1//===- ASTReaderDecl.cpp - Decl Deserialization ---------------------------===//
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 implements the ASTReader::readDeclRecord method, which is the
10// entrypoint for loading a decl.
11//
12//===----------------------------------------------------------------------===//
13
14#include "ASTCommon.h"
15#include "ASTReaderInternals.h"
16#include "clang/AST/ASTContext.h"
17#include "clang/AST/Attr.h"
18#include "clang/AST/AttrIterator.h"
19#include "clang/AST/Decl.h"
20#include "clang/AST/DeclBase.h"
21#include "clang/AST/DeclCXX.h"
22#include "clang/AST/DeclFriend.h"
23#include "clang/AST/DeclObjC.h"
24#include "clang/AST/DeclOpenMP.h"
25#include "clang/AST/DeclTemplate.h"
26#include "clang/AST/DeclVisitor.h"
27#include "clang/AST/DeclarationName.h"
28#include "clang/AST/Expr.h"
29#include "clang/AST/ExternalASTSource.h"
30#include "clang/AST/LambdaCapture.h"
31#include "clang/AST/NestedNameSpecifier.h"
32#include "clang/AST/OpenMPClause.h"
33#include "clang/AST/Redeclarable.h"
34#include "clang/AST/Stmt.h"
35#include "clang/AST/TemplateBase.h"
36#include "clang/AST/Type.h"
37#include "clang/AST/UnresolvedSet.h"
38#include "clang/Basic/AttrKinds.h"
39#include "clang/Basic/ExceptionSpecificationType.h"
40#include "clang/Basic/IdentifierTable.h"
41#include "clang/Basic/LLVM.h"
42#include "clang/Basic/Lambda.h"
43#include "clang/Basic/LangOptions.h"
44#include "clang/Basic/Linkage.h"
45#include "clang/Basic/Module.h"
46#include "clang/Basic/PragmaKinds.h"
47#include "clang/Basic/SourceLocation.h"
48#include "clang/Basic/Specifiers.h"
49#include "clang/Sema/IdentifierResolver.h"
50#include "clang/Serialization/ASTBitCodes.h"
51#include "clang/Serialization/ASTRecordReader.h"
52#include "clang/Serialization/ContinuousRangeMap.h"
53#include "clang/Serialization/ModuleFile.h"
54#include "llvm/ADT/DenseMap.h"
55#include "llvm/ADT/FoldingSet.h"
56#include "llvm/ADT/STLExtras.h"
57#include "llvm/ADT/SmallPtrSet.h"
58#include "llvm/ADT/SmallVector.h"
59#include "llvm/ADT/iterator_range.h"
60#include "llvm/Bitstream/BitstreamReader.h"
61#include "llvm/Support/Casting.h"
62#include "llvm/Support/ErrorHandling.h"
63#include "llvm/Support/SaveAndRestore.h"
64#include <algorithm>
65#include <cassert>
66#include <cstdint>
67#include <cstring>
68#include <string>
69#include <utility>
70
71using namespace clang;
72using namespace serialization;
73
74//===----------------------------------------------------------------------===//
75// Declaration deserialization
76//===----------------------------------------------------------------------===//
77
78namespace clang {
79
80  class ASTDeclReader : public DeclVisitor<ASTDeclReader, void> {
81    ASTReader &Reader;
82    ASTRecordReader &Record;
83    ASTReader::RecordLocation Loc;
84    const DeclID ThisDeclID;
85    const SourceLocation ThisDeclLoc;
86
87    using RecordData = ASTReader::RecordData;
88
89    TypeID DeferredTypeID = 0;
90    unsigned AnonymousDeclNumber;
91    GlobalDeclID NamedDeclForTagDecl = 0;
92    IdentifierInfo *TypedefNameForLinkage = nullptr;
93
94    bool HasPendingBody = false;
95
96    ///A flag to carry the information for a decl from the entity is
97    /// used. We use it to delay the marking of the canonical decl as used until
98    /// the entire declaration is deserialized and merged.
99    bool IsDeclMarkedUsed = false;
100
101    uint64_t GetCurrentCursorOffset();
102
103    uint64_t ReadLocalOffset() {
104      uint64_t LocalOffset = Record.readInt();
105      assert(LocalOffset < Loc.Offset && "offset point after current record");
106      return LocalOffset ? Loc.Offset - LocalOffset : 0;
107    }
108
109    uint64_t ReadGlobalOffset() {
110      uint64_t Local = ReadLocalOffset();
111      return Local ? Record.getGlobalBitOffset(Local) : 0;
112    }
113
114    SourceLocation readSourceLocation() {
115      return Record.readSourceLocation();
116    }
117
118    SourceRange readSourceRange() {
119      return Record.readSourceRange();
120    }
121
122    TypeSourceInfo *readTypeSourceInfo() {
123      return Record.readTypeSourceInfo();
124    }
125
126    serialization::DeclID readDeclID() {
127      return Record.readDeclID();
128    }
129
130    std::string readString() {
131      return Record.readString();
132    }
133
134    void readDeclIDList(SmallVectorImpl<DeclID> &IDs) {
135      for (unsigned I = 0, Size = Record.readInt(); I != Size; ++I)
136        IDs.push_back(readDeclID());
137    }
138
139    Decl *readDecl() {
140      return Record.readDecl();
141    }
142
143    template<typename T>
144    T *readDeclAs() {
145      return Record.readDeclAs<T>();
146    }
147
148    serialization::SubmoduleID readSubmoduleID() {
149      if (Record.getIdx() == Record.size())
150        return 0;
151
152      return Record.getGlobalSubmoduleID(Record.readInt());
153    }
154
155    Module *readModule() {
156      return Record.getSubmodule(readSubmoduleID());
157    }
158
159    void ReadCXXRecordDefinition(CXXRecordDecl *D, bool Update);
160    void ReadCXXDefinitionData(struct CXXRecordDecl::DefinitionData &Data,
161                               const CXXRecordDecl *D);
162    void MergeDefinitionData(CXXRecordDecl *D,
163                             struct CXXRecordDecl::DefinitionData &&NewDD);
164    void ReadObjCDefinitionData(struct ObjCInterfaceDecl::DefinitionData &Data);
165    void MergeDefinitionData(ObjCInterfaceDecl *D,
166                             struct ObjCInterfaceDecl::DefinitionData &&NewDD);
167    void ReadObjCDefinitionData(struct ObjCProtocolDecl::DefinitionData &Data);
168    void MergeDefinitionData(ObjCProtocolDecl *D,
169                             struct ObjCProtocolDecl::DefinitionData &&NewDD);
170
171    static DeclContext *getPrimaryDCForAnonymousDecl(DeclContext *LexicalDC);
172
173    static NamedDecl *getAnonymousDeclForMerging(ASTReader &Reader,
174                                                 DeclContext *DC,
175                                                 unsigned Index);
176    static void setAnonymousDeclForMerging(ASTReader &Reader, DeclContext *DC,
177                                           unsigned Index, NamedDecl *D);
178
179    /// Results from loading a RedeclarableDecl.
180    class RedeclarableResult {
181      Decl *MergeWith;
182      GlobalDeclID FirstID;
183      bool IsKeyDecl;
184
185    public:
186      RedeclarableResult(Decl *MergeWith, GlobalDeclID FirstID, bool IsKeyDecl)
187          : MergeWith(MergeWith), FirstID(FirstID), IsKeyDecl(IsKeyDecl) {}
188
189      /// Retrieve the first ID.
190      GlobalDeclID getFirstID() const { return FirstID; }
191
192      /// Is this declaration a key declaration?
193      bool isKeyDecl() const { return IsKeyDecl; }
194
195      /// Get a known declaration that this should be merged with, if
196      /// any.
197      Decl *getKnownMergeTarget() const { return MergeWith; }
198    };
199
200    /// Class used to capture the result of searching for an existing
201    /// declaration of a specific kind and name, along with the ability
202    /// to update the place where this result was found (the declaration
203    /// chain hanging off an identifier or the DeclContext we searched in)
204    /// if requested.
205    class FindExistingResult {
206      ASTReader &Reader;
207      NamedDecl *New = nullptr;
208      NamedDecl *Existing = nullptr;
209      bool AddResult = false;
210      unsigned AnonymousDeclNumber = 0;
211      IdentifierInfo *TypedefNameForLinkage = nullptr;
212
213    public:
214      FindExistingResult(ASTReader &Reader) : Reader(Reader) {}
215
216      FindExistingResult(ASTReader &Reader, NamedDecl *New, NamedDecl *Existing,
217                         unsigned AnonymousDeclNumber,
218                         IdentifierInfo *TypedefNameForLinkage)
219          : Reader(Reader), New(New), Existing(Existing), AddResult(true),
220            AnonymousDeclNumber(AnonymousDeclNumber),
221            TypedefNameForLinkage(TypedefNameForLinkage) {}
222
223      FindExistingResult(FindExistingResult &&Other)
224          : Reader(Other.Reader), New(Other.New), Existing(Other.Existing),
225            AddResult(Other.AddResult),
226            AnonymousDeclNumber(Other.AnonymousDeclNumber),
227            TypedefNameForLinkage(Other.TypedefNameForLinkage) {
228        Other.AddResult = false;
229      }
230
231      FindExistingResult &operator=(FindExistingResult &&) = delete;
232      ~FindExistingResult();
233
234      /// Suppress the addition of this result into the known set of
235      /// names.
236      void suppress() { AddResult = false; }
237
238      operator NamedDecl*() const { return Existing; }
239
240      template<typename T>
241      operator T*() const { return dyn_cast_or_null<T>(Existing); }
242    };
243
244    static DeclContext *getPrimaryContextForMerging(ASTReader &Reader,
245                                                    DeclContext *DC);
246    FindExistingResult findExisting(NamedDecl *D);
247
248  public:
249    ASTDeclReader(ASTReader &Reader, ASTRecordReader &Record,
250                  ASTReader::RecordLocation Loc,
251                  DeclID thisDeclID, SourceLocation ThisDeclLoc)
252        : Reader(Reader), Record(Record), Loc(Loc), ThisDeclID(thisDeclID),
253          ThisDeclLoc(ThisDeclLoc) {}
254
255    template <typename T> static
256    void AddLazySpecializations(T *D,
257                                SmallVectorImpl<serialization::DeclID>& IDs) {
258      if (IDs.empty())
259        return;
260
261      // FIXME: We should avoid this pattern of getting the ASTContext.
262      ASTContext &C = D->getASTContext();
263
264      auto *&LazySpecializations = D->getCommonPtr()->LazySpecializations;
265
266      if (auto &Old = LazySpecializations) {
267        IDs.insert(IDs.end(), Old + 1, Old + 1 + Old[0]);
268        llvm::sort(IDs);
269        IDs.erase(std::unique(IDs.begin(), IDs.end()), IDs.end());
270      }
271
272      auto *Result = new (C) serialization::DeclID[1 + IDs.size()];
273      *Result = IDs.size();
274      std::copy(IDs.begin(), IDs.end(), Result + 1);
275
276      LazySpecializations = Result;
277    }
278
279    template <typename DeclT>
280    static Decl *getMostRecentDeclImpl(Redeclarable<DeclT> *D);
281    static Decl *getMostRecentDeclImpl(...);
282    static Decl *getMostRecentDecl(Decl *D);
283
284    template <typename DeclT>
285    static void attachPreviousDeclImpl(ASTReader &Reader,
286                                       Redeclarable<DeclT> *D, Decl *Previous,
287                                       Decl *Canon);
288    static void attachPreviousDeclImpl(ASTReader &Reader, ...);
289    static void attachPreviousDecl(ASTReader &Reader, Decl *D, Decl *Previous,
290                                   Decl *Canon);
291
292    template <typename DeclT>
293    static void attachLatestDeclImpl(Redeclarable<DeclT> *D, Decl *Latest);
294    static void attachLatestDeclImpl(...);
295    static void attachLatestDecl(Decl *D, Decl *latest);
296
297    template <typename DeclT>
298    static void markIncompleteDeclChainImpl(Redeclarable<DeclT> *D);
299    static void markIncompleteDeclChainImpl(...);
300
301    /// Determine whether this declaration has a pending body.
302    bool hasPendingBody() const { return HasPendingBody; }
303
304    void ReadFunctionDefinition(FunctionDecl *FD);
305    void Visit(Decl *D);
306
307    void UpdateDecl(Decl *D, SmallVectorImpl<serialization::DeclID> &);
308
309    static void setNextObjCCategory(ObjCCategoryDecl *Cat,
310                                    ObjCCategoryDecl *Next) {
311      Cat->NextClassCategory = Next;
312    }
313
314    void VisitDecl(Decl *D);
315    void VisitPragmaCommentDecl(PragmaCommentDecl *D);
316    void VisitPragmaDetectMismatchDecl(PragmaDetectMismatchDecl *D);
317    void VisitTranslationUnitDecl(TranslationUnitDecl *TU);
318    void VisitNamedDecl(NamedDecl *ND);
319    void VisitLabelDecl(LabelDecl *LD);
320    void VisitNamespaceDecl(NamespaceDecl *D);
321    void VisitUsingDirectiveDecl(UsingDirectiveDecl *D);
322    void VisitNamespaceAliasDecl(NamespaceAliasDecl *D);
323    void VisitTypeDecl(TypeDecl *TD);
324    RedeclarableResult VisitTypedefNameDecl(TypedefNameDecl *TD);
325    void VisitTypedefDecl(TypedefDecl *TD);
326    void VisitTypeAliasDecl(TypeAliasDecl *TD);
327    void VisitUnresolvedUsingTypenameDecl(UnresolvedUsingTypenameDecl *D);
328    RedeclarableResult VisitTagDecl(TagDecl *TD);
329    void VisitEnumDecl(EnumDecl *ED);
330    RedeclarableResult VisitRecordDeclImpl(RecordDecl *RD);
331    void VisitRecordDecl(RecordDecl *RD) { VisitRecordDeclImpl(RD); }
332    RedeclarableResult VisitCXXRecordDeclImpl(CXXRecordDecl *D);
333    void VisitCXXRecordDecl(CXXRecordDecl *D) { VisitCXXRecordDeclImpl(D); }
334    RedeclarableResult VisitClassTemplateSpecializationDeclImpl(
335                                            ClassTemplateSpecializationDecl *D);
336
337    void VisitClassTemplateSpecializationDecl(
338        ClassTemplateSpecializationDecl *D) {
339      VisitClassTemplateSpecializationDeclImpl(D);
340    }
341
342    void VisitClassTemplatePartialSpecializationDecl(
343                                     ClassTemplatePartialSpecializationDecl *D);
344    void VisitClassScopeFunctionSpecializationDecl(
345                                       ClassScopeFunctionSpecializationDecl *D);
346    RedeclarableResult
347    VisitVarTemplateSpecializationDeclImpl(VarTemplateSpecializationDecl *D);
348
349    void VisitVarTemplateSpecializationDecl(VarTemplateSpecializationDecl *D) {
350      VisitVarTemplateSpecializationDeclImpl(D);
351    }
352
353    void VisitVarTemplatePartialSpecializationDecl(
354        VarTemplatePartialSpecializationDecl *D);
355    void VisitTemplateTypeParmDecl(TemplateTypeParmDecl *D);
356    void VisitValueDecl(ValueDecl *VD);
357    void VisitEnumConstantDecl(EnumConstantDecl *ECD);
358    void VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D);
359    void VisitDeclaratorDecl(DeclaratorDecl *DD);
360    void VisitFunctionDecl(FunctionDecl *FD);
361    void VisitCXXDeductionGuideDecl(CXXDeductionGuideDecl *GD);
362    void VisitCXXMethodDecl(CXXMethodDecl *D);
363    void VisitCXXConstructorDecl(CXXConstructorDecl *D);
364    void VisitCXXDestructorDecl(CXXDestructorDecl *D);
365    void VisitCXXConversionDecl(CXXConversionDecl *D);
366    void VisitFieldDecl(FieldDecl *FD);
367    void VisitMSPropertyDecl(MSPropertyDecl *FD);
368    void VisitIndirectFieldDecl(IndirectFieldDecl *FD);
369    RedeclarableResult VisitVarDeclImpl(VarDecl *D);
370    void VisitVarDecl(VarDecl *VD) { VisitVarDeclImpl(VD); }
371    void VisitImplicitParamDecl(ImplicitParamDecl *PD);
372    void VisitParmVarDecl(ParmVarDecl *PD);
373    void VisitDecompositionDecl(DecompositionDecl *DD);
374    void VisitBindingDecl(BindingDecl *BD);
375    void VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D);
376    DeclID VisitTemplateDecl(TemplateDecl *D);
377    void VisitConceptDecl(ConceptDecl *D);
378    void VisitRequiresExprBodyDecl(RequiresExprBodyDecl *D);
379    RedeclarableResult VisitRedeclarableTemplateDecl(RedeclarableTemplateDecl *D);
380    void VisitClassTemplateDecl(ClassTemplateDecl *D);
381    void VisitBuiltinTemplateDecl(BuiltinTemplateDecl *D);
382    void VisitVarTemplateDecl(VarTemplateDecl *D);
383    void VisitFunctionTemplateDecl(FunctionTemplateDecl *D);
384    void VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D);
385    void VisitTypeAliasTemplateDecl(TypeAliasTemplateDecl *D);
386    void VisitUsingDecl(UsingDecl *D);
387    void VisitUsingPackDecl(UsingPackDecl *D);
388    void VisitUsingShadowDecl(UsingShadowDecl *D);
389    void VisitConstructorUsingShadowDecl(ConstructorUsingShadowDecl *D);
390    void VisitLinkageSpecDecl(LinkageSpecDecl *D);
391    void VisitExportDecl(ExportDecl *D);
392    void VisitFileScopeAsmDecl(FileScopeAsmDecl *AD);
393    void VisitImportDecl(ImportDecl *D);
394    void VisitAccessSpecDecl(AccessSpecDecl *D);
395    void VisitFriendDecl(FriendDecl *D);
396    void VisitFriendTemplateDecl(FriendTemplateDecl *D);
397    void VisitStaticAssertDecl(StaticAssertDecl *D);
398    void VisitBlockDecl(BlockDecl *BD);
399    void VisitCapturedDecl(CapturedDecl *CD);
400    void VisitEmptyDecl(EmptyDecl *D);
401    void VisitLifetimeExtendedTemporaryDecl(LifetimeExtendedTemporaryDecl *D);
402
403    std::pair<uint64_t, uint64_t> VisitDeclContext(DeclContext *DC);
404
405    template<typename T>
406    RedeclarableResult VisitRedeclarable(Redeclarable<T> *D);
407
408    template<typename T>
409    void mergeRedeclarable(Redeclarable<T> *D, RedeclarableResult &Redecl,
410                           DeclID TemplatePatternID = 0);
411
412    template<typename T>
413    void mergeRedeclarable(Redeclarable<T> *D, T *Existing,
414                           RedeclarableResult &Redecl,
415                           DeclID TemplatePatternID = 0);
416
417    template<typename T>
418    void mergeMergeable(Mergeable<T> *D);
419
420    void mergeMergeable(LifetimeExtendedTemporaryDecl *D);
421
422    void mergeTemplatePattern(RedeclarableTemplateDecl *D,
423                              RedeclarableTemplateDecl *Existing,
424                              DeclID DsID, bool IsKeyDecl);
425
426    ObjCTypeParamList *ReadObjCTypeParamList();
427
428    // FIXME: Reorder according to DeclNodes.td?
429    void VisitObjCMethodDecl(ObjCMethodDecl *D);
430    void VisitObjCTypeParamDecl(ObjCTypeParamDecl *D);
431    void VisitObjCContainerDecl(ObjCContainerDecl *D);
432    void VisitObjCInterfaceDecl(ObjCInterfaceDecl *D);
433    void VisitObjCIvarDecl(ObjCIvarDecl *D);
434    void VisitObjCProtocolDecl(ObjCProtocolDecl *D);
435    void VisitObjCAtDefsFieldDecl(ObjCAtDefsFieldDecl *D);
436    void VisitObjCCategoryDecl(ObjCCategoryDecl *D);
437    void VisitObjCImplDecl(ObjCImplDecl *D);
438    void VisitObjCCategoryImplDecl(ObjCCategoryImplDecl *D);
439    void VisitObjCImplementationDecl(ObjCImplementationDecl *D);
440    void VisitObjCCompatibleAliasDecl(ObjCCompatibleAliasDecl *D);
441    void VisitObjCPropertyDecl(ObjCPropertyDecl *D);
442    void VisitObjCPropertyImplDecl(ObjCPropertyImplDecl *D);
443    void VisitOMPThreadPrivateDecl(OMPThreadPrivateDecl *D);
444    void VisitOMPAllocateDecl(OMPAllocateDecl *D);
445    void VisitOMPDeclareReductionDecl(OMPDeclareReductionDecl *D);
446    void VisitOMPDeclareMapperDecl(OMPDeclareMapperDecl *D);
447    void VisitOMPRequiresDecl(OMPRequiresDecl *D);
448    void VisitOMPCapturedExprDecl(OMPCapturedExprDecl *D);
449  };
450
451} // namespace clang
452
453namespace {
454
455/// Iterator over the redeclarations of a declaration that have already
456/// been merged into the same redeclaration chain.
457template<typename DeclT>
458class MergedRedeclIterator {
459  DeclT *Start;
460  DeclT *Canonical = nullptr;
461  DeclT *Current = nullptr;
462
463public:
464  MergedRedeclIterator() = default;
465  MergedRedeclIterator(DeclT *Start) : Start(Start), Current(Start) {}
466
467  DeclT *operator*() { return Current; }
468
469  MergedRedeclIterator &operator++() {
470    if (Current->isFirstDecl()) {
471      Canonical = Current;
472      Current = Current->getMostRecentDecl();
473    } else
474      Current = Current->getPreviousDecl();
475
476    // If we started in the merged portion, we'll reach our start position
477    // eventually. Otherwise, we'll never reach it, but the second declaration
478    // we reached was the canonical declaration, so stop when we see that one
479    // again.
480    if (Current == Start || Current == Canonical)
481      Current = nullptr;
482    return *this;
483  }
484
485  friend bool operator!=(const MergedRedeclIterator &A,
486                         const MergedRedeclIterator &B) {
487    return A.Current != B.Current;
488  }
489};
490
491} // namespace
492
493template <typename DeclT>
494static llvm::iterator_range<MergedRedeclIterator<DeclT>>
495merged_redecls(DeclT *D) {
496  return llvm::make_range(MergedRedeclIterator<DeclT>(D),
497                          MergedRedeclIterator<DeclT>());
498}
499
500uint64_t ASTDeclReader::GetCurrentCursorOffset() {
501  return Loc.F->DeclsCursor.GetCurrentBitNo() + Loc.F->GlobalBitOffset;
502}
503
504void ASTDeclReader::ReadFunctionDefinition(FunctionDecl *FD) {
505  if (Record.readInt())
506    Reader.DefinitionSource[FD] = Loc.F->Kind == ModuleKind::MK_MainFile;
507  if (auto *CD = dyn_cast<CXXConstructorDecl>(FD)) {
508    CD->setNumCtorInitializers(Record.readInt());
509    if (CD->getNumCtorInitializers())
510      CD->CtorInitializers = ReadGlobalOffset();
511  }
512  // Store the offset of the body so we can lazily load it later.
513  Reader.PendingBodies[FD] = GetCurrentCursorOffset();
514  HasPendingBody = true;
515}
516
517void ASTDeclReader::Visit(Decl *D) {
518  DeclVisitor<ASTDeclReader, void>::Visit(D);
519
520  // At this point we have deserialized and merged the decl and it is safe to
521  // update its canonical decl to signal that the entire entity is used.
522  D->getCanonicalDecl()->Used |= IsDeclMarkedUsed;
523  IsDeclMarkedUsed = false;
524
525  if (auto *DD = dyn_cast<DeclaratorDecl>(D)) {
526    if (auto *TInfo = DD->getTypeSourceInfo())
527      Record.readTypeLoc(TInfo->getTypeLoc());
528  }
529
530  if (auto *TD = dyn_cast<TypeDecl>(D)) {
531    // We have a fully initialized TypeDecl. Read its type now.
532    TD->setTypeForDecl(Reader.GetType(DeferredTypeID).getTypePtrOrNull());
533
534    // If this is a tag declaration with a typedef name for linkage, it's safe
535    // to load that typedef now.
536    if (NamedDeclForTagDecl)
537      cast<TagDecl>(D)->TypedefNameDeclOrQualifier =
538          cast<TypedefNameDecl>(Reader.GetDecl(NamedDeclForTagDecl));
539  } else if (auto *ID = dyn_cast<ObjCInterfaceDecl>(D)) {
540    // if we have a fully initialized TypeDecl, we can safely read its type now.
541    ID->TypeForDecl = Reader.GetType(DeferredTypeID).getTypePtrOrNull();
542  } else if (auto *FD = dyn_cast<FunctionDecl>(D)) {
543    // FunctionDecl's body was written last after all other Stmts/Exprs.
544    // We only read it if FD doesn't already have a body (e.g., from another
545    // module).
546    // FIXME: Can we diagnose ODR violations somehow?
547    if (Record.readInt())
548      ReadFunctionDefinition(FD);
549  }
550}
551
552void ASTDeclReader::VisitDecl(Decl *D) {
553  if (D->isTemplateParameter() || D->isTemplateParameterPack() ||
554      isa<ParmVarDecl>(D) || isa<ObjCTypeParamDecl>(D)) {
555    // We don't want to deserialize the DeclContext of a template
556    // parameter or of a parameter of a function template immediately.   These
557    // entities might be used in the formulation of its DeclContext (for
558    // example, a function parameter can be used in decltype() in trailing
559    // return type of the function).  Use the translation unit DeclContext as a
560    // placeholder.
561    GlobalDeclID SemaDCIDForTemplateParmDecl = readDeclID();
562    GlobalDeclID LexicalDCIDForTemplateParmDecl = readDeclID();
563    if (!LexicalDCIDForTemplateParmDecl)
564      LexicalDCIDForTemplateParmDecl = SemaDCIDForTemplateParmDecl;
565    Reader.addPendingDeclContextInfo(D,
566                                     SemaDCIDForTemplateParmDecl,
567                                     LexicalDCIDForTemplateParmDecl);
568    D->setDeclContext(Reader.getContext().getTranslationUnitDecl());
569  } else {
570    auto *SemaDC = readDeclAs<DeclContext>();
571    auto *LexicalDC = readDeclAs<DeclContext>();
572    if (!LexicalDC)
573      LexicalDC = SemaDC;
574    DeclContext *MergedSemaDC = Reader.MergedDeclContexts.lookup(SemaDC);
575    // Avoid calling setLexicalDeclContext() directly because it uses
576    // Decl::getASTContext() internally which is unsafe during derialization.
577    D->setDeclContextsImpl(MergedSemaDC ? MergedSemaDC : SemaDC, LexicalDC,
578                           Reader.getContext());
579  }
580  D->setLocation(ThisDeclLoc);
581  D->setInvalidDecl(Record.readInt());
582  if (Record.readInt()) { // hasAttrs
583    AttrVec Attrs;
584    Record.readAttributes(Attrs);
585    // Avoid calling setAttrs() directly because it uses Decl::getASTContext()
586    // internally which is unsafe during derialization.
587    D->setAttrsImpl(Attrs, Reader.getContext());
588  }
589  D->setImplicit(Record.readInt());
590  D->Used = Record.readInt();
591  IsDeclMarkedUsed |= D->Used;
592  D->setReferenced(Record.readInt());
593  D->setTopLevelDeclInObjCContainer(Record.readInt());
594  D->setAccess((AccessSpecifier)Record.readInt());
595  D->FromASTFile = true;
596  bool ModulePrivate = Record.readInt();
597
598  // Determine whether this declaration is part of a (sub)module. If so, it
599  // may not yet be visible.
600  if (unsigned SubmoduleID = readSubmoduleID()) {
601    // Store the owning submodule ID in the declaration.
602    D->setModuleOwnershipKind(
603        ModulePrivate ? Decl::ModuleOwnershipKind::ModulePrivate
604                      : Decl::ModuleOwnershipKind::VisibleWhenImported);
605    D->setOwningModuleID(SubmoduleID);
606
607    if (ModulePrivate) {
608      // Module-private declarations are never visible, so there is no work to
609      // do.
610    } else if (Reader.getContext().getLangOpts().ModulesLocalVisibility) {
611      // If local visibility is being tracked, this declaration will become
612      // hidden and visible as the owning module does.
613    } else if (Module *Owner = Reader.getSubmodule(SubmoduleID)) {
614      // Mark the declaration as visible when its owning module becomes visible.
615      if (Owner->NameVisibility == Module::AllVisible)
616        D->setVisibleDespiteOwningModule();
617      else
618        Reader.HiddenNamesMap[Owner].push_back(D);
619    }
620  } else if (ModulePrivate) {
621    D->setModuleOwnershipKind(Decl::ModuleOwnershipKind::ModulePrivate);
622  }
623}
624
625void ASTDeclReader::VisitPragmaCommentDecl(PragmaCommentDecl *D) {
626  VisitDecl(D);
627  D->setLocation(readSourceLocation());
628  D->CommentKind = (PragmaMSCommentKind)Record.readInt();
629  std::string Arg = readString();
630  memcpy(D->getTrailingObjects<char>(), Arg.data(), Arg.size());
631  D->getTrailingObjects<char>()[Arg.size()] = '\0';
632}
633
634void ASTDeclReader::VisitPragmaDetectMismatchDecl(PragmaDetectMismatchDecl *D) {
635  VisitDecl(D);
636  D->setLocation(readSourceLocation());
637  std::string Name = readString();
638  memcpy(D->getTrailingObjects<char>(), Name.data(), Name.size());
639  D->getTrailingObjects<char>()[Name.size()] = '\0';
640
641  D->ValueStart = Name.size() + 1;
642  std::string Value = readString();
643  memcpy(D->getTrailingObjects<char>() + D->ValueStart, Value.data(),
644         Value.size());
645  D->getTrailingObjects<char>()[D->ValueStart + Value.size()] = '\0';
646}
647
648void ASTDeclReader::VisitTranslationUnitDecl(TranslationUnitDecl *TU) {
649  llvm_unreachable("Translation units are not serialized");
650}
651
652void ASTDeclReader::VisitNamedDecl(NamedDecl *ND) {
653  VisitDecl(ND);
654  ND->setDeclName(Record.readDeclarationName());
655  AnonymousDeclNumber = Record.readInt();
656}
657
658void ASTDeclReader::VisitTypeDecl(TypeDecl *TD) {
659  VisitNamedDecl(TD);
660  TD->setLocStart(readSourceLocation());
661  // Delay type reading until after we have fully initialized the decl.
662  DeferredTypeID = Record.getGlobalTypeID(Record.readInt());
663}
664
665ASTDeclReader::RedeclarableResult
666ASTDeclReader::VisitTypedefNameDecl(TypedefNameDecl *TD) {
667  RedeclarableResult Redecl = VisitRedeclarable(TD);
668  VisitTypeDecl(TD);
669  TypeSourceInfo *TInfo = readTypeSourceInfo();
670  if (Record.readInt()) { // isModed
671    QualType modedT = Record.readType();
672    TD->setModedTypeSourceInfo(TInfo, modedT);
673  } else
674    TD->setTypeSourceInfo(TInfo);
675  // Read and discard the declaration for which this is a typedef name for
676  // linkage, if it exists. We cannot rely on our type to pull in this decl,
677  // because it might have been merged with a type from another module and
678  // thus might not refer to our version of the declaration.
679  readDecl();
680  return Redecl;
681}
682
683void ASTDeclReader::VisitTypedefDecl(TypedefDecl *TD) {
684  RedeclarableResult Redecl = VisitTypedefNameDecl(TD);
685  mergeRedeclarable(TD, Redecl);
686}
687
688void ASTDeclReader::VisitTypeAliasDecl(TypeAliasDecl *TD) {
689  RedeclarableResult Redