordData Record;
4237   AddAlignPackInfo(SemaRef.AlignPackStack.CurrentValue, Record);
4238   AddSourceLocation(SemaRef.AlignPackStack.CurrentPragmaLocation, Record);
4239   Record.push_back(SemaRef.AlignPackStack.Stack.size());
4240   for (const auto &StackEntry : SemaRef.AlignPackStack.Stack) {
4241     AddAlignPackInfo(StackEntry.Value, Record);
4242     AddSourceLocation(StackEntry.PragmaLocation, Record);
4243     AddSourceLocation(StackEntry.PragmaPushLocation, Record);
4244     AddString(StackEntry.StackSlotLabel, Record);
4245   }
4246   Stream.EmitRecord(ALIGN_PACK_PRAGMA_OPTIONS, Record);
4247 }
4248 
4249 /// Write the state of 'pragma float_control' at the end of the module.
4250 void ASTWriter::WriteFloatControlPragmaOptions(Sema &SemaRef) {
4251   // Don't serialize pragma float_control state for modules,
4252   // since it should only take effect on a per-submodule basis.
4253   if (WritingModule)
4254     return;
4255 
4256   RecordData Record;
4257   Record.push_back(SemaRef.FpPragmaStack.CurrentValue.getAsOpaqueInt());
4258   AddSourceLocation(SemaRef.FpPragmaStack.CurrentPragmaLocation, Record);
4259   Record.push_back(SemaRef.FpPragmaStack.Stack.size());
4260   for (const auto &StackEntry : SemaRef.FpPragmaStack.Stack) {
4261     Record.push_back(StackEntry.Value.getAsOpaqueInt());
4262     AddSourceLocation(StackEntry.PragmaLocation, Record);
4263     AddSourceLocation(StackEntry.PragmaPushLocation, Record);
4264     AddString(StackEntry.StackSlotLabel, Record);
4265   }
4266   Stream.EmitRecord(FLOAT_CONTROL_PRAGMA_OPTIONS, Record);
4267 }
4268 
4269 void ASTWriter::WriteModuleFileExtension(Sema &SemaRef,
4270                                          ModuleFileExtensionWriter &Writer) {
4271   // Enter the extension block.
4272   Stream.EnterSubblock(EXTENSION_BLOCK_ID, 4);
4273 
4274   // Emit the metadata record abbreviation.
4275   auto Abv = std::make_shared<llvm::BitCodeAbbrev>();
4276   Abv->Add(llvm::BitCodeAbbrevOp(EXTENSION_METADATA));
4277   Abv->Add(llvm::BitCodeAbbrevOp(llvm::BitCodeAbbrevOp::VBR, 6));
4278   Abv->Add(llvm::BitCodeAbbrevOp(llvm::BitCodeAbbrevOp::VBR, 6));
4279   Abv->Add(llvm::BitCodeAbbrevOp(llvm::BitCodeAbbrevOp::VBR, 6));
4280   Abv->Add(llvm::BitCodeAbbrevOp(llvm::BitCodeAbbrevOp::VBR, 6));
4281   Abv->Add(llvm::BitCodeAbbrevOp(llvm::BitCodeAbbrevOp::Blob));
4282   unsigned Abbrev = Stream.EmitAbbrev(std::move(Abv));
4283 
4284   // Emit the metadata record.
4285   RecordData Record;
4286   auto Metadata = Writer.getExtension()->getExtensionMetadata();
4287   Record.push_back(EXTENSION_METADATA);
4288   Record.push_back(Metadata.MajorVersion);
4289   Record.push_back(Metadata.MinorVersion);
4290   Record.push_back(Metadata.BlockName.size());
4291   Record.push_back(Metadata.UserInfo.size());
4292   SmallString<64> Buffer;
4293   Buffer += Metadata.BlockName;
4294   Buffer += Metadata.UserInfo;
4295   Stream.EmitRecordWithBlob(Abbrev, Record, Buffer);
4296 
4297   // Emit the contents of the extension block.
4298   Writer.writeExtensionContents(SemaRef, Stream);
4299 
4300   // Exit the extension block.
4301   Stream.ExitBlock();
4302 }
4303 
4304 //===----------------------------------------------------------------------===//
4305 // General Serialization Routines
4306 //===----------------------------------------------------------------------===//
4307 
4308 void ASTRecordWriter::AddAttr(const Attr *A) {
4309   auto &Record = *this;
4310   if (!A)
4311     return Record.push_back(0);
4312   Record.push_back(A->getKind() + 1); // FIXME: stable encoding, target attrs
4313 
4314   Record.AddIdentifierRef(A->getAttrName());
4315   Record.AddIdentifierRef(A->getScopeName());
4316   Record.AddSourceRange(A->getRange());
4317   Record.AddSourceLocation(A->getScopeLoc());
4318   Record.push_back(A->getParsedKind());
4319   Record.push_back(A->getSyntax());
4320   Record.push_back(A->getAttributeSpellingListIndexRaw());
4321 
4322 #include "clang/Serialization/AttrPCHWrite.inc"
4323 }
4324 
4325 /// Emit the list of attributes to the specified record.
4326 void ASTRecordWriter::AddAttributes(ArrayRef<const Attr *> Attrs) {
4327   push_back(Attrs.size());
4328   for (const auto *A : Attrs)
4329     AddAttr(A);
4330 }
4331 
4332 void ASTWriter::AddToken(const Token &Tok, RecordDataImpl &Record) {
4333   AddSourceLocation(Tok.getLocation(), Record);
4334   Record.push_back(Tok.getLength());
4335 
4336   // FIXME: When reading literal tokens, reconstruct the literal pointer
4337   // if it is needed.
4338   AddIdentifierRef(Tok.getIdentifierInfo(), Record);
4339   // FIXME: Should translate token kind to a stable encoding.
4340   Record.push_back(Tok.getKind());
4341   // FIXME: Should translate token flags to a stable encoding.
4342   Record.push_back(Tok.getFlags());
4343 }
4344 
4345 void ASTWriter::AddString(StringRef Str, RecordDataImpl &Record) {
4346   Record.push_back(Str.size());
4347   Record.insert(Record.end(), Str.begin(), Str.end());
4348 }
4349 
4350 bool ASTWriter::PreparePathForOutput(SmallVectorImpl<char> &Path) {
4351   assert(Context && "should have context when outputting path");
4352 
4353   bool Changed =
4354       cleanPathForOutput(Context->getSourceManager().getFileManager(), Path);
4355 
4356   // Remove a prefix to make the path relative, if relevant.
4357   const char *PathBegin = Path.data();
4358   const char *PathPtr =
4359       adjustFilenameForRelocatableAST(PathBegin, BaseDirectory);
4360   if (PathPtr != PathBegin) {
4361     Path.erase(Path.begin(), Path.begin() + (PathPtr - PathBegin));
4362     Changed = true;
4363   }
4364 
4365   return Changed;
4366 }
4367 
4368 void ASTWriter::AddPath(StringRef Path, RecordDataImpl &Record) {
4369   SmallString<128> FilePath(Path);
4370   PreparePathForOutput(FilePath);
4371   AddString(FilePath, Record);
4372 }
4373 
4374 void ASTWriter::EmitRecordWithPath(unsigned Abbrev, RecordDataRef Record,
4375                                    StringRef Path) {
4376   SmallString<128> FilePath(Path);
4377   PreparePathForOutput(FilePath);
4378   Stream.EmitRecordWithBlob(Abbrev, Record, FilePath);
4379 }
4380 
4381 void ASTWriter::AddVersionTuple(const VersionTuple &Version,
4382                                 RecordDataImpl &Record) {
4383   Record.push_back(Version.getMajor());
4384   if (Optional<unsigned> Minor = Version.getMinor())
4385     Record.push_back(*Minor + 1);
4386   else
4387     Record.push_back(0);
4388   if (Optional<unsigned> Subminor = Version.getSubminor())
4389     Record.push_back(*Subminor + 1);
4390   else
4391     Record.push_back(0);
4392 }
4393 
4394 /// Note that the identifier II occurs at the given offset
4395 /// within the identifier table.
4396 void ASTWriter::SetIdentifierOffset(const IdentifierInfo *II, uint32_t Offset) {
4397   IdentID ID = IdentifierIDs[II];
4398   // Only store offsets new to this AST file. Other identifier names are looked
4399   // up earlier in the chain and thus don't need an offset.
4400   if (ID >= FirstIdentID)
4401     IdentifierOffsets[ID - FirstIdentID] = Offset;
4402 }
4403 
4404 /// Note that the selector Sel occurs at the given offset
4405 /// within the method pool/selector table.
4406 void ASTWriter::SetSelectorOffset(Selector Sel, uint32_t Offset) {
4407   unsigned ID = SelectorIDs[Sel];
4408   assert(ID && "Unknown selector");
4409   // Don't record offsets for selectors that are also available in a different
4410   // file.
4411   if (ID < FirstSelectorID)
4412     return;
4413   SelectorOffsets[ID - FirstSelectorID] = Offset;
4414 }
4415 
4416 ASTWriter::ASTWriter(llvm::BitstreamWriter &Stream,
4417                      SmallVectorImpl<char> &Buffer,
4418                      InMemoryModuleCache &ModuleCache,
4419                      ArrayRef<std::shared_ptr<ModuleFileExtension>> Extensions,
4420                      bool IncludeTimestamps)
4421     : Stream(Stream), Buffer(Buffer), ModuleCache(ModuleCache),
4422       IncludeTimestamps(IncludeTimestamps) {
4423   for (const auto &Ext : Extensions) {
4424     if (auto Writer = Ext->createExtensionWriter(*this))
4425       ModuleFileExtensionWriters.push_back(std::move(Writer));
4426   }
4427 }
4428 
4429 ASTWriter::~ASTWriter() = default;
4430 
4431 const LangOptions &ASTWriter::getLangOpts() const {
4432   assert(WritingAST && "can't determine lang opts when not writing AST");
4433   return Context->getLangOpts();
4434 }
4435 
4436 time_t ASTWriter::getTimestampForOutput(const FileEntry *E) const {
4437   return IncludeTimestamps ? E->getModificationTime() : 0;
4438 }
4439 
4440 ASTFileSignature ASTWriter::WriteAST(Sema &SemaRef,
4441                                      const std::string &OutputFile,
4442                                      Module *WritingModule, StringRef isysroot,
4443                                      bool hasErrors,
4444                                      bool ShouldCacheASTInMemory) {
4445   WritingAST = true;
4446 
4447   ASTHasCompilerErrors = hasErrors;
4448 
4449   // Emit the file header.
4450   Stream.Emit((unsigned)'C', 8);
4451   Stream.Emit((unsigned)'P', 8);
4452   Stream.Emit((unsigned)'C', 8);
4453   Stream.Emit((unsigned)'H', 8);
4454 
4455   WriteBlockInfoBlock();
4456 
4457   Context = &SemaRef.Context;
4458   PP = &SemaRef.PP;
4459   this->WritingModule = WritingModule;
4460   ASTFileSignature Signature =
4461       WriteASTCore(SemaRef, isysroot, OutputFile, WritingModule);
4462   Context = nullptr;
4463   PP = nullptr;
4464   this->WritingModule = nullptr;
4465   this->BaseDirectory.clear();
4466 
4467   WritingAST = false;
4468   if (ShouldCacheASTInMemory) {
4469     // Construct MemoryBuffer and update buffer manager.
4470     ModuleCache.addBuiltPCM(OutputFile,
4471                             llvm::MemoryBuffer::getMemBufferCopy(
4472                                 StringRef(Buffer.begin(), Buffer.size())));
4473   }
4474   return Signature;
4475 }
4476 
4477 template<typename Vector>
4478 static void AddLazyVectorDecls(ASTWriter &Writer, Vector &Vec,
4479                                ASTWriter::RecordData &Record) {
4480   for (typename Vector::iterator I = Vec.begin(nullptr, true), E = Vec.end();
4481        I != E; ++I) {
4482     Writer.AddDeclRef(*I, Record);
4483   }
4484 }
4485 
4486 ASTFileSignature ASTWriter::WriteASTCore(Sema &SemaRef, StringRef isysroot,
4487                                          const std::string &OutputFile,
4488                                          Module *WritingModule) {
4489   using namespace llvm;
4490 
4491   bool isModule = WritingModule != nullptr;
4492 
4493   // Make sure that the AST reader knows to finalize itself.
4494   if (Chain)
4495     Chain->finalizeForWriting();
4496 
4497   ASTContext &Context = SemaRef.Context;
4498   Preprocessor &PP = SemaRef.PP;
4499 
4500   // Set up predefined declaration IDs.
4501   auto RegisterPredefDecl = [&] (Decl *D, PredefinedDeclIDs ID) {
4502     if (D) {
4503       assert(D->isCanonicalDecl() && "predefined decl is not canonical");
4504       DeclIDs[D] = ID;
4505     }
4506   };
4507   RegisterPredefDecl(Context.getTranslationUnitDecl(),
4508                      PREDEF_DECL_TRANSLATION_UNIT_ID);
4509   RegisterPredefDecl(Context.ObjCIdDecl, PREDEF_DECL_OBJC_ID_ID);
4510   RegisterPredefDecl(Context.ObjCSelDecl, PREDEF_DECL_OBJC_SEL_ID);
4511   RegisterPredefDecl(Context.ObjCClassDecl, PREDEF_DECL_OBJC_CLASS_ID);
4512   RegisterPredefDecl(Context.ObjCProtocolClassDecl,
4513                      PREDEF_DECL_OBJC_PROTOCOL_ID);
4514   RegisterPredefDecl(Context.Int128Decl, PREDEF_DECL_INT_128_ID);
4515   RegisterPredefDecl(Context.UInt128Decl, PREDEF_DECL_UNSIGNED_INT_128_ID);
4516   RegisterPredefDecl(Context.ObjCInstanceTypeDecl,
4517                      PREDEF_DECL_OBJC_INSTANCETYPE_ID);
4518   RegisterPredefDecl(Context.BuiltinVaListDecl, PREDEF_DECL_BUILTIN_VA_LIST_ID);
4519   RegisterPredefDecl(Context.VaListTagDecl, PREDEF_DECL_VA_LIST_TAG);
4520   RegisterPredefDecl(Context.BuiltinMSVaListDecl,
4521                      PREDEF_DECL_BUILTIN_MS_VA_LIST_ID);
4522   RegisterPredefDecl(Context.MSGuidTagDecl,
4523                      PREDEF_DECL_BUILTIN_MS_GUID_ID);
4524   RegisterPredefDecl(Context.ExternCContext, PREDEF_DECL_EXTERN_C_CONTEXT_ID);
4525   RegisterPredefDecl(Context.MakeIntegerSeqDecl,
4526                      PREDEF_DECL_MAKE_INTEGER_SEQ_ID);
4527   RegisterPredefDecl(Context.CFConstantStringTypeDecl,
4528                      PREDEF_DECL_CF_CONSTANT_STRING_ID);
4529   RegisterPredefDecl(Context.CFConstantStringTagDecl,
4530                      PREDEF_DECL_CF_CONSTANT_STRING_TAG_ID);
4531   RegisterPredefDecl(Context.TypePackElementDecl,
4532                      PREDEF_DECL_TYPE_PACK_ELEMENT_ID);
4533 
4534   // Build a record containing all of the tentative definitions in this file, in
4535   // TentativeDefinitions order.  Generally, this record will be empty for
4536   // headers.
4537   RecordData TentativeDefinitions;
4538   AddLazyVectorDecls(*this, SemaRef.TentativeDefinitions, TentativeDefinitions);
4539 
4540   // Build a record containing all of the file scoped decls in this file.
4541   RecordData UnusedFileScopedDecls;
4542   if (!isModule)
4543     AddLazyVectorDecls(*this, SemaRef.UnusedFileScopedDecls,
4544                        UnusedFileScopedDecls);
4545 
4546   // Build a record containing all of the delegating constructors we still need
4547   // to resolve.
4548   RecordData DelegatingCtorDecls;
4549   if (!isModule)
4550     AddLazyVectorDecls(*this, SemaRef.DelegatingCtorDecls, DelegatingCtorDecls);
4551 
4552   // Write the set of weak, undeclared identifiers. We always write the
4553   // entire table, since later PCH files in a PCH chain are only interested in
4554   // the results at the end of the chain.
4555   RecordData WeakUndeclaredIdentifiers;
4556   for (auto &WeakUndeclaredIdentifier : SemaRef.WeakUndeclaredIdentifiers) {
4557     IdentifierInfo *II = WeakUndeclaredIdentifier.first;
4558     WeakInfo &WI = WeakUndeclaredIdentifier.second;
4559     AddIdentifierRef(II, WeakUndeclaredIdentifiers);
4560     AddIdentifierRef(WI.getAlias(), WeakUndeclaredIdentifiers);
4561     AddSourceLocation(WI.getLocation(), WeakUndeclaredIdentifiers);
4562     WeakUndeclaredIdentifiers.push_back(WI.getUsed());
4563   }
4564 
4565   // Build a record containing all of the ext_vector declarations.
4566   RecordData ExtVectorDecls;
4567   AddLazyVectorDecls(*this, SemaRef.ExtVectorDecls, ExtVectorDecls);
4568 
4569   // Build a record containing all of the VTable uses information.
4570   RecordData VTableUses;
4571   if (!SemaRef.VTableUses.empty()) {
4572     for (unsigned I = 0, N = SemaRef.VTableUses.size(); I != N; ++I) {
4573       AddDeclRef(SemaRef.VTableUses[I].first, VTableUses);
4574       AddSourceLocation(SemaRef.VTableUses[I].second, VTableUses);
4575       VTableUses.push_back(SemaRef.VTablesUsed[SemaRef.VTableUses[I].first]);
4576     }
4577   }
4578 
4579   // Build a record containing all of the UnusedLocalTypedefNameCandidates.
4580   RecordData UnusedLocalTypedefNameCandidates;
4581   for (const TypedefNameDecl *TD : SemaRef.UnusedLocalTypedefNameCandidates)
4582     AddDeclRef(TD, UnusedLocalTypedefNameCandidates);
4583 
4584   // Build a record containing all of pending implicit instantiations.
4585   RecordData PendingInstantiations;
4586   for (const auto &I : SemaRef.PendingInstantiations) {
4587     AddDeclRef(I.first, PendingInstantiations);
4588     AddSourceLocation(I.second, PendingInstantiations);
4589   }
4590   assert(SemaRef.PendingLocalImplicitInstantiations.empty() &&
4591          "There are local ones at end of translation unit!");
4592 
4593   // Build a record containing some declaration references.
4594   RecordData SemaDeclRefs;
4595   if (SemaRef.StdNamespace || SemaRef.StdBadAlloc || SemaRef.StdAlignValT) {
4596     AddDeclRef(SemaRef.getStdNamespace(), SemaDeclRefs);
4597     AddDeclRef(SemaRef.getStdBadAlloc(), SemaDeclRefs);
4598     AddDeclRef(SemaRef.getStdAlignValT(), SemaDeclRefs);
4599   }
4600 
4601   RecordData CUDASpecialDeclRefs;
4602   if (Context.getcudaConfigureCallDecl()) {
4603     AddDeclRef(Context.getcudaConfigureCallDecl(), CUDASpecialDeclRefs);
4604   }
4605 
4606   // Build a record containing all of the known namespaces.
4607   RecordData KnownNamespaces;
4608   for (const auto &I : SemaRef.KnownNamespaces) {
4609     if (!I.second)
4610       AddDeclRef(I.first, KnownNamespaces);
4611   }
4612 
4613   // Build a record of all used, undefined objects that require definitions.
4614   RecordData UndefinedButUsed;
4615 
4616   SmallVector<std::pair<NamedDecl *, SourceLocation>, 16> Undefined;
4617   SemaRef.getUndefinedButUsed(Undefined);
4618   for (const auto &I : Undefined) {
4619     AddDeclRef(I.first, UndefinedButUsed);
4620     AddSourceLocation(I.second, UndefinedButUsed);
4621   }
4622 
4623   // Build a record containing all delete-expressions that we would like to
4624   // analyze later in AST.
4625   RecordData DeleteExprsToAnalyze;
4626 
4627   if (!isModule) {
4628     for (const auto &DeleteExprsInfo :
4629          SemaRef.getMismatchingDeleteExpressions()) {
4630       AddDeclRef(DeleteExprsInfo.first, DeleteExprsToAnalyze);
4631       DeleteExprsToAnalyze.push_back(DeleteExprsInfo.second.size());
4632       for (const auto &DeleteLoc : DeleteExprsInfo.second) {
4633         AddSourceLocation(DeleteLoc.first, DeleteExprsToAnalyze);
4634         DeleteExprsToAnalyze.push_back(DeleteLoc.second);
4635       }
4636     }
4637   }
4638 
4639   // Write the control block
4640   WriteControlBlock(PP, Context, isysroot, OutputFile);
4641 
4642   // Write the remaining AST contents.
4643   Stream.FlushToWord();
4644   ASTBlockRange.first = Stream.GetCurrentBitNo();
4645   Stream.EnterSubblock(AST_BLOCK_ID, 5);
4646   ASTBlockStartOffset = Stream.GetCurrentBitNo();
4647 
4648   // This is so that older clang versions, before the introduction
4649   // of the control block, can read and reject the newer PCH format.
4650   {
4651     RecordData Record = {VERSION_MAJOR};
4652     Stream.EmitRecord(METADATA_OLD_FORMAT, Record);
4653   }
4654 
4655   // Create a lexical update block containing all of the declarations in the
4656   // translation unit that do not come from other AST files.
4657   const TranslationUnitDecl *TU = Context.getTranslationUnitDecl();
4658   SmallVector<uint32_t, 128> NewGlobalKindDeclPairs;
4659   for (const auto *D : TU->noload_decls()) {
4660     if (!D->isFromASTFile()) {
4661       NewGlobalKindDeclPairs.push_back(D->getKind());
4662       NewGlobalKindDeclPairs.push_back(GetDeclRef(D));
4663     }
4664   }
4665 
4666   auto Abv = std::make_shared<BitCodeAbbrev>();
4667   Abv->Add(llvm::BitCodeAbbrevOp(TU_UPDATE_LEXICAL));
4668   Abv->Add(llvm::BitCodeAbbrevOp(llvm::BitCodeAbbrevOp::Blob));
4669   unsigned TuUpdateLexicalAbbrev = Stream.EmitAbbrev(std::move(Abv));
4670   {
4671     RecordData::value_type Record[] = {TU_UPDATE_LEXICAL};
4672     Stream.EmitRecordWithBlob(TuUpdateLexicalAbbrev, Record,
4673                               bytes(NewGlobalKindDeclPairs));
4674   }
4675 
4676   // And a visible updates block for the translation unit.
4677   Abv = std::make_shared<BitCodeAbbrev>();
4678   Abv->Add(llvm::BitCodeAbbrevOp(UPDATE_VISIBLE));
4679   Abv->Add(llvm::BitCodeAbbrevOp(llvm::BitCodeAbbrevOp::VBR, 6));
4680   Abv->Add(llvm::BitCodeAbbrevOp(llvm::BitCodeAbbrevOp::Blob));
4681   UpdateVisibleAbbrev = Stream.EmitAbbrev(std::move(Abv));
4682   WriteDeclContextVisibleUpdate(TU);
4683 
4684   // If we have any extern "C" names, write out a visible update for them.
4685   if (Context.ExternCContext)
4686     WriteDeclContextVisibleUpdate(Context.ExternCContext);
4687 
4688   // If the translation unit has an anonymous namespace, and we don't already
4689   // have an update block for it, write it as an update block.
4690   // FIXME: Why do we not do this if there's already an update block?
4691   if (NamespaceDecl *NS = TU->getAnonymousNamespace()) {
4692     ASTWriter::UpdateRecord &Record = DeclUpdates[TU];
4693     if (Record.empty())
4694       Record.push_back(DeclUpdate(UPD_CXX_ADDED_ANONYMOUS_NAMESPACE, NS));
4695   }
4696 
4697   // Add update records for all mangling numbers and static local numbers.
4698   // These aren't really update records, but this is a convenient way of
4699   // tagging this rare extra data onto the declarations.
4700   for (const auto &Number : Context.MangleNumbers)
4701     if (!Number.first->isFromASTFile())
4702       DeclUpdates[Number.first].push_back(DeclUpdate(UPD_MANGLING_NUMBER,
4703                                                      Number.second));
4704   for (const auto &Number : Context.StaticLocalNumbers)
4705     if (!Number.first->isFromASTFile())
4706       DeclUpdates[Number.first].push_back(DeclUpdate(UPD_STATIC_LOCAL_NUMBER,
4707                                                      Number.second));
4708 
4709   // Make sure visible decls, added to DeclContexts previously loaded from
4710   // an AST file, are registered for serialization. Likewise for template
4711   // specializations added to imported templates.
4712   for (const auto *I : DeclsToEmitEvenIfUnreferenced) {
4713     GetDeclRef(I);
4714   }
4715 
4716   // Make sure all decls associated with an identifier are registered for
4717   // serialization, if we're storing decls with identifiers.
4718   if (!WritingModule || !getLangOpts().CPlusPlus) {
4719     llvm::SmallVector<const IdentifierInfo*, 256> IIs;
4720     for (const auto &ID : PP.getIdentifierTable()) {
4721       const IdentifierInfo *II = ID.second;
4722       if (!Chain || !II->isFromAST() || II->hasChangedSinceDeserialization())
4723         IIs.push_back(II);
4724     }
4725     // Sort the identifiers to visit based on their name.
4726     llvm::sort(IIs, llvm::deref<std::less<>>());
4727     for (const IdentifierInfo *II : IIs) {
4728       for (IdentifierResolver::iterator D = SemaRef.IdResolver.begin(II),
4729                                      DEnd = SemaRef.IdResolver.end();
4730            D != DEnd; ++D) {
4731         GetDeclRef(*D);
4732       }
4733     }
4734   }
4735 
4736   // For method pool in the module, if it contains an entry for a selector,
4737   // the entry should be complete, containing everything introduced by that
4738   // module and all modules it imports. It's possible that the entry is out of
4739   // date, so we need to pull in the new content here.
4740 
4741   // It's possible that updateOutOfDateSelector can update SelectorIDs. To be
4742   // safe, we copy all selectors out.
4743   llvm::SmallVector<Selector, 256> AllSelectors;
4744   for (auto &SelectorAndID : SelectorIDs)
4745     AllSelectors.push_back(SelectorAndID.first);
4746   for (auto &Selector : AllSelectors)
4747     SemaRef.updateOutOfDateSelector(Selector);
4748 
4749   // Form the record of special types.
4750   RecordData SpecialTypes;
4751   AddTypeRef(Context.getRawCFConstantStringType(), SpecialTypes);
4752   AddTypeRef(Context.getFILEType(), SpecialTypes);
4753   AddTypeRef(Context.getjmp_bufType(), SpecialTypes);
4754   AddTypeRef(Context.getsigjmp_bufType(), SpecialTypes);
4755   AddTypeRef(Context.ObjCIdRedefinitionType, SpecialTypes);
4756   AddTypeRef(Context.ObjCClassRedefinitionType, SpecialTypes);
4757   AddTypeRef(Context.ObjCSelRedefinitionType, SpecialTypes);
4758   AddTypeRef(Context.getucontext_tType(), SpecialTypes);
4759 
4760   if (Chain) {
4761     // Write the mapping information describing our module dependencies and how
4762     // each of those modules were mapped into our own offset/ID space, so that
4763     // the reader can build the appropriate mapping to its own offset/ID space.
4764     // The map consists solely of a blob with the following format:
4765     // *(module-kind:i8
4766     //   module-name-len:i16 module-name:len*i8
4767     //   source-location-offset:i32
4768     //   identifier-id:i32
4769     //   preprocessed-entity-id:i32
4770     //   macro-definition-id:i32
4771     //   submodule-id:i32
4772     //   selector-id:i32
4773     //   declaration-id:i32
4774     //   c++-base-specifiers-id:i32
4775     //   type-id:i32)
4776     //
4777     // module-kind is the ModuleKind enum value. If it is MK_PrebuiltModule,
4778     // MK_ExplicitModule or MK_ImplicitModule, then the module-name is the
4779     // module name. Otherwise, it is the module file name.
4780     auto Abbrev = std::make_shared<BitCodeAbbrev>();
4781     Abbrev->Add(BitCodeAbbrevOp(MODULE_OFFSET_MAP));
4782     Abbrev->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
4783     unsigned ModuleOffsetMapAbbrev = Stream.EmitAbbrev(std::move(Abbrev));
4784     SmallString<2048> Buffer;
4785     {
4786       llvm::raw_svector_ostream Out(Buffer);
4787       for (ModuleFile &M : Chain->ModuleMgr) {
4788         using namespace llvm::support;
4789 
4790         endian::Writer LE(Out, little);
4791         LE.write<uint8_t>(static_cast<uint8_t>(M.Kind));
4792         StringRef Name = M.isModule() ? M.ModuleName : M.FileName;
4793         LE.write<uint16_t>(Name.size());
4794         Out.write(Name.data(), Name.size());
4795 
4796         // Note: if a base ID was uint max, it would not be possible to load
4797         // another module after it or have more than one entity inside it.
4798         uint32_t None = std::numeric_limits<uint32_t>::max();
4799 
4800         auto writeBaseIDOrNone = [&](auto BaseID, bool ShouldWrite) {
4801           assert(BaseID < std::numeric_limits<uint32_t>::max() && "base id too high");
4802           if (ShouldWrite)
4803             LE.write<uint32_t>(BaseID);
4804           else
4805             LE.write<uint32_t>(None);
4806         };
4807 
4808         // These values should be unique within a chain, since they will be read
4809         // as keys into ContinuousRangeMaps.
4810         writeBaseIDOrNone(M.SLocEntryBaseOffset, M.LocalNumSLocEntries);
4811         writeBaseIDOrNone(M.BaseIdentifierID, M.LocalNumIdentifiers);
4812         writeBaseIDOrNone(M.BaseMacroID, M.LocalNumMacros);
4813         writeBaseIDOrNone(M.BasePreprocessedEntityID,
4814                           M.NumPreprocessedEntities);
4815         writeBaseIDOrNone(M.BaseSubmoduleID, M.LocalNumSubmodules);
4816         writeBaseIDOrNone(M.BaseSelectorID, M.LocalNumSelectors);
4817         writeBaseIDOrNone(M.BaseDeclID, M.LocalNumDecls);
4818         writeBaseIDOrNone(M.BaseTypeIndex, M.LocalNumTypes);
4819       }
4820     }
4821     RecordData::value_type Record[] = {MODULE_OFFSET_MAP};
4822     Stream.EmitRecordWithBlob(ModuleOffsetMapAbbrev, Record,
4823                               Buffer.data(), Buffer.size());
4824   }
4825 
4826   // Build a record containing all of the DeclsToCheckForDeferredDiags.
4827   SmallVector<serialization::DeclID, 64> DeclsToCheckForDeferredDiags;
4828   for (auto *D : SemaRef.DeclsToCheckForDeferredDiags)
4829     DeclsToCheckForDeferredDiags.push_back(GetDeclRef(D));
4830 
4831   RecordData DeclUpdatesOffsetsRecord;
4832 
4833   // Keep writing types, declarations, and declaration update records
4834   // until we've emitted all of them.
4835   Stream.EnterSubblock(DECLTYPES_BLOCK_ID, /*bits for abbreviations*/5);
4836   DeclTypesBlockStartOffset = Stream.GetCurrentBitNo();
4837   WriteTypeAbbrevs();
4838   WriteDeclAbbrevs();
4839   do {
4840     WriteDeclUpdatesBlocks(DeclUpdatesOffsetsRecord);
4841     while (!DeclTypesToEmit.empty()) {
4842       DeclOrType DOT = DeclTypesToEmit.front();
4843       DeclTypesToEmit.pop();
4844       if (DOT.isType())
4845         WriteType(DOT.getType());
4846       else
4847         WriteDecl(Context, DOT.getDecl());
4848     }
4849   } while (!DeclUpdates.empty());
4850   Stream.ExitBlock();
4851 
4852   DoneWritingDeclsAndTypes = true;
4853 
4854   // These things can only be done once we've written out decls and types.
4855   WriteTypeDeclOffsets();
4856   if (!DeclUpdatesOffsetsRecord.empty())
4857     Stream.EmitRecord(DECL_UPDATE_OFFSETS, DeclUpdatesOffsetsRecord);
4858   WriteFileDeclIDsMap();
4859   WriteSourceManagerBlock(Context.getSourceManager(), PP);
4860   WriteComments();
4861   WritePreprocessor(PP, isModule);
4862   WriteHeaderSearch(PP.getHeaderSearchInfo());
4863   WriteSelectors(SemaRef);
4864   WriteReferencedSelectorsPool(SemaRef);
4865   WriteLateParsedTemplates(SemaRef);
4866   WriteIdentifierTable(PP, SemaRef.IdResolver, isModule);
4867   WriteFPPragmaOptions(SemaRef.CurFPFeatureOverrides());
4868   WriteOpenCLExtensions(SemaRef);
4869   WriteCUDAPragmas(SemaRef);
4870 
4871   // If we're emitting a module, write out the submodule information.
4872   if (WritingModule)
4873     WriteSubmodules(WritingModule);
4874 
4875   Stream.EmitRecord(SPECIAL_TYPES, SpecialTypes);
4876 
4877   // Write the record containing external, unnamed definitions.
4878   if (!EagerlyDeserializedDecls.empty())
4879     Stream.EmitRecord(EAGERLY_DESERIALIZED_DECLS, EagerlyDeserializedDecls);
4880 
4881   if (!ModularCodegenDecls.empty())
4882     Stream.EmitRecord(MODULAR_CODEGEN_DECLS, ModularCodegenDecls);
4883 
4884   // Write the record containing tentative definitions.
4885   if (!TentativeDefinitions.empty())
4886     Stream.EmitRecord(TENTATIVE_DEFINITIONS, TentativeDefinitions);
4887 
4888   // Write the record containing unused file scoped decls.
4889   if (!UnusedFileScopedDecls.empty())
4890     Stream.EmitRecord(UNUSED_FILESCOPED_DECLS, UnusedFileScopedDecls);
4891 
4892   // Write the record containing weak undeclared identifiers.
4893   if (!WeakUndeclaredIdentifiers.empty())
4894     Stream.EmitRecord(WEAK_UNDECLARED_IDENTIFIERS,
4895                       WeakUndeclaredIdentifiers);
4896 
4897   // Write the record containing ext_vector type names.
4898   if (!ExtVectorDecls.empty())
4899     Stream.EmitRecord(EXT_VECTOR_DECLS, ExtVectorDecls);
4900 
4901   // Write the record containing VTable uses information.
4902   if (!VTableUses.empty())
4903     Stream.EmitRecord(VTABLE_USES, VTableUses);
4904 
4905   // Write the record containing potentially unused local typedefs.
4906   if (!UnusedLocalTypedefNameCandidates.empty())
4907     Stream.EmitRecord(UNUSED_LOCAL_TYPEDEF_NAME_CANDIDATES,
4908                       UnusedLocalTypedefNameCandidates);
4909 
4910   // Write the record containing pending implicit instantiations.
4911   if (!PendingInstantiations.empty())
4912     Stream.EmitRecord(PENDING_IMPLICIT_INSTANTIATIONS, PendingInstantiations);
4913 
4914   // Write the record containing declaration references of Sema.
4915   if (!SemaDeclRefs.empty())
4916     Stream.EmitRecord(SEMA_DECL_REFS, SemaDeclRefs);
4917 
4918   // Write the record containing decls to be checked for deferred diags.
4919   if (!DeclsToCheckForDeferredDiags.empty())
4920     Stream.EmitRecord(DECLS_TO_CHECK_FOR_DEFERRED_DIAGS,
4921         DeclsToCheckForDeferredDiags);
4922 
4923   // Write the record containing CUDA-specific declaration references.
4924   if (!CUDASpecialDeclRefs.empty())
4925     Stream.EmitRecord(CUDA_SPECIAL_DECL_REFS, CUDASpecialDeclRefs);
4926 
4927   // Write the delegating constructors.
4928   if (!DelegatingCtorDecls.empty())
4929     Stream.EmitRecord(DELEGATING_CTORS, DelegatingCtorDecls);
4930 
4931   // Write the known namespaces.
4932   if (!KnownNamespaces.empty())
4933     Stream.EmitRecord(KNOWN_NAMESPACES, KnownNamespaces);
4934 
4935   // Write the undefined internal functions and variables, and inline functions.
4936   if (!UndefinedButUsed.empty())
4937     Stream.EmitRecord(UNDEFINED_BUT_USED, UndefinedButUsed);
4938 
4939   if (!DeleteExprsToAnalyze.empty())
4940     Stream.EmitRecord(DELETE_EXPRS_TO_ANALYZE, DeleteExprsToAnalyze);
4941 
4942   // Write the visible updates to DeclContexts.
4943   for (auto *DC : UpdatedDeclContexts)
4944     WriteDeclContextVisibleUpdate(DC);
4945 
4946   if (!WritingModule) {
4947     // Write the submodules that were imported, if any.
4948     struct ModuleInfo {
4949       uint64_t ID;
4950       Module *M;
4951       ModuleInfo(uint64_t ID, Module *M) : ID(ID), M(M) {}
4952     };
4953     llvm::SmallVector<ModuleInfo, 64> Imports;
4954     for (const auto *I : Context.local_imports()) {
4955       assert(SubmoduleIDs.find(I->getImportedModule()) != SubmoduleIDs.end());
4956       Imports.push_back(ModuleInfo(SubmoduleIDs[I->getImportedModule()],
4957                          I->getImportedModule()));
4958     }
4959 
4960     if (!Imports.empty()) {
4961       auto Cmp = [](const ModuleInfo &A, const ModuleInfo &B) {
4962         return A.ID < B.ID;
4963       };
4964       auto Eq = [](const ModuleInfo &A, const ModuleInfo &B) {
4965         return A.ID == B.ID;
4966       };
4967 
4968       // Sort and deduplicate module IDs.
4969       llvm::sort(Imports, Cmp);
4970       Imports.erase(std::unique(Imports.begin(), Imports.end(), Eq),
4971                     Imports.end());
4972 
4973       RecordData ImportedModules;
4974       for (const auto &Import : Imports) {
4975         ImportedModules.push_back(Import.ID);
4976         // FIXME: If the module has macros imported then later has declarations
4977         // imported, this location won't be the right one as a location for the
4978         // declaration imports.
4979         AddSourceLocation(PP.getModuleImportLoc(Import.M), ImportedModules);
4980       }
4981 
4982       Stream.EmitRecord(IMPORTED_MODULES, ImportedModules);
4983     }
4984   }
4985 
4986   WriteObjCCategories();
4987   if(!WritingModule) {
4988     WriteOptimizePragmaOptions(SemaRef);
4989     WriteMSStructPragmaOptions(SemaRef);
4990     WriteMSPointersToMembersPragmaOptions(SemaRef);
4991   }
4992   WritePackPragmaOptions(SemaRef);
4993   WriteFloatControlPragmaOptions(SemaRef);
4994 
4995   // Some simple statistics
4996   RecordData::value_type Record[] = {
4997       NumStatements, NumMacros, NumLexicalDeclContexts, NumVisibleDeclContexts};
4998   Stream.EmitRecord(STATISTICS, Record);
4999   Stream.ExitBlock();
5000   Stream.FlushToWord();
5001   ASTBlockRange.second = Stream.GetCurrentBitNo();
5002 
5003   // Write the module file extension blocks.
5004   for (const auto &ExtWriter : ModuleFileExtensionWriters)
5005     WriteModuleFileExtension(SemaRef, *ExtWriter);
5006 
5007   return writeUnhashedControlBlock(PP, Context);
5008 }
5009 
5010 void ASTWriter::WriteDeclUpdatesBlocks(RecordDataImpl &OffsetsRecord) {
5011   if (DeclUpdates.empty())
5012     return;
5013 
5014   DeclUpdateMap LocalUpdates;
5015   LocalUpdates.swap(DeclUpdates);
5016 
5017   for (auto &DeclUpdate : LocalUpdates) {
5018     const Decl *D = DeclUpdate.first;
5019 
5020     bool HasUpdatedBody = false;
5021     RecordData RecordData;
5022     ASTRecordWriter Record(*this, RecordData);
5023     for (auto &Update : DeclUpdate.second) {
5024       DeclUpdateKind Kind = (DeclUpdateKind)Update.getKind();
5025 
5026       // An updated body is emitted last, so that the reader doesn't need
5027       // to skip over the lazy body to reach statements for other records.
5028       if (Kind == UPD_CXX_ADDED_FUNCTION_DEFINITION)
5029         HasUpdatedBody = true;
5030       else
5031         Record.push_back(Kind);
5032 
5033       switch (Kind) {
5034       case UPD_CXX_ADDED_IMPLICIT_MEMBER:
5035       case UPD_CXX_ADDED_TEMPLATE_SPECIALIZATION:
5036       case UPD_CXX_ADDED_ANONYMOUS_NAMESPACE:
5037         assert(Update.getDecl() && "no decl to add?");
5038         Record.push_back(GetDeclRef(Update.getDecl()));
5039         break;
5040 
5041       case UPD_CXX_ADDED_FUNCTION_DEFINITION:
5042         break;
5043 
5044       case UPD_CXX_POINT_OF_INSTANTIATION:
5045         // FIXME: Do we need to also save the template specialization kind here?
5046         Record.AddSourceLocation(Update.getLoc());
5047         break;
5048 
5049       case UPD_CXX_ADDED_VAR_DEFINITION: {
5050         const VarDecl *VD = cast<VarDecl>(D);
5051         Record.push_back(VD->isInline());
5052         Record.push_back(VD->isInlineSpecified());
5053         Record.AddVarDeclInit(VD);
5054         break;
5055       }
5056 
5057       case UPD_CXX_INSTANTIATED_DEFAULT_ARGUMENT:
5058         Record.AddStmt(const_cast<Expr *>(
5059             cast<ParmVarDecl>(Update.getDecl())->getDefaultArg()));
5060         break;
5061 
5062       case UPD_CXX_INSTANTIATED_DEFAULT_MEMBER_INITIALIZER:
5063         Record.AddStmt(
5064             cast<FieldDecl>(Update.getDecl())->getInClassInitializer());
5065         break;
5066 
5067       case UPD_CXX_INSTANTIATED_CLASS_DEFINITION: {
5068         auto *RD = cast<CXXRecordDecl>(D);
5069         UpdatedDeclContexts.insert(RD->getPrimaryContext());
5070         Record.push_back(RD->isParamDestroyedInCallee());
5071         Record.push_back(RD->getArgPassingRestrictions());
5072         Record.AddCXXDefinitionData(RD);
5073         Record.AddOffset(WriteDeclContextLexicalBlock(
5074             *Context, const_cast<CXXRecordDecl *>(RD)));
5075 
5076         // This state is sometimes updated by template instantiation, when we
5077         // switch from the specialization referring to the template declaration
5078         // to it referring to the template definition.
5079         if (auto *MSInfo = RD->getMemberSpecializationInfo()) {
5080           Record.push_back(MSInfo->getTemplateSpecializationKind());
5081           Record.AddSourceLocation(MSInfo->getPointOfInstantiation());
5082         } else {
5083           auto *Spec = cast<ClassTemplateSpecializationDecl>(RD);
5084           Record.push_back(Spec->getTemplateSpecializationKind());
5085           Record.AddSourceLocation(Spec->getPointOfInstantiation());
5086 
5087           // The instantiation might have been resolved to a partial
5088           // specialization. If so, record which one.
5089           auto From = Spec->getInstantiatedFrom();
5090           if (auto PartialSpec =
5091                 From.dyn_cast<ClassTemplatePartialSpecializationDecl*>()) {
5092             Record.push_back(true);
5093             Record.AddDeclRef(PartialSpec);
5094             Record.AddTemplateArgumentList(
5095                 &Spec->getTemplateInstantiationArgs());
5096           } else {
5097             Record.push_back(false);
5098           }
5099         }
5100         Record.push_back(RD->getTagKind());
5101         Record.AddSourceLocation(RD->getLocation());
5102         Record.AddSourceLocation(RD->getBeginLoc());
5103         Record.AddSourceRange(RD->getBraceRange());
5104 
5105         // Instantiation may change attributes; write them all out afresh.
5106         Record.push_back(D->hasAttrs());
5107         if (D->hasAttrs())
5108           Record.AddAttributes(D->getAttrs());
5109 
5110         // FIXME: Ensure we don't get here for explicit instantiations.
5111         break;
5112       }
5113 
5114       case UPD_CXX_RESOLVED_DTOR_DELETE:
5115         Record.AddDeclRef(Update.getDecl());
5116         Record.AddStmt(cast<CXXDestructorDecl>(D)->getOperatorDeleteThisArg());
5117         break;
5118 
5119       case UPD_CXX_RESOLVED_EXCEPTION_SPEC: {
5120         auto prototype =
5121           cast<FunctionDecl>(D)->getType()->castAs<FunctionProtoType>();
5122         Record.writeExceptionSpecInfo(prototype->getExceptionSpecInfo());
5123         break;
5124       }
5125 
5126       case UPD_CXX_DEDUCED_RETURN_TYPE:
5127         Record.push_back(GetOrCreateTypeID(Update.getType()));
5128         break;
5129 
5130       case UPD_DECL_MARKED_USED:
5131         break;
5132 
5133       case UPD_MANGLING_NUMBER:
5134       case UPD_STATIC_LOCAL_NUMBER:
5135         Record.push_back(Update.getNumber());
5136         break;
5137 
5138       case UPD_DECL_MARKED_OPENMP_THREADPRIVATE:
5139         Record.AddSourceRange(
5140             D->getAttr<OMPThreadPrivateDeclAttr>()->getRange());
5141         break;
5142 
5143       case UPD_DECL_MARKED_OPENMP_ALLOCATE: {
5144         auto *A = D->getAttr<OMPAllocateDeclAttr>();
5145         Record.push_back(A->getAllocatorType());
5146         Record.AddStmt(A->getAllocator());
5147         Record.AddStmt(A->getAlignment());
5148         Record.AddSourceRange(A->getRange());
5149         break;
5150       }
5151 
5152       case UPD_DECL_MARKED_OPENMP_DECLARETARGET:
5153         Record.push_back(D->getAttr<OMPDeclareTargetDeclAttr>()->getMapType());
5154         Record.AddSourceRange(
5155             D->getAttr<OMPDeclareTargetDeclAttr>()->getRange());
5156         break;
5157 
5158       case UPD_DECL_EXPORTED:
5159         Record.push_back(getSubmoduleID(Update.getModule()));
5160         break;
5161 
5162       case UPD_ADDED_ATTR_TO_RECORD:
5163         Record.AddAttributes(llvm::makeArrayRef(Update.getAttr()));
5164         break;
5165       }
5166     }
5167 
5168     if (HasUpdatedBody) {
5169       const auto *Def = cast<FunctionDecl>(D);
5170       Record.push_back(UPD_CXX_ADDED_FUNCTION_DEFINITION);
5171       Record.push_back(Def->isInlined());
5172       Record.AddSourceLocation(Def->getInnerLocStart());
5173       Record.AddFunctionDefinition(Def);
5174     }
5175 
5176     OffsetsRecord.push_back(GetDeclRef(D));
5177     OffsetsRecord.push_back(Record.Emit(DECL_UPDATES));
5178   }
5179 }
5180 
5181 void ASTWriter::AddAlignPackInfo(const Sema::AlignPackInfo &Info,
5182                                  RecordDataImpl &Record) {
5183   uint32_t Raw = Sema::AlignPackInfo::getRawEncoding(Info);
5184   Record.push_back(Raw);
5185 }
5186 
5187 void ASTWriter::AddSourceLocation(SourceLocation Loc, RecordDataImpl &Record) {
5188   SourceLocation::UIntTy Raw = Loc.getRawEncoding();
5189   Record.push_back((Raw << 1) | (Raw >> (8 * sizeof(Raw) - 1)));
5190 }
5191 
5192 void ASTWriter::AddSourceRange(SourceRange Range, RecordDataImpl &Record) {
5193   AddSourceLocation(Range.getBegin(), Record);
5194   AddSourceLocation(Range.getEnd(), Record);
5195 }
5196 
5197 void ASTRecordWriter::AddAPFloat(const llvm::APFloat &Value) {
5198   AddAPInt(Value.bitcastToAPInt());
5199 }
5200 
5201 void ASTWriter::AddIdentifierRef(const IdentifierInfo *II, RecordDataImpl &Record) {
5202   Record.push_back(getIdentifierRef(II));
5203 }
5204 
5205 IdentID ASTWriter::getIdentifierRef(const IdentifierInfo *II) {
5206   if (!II)
5207     return 0;
5208 
5209   IdentID &ID = IdentifierIDs[II];
5210   if (ID == 0)
5211     ID = NextIdentID++;
5212   return ID;
5213 }
5214 
5215 MacroID ASTWriter::getMacroRef(MacroInfo *MI, const IdentifierInfo *Name) {
5216   // Don't emit builtin macros like __LINE__ to the AST file unless they
5217   // have been redefined by the header (in which case they are not
5218   // isBuiltinMacro).
5219   if (!MI || MI->isBuiltinMacro())
5220     return 0;
5221 
5222   MacroID &ID = MacroIDs[MI];
5223   if (ID == 0) {
5224     ID = NextMacroID++;
5225     MacroInfoToEmitData Info = { Name, MI, ID };
5226     MacroInfosToEmit.push_back(Info);
5227   }
5228   return ID;
5229 }
5230 
5231 MacroID ASTWriter::getMacroID(MacroInfo *MI) {
5232   if (!MI || MI->isBuiltinMacro())
5233     return 0;
5234 
5235   assert(MacroIDs.find(MI) != MacroIDs.end() && "Macro not emitted!");
5236   return MacroIDs[MI];
5237 }
5238 
5239 uint32_t ASTWriter::getMacroDirectivesOffset(const IdentifierInfo *Name) {
5240   return IdentMacroDirectivesOffsetMap.lookup(Name);
5241 }
5242 
5243 void ASTRecordWriter::AddSelectorRef(const Selector SelRef) {
5244   Record->push_back(Writer->getSelectorRef(SelRef));
5245 }
5246 
5247 SelectorID ASTWriter::getSelectorRef(Selector Sel) {
5248   if (Sel.getAsOpaquePtr() == nullptr) {
5249     return 0;
5250   }
5251 
5252   SelectorID SID = SelectorIDs[Sel];
5253   if (SID == 0 && Chain) {
5254     // This might trigger a ReadSelector callback, which will set the ID for
5255     // this selector.
5256     Chain->LoadSelector(Sel);
5257     SID = SelectorIDs[Sel];
5258   }
5259   if (SID == 0) {
5260     SID = NextSelectorID++;
5261     SelectorIDs[Sel] = SID;
5262   }
5263   return SID;
5264 }
5265 
5266 void ASTRecordWriter::AddCXXTemporary(const CXXTemporary *Temp) {
5267   AddDeclRef(Temp->getDestructor());
5268 }
5269 
5270 void ASTRecordWriter::AddTemplateArgumentLocInfo(
5271     TemplateArgument::ArgKind Kind, const TemplateArgumentLocInfo &Arg) {
5272   switch (Kind) {
5273   case TemplateArgument::Expression:
5274     AddStmt(Arg.getAsExpr());
5275     break;
5276   case TemplateArgument::Type:
5277     AddTypeSourceInfo(Arg.getAsTypeSourceInfo());
5278     break;
5279   case TemplateArgument::Template:
5280     AddNestedNameSpecifierLoc(Arg.getTemplateQualifierLoc());
5281     AddSourceLocation(Arg.getTemplateNameLoc());
5282     break;
5283   case TemplateArgument::TemplateExpansion:
5284     AddNestedNameSpecifierLoc(Arg.getTemplateQualifierLoc());
5285     AddSourceLocation(Arg.getTemplateNameLoc());
5286     AddSourceLocation(Arg.getTemplateEllipsisLoc());
5287     break;
5288   case TemplateArgument::Null:
5289   case TemplateArgument::Integral:
5290   case TemplateArgument::Declaration:
5291   case TemplateArgument::NullPtr:
5292   case TemplateArgument::Pack:
5293     // FIXME: Is this right?
5294     break;
5295   }
5296 }
5297 
5298 void ASTRecordWriter::AddTemplateArgumentLoc(const TemplateArgumentLoc &Arg) {
5299   AddTemplateArgument(Arg.getArgument());
5300 
5301   if (Arg.getArgument().getKind() == TemplateArgument::Expression) {
5302     bool InfoHasSameExpr
5303       = Arg.getArgument().getAsExpr() == Arg.getLocInfo().getAsExpr();
5304     Record->push_back(InfoHasSameExpr);
5305     if (InfoHasSameExpr)
5306       return; // Avoid storing the same expr twice.
5307   }
5308   AddTemplateArgumentLocInfo(Arg.getArgument().getKind(), Arg.getLocInfo());
5309 }
5310 
5311 void ASTRecordWriter::AddTypeSourceInfo(TypeSourceInfo *TInfo) {
5312   if (!TInfo) {
5313     AddTypeRef(QualType());
5314     return;
5315   }
5316 
5317   AddTypeRef(TInfo->getType());
5318   AddTypeLoc(TInfo->getTypeLoc());
5319 }
5320 
5321 void ASTRecordWriter::AddTypeLoc(TypeLoc TL) {
5322   TypeLocWriter TLW(*this);
5323   for (; !TL.isNull(); TL = TL.getNextTypeLoc())
5324     TLW.Visit(TL);
5325 }
5326 
5327 void ASTWriter::AddTypeRef(QualType T, RecordDataImpl &Record) {
5328   Record.push_back(GetOrCreateTypeID(T));
5329 }
5330 
5331 TypeID ASTWriter::GetOrCreateTypeID(QualType T) {
5332   assert(Context);
5333   return MakeTypeID(*Context, T, [&](QualType T) -> TypeIdx {
5334     if (T.isNull())
5335       return TypeIdx();
5336     assert(!T.getLocalFastQualifiers());
5337 
5338     TypeIdx &Idx = TypeIdxs[T];
5339     if (Idx.getIndex() == 0) {
5340       if (DoneWritingDeclsAndTypes) {
5341         assert(0 && "New type seen after serializing all the types to emit!");
5342         return TypeIdx();
5343       }
5344 
5345       // We haven't seen this type before. Assign it a new ID and put it
5346       // into the queue of types to emit.
5347       Idx = TypeIdx(NextTypeID++);
5348       DeclTypesToEmit.push(T);
5349     }
5350     return Idx;
5351   });
5352 }
5353 
5354 TypeID ASTWriter::getTypeID(QualType T) const {
5355   assert(Context);
5356   return MakeTypeID(*Context, T, [&](QualType T) -> TypeIdx {
5357     if (T.isNull())
5358       return TypeIdx();
5359     assert(!T.getLocalFastQualifiers());
5360 
5361     TypeIdxMap::const_iterator I = TypeIdxs.find(T);
5362     assert(I != TypeIdxs.end() && "Type not emitted!");
5363     return I->second;
5364   });
5365 }
5366 
5367 void ASTWriter::AddDeclRef(const Decl *D, RecordDataImpl &Record) {
5368   Record.push_back(GetDeclRef(D));
5369 }
5370 
5371 DeclID ASTWriter::GetDeclRef(const Decl *D) {
5372   assert(WritingAST && "Cannot request a declaration ID before AST writing");
5373 
5374   if (!D) {
5375     return 0;
5376   }
5377 
5378   // If D comes from an AST file, its declaration ID is already known and
5379   // fixed.
5380   if (D->isFromASTFile())
5381     return D->getGlobalID();
5382 
5383   assert(!(reinterpret_cast<uintptr_t>(D) & 0x01) && "Invalid decl pointer");
5384   DeclID &ID = DeclIDs[D];
5385   if (ID == 0) {
5386     if (DoneWritingDeclsAndTypes) {
5387       assert(0 && "New decl seen after serializing all the decls to emit!");
5388       return 0;
5389     }
5390 
5391     // We haven't seen this declaration before. Give it a new ID and
5392     // enqueue it in the list of declarations to emit.
5393     ID = NextDeclID++;
5394     DeclTypesToEmit.push(const_cast<Decl *>(D));
5395   }
5396 
5397   return ID;
5398 }
5399 
5400 DeclID ASTWriter::getDeclID(const Decl *D) {
5401   if (!D)
5402     return 0;
5403 
5404   // If D comes from an AST file, its declaration ID is already known and
5405   // fixed.
5406   if (D->isFromASTFile())
5407     return D->getGlobalID();
5408 
5409   assert(DeclIDs.find(D) != DeclIDs.end() && "Declaration not emitted!");
5410   return DeclIDs[D];
5411 }
5412 
5413 void ASTWriter::associateDeclWithFile(const Decl *D, DeclID ID) {
5414   assert(ID);
5415   assert(D);
5416 
5417   SourceLocation Loc = D->getLocation();
5418   if (Loc.isInvalid())
5419     return;
5420 
5421   // We only keep track of the file-level declarations of each file.
5422   if (!D->getLexicalDeclContext()->isFileContext())
5423     return;
5424   // FIXME: ParmVarDecls that are part of a function type of a parameter of
5425   // a function/objc method, should not have TU as lexical context.
5426   // TemplateTemplateParmDecls that are part of an alias template, should not
5427   // have TU as lexical context.
5428   if (isa<ParmVarDecl>(D) || isa<TemplateTemplateParmDecl>(D))
5429     return;
5430 
5431   SourceManager &SM = Context->getSourceManager();
5432   SourceLocation FileLoc = SM.getFileLoc(Loc);
5433   assert(SM.isLocalSourceLocation(FileLoc));
5434   FileID FID;
5435   unsigned Offset;
5436   std::tie(FID, Offset) = SM.getDecomposedLoc(FileLoc);
5437   if (FID.isInvalid())
5438     return;
5439   assert(SM.getSLocEntry(FID).isFile());
5440 
5441   std::unique_ptr<DeclIDInFileInfo> &Info = FileDeclIDs[FID];
5442   if (!Info)
5443     Info = std::make_unique<DeclIDInFileInfo>();
5444 
5445   std::pair<unsigned, serialization::DeclID> LocDecl(Offset, ID);
5446   LocDeclIDsTy &Decls = Info->DeclIDs;
5447 
5448   if (Decls.empty() || Decls.back().first <= Offset) {
5449     Decls.push_back(LocDecl);
5450     return;
5451   }
5452 
5453   LocDeclIDsTy::iterator I =
5454       llvm::upper_bound(Decls, LocDecl, llvm::less_first());
5455 
5456   Decls.insert(I, LocDecl);
5457 }
5458 
5459 unsigned ASTWriter::getAnonymousDeclarationNumber(const NamedDecl *D) {
5460   assert(needsAnonymousDeclarationNumber(D) &&
5461          "expected an anonymous declaration");
5462 
5463   // Number the anonymous declarations within this context, if we've not
5464   // already done so.
5465   auto It = AnonymousDeclarationNumbers.find(D);
5466   if (It == AnonymousDeclarationNumbers.end()) {
5467     auto *DC = D->getLexicalDeclContext();
5468     numberAnonymousDeclsWithin(DC, [&](const NamedDecl *ND, unsigned Number) {
5469       AnonymousDeclarationNumbers[ND] = Number;
5470     });
5471 
5472     It = AnonymousDeclarationNumbers.find(D);
5473     assert(It != AnonymousDeclarationNumbers.end() &&
5474            "declaration not found within its lexical context");
5475   }
5476 
5477   return It->second;
5478 }
5479 
5480 void ASTRecordWriter::AddDeclarationNameLoc(const DeclarationNameLoc &DNLoc,
5481                                             DeclarationName Name) {
5482   switch (Name.getNameKind()) {
5483   case DeclarationName::CXXConstructorName:
5484   case DeclarationName::CXXDestructorName:
5485   case DeclarationName::CXXConversionFunctionName:
5486     AddTypeSourceInfo(DNLoc.getNamedTypeInfo());
5487     break;
5488 
5489   case DeclarationName::CXXOperatorName:
5490     AddSourceRange(DNLoc.getCXXOperatorNameRange());
5491     break;
5492 
5493   case DeclarationName::CXXLiteralOperatorName:
5494     AddSourceLocation(DNLoc.getCXXLiteralOperatorNameLoc());
5495     break;
5496 
5497   case DeclarationName::Identifier:
5498   case DeclarationName::ObjCZeroArgSelector:
5499   case DeclarationName::ObjCOneArgSelector:
5500   case DeclarationName::ObjCMultiArgSelector:
5501   case DeclarationName::CXXUsingDirective:
5502   case DeclarationName::CXXDeductionGuideName:
5503     break;
5504   }
5505 }
5506 
5507 void ASTRecordWriter::AddDeclarationNameInfo(
5508     const DeclarationNameInfo &NameInfo) {
5509   AddDeclarationName(NameInfo.getName());
5510   AddSourceLocation(NameInfo.getLoc());
5511   AddDeclarationNameLoc(NameInfo.getInfo(), NameInfo.getName());
5512 }
5513 
5514 void ASTRecordWriter::AddQualifierInfo(const QualifierInfo &Info) {
5515   AddNestedNameSpecifierLoc(Info.QualifierLoc);
5516   Record->push_back(Info.NumTemplParamLists);
5517   for (unsigned i = 0, e = Info.NumTemplParamLists; i != e; ++i)
5518     AddTemplateParameterList(Info.TemplParamLists[i]);
5519 }
5520 
5521 void ASTRecordWriter::AddNestedNameSpecifierLoc(NestedNameSpecifierLoc NNS) {
5522   // Nested name specifiers usually aren't too long. I think that 8 would
5523   // typically accommodate the vast majority.
5524   SmallVector<NestedNameSpecifierLoc , 8> NestedNames;
5525 
5526   // Push each of the nested-name-specifiers's onto a stack for
5527   // serialization in reverse order.
5528   while (NNS) {
5529     NestedNames.push_back(NNS);
5530     NNS = NNS.getPrefix();
5531   }
5532 
5533   Record->push_back(NestedNames.size());
5534   while(!NestedNames.empty()) {
5535     NNS = NestedNames.pop_back_val();
5536     NestedNameSpecifier::SpecifierKind Kind
5537       = NNS.getNestedNameSpecifier()->getKind();
5538     Record->push_back(Kind);
5539     switch (Kind) {
5540     case NestedNameSpecifier::Identifier:
5541       AddIdentifierRef(NNS.getNestedNameSpecifier()->getAsIdentifier());
5542       AddSourceRange(NNS.getLocalSourceRange());
5543       break;
5544 
5545     case NestedNameSpecifier::Namespace:
5546       AddDeclRef(NNS.getNestedNameSpecifier()->getAsNamespace());
5547       AddSourceRange(NNS.getLocalSourceRange());
5548       break;
5549 
5550     case NestedNameSpecifier::NamespaceAlias:
5551       AddDeclRef(NNS.getNestedNameSpecifier()->getAsNamespaceAlias());
5552       AddSourceRange(NNS.getLocalSourceRange());
5553       break;
5554 
5555     case NestedNameSpecifier::TypeSpec:
5556     case NestedNameSpecifier::TypeSpecWithTemplate:
5557       Record->push_back(Kind == NestedNameSpecifier::TypeSpecWithTemplate);
5558       AddTypeRef(NNS.getTypeLoc().getType());
5559       AddTypeLoc(NNS.getTypeLoc());
5560       AddSourceLocation(NNS.getLocalSourceRange().getEnd());
5561       break;
5562 
5563     case NestedNameSpecifier::Global:
5564       AddSourceLocation(NNS.getLocalSourceRange().getEnd());
5565       break;
5566 
5567     case NestedNameSpecifier::Super:
5568       AddDeclRef(NNS.getNestedNameSpecifier()->getAsRecordDecl());
5569       AddSourceRange(NNS.getLocalSourceRange());
5570       break;
5571     }
5572   }
5573 }
5574 
5575 void ASTRecordWriter::AddTemplateParameterList(
5576     const TemplateParameterList *TemplateParams) {
5577   assert(TemplateParams && "No TemplateParams!");
5578   AddSourceLocation(TemplateParams->getTemplateLoc());
5579   AddSourceLocation(TemplateParams->getLAngleLoc());
5580   AddSourceLocation(TemplateParams->getRAngleLoc());
5581 
5582   Record->push_back(TemplateParams->size());
5583   for (const auto &P : *TemplateParams)
5584     AddDeclRef(P);
5585   if (const Expr *RequiresClause = TemplateParams->getRequiresClause()) {
5586     Record->push_back(true);
5587     AddStmt(const_cast<Expr*>(RequiresClause));
5588   } else {
5589     Record->push_back(false);
5590   }
5591 }
5592 
5593 /// Emit a template argument list.
5594 void ASTRecordWriter::AddTemplateArgumentList(
5595     const TemplateArgumentList *TemplateArgs) {
5596   assert(TemplateArgs && "No TemplateArgs!");
5597   Record->push_back(TemplateArgs->size());
5598   for (int i = 0, e = TemplateArgs->size(); i != e; ++i)
5599     AddTemplateArgument(TemplateArgs->get(i));
5600 }
5601 
5602 void ASTRecordWriter::AddASTTemplateArgumentListInfo(
5603     const ASTTemplateArgumentListInfo *ASTTemplArgList) {
5604   assert(ASTTemplArgList && "No ASTTemplArgList!");
5605   AddSourceLocation(ASTTemplArgList->LAngleLoc);
5606   AddSourceLocation(ASTTemplArgList->RAngleLoc);
5607   Record->push_back(ASTTemplArgList->NumTemplateArgs);
5608   const TemplateArgumentLoc *TemplArgs = ASTTemplArgList->getTemplateArgs();
5609   for (int i = 0, e = ASTTemplArgList->NumTemplateArgs; i != e; ++i)
5610     AddTemplateArgumentLoc(TemplArgs[i]);
5611 }
5612 
5613 void ASTRecordWriter::AddUnresolvedSet(const ASTUnresolvedSet &Set) {
5614   Record->push_back(Set.size());
5615   for (ASTUnresolvedSet::const_iterator
5616          I = Set.begin(), E = Set.end(); I != E; ++I) {
5617     AddDeclRef(I.getDecl());
5618     Record->push_back(I.getAccess());
5619   }
5620 }
5621 
5622 // FIXME: Move this out of the main ASTRecordWriter interface.
5623 void ASTRecordWriter::AddCXXBaseSpecifier(const CXXBaseSpecifier &Base) {
5624   Record->push_back(Base.isVirtual());
5625   Record->push_back(Base.isBaseOfClass());
5626   Record->push_back(Base.getAccessSpecifierAsWritten());
5627   Record->push_back(Base.getInheritConstructors());
5628   AddTypeSourceInfo(Base.getTypeSourceInfo());
5629   AddSourceRange(Base.getSourceRange());
5630   AddSourceLocation(Base.isPackExpansion()? Base.getEllipsisLoc()
5631                                           : SourceLocation());
5632 }
5633 
5634 static uint64_t EmitCXXBaseSpecifiers(ASTWriter &W,
5635                                       ArrayRef<CXXBaseSpecifier> Bases) {
5636   ASTWriter::RecordData Record;
5637   ASTRecordWriter Writer(W, Record);
5638   Writer.push_back(Bases.size());
5639 
5640   for (auto &Base : Bases)
5641     Writer.AddCXXBaseSpecifier(Base);
5642 
5643   return Writer.Emit(serialization::DECL_CXX_BASE_SPECIFIERS);
5644 }
5645 
5646 // FIXME: Move this out of the main ASTRecordWriter interface.
5647 void ASTRecordWriter::AddCXXBaseSpecifiers(ArrayRef<CXXBaseSpecifier> Bases) {
5648   AddOffset(EmitCXXBaseSpecifiers(*Writer, Bases));
5649 }
5650 
5651 static uint64_t
5652 EmitCXXCtorInitializers(ASTWriter &W,
5653                         ArrayRef<CXXCtorInitializer *> CtorInits) {
5654   ASTWriter::RecordData Record;
5655   ASTRecordWriter Writer(W, Record);
5656   Writer.push_back(CtorInits.size());
5657 
5658   for (auto *Init : CtorInits) {
5659     if (Init->isBaseInitializer()) {
5660       Writer.push_back(CTOR_INITIALIZER_BASE);
5661       Writer.AddTypeSourceInfo(Init->getTypeSourceInfo());
5662       Writer.push_back(Init->isBaseVirtual());
5663     } else if (Init->isDelegatingInitializer()) {
5664       Writer.push_back(CTOR_INITIALIZER_DELEGATING);
5665       Writer.AddTypeSourceInfo(Init->getTypeSourceInfo());
5666     } else if (Init->isMemberInitializer()){
5667       Writer.push_back(CTOR_INITIALIZER_MEMBER);
5668       Writer.AddDeclRef(Init->getMember());
5669     } else {
5670       Writer.push_back(CTOR_INITIALIZER_INDIRECT_MEMBER);
5671       Writer.AddDeclRef(Init->getIndirectMember());
5672     }
5673 
5674     Writer.AddSourceLocation(Init->getMemberLocation());
5675     Writer.AddStmt(Init->getInit());
5676     Writer.AddSourceLocation(Init->getLParenLoc());
5677     Writer.AddSourceLocation(Init->getRParenLoc());
5678     Writer.push_back(Init->isWritten());
5679     if (Init->isWritten())
5680       Writer.push_back(Init->getSourceOrder());
5681   }
5682 
5683   return Writer.Emit(serialization::DECL_CXX_CTOR_INITIALIZERS);
5684 }
5685 
5686 // FIXME: Move this out of the main ASTRecordWriter interface.
5687 void ASTRecordWriter::AddCXXCtorInitializers(
5688     ArrayRef<CXXCtorInitializer *> CtorInits) {
5689   AddOffset(EmitCXXCtorInitializers(*Writer, CtorInits));
5690 }
5691 
5692 void ASTRecordWriter::AddCXXDefinitionData(const CXXRecordDecl *D) {
5693   auto &Data = D->data();
5694   Record->push_back(Data.IsLambda);
5695 
5696   #define FIELD(Name, Width, Merge) \
5697   Record->push_back(Data.Name);
5698   #include "clang/AST/CXXRecordDeclDefinitionBits.def"
5699 
5700   // getODRHash will compute the ODRHash if it has not been previously computed.
5701   Record->push_back(D->getODRHash());
5702   bool ModulesDebugInfo =
5703       Writer->Context->getLangOpts().ModulesDebugInfo && !D->isDependentType();
5704   Record->push_back(ModulesDebugInfo);
5705   if (ModulesDebugInfo)
5706     Writer->ModularCodegenDecls.push_back(Writer->GetDeclRef(D));
5707 
5708   // IsLambda bit is already saved.
5709 
5710   Record->push_back(Data.NumBases);
5711   if (Data.NumBases > 0)
5712     AddCXXBaseSpecifiers(Data.bases());
5713 
5714   // FIXME: Make VBases lazily computed when needed to avoid storing them.
5715   Record->push_back(Data.NumVBases);
5716   if (Data.NumVBases > 0)
5717     AddCXXBaseSpecifiers(Data.vbases());
5718 
5719   AddUnresolvedSet(Data.Conversions.get(*Writer->Context));
5720   Record->push_back(Data.ComputedVisibleConversions);
5721   if (Data.ComputedVisibleConversions)
5722     AddUnresolvedSet(Data.VisibleConversions.get(*Writer->Context));
5723   // Data.Definition is the owning decl, no need to write it.
5724   AddDeclRef(D->getFirstFriend());
5725 
5726   // Add lambda-specific data.
5727   if (Data.IsLambda) {
5728     auto &Lambda = D->getLambdaData();
5729     Record->push_back(Lambda.Dependent);
5730     Record->push_back(Lambda.IsGenericLambda);
5731     Record->push_back(Lambda.CaptureDefault);
5732     Record->push_back(Lambda.NumCaptures);
5733     Record->push_back(Lambda.NumExplicitCaptures);
5734     Record->push_back(Lambda.HasKnownInternalLinkage);
5735     Record->push_back(Lambda.ManglingNumber);
5736     Record->push_back(D->getDeviceLambdaManglingNumber());
5737     AddDeclRef(D->getLambdaContextDecl());
5738     AddTypeSourceInfo(Lambda.MethodTyInfo);
5739     for (unsigned I = 0, N = Lambda.NumCaptures; I != N; ++I) {
5740       const LambdaCapture &Capture = Lambda.Captures[I];
5741       AddSourceLocation(Capture.getLocation());
5742       Record->push_back(Capture.isImplicit());
5743       Record->push_back(Capture.getCaptureKind());
5744       switch (Capture.getCaptureKind()) {
5745       case LCK_StarThis:
5746       case LCK_This:
5747       case LCK_VLAType:
5748         break;
5749       case LCK_ByCopy:
5750       case LCK_ByRef:
5751         VarDecl *Var =
5752             Capture.capturesVariable() ? Capture.getCapturedVar() : nullptr;
5753         AddDeclRef(Var);
5754         AddSourceLocation(Capture.isPackExpansion() ? Capture.getEllipsisLoc()
5755                                                     : SourceLocation());
5756         break;
5757       }
5758     }
5759   }
5760 }
5761 
5762 void ASTRecordWriter::AddVarDeclInit(const VarDecl *VD) {
5763   const Expr *Init = VD->getInit();
5764   if (!Init) {
5765     push_back(0);
5766     return;
5767   }
5768 
5769   unsigned Val = 1;
5770   if (EvaluatedStmt *ES = VD->getEvaluatedStmt()) {
5771     Val |= (ES->HasConstantInitialization ? 2 : 0);
5772     Val |= (ES->HasConstantDestruction ? 4 : 0);
5773     // FIXME: Also emit the constant initializer value.
5774   }
5775   push_back(Val);
5776   writeStmtRef(Init);
5777 }
5778 
5779 void ASTWriter::ReaderInitialized(ASTReader *Reader) {
5780   assert(Reader && "Cannot remove chain");
5781   assert((!Chain || Chain == Reader) && "Cannot replace chain");
5782   assert(FirstDeclID == NextDeclID &&
5783          FirstTypeID == NextTypeID &&
5784          FirstIdentID == NextIdentID &&
5785          FirstMacroID == NextMacroID &&
5786          FirstSubmoduleID == NextSubmoduleID &&
5787          FirstSelectorID == NextSelectorID &&
5788          "Setting chain after writing has started.");
5789 
5790   Chain = Reader;
5791 
5792   // Note, this will get called multiple times, once one the reader starts up
5793   // and again each time it's done reading a PCH or module.
5794   FirstDeclID = NUM_PREDEF_DECL_IDS + Chain->getTotalNumDecls();
5795   FirstTypeID = NUM_PREDEF_TYPE_IDS + Chain->getTotalNumTypes();
5796   FirstIdentID = NUM_PREDEF_IDENT_IDS + Chain->getTotalNumIdentifiers();
5797   FirstMacroID = NUM_PREDEF_MACRO_IDS + Chain->getTotalNumMacros();
5798   FirstSubmoduleID = NUM_PREDEF_SUBMODULE_IDS + Chain->getTotalNumSubmodules();
5799   FirstSelectorID = NUM_PREDEF_SELECTOR_IDS + Chain->getTotalNumSelectors();
5800   NextDeclID = FirstDeclID;
5801   NextTypeID = FirstTypeID;
5802   NextIdentID = FirstIdentID;
5803   NextMacroID = FirstMacroID;
5804   NextSelectorID = FirstSelectorID;
5805   NextSubmoduleID = FirstSubmoduleID;
5806 }
5807 
5808 void ASTWriter::IdentifierRead(IdentID ID, IdentifierInfo *II) {
5809   // Always keep the highest ID. See \p TypeRead() for more information.
5810   IdentID &StoredID = IdentifierIDs[II];
5811   if (ID > StoredID)
5812     StoredID = ID;
5813 }
5814 
5815 void ASTWriter::MacroRead(serialization::MacroID ID, MacroInfo *MI) {
5816   // Always keep the highest ID. See \p TypeRead() for more information.
5817   MacroID &StoredID = MacroIDs[MI];
5818   if (ID > StoredID)
5819     StoredID = ID;
5820 }
5821 
5822 void ASTWriter::TypeRead(TypeIdx Idx, QualType T) {
5823   // Always take the highest-numbered type index. This copes with an interesting
5824   // case for chained AST writing where we schedule writing the type and then,
5825   // later, deserialize the type from another AST. In this case, we want to
5826   // keep the higher-numbered entry so that we can properly write it out to
5827   // the AST file.
5828   TypeIdx &StoredIdx = TypeIdxs[T];
5829   if (Idx.getIndex() >= StoredIdx.getIndex())
5830     StoredIdx = Idx;
5831 }
5832 
5833 void ASTWriter::SelectorRead(SelectorID ID, Selector S) {
5834   // Always keep the highest ID. See \p TypeRead() for more information.
5835   SelectorID &StoredID = SelectorIDs[S];
5836   if (ID > StoredID)
5837     StoredID = ID;
5838 }
5839 
5840 void ASTWriter::MacroDefinitionRead(serialization::PreprocessedEntityID ID,
5841                                     MacroDefinitionRecord *MD) {
5842   assert(MacroDefinitions.find(MD) == MacroDefinitions.end());
5843   MacroDefinitions[MD] = ID;
5844 }
5845 
5846 void ASTWriter::ModuleRead(serialization::SubmoduleID ID, Module *Mod) {
5847   assert(SubmoduleIDs.find(Mod) == SubmoduleIDs.end());
5848   SubmoduleIDs[Mod] = ID;
5849 }
5850 
5851 void ASTWriter::CompletedTagDefinition(const TagDecl *D) {
5852   if (Chain && Chain->isProcessingUpdateRecords()) return;
5853   assert(D->isCompleteDefinition());
5854   assert(!WritingAST && "Already writing the AST!");
5855   if (auto *RD = dyn_cast<CXXRecordDecl>(D)) {
5856     // We are interested when a PCH decl is modified.
5857     if (RD->isFromASTFile()) {
5858       // A forward reference was mutated into a definition. Rewrite it.
5859       // FIXME: This happens during template instantiation, should we
5860       // have created a new definition decl instead ?
5861       assert(isTemplateInstantiation(RD->getTemplateSpecializationKind()) &&
5862              "completed a tag from another module but not by instantiation?");
5863       DeclUpdates[RD].push_back(
5864           DeclUpdate(UPD_CXX_INSTANTIATED_CLASS_DEFINITION));
5865     }
5866   }
5867 }
5868 
5869 static bool isImportedDeclContext(ASTReader *Chain, const Decl *D) {
5870   if (D->isFromASTFile())
5871     return true;
5872 
5873   // The predefined __va_list_tag struct is imported if we imported any decls.
5874   // FIXME: This is a gross hack.
5875   return D == D->getASTContext().getVaListTagDecl();
5876 }
5877 
5878 void ASTWriter::AddedVisibleDecl(const DeclContext *DC, const Decl *D) {
5879   if (Chain && Chain->isProcessingUpdateRecords()) return;
5880   assert(DC->isLookupContext() &&
5881           "Should not add lookup results to non-lookup contexts!");
5882 
5883   // TU is handled elsewhere.
5884   if (isa<TranslationUnitDecl>(DC))
5885     return;
5886 
5887   // Namespaces are handled elsewhere, except for template instantiations of
5888   // FunctionTemplateDecls in namespaces. We are interested in cases where the
5889   // local instantiations are added to an imported context. Only happens when
5890   // adding ADL lookup candidates, for example templated friends.
5891   if (isa<NamespaceDecl>(DC) && D->getFriendObjectKind() == Decl::FOK_None &&
5892       !isa<FunctionTemplateDecl>(D))
5893     return;
5894 
5895   // We're only interested in cases where a local declaration is added to an
5896   // imported context.
5897   if (D->isFromASTFile() || !isImportedDeclContext(Chain, cast<Decl>(DC)))
5898     return;
5899 
5900   assert(DC == DC->getPrimaryContext() && "added to non-primary context");
5901   assert(!getDefinitiveDeclContext(DC) && "DeclContext not definitive!");
5902   assert(!WritingAST && "Already writing the AST!");
5903   if (UpdatedDeclContexts.insert(DC) && !cast<Decl>(DC)->isFromASTFile()) {
5904     // We're adding a visible declaration to a predefined decl context. Ensure
5905     // that we write out all of its lookup results so we don't get a nasty
5906     // surprise when we try to emit its lookup table.
5907     for (auto *Child : DC->decls())
5908       DeclsToEmitEvenIfUnreferenced.push_back(Child);
5909   }
5910   DeclsToEmitEvenIfUnreferenced.push_back(D);
5911 }
5912 
5913 void ASTWriter::AddedCXXImplicitMember(const CXXRecordDecl *RD, const Decl *D) {
5914   if (Chain && Chain->isProcessingUpdateRecords()) return;
5915   assert(D->isImplicit());
5916 
5917   // We're only interested in cases where a local declaration is added to an
5918   // imported context.
5919   if (D->isFromASTFile() || !isImportedDeclContext(Chain, RD))
5920     return;
5921 
5922   if (!isa<CXXMethodDecl>(D))
5923     return;
5924 
5925   // A decl coming from PCH was modified.
5926   assert(RD->isCompleteDefinition());
5927   assert(!WritingAST && "Already writing the AST!");
5928   DeclUpdates[RD].push_back(DeclUpdate(UPD_CXX_ADDED_IMPLICIT_MEMBER, D));
5929 }
5930 
5931 void ASTWriter::ResolvedExceptionSpec(const FunctionDecl *FD) {
5932   if (Chain && Chain->isProcessingUpdateRecords()) return;
5933   assert(!DoneWritingDeclsAndTypes && "Already done writing updates!");
5934   if (!Chain) return;
5935   Chain->forEachImportedKeyDecl(FD, [&](const Decl *D) {
5936     // If we don't already know the exception specification for this redecl
5937     // chain, add an update record for it.
5938     if (isUnresolvedExceptionSpec(cast<FunctionDecl>(D)
5939                                       ->getType()
5940                                       ->castAs<FunctionProtoType>()
5941                                       ->getExceptionSpecType()))
5942       DeclUpdates[D].push_back(UPD_CXX_RESOLVED_EXCEPTION_SPEC);
5943   });
5944 }
5945 
5946 void ASTWriter::DeducedReturnType(const FunctionDecl *FD, QualType ReturnType) {
5947   if (Chain && Chain->isProcessingUpdateRecords()) return;
5948   assert(!WritingAST && "Already writing the AST!");
5949   if (!Chain) return;
5950   Chain->forEachImportedKeyDecl(FD, [&](const Decl *D) {
5951     DeclUpdates[D].push_back(
5952         DeclUpdate(UPD_CXX_DEDUCED_RETURN_TYPE, ReturnType));
5953   });
5954 }
5955 
5956 void ASTWriter::ResolvedOperatorDelete(const CXXDestructorDecl *DD,
5957                                        const FunctionDecl *Delete,
5958                                        Expr *ThisArg) {
5959   if (Chain && Chain->isProcessingUpdateRecords()) return;
5960   assert(!WritingAST && "Already writing the AST!");
5961   assert(Delete && "Not given an operator delete");
5962   if (!Chain) return;
5963   Chain->forEachImportedKeyDecl(DD, [&](const Decl *D) {
5964     DeclUpdates[D].push_back(DeclUpdate(UPD_CXX_RESOLVED_DTOR_DELETE, Delete));
5965   });
5966 }
5967 
5968 void ASTWriter::CompletedImplicitDefinition(const FunctionDecl *D) {
5969   if (Chain && Chain->isProcessingUpdateRecords()) return;
5970   assert(!WritingAST && "Already writing the AST!");
5971   if (!D->isFromASTFile())
5972     return; // Declaration not imported from PCH.
5973 
5974   // Implicit function decl from a PCH was defined.
5975   DeclUpdates[D].push_back(DeclUpdate(UPD_CXX_ADDED_FUNCTION_DEFINITION));
5976 }
5977 
5978 void ASTWriter::VariableDefinitionInstantiated(const VarDecl *D) {
5979   if (Chain && Chain->isProcessingUpdateRecords()) return;
5980   assert(!WritingAST && "Already writing the AST!");
5981   if (!D->isFromASTFile())
5982     return;
5983 
5984   DeclUpdates[D].push_back(DeclUpdate(UPD_CXX_ADDED_VAR_DEFINITION));
5985 }
5986 
5987 void ASTWriter::FunctionDefinitionInstantiated(const FunctionDecl *D) {
5988   if (Chain && Chain->isProcessingUpdateRecords()) return;
5989   assert(!WritingAST && "Already writing the AST!");
5990   if (!D->isFromASTFile())
5991     return;
5992 
5993   DeclUpdates[D].push_back(DeclUpdate(UPD_CXX_ADDED_FUNCTION_DEFINITION));
5994 }
5995 
5996 void ASTWriter::InstantiationRequested(const ValueDecl *D) {
5997   if (Chain && Chain->isProcessingUpdateRecords()) return;
5998   assert(!WritingAST && "Already writing the AST!");
5999   if (!D->isFromASTFile())
6000     return;
6001 
6002   // Since the actual instantiation is delayed, this really means that we need
6003   // to update the instantiation location.
6004   SourceLocation POI;
6005   if (auto *VD = dyn_cast<VarDecl>(D))
6006     POI = VD->getPointOfInstantiation();
6007   else
6008     POI = cast<FunctionDecl>(D)->getPointOfInstantiation();
6009   DeclUpdates[D].push_back(DeclUpdate(UPD_CXX_POINT_OF_INSTANTIATION, POI));
6010 }
6011 
6012 void ASTWriter::DefaultArgumentInstantiated(const ParmVarDecl *D) {
6013   if (Chain && Chain->isProcessingUpdateRecords()) return;
6014   assert(!WritingAST && "Already writing the AST!");
6015   if (!D->isFromASTFile())
6016     return;
6017 
6018   DeclUpdates[D].push_back(
6019       DeclUpdate(UPD_CXX_INSTANTIATED_DEFAULT_ARGUMENT, D));
6020 }
6021 
6022 void ASTWriter::DefaultMemberInitializerInstantiated(const FieldDecl *D) {
6023   assert(!WritingAST && "Already writing the AST!");
6024   if (!D->isFromASTFile())
6025     return;
6026 
6027   DeclUpdates[D].push_back(
6028       DeclUpdate(UPD_CXX_INSTANTIATED_DEFAULT_MEMBER_INITIALIZER, D));
6029 }
6030 
6031 void ASTWriter::AddedObjCCategoryToInterface(const ObjCCategoryDecl *CatD,
6032                                              const ObjCInterfaceDecl *IFD) {
6033   if (Chain && Chain->isProcessingUpdateRecords()) return;
6034   assert(!WritingAST && "Already writing the AST!");
6035   if (!IFD->isFromASTFile())
6036     return; // Declaration not imported from PCH.
6037 
6038   assert(IFD->getDefinition() && "Category on a class without a definition?");
6039   ObjCClassesWithCategories.insert(
6040     const_cast<ObjCInterfaceDecl *>(IFD->getDefinition()));
6041 }
6042 
6043 void ASTWriter::DeclarationMarkedUsed(const Decl *D) {
6044   if (Chain && Chain->isProcessingUpdateRecords()) return;
6045   assert(!WritingAST && "Already writing the AST!");
6046 
6047   // If there is *any* declaration of the entity that's not from an AST file,
6048   // we can skip writing the update record. We make sure that isUsed() triggers
6049   // completion of the redeclaration chain of the entity.
6050   for (auto Prev = D->getMostRecentDecl(); Prev; Prev = Prev->getPreviousDecl())
6051     if (IsLocalDecl(Prev))
6052       return;
6053 
6054   DeclUpdates[D].push_back(DeclUpdate(UPD_DECL_MARKED_USED));
6055 }
6056 
6057 void ASTWriter::DeclarationMarkedOpenMPThreadPrivate(const Decl *D) {
6058   if (Chain && Chain->isProcessingUpdateRecords()) return;
6059   assert(!WritingAST && "Already writing the AST!");
6060   if (!D->isFromASTFile())
6061     return;
6062 
6063   DeclUpdates[D].push_back(DeclUpdate(UPD_DECL_MARKED_OPENMP_THREADPRIVATE));
6064 }
6065 
6066 void ASTWriter::DeclarationMarkedOpenMPAllocate(const Decl *D, const Attr *A) {
6067   if (Chain && Chain->isProcessingUpdateRecords()) return;
6068   assert(!WritingAST && "Already writing the AST!");
6069   if (!D->isFromASTFile())
6070     return;
6071 
6072   DeclUpdates[D].push_back(DeclUpdate(UPD_DECL_MARKED_OPENMP_ALLOCATE, A));
6073 }
6074 
6075 void ASTWriter::DeclarationMarkedOpenMPDeclareTarget(const Decl *D,
6076                                                      const Attr *Attr) {
6077   if (Chain && Chain->isProcessingUpdateRecords()) return;
6078   assert(!WritingAST && "Already writing the AST!");
6079   if (!D->isFromASTFile())
6080     return;
6081 
6082   DeclUpdates[D].push_back(
6083       DeclUpdate(UPD_DECL_MARKED_OPENMP_DECLARETARGET, Attr));
6084 }
6085 
6086 void ASTWriter::RedefinedHiddenDefinition(const NamedDecl *D, Module *M) {
6087   if (Chain && Chain->isProcessingUpdateRecords()) return;
6088   assert(!WritingAST && "Already writing the AST!");
6089   assert(!D->isUnconditionallyVisible() && "expected a hidden declaration");
6090   DeclUpdates[D].push_back(DeclUpdate(UPD_DECL_EXPORTED, M));
6091 }
6092 
6093 void ASTWriter::AddedAttributeToRecord(const Attr *Attr,
6094                                        const RecordDecl *Record) {
6095   if (Chain && Chain->isProcessingUpdateRecords()) return;
6096   assert(!WritingAST && "Already writing the AST!");
6097   if (!Record->isFromASTFile())
6098     return;
6099   DeclUpdates[Record].push_back(DeclUpdate(UPD_ADDED_ATTR_TO_RECORD, Attr));
6100 }
6101 
6102 void ASTWriter::AddedCXXTemplateSpecialization(
6103     const ClassTemplateDecl *TD, const ClassTemplateSpecializationDecl *D) {
6104   assert(!WritingAST && "Already writing the AST!");
6105 
6106   if (!TD->getFirstDecl()->isFromASTFile())
6107     return;
6108   if (Chain && Chain->isProcessingUpdateRecords())
6109     return;
6110 
6111   DeclsToEmitEvenIfUnreferenced.push_back(D);
6112 }
6113 
6114 void ASTWriter::AddedCXXTemplateSpecialization(
6115     const VarTemplateDecl *TD, const VarTemplateSpecializationDecl *D) {
6116   assert(!WritingAST && "Already writing the AST!");
6117 
6118   if (!TD->getFirstDecl()->isFromASTFile())
6119     return;
6120   if (Chain && Chain->isProcessingUpdateRecords())
6121     return;
6122 
6123   DeclsToEmitEvenIfUnreferenced.push_back(D);
6124 }
6125 
6126 void ASTWriter::AddedCXXTemplateSpecialization(const FunctionTemplateDecl *TD,
6127                                                const FunctionDecl *D) {
6128   assert(!WritingAST && "Already writing the AST!");
6129 
6130   if (!TD->getFirstDecl()->isFromASTFile())
6131     return;
6132   if (Chain && Chain->isProcessingUpdateRecords())
6133     return;
6134 
6135   DeclsToEmitEvenIfUnreferenced.push_back(D);
6136 }
6137 
6138 //===----------------------------------------------------------------------===//
6139 //// OMPClause Serialization
6140 ////===----------------------------------------------------------------------===//
6141 
6142 namespace {
6143 
6144 class OMPClauseWriter : public OMPClauseVisitor<OMPClauseWriter> {
6145   ASTRecordWriter &Record;
6146 
6147 public:
6148   OMPClauseWriter(ASTRecordWriter &Record) : Record(Record) {}
6149 #define GEN_CLANG_CLAUSE_CLASS
6150 #define CLAUSE_CLASS(Enum, Str, Class) void Visit##Class(Class *S);
6151 #include "llvm/Frontend/OpenMP/OMP.inc"
6152   void writeClause(OMPClause *C);
6153   void VisitOMPClauseWithPreInit(OMPClauseWithPreInit *C);
6154   void VisitOMPClauseWithPostUpdate(OMPClauseWithPostUpdate *C);
6155 };
6156 
6157 }
6158 
6159 void ASTRecordWriter::writeOMPClause(OMPClause *C) {
6160   OMPClauseWriter(*this).writeClause(C);
6161 }
6162 
6163 void OMPClauseWriter::writeClause(OMPClause *C) {
6164   Record.push_back(unsigned(C->getClauseKind()));
6165   Visit(C);
6166   Record.AddSourceLocation(C->getBeginLoc());
6167   Record.AddSourceLocation(C->getEndLoc());
6168 }
6169 
6170 void OMPClauseWriter::VisitOMPClauseWithPreInit(OMPClauseWithPreInit *C) {
6171   Record.push_back(uint64_t(C->getCaptureRegion()));
6172   Record.AddStmt(C->getPreInitStmt());
6173 }
6174 
6175 void OMPClauseWriter::VisitOMPClauseWithPostUpdate(OMPClauseWithPostUpdate *C) {
6176   VisitOMPClauseWithPreInit(C);
6177   Record.AddStmt(C->getPostUpdateExpr());
6178 }
6179 
6180 void OMPClauseWriter::VisitOMPIfClause(OMPIfClause *C) {
6181   VisitOMPClauseWithPreInit(C);
6182   Record.push_back(uint64_t(C->getNameModifier()));
6183   Record.AddSourceLocation(C->getNameModifierLoc());
6184   Record.AddSourceLocation(C->getColonLoc());
6185   Record.AddStmt(C->getCondition());
6186   Record.AddSourceLocation(C->getLParenLoc());
6187 }
6188 
6189 void OMPClauseWriter::VisitOMPFinalClause(OMPFinalClause *C) {
6190   VisitOMPClauseWithPreInit(C);
6191   Record.AddStmt(C->getCondition());
6192   Record.AddSourceLocation(C->getLParenLoc());
6193 }
6194 
6195 void OMPClauseWriter::VisitOMPNumThreadsClause(OMPNumThreadsClause *C) {
6196   VisitOMPClauseWithPreInit(C);
6197   Record.AddStmt(C->getNumThreads());
6198   Record.AddSourceLocation(C->getLParenLoc());
6199 }
6200 
6201 void OMPClauseWriter::VisitOMPSafelenClause(OMPSafelenClause *C) {
6202   Record.AddStmt(C->getSafelen());
6203   Record.AddSourceLocation(C->getLParenLoc());
6204 }
6205 
6206 void OMPClauseWriter::VisitOMPSimdlenClause(OMPSimdlenClause *C) {
6207   Record.AddStmt(C->getSimdlen());
6208   Record.AddSourceLocation(C->getLParenLoc());
6209 }
6210 
6211 void OMPClauseWriter::VisitOMPSizesClause(OMPSizesClause *C) {
6212   Record.push_back(C->getNumSizes());
6213   for (Expr *Size : C->getSizesRefs())
6214     Record.AddStmt(Size);
6215   Record.AddSourceLocation(C->getLParenLoc());
6216 }
6217 
6218 void OMPClauseWriter::VisitOMPFullClause(OMPFullClause *C) {}
6219 
6220 void OMPClauseWriter::VisitOMPPartialClause(OMPPartialClause *C) {
6221   Record.AddStmt(C->getFactor());
6222   Record.AddSourceLocation(C->getLParenLoc());
6223 }
6224 
6225 void OMPClauseWriter::VisitOMPAllocatorClause(OMPAllocatorClause *C) {
6226   Record.AddStmt(C->getAllocator());
6227   Record.AddSourceLocation(C->getLParenLoc());
6228 }
6229 
6230 void OMPClauseWriter::VisitOMPCollapseClause(OMPCollapseClause *C) {
6231   Record.AddStmt(C->getNumForLoops());
6232   Record.AddSourceLocation(C->getLParenLoc());
6233 }
6234 
6235 void OMPClauseWriter::VisitOMPDetachClause(OMPDetachClause *C) {
6236   Record.AddStmt(C->getEventHandler());
6237   Record.AddSourceLocation(C->getLParenLoc());
6238 }
6239 
6240 void OMPClauseWriter::VisitOMPDefaultClause(OMPDefaultClause *C) {
6241   Record.push_back(unsigned(C->getDefaultKind()));
6242   Record.AddSourceLocation(C->getLParenLoc());
6243   Record.AddSourceLocation(C->getDefaultKindKwLoc());
6244 }
6245 
6246 void OMPClauseWriter::VisitOMPProcBindClause(OMPProcBindClause *C) {
6247   Record.push_back(unsigned(C->getProcBindKind()));
6248   Record.AddSourceLocation(C->getLParenLoc());
6249   Record.AddSourceLocation(C->getProcBindKindKwLoc());
6250 }
6251 
6252 void OMPClauseWriter::VisitOMPScheduleClause(OMPScheduleClause *C) {
6253   VisitOMPClauseWithPreInit(C);
6254   Record.push_back(C->getScheduleKind());
6255   Record.push_back(C->getFirstScheduleModifier());
6256   Record.push_back(C->getSecondScheduleModifier());
6257   Record.AddStmt(C->getChunkSize());
6258   Record.AddSourceLocation(C->getLParenLoc());
6259   Record.AddSourceLocation(C->getFirstScheduleModifierLoc());
6260   Record.AddSourceLocation(C->getSecondScheduleModifierLoc());
6261   Record.AddSourceLocation(C->getScheduleKindLoc());
6262   Record.AddSourceLocation(C->getCommaLoc());
6263 }
6264 
6265 void OMPClauseWriter::VisitOMPOrderedClause(OMPOrderedClause *C) {
6266   Record.push_back(C->getLoopNumIterations().size());
6267   Record.AddStmt(C->getNumForLoops());
6268   for (Expr *NumIter : C->getLoopNumIterations())
6269     Record.AddStmt(NumIter);
6270   for (unsigned I = 0, E = C->getLoopNumIterations().size(); I <E; ++I)
6271     Record.AddStmt(C->getLoopCounter(I));
6272   Record.AddSourceLocation(C->getLParenLoc());
6273 }
6274 
6275 void OMPClauseWriter::VisitOMPNowaitClause(OMPNowaitClause *) {}
6276 
6277 void OMPClauseWriter::VisitOMPUntiedClause(OMPUntiedClause *) {}
6278 
6279 void OMPClauseWriter::VisitOMPMergeableClause(OMPMergeableClause *) {}
6280 
6281 void OMPClauseWriter::VisitOMPReadClause(OMPReadClause *) {}
6282 
6283 void OMPClauseWriter::VisitOMPWriteClause(OMPWriteClause *) {}
6284 
6285 void OMPClauseWriter::VisitOMPUpdateClause(OMPUpdateClause *C) {
6286   Record.push_back(C->isExtended() ? 1 : 0);
6287   if (C->isExtended()) {
6288     Record.AddSourceLocation(C->getLParenLoc());
6289     Record.AddSourceLocation(C->getArgumentLoc());
6290     Record.writeEnum(C->getDependencyKind());
6291   }
6292 }
6293 
6294 void OMPClauseWriter::VisitOMPCaptureClause(OMPCaptureClause *) {}
6295 
6296 void OMPClauseWriter::VisitOMPCompareClause(OMPCompareClause *) {}
6297 
6298 void OMPClauseWriter::VisitOMPSeqCstClause(OMPSeqCstClause *) {}
6299 
6300 void OMPClauseWriter::VisitOMPAcqRelClause(OMPAcqRelClause *) {}
6301 
6302 void OMPClauseWriter::VisitOMPAcquireClause(OMPAcquireClause *) {}
6303 
6304 void OMPClauseWriter::VisitOMPReleaseClause(OMPReleaseClause *) {}
6305 
6306 void OMPClauseWriter::VisitOMPRelaxedClause(OMPRelaxedClause *) {}
6307 
6308 void OMPClauseWriter::VisitOMPThreadsClause(OMPThreadsClause *) {}
6309 
6310 void OMPClauseWriter::VisitOMPSIMDClause(OMPSIMDClause *) {}
6311 
6312 void OMPClauseWriter::VisitOMPNogroupClause(OMPNogroupClause *) {}
6313 
6314 void OMPClauseWriter::VisitOMPInitClause(OMPInitClause *C) {
6315   Record.push_back(C->varlist_size());
6316   for (Expr *VE : C->varlists())
6317     Record.AddStmt(VE);
6318   Record.writeBool(C->getIsTarget());
6319   Record.writeBool(C->getIsTargetSync());
6320   Record.AddSourceLocation(C->getLParenLoc());
6321   Record.AddSourceLocation(C->getVarLoc());
6322 }
6323 
6324 void OMPClauseWriter::VisitOMPUseClause(OMPUseClause *C) {
6325   Record.AddStmt(C->getInteropVar());
6326   Record.AddSourceLocation(C->getLParenLoc());
6327   Record.AddSourceLocation(C->getVarLoc());
6328 }
6329 
6330 void OMPClauseWriter::VisitOMPDestroyClause(OMPDestroyClause *C) {
6331   Record.AddStmt(C->getInteropVar());
6332   Record.AddSourceLocation(C->getLParenLoc());
6333   Record.AddSourceLocation(C->getVarLoc());
6334 }
6335 
6336 void OMPClauseWriter::VisitOMPNovariantsClause(OMPNovariantsClause *C) {
6337   VisitOMPClauseWithPreInit(C);
6338   Record.AddStmt(C->getCondition());
6339   Record.AddSourceLocation(C->getLParenLoc());
6340 }
6341 
6342 void OMPClauseWriter::VisitOMPNocontextClause(OMPNocontextClause *C) {
6343   VisitOMPClauseWithPreInit(C);
6344   Record.AddStmt(C->getCondition());
6345   Record.AddSourceLocation(C->getLParenLoc());
6346 }
6347 
6348 void OMPClauseWriter::VisitOMPFilterClause(OMPFilterClause *C) {
6349   VisitOMPClauseWithPreInit(C);
6350   Record.AddStmt(C->getThreadID());
6351   Record.AddSourceLocation(C->getLParenLoc());
6352 }
6353 
6354 void OMPClauseWriter::VisitOMPAlignClause(OMPAlignClause *C) {
6355   Record.AddStmt(C->getAlignment());
6356   Record.AddSourceLocation(C->getLParenLoc());
6357 }
6358 
6359 void OMPClauseWriter::VisitOMPPrivateClause(OMPPrivateClause *C) {
6360   Record.push_back(C->varlist_size());
6361   Record.AddSourceLocation(C->getLParenLoc());
6362   for (auto *VE : C->varlists()) {
6363     Record.AddStmt(VE);
6364   }
6365   for (auto *VE : C->private_copies()) {
6366     Record.AddStmt(VE);
6367   }
6368 }
6369 
6370 void OMPClauseWriter::VisitOMPFirstprivateClause(OMPFirstprivateClause *C) {
6371   Record.push_back(C->varlist_size());
6372   VisitOMPClauseWithPreInit(C);
6373   Record.AddSourceLocation(C->getLParenLoc());
6374   for (auto *VE : C->varlists()) {
6375     Record.AddStmt(VE);
6376   }
6377   for (auto *VE : C->private_copies()) {
6378     Record.AddStmt(VE);
6379   }
6380   for (auto *VE : C->inits()) {
6381     Record.AddStmt(VE);
6382   }
6383 }
6384 
6385 void OMPClauseWriter::VisitOMPLastprivateClause(OMPLastprivateClause *C) {
6386   Record.push_back(C->varlist_size());
6387   VisitOMPClauseWithPostUpdate(C);
6388   Record.AddSourceLocation(C->getLParenLoc());
6389   Record.writeEnum(C->getKind());
6390   Record.AddSourceLocation(C->getKindLoc());
6391   Record.AddSourceLocation(C->getColonLoc());
6392   for (auto *VE : C->varlists())
6393     Record.AddStmt(VE);
6394   for (auto *E : C->private_copies())
6395     Record.AddStmt(E);
6396   for (auto *E : C->source_exprs())
6397     Record.AddStmt(E);
6398   for (auto *E : C->destination_exprs())
6399     Record.AddStmt(E);
6400   for (auto *E : C->assignment_ops())
6401     Record.AddStmt(E);
6402 }
6403 
6404 void OMPClauseWriter::VisitOMPSharedClause(OMPSharedClause *C) {
6405   Record.push_back(C->varlist_size());
6406   Record.AddSourceLocation(C->getLParenLoc());
6407   for (auto *VE : C->varlists())
6408     Record.AddStmt(VE);
6409 }
6410 
6411 void OMPClauseWriter::VisitOMPReductionClause(OMPReductionClause *C) {
6412   Record.push_back(C->varlist_size());
6413   Record.writeEnum(C->getModifier());
6414   VisitOMPClauseWithPostUpdate(C);
6415   Record.AddSourceLocation(C->getLParenLoc());
6416   Record.AddSourceLocation(C->getModifierLoc());
6417   Record.AddSourceLocation(C->getColonLoc());
6418   Record.AddNestedNameSpecifierLoc(C->getQualifierLoc());
6419   Record.AddDeclarationNameInfo(C->getNameInfo());
6420   for (auto *VE : C->varlists())
6421     Record.AddStmt(VE);
6422   for (auto *VE : C->privates())
6423     Record.AddStmt(VE);
6424   for (auto *E : C->lhs_exprs())
6425     Record.AddStmt(E);
6426   for (auto *E : C->rhs_exprs())
6427     Record.AddStmt(E);
6428   for (auto *E : C->reduction_ops())
6429     Record.AddStmt(E);
6430   if (C->getModifier() == clang::OMPC_REDUCTION_inscan) {
6431     for (auto *E : C->copy_ops())
6432       Record.AddStmt(E);
6433     for (auto *E : C->copy_array_temps())
6434       Record.AddStmt(E);
6435     for (auto *E : C->copy_array_elems())
6436       Record.AddStmt(E);
6437   }
6438 }
6439 
6440 void OMPClauseWriter::VisitOMPTaskReductionClause(OMPTaskReductionClause *C) {
6441   Record.push_back(C->varlist_size());
6442   VisitOMPClauseWithPostUpdate(C);
6443   Record.AddSourceLocation(C->getLParenLoc());
6444   Record.AddSourceLocation(C->getColonLoc());
6445   Record.AddNestedNameSpecifierLoc(C->getQualifierLoc());
6446   Record.AddDeclarationNameInfo(C->getNameInfo());
6447   for (auto *VE : C->varlists())
6448     Record.AddStmt(VE);
6449   for (auto *VE : C->privates())
6450     Record.AddStmt(VE);
6451   for (auto *E : C->lhs_exprs())
6452     Record.AddStmt(E);
6453   for (auto *E : C->rhs_exprs())
6454     Record.AddStmt(E);
6455   for (auto *E : C->reduction_ops())
6456     Record.AddStmt(E);
6457 }
6458 
6459 void OMPClauseWriter::VisitOMPInReductionClause(OMPInReductionClause *C) {
6460   Record.push_back(C->varlist_size());
6461   VisitOMPClauseWithPostUpdate(C);
6462   Record.AddSourceLocation(C->getLParenLoc());
6463   Record.AddSourceLocation(C->getColonLoc());
6464   Record.AddNestedNameSpecifierLoc(C->getQualifierLoc());
6465   Record.AddDeclarationNameInfo(C->getNameInfo());
6466   for (auto *VE : C->varlists())
6467     Record.AddStmt(VE);
6468   for (auto *VE : C->privates())
6469     Record.AddStmt(VE);
6470   for (auto *E : C->lhs_exprs())
6471     Record.AddStmt(E);
6472   for (auto *E : C->rhs_exprs())
6473     Record.AddStmt(E);
6474   for (auto *E : C->reduction_ops())
6475     Record.AddStmt(E);
6476   for (auto *E : C->taskgroup_descriptors())
6477     Record.AddStmt(E);
6478 }
6479 
6480 void OMPClauseWriter::VisitOMPLinearClause(OMPLinearClause *C) {
6481   Record.push_back(C->varlist_size());
6482   VisitOMPClauseWithPostUpdate(C);
6483   Record.AddSourceLocation(C->getLParenLoc());
6484   Record.AddSourceLocation(C->getColonLoc());
6485   Record.push_back(C->getModifier());
6486   Record.AddSourceLocation(C->getModifierLoc());
6487   for (auto *VE : C->varlists()) {
6488     Record.AddStmt(VE);
6489   }
6490   for (auto *VE : C->privates()) {
6491     Record.AddStmt(VE);
6492   }
6493   for (auto *VE : C->inits()) {
6494     Record.AddStmt(VE);
6495   }
6496   for (auto *VE : C->updates()) {
6497     Record.AddStmt(VE);
6498   }
6499   for (auto *VE : C->finals()) {
6500     Record.AddStmt(VE);
6501   }
6502   Record.AddStmt(C->getStep());
6503   Record.AddStmt(C->getCalcStep());
6504   for (auto *VE : C->used_expressions())
6505     Record.AddStmt(VE);
6506 }
6507 
6508 void OMPClauseWriter::VisitOMPAlignedClause(OMPAlignedClause *C) {
6509   Record.push_back(C->varlist_size());
6510   Record.AddSourceLocation(C->getLParenLoc());
6511   Record.AddSourceLocation(C->getColonLoc());
6512   for (auto *VE : C->varlists())
6513     Record.AddStmt(VE);
6514   Record.AddStmt(C->getAlignment());
6515 }
6516 
6517 void OMPClauseWriter::VisitOMPCopyinClause(OMPCopyinClause *C) {
6518   Record.push_back(C->varlist_size());
6519   Record.AddSourceLocation(C->getLParenLoc());
6520   for (auto *VE : C->varlists())
6521     Record.AddStmt(VE);
6522   for (auto *E : C->source_exprs())
6523     Record.AddStmt(E);
6524   for (auto *E : C->destination_exprs())
6525     Record.AddStmt(E);
6526   for (auto *E : C->assignment_ops())
6527     Record.AddStmt(E);
6528 }
6529 
6530 void OMPClauseWriter::VisitOMPCopyprivateClause(OMPCopyprivateClause *C) {
6531   Record.push_back(C->varlist_size());
6532   Record.AddSourceLocation(C->getLParenLoc());
6533   for (auto *VE : C->varlists())
6534     Record.AddStmt(VE);
6535   for (auto *E : C->source_exprs())
6536     Record.AddStmt(E);
6537   for (auto *E : C->destination_exprs())
6538     Record.AddStmt(E);
6539   for (auto *E : C->assignment_ops())
6540     Record.AddStmt(E);
6541 }
6542 
6543 void OMPClauseWriter::VisitOMPFlushClause(OMPFlushClause *C) {
6544   Record.push_back(C->varlist_size());
6545   Record.AddSourceLocation(C->getLParenLoc());
6546   for (auto *VE : C->varlists())
6547     Record.AddStmt(VE);
6548 }
6549 
6550 void OMPClauseWriter::VisitOMPDepobjClause(OMPDepobjClause *C) {
6551   Record.AddStmt(C->getDepobj());
6552   Record.AddSourceLocation(C->getLParenLoc());
6553 }
6554 
6555 void OMPClauseWriter::VisitOMPDependClause(OMPDependClause *C) {
6556   Record.push_back(C->varlist_size());
6557   Record.push_back(C->getNumLoops());
6558   Record.AddSourceLocation(C->getLParenLoc());
6559   Record.AddStmt(C->getModifier());
6560   Record.push_back(C->getDependencyKind());
6561   Record.AddSourceLocation(C->getDependencyLoc());
6562   Record.AddSourceLocation(C->getColonLoc());
6563   for (auto *VE : C->varlists())
6564     Record.AddStmt(VE);
6565   for (unsigned I = 0, E = C->getNumLoops(); I < E; ++I)
6566     Record.AddStmt(C->getLoopData(I));
6567 }
6568 
6569 void OMPClauseWriter::VisitOMPDeviceClause(OMPDeviceClause *C) {
6570   VisitOMPClauseWithPreInit(C);
6571   Record.writeEnum(C->getModifier());
6572   Record.AddStmt(C->getDevice());
6573   Record.AddSourceLocation(C->getModifierLoc());
6574   Record.AddSourceLocation(C->getLParenLoc());
6575 }
6576 
6577 void OMPClauseWriter::VisitOMPMapClause(OMPMapClause *C) {
6578   Record.push_back(C->varlist_size());
6579   Record.push_back(C->getUniqueDeclarationsNum());
6580   Record.push_back(C->getTotalComponentListNum());
6581   Record.push_back(C->getTotalComponentsNum());
6582   Record.AddSourceLocation(C->getLParenLoc());
6583   for (unsigned I = 0; I < NumberOfOMPMapClauseModifiers; ++I) {
6584     Record.push_back(C->getMapTypeModifier(I));
6585     Record.AddSourceLocation(C->getMapTypeModifierLoc(I));
6586   }
6587   Record.AddNestedNameSpecifierLoc(C->getMapperQualifierLoc());
6588   Record.AddDeclarationNameInfo(C->getMapperIdInfo());
6589   Record.push_back(C->getMapType());
6590   Record.AddSourceLocation(C->getMapLoc());
6591   Record.AddSourceLocation(C->getColonLoc());
6592   for (auto *E : C->varlists())
6593     Record.AddStmt(E);
6594   for (auto *E : C->mapperlists())
6595     Record.AddStmt(E);
6596   for (auto *D : C->all_decls())
6597     Record.AddDeclRef(D);
6598   for (auto N : C->all_num_lists())
6599     Record.push_back(N);
6600   for (auto N : C->all_lists_sizes())
6601     Record.push_back(N);
6602   for (auto &M : C->all_components()) {
6603     Record.AddStmt(M.getAssociatedExpression());
6604     Record.AddDeclRef(M.getAssociatedDeclaration());
6605   }
6606 }
6607 
6608 void OMPClauseWriter::VisitOMPAllocateClause(OMPAllocateClause *C) {
6609   Record.push_back(C->varlist_size());
6610   Record.AddSourceLocation(C->getLParenLoc());
6611   Record.AddSourceLocation(C->getColonLoc());
6612   Record.AddStmt(C->getAllocator());
6613   for (auto *VE : C->varlists())
6614     Record.AddStmt(VE);
6615 }
6616 
6617 void OMPClauseWriter::VisitOMPNumTeamsClause(OMPNumTeamsClause *C) {
6618   VisitOMPClauseWithPreInit(C);
6619   Record.AddStmt(C->getNumTeams());
6620   Record.AddSourceLocation(C->getLParenLoc());
6621 }
6622 
6623 void OMPClauseWriter::VisitOMPThreadLimitClause(OMPThreadLimitClause *C) {
6624   VisitOMPClauseWithPreInit(C);
6625   Record.AddStmt(C->getThreadLimit());
6626   Record.AddSourceLocation(C->getLParenLoc());
6627 }
6628 
6629 void OMPClauseWriter::VisitOMPPriorityClause(OMPPriorityClause *C) {
6630   VisitOMPClauseWithPreInit(C);
6631   Record.AddStmt(C->getPriority());
6632   Record.AddSourceLocation(C->getLParenLoc());
6633 }
6634 
6635 void OMPClauseWriter::VisitOMPGrainsizeClause(OMPGrainsizeClause *C) {
6636   VisitOMPClauseWithPreInit(C);
6637   Record.AddStmt(C->getGrainsize());
6638   Record.AddSourceLocation(C->getLParenLoc());
6639 }
6640 
6641 void OMPClauseWriter::VisitOMPNumTasksClause(OMPNumTasksClause *C) {
6642   VisitOMPClauseWithPreInit(C);
6643   Record.AddStmt(C->getNumTasks());
6644   Record.AddSourceLocation(C->getLParenLoc());
6645 }
6646 
6647 void OMPClauseWriter::VisitOMPHintClause(OMPHintClause *C) {
6648   Record.AddStmt(C->getHint());
6649   Record.AddSourceLocation(C->getLParenLoc());
6650 }
6651 
6652 void OMPClauseWriter::VisitOMPDistScheduleClause(OMPDistScheduleClause *C) {
6653   VisitOMPClauseWithPreInit(C);
6654   Record.push_back(C->getDistScheduleKind());
6655   Record.AddStmt(C->getChunkSize());
6656   Record.AddSourceLocation(C->getLParenLoc());
6657   Record.AddSourceLocation(C->getDistScheduleKindLoc());
6658   Record.AddSourceLocation(C->getCommaLoc());
6659 }
6660 
6661 void OMPClauseWriter::VisitOMPDefaultmapClause(OMPDefaultmapClause *C) {
6662   Record.push_back(C->getDefaultmapKind());
6663   Record.push_back(C->getDefaultmapModifier());
6664   Record.AddSourceLocation(C->getLParenLoc());
6665   Record.AddSourceLocation(C->getDefaultmapModifierLoc());
6666   Record.AddSourceLocation(C->getDefaultmapKindLoc());
6667 }
6668 
6669 void OMPClauseWriter::VisitOMPToClause(OMPToClause *C) {
6670   Record.push_back(C->varlist_size());
6671   Record.push_back(C->getUniqueDeclarationsNum());
6672   Record.push_back(C->getTotalComponentListNum());
6673   Record.push_back(C->getTotalComponentsNum());
6674   Record.AddSourceLocation(C->getLParenLoc());
6675   for (unsigned I = 0; I < NumberOfOMPMotionModifiers; ++I) {
6676     Record.push_back(C->getMotionModifier(I));
6677     Record.AddSourceLocation(C->getMotionModifierLoc(I));
6678   }
6679   Record.AddNestedNameSpecifierLoc(C->getMapperQualifierLoc());
6680   Record.AddDeclarationNameInfo(C->getMapperIdInfo());
6681   Record.AddSourceLocation(C->getColonLoc());
6682   for (auto *E : C->varlists())
6683     Record.AddStmt(E);
6684   for (auto *E : C->mapperlists())
6685     Record.AddStmt(E);
6686   for (auto *D : C->all_decls())
6687     Record.AddDeclRef(D);
6688   for (auto N : C->all_num_lists())
6689     Record.push_back(N);
6690   for (auto N : C->all_lists_sizes())
6691     Record.push_back(N);
6692   for (auto &M : C->all_components()) {
6693     Record.AddStmt(M.getAssociatedExpression());
6694     Record.writeBool(M.isNonContiguous());
6695     Record.AddDeclRef(M.getAssociatedDeclaration());
6696   }
6697 }
6698 
6699 void OMPClauseWriter::VisitOMPFromClause(OMPFromClause *C) {
6700   Record.push_back(C->varlist_size());
6701   Record.push_back(C->getUniqueDeclarationsNum());
6702   Record.push_back(C->getTotalComponentListNum());
6703   Record.push_back(C->getTotalComponentsNum());
6704   Record.AddSourceLocation(C->getLParenLoc());
6705   for (unsigned I = 0; I < NumberOfOMPMotionModifiers; ++I) {
6706     Record.push_back(C->getMotionModifier(I));
6707     Record.AddSourceLocation(C->getMotionModifierLoc(I));
6708   }
6709   Record.AddNestedNameSpecifierLoc(C->getMapperQualifierLoc());
6710   Record.AddDeclarationNameInfo(C->getMapperIdInfo());
6711   Record.AddSourceLocation(C->getColonLoc());
6712   for (auto *E : C->varlists())
6713     Record.AddStmt(E);
6714   for (auto *E : C->mapperlists())
6715     Record.AddStmt(E);
6716   for (auto *D : C->all_decls())
6717     Record.AddDeclRef(D);
6718   for (auto N : C->all_num_lists())
6719     Record.push_back(N);
6720   for (auto N : C->all_lists_sizes())
6721     Record.push_back(N);
6722   for (auto &M : C->all_components()) {
6723     Record.AddStmt(M.getAssociatedExpression());
6724     Record.writeBool(M.isNonContiguous());
6725     Record.AddDeclRef(M.getAssociatedDeclaration());
6726   }
6727 }
6728 
6729 void OMPClauseWriter::VisitOMPUseDevicePtrClause(OMPUseDevicePtrClause *C) {
6730   Record.push_back(C->varlist_size());
6731   Record.push_back(C->getUniqueDeclarationsNum());
6732   Record.push_back(C->getTotalComponentListNum());
6733   Record.push_back(C->getTotalComponentsNum());
6734   Record.AddSourceLocation(C->getLParenLoc());
6735   for (auto *E : C->varlists())
6736     Record.AddStmt(E);
6737   for (auto *VE : C->private_copies())
6738     Record.AddStmt(VE);
6739   for (auto *VE : C->inits())
6740     Record.AddStmt(VE);
6741   for (auto *D : C->all_decls())
6742     Record.AddDeclRef(D);
6743   for (auto N : C->all_num_lists())
6744     Record.push_back(N);
6745   for (auto N : C->all_lists_sizes())
6746     Record.push_back(N);
6747   for (auto &M : C->all_components()) {
6748     Record.AddStmt(M.getAssociatedExpression());
6749     Record.AddDeclRef(M.getAssociatedDeclaration());
6750   }
6751 }
6752 
6753 void OMPClauseWriter::VisitOMPUseDeviceAddrClause(OMPUseDeviceAddrClause *C) {
6754   Record.push_back(C->varlist_size());
6755   Record.push_back(C->getUniqueDeclarationsNum());
6756   Record.push_back(C->getTotalComponentListNum());
6757   Record.push_back(C->getTotalComponentsNum());
6758   Record.AddSourceLocation(C->getLParenLoc());
6759   for (auto *E : C->varlists())
6760     Record.AddStmt(E);
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::VisitOMPIsDevicePtrClause(OMPIsDevicePtrClause *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::VisitOMPUnifiedAddressClause(OMPUnifiedAddressClause *) {}
6794 
6795 void OMPClauseWriter::VisitOMPUnifiedSharedMemoryClause(
6796     OMPUnifiedSharedMemoryClause *) {}
6797 
6798 void OMPClauseWriter::VisitOMPReverseOffloadClause(OMPReverseOffloadClause *) {}
6799 
6800 void
6801 OMPClauseWriter::VisitOMPDynamicAllocatorsClause(OMPDynamicAllocatorsClause *) {
6802 }
6803 
6804 void OMPClauseWriter::VisitOMPAtomicDefaultMemOrderClause(
6805     OMPAtomicDefaultMemOrderClause *C) {
6806   Record.push_back(C->getAtomicDefaultMemOrderKind());
6807   Record.AddSourceLocation(C->getLParenLoc());
6808   Record.AddSourceLocation(C->getAtomicDefaultMemOrderKindKwLoc());
6809 }
6810 
6811 void OMPClauseWriter::VisitOMPNontemporalClause(OMPNontemporalClause *C) {
6812   Record.push_back(C->varlist_size());
6813   Record.AddSourceLocation(C->getLParenLoc());
6814   for (auto *VE : C->varlists())
6815     Record.AddStmt(VE);
6816   for (auto *E : C->private_refs())
6817     Record.AddStmt(E);
6818 }
6819 
6820 void OMPClauseWriter::VisitOMPInclusiveClause(OMPInclusiveClause *C) {
6821   Record.push_back(C->varlist_size());
6822   Record.AddSourceLocation(C->getLParenLoc());
6823   for (auto *VE : C->varlists())
6824     Record.AddStmt(VE);
6825 }
6826 
6827 void OMPClauseWriter::VisitOMPExclusiveClause(OMPExclusiveClause *C) {
6828   Record.push_back(C->varlist_size());
6829   Record.AddSourceLocation(C->getLParenLoc());
6830   for (auto *VE : C->varlists())
6831     Record.AddStmt(VE);
6832 }
6833 
6834 void OMPClauseWriter::VisitOMPOrderClause(OMPOrderClause *C) {
6835   Record.writeEnum(C->getKind());
6836   Record.AddSourceLocation(C->getLParenLoc());
6837   Record.AddSourceLocation(C->getKindKwLoc());
6838 }
6839 
6840 void OMPClauseWriter::VisitOMPUsesAllocatorsClause(OMPUsesAllocatorsClause *C) {
6841   Record.push_back(C->getNumberOfAllocators());
6842   Record.AddSourceLocation(C->getLParenLoc());
6843   for (unsigned I = 0, E = C->getNumberOfAllocators(); I < E; ++I) {
6844     OMPUsesAllocatorsClause::Data Data = C->getAllocatorData(I);
6845     Record.AddStmt(Data.Allocator);
6846     Record.AddStmt(Data.AllocatorTraits);
6847     Record.AddSourceLocation(Data.LParenLoc);
6848     Record.AddSourceLocation(Data.RParenLoc);
6849   }
6850 }
6851 
6852 void OMPClauseWriter::VisitOMPAffinityClause(OMPAffinityClause *C) {
6853   Record.push_back(C->varlist_size());
6854   Record.AddSourceLocation(C->getLParenLoc());
6855   Record.AddStmt(C->getModifier());
6856   Record.AddSourceLocation(C->getColonLoc());
6857   for (Expr *E : C->varlists())
6858     Record.AddStmt(E);
6859 }
6860 
6861 void OMPClauseWriter::VisitOMPBindClause(OMPBindClause *C) {
6862   Record.writeEnum(C->getBindKind());
6863   Record.AddSourceLocation(C->getLParenLoc());
6864   Record.AddSourceLocation(C->getBindKindLoc());
6865 }
6866 
6867 void ASTRecordWriter::writeOMPTraitInfo(const OMPTraitInfo *TI) {
6868   writeUInt32(TI->Sets.size());
6869   for (const auto &Set : TI->Sets) {
6870     writeEnum(Set.Kind);
6871     writeUInt32(Set.Selectors.size());
6872     for (const auto &Selector : Set.Selectors) {
6873       writeEnum(Selector.Kind);
6874       writeBool(Selector.ScoreOrCondition);
6875       if (Selector.ScoreOrCondition)
6876         writeExprRef(Selector.ScoreOrCondition);
6877       writeUInt32(Selector.Properties.size());
6878       for (const auto &Property : Selector.Properties)
6879         writeEnum(Property.Kind);
6880     }
6881   }
6882 }
6883 
6884 void ASTRecordWriter::writeOMPChildren(OMPChildren *Data) {
6885   if (!Data)
6886     return;
6887   writeUInt32(Data->getNumClauses());
6888   writeUInt32(Data->getNumChildren());
6889   writeBool(Data->hasAssociatedStmt());
6890   for (unsigned I = 0, E = Data->getNumClauses(); I < E; ++I)
6891     writeOMPClause(Data->getClauses()[I]);
6892   if (Data->hasAssociatedStmt())
6893     AddStmt(Data->getAssociatedStmt());
6894   for (unsigned I = 0, E = Data->getNumChildren(); I < E; ++I)
6895     AddStmt(Data->getChildren()[I]);
6896 }
6897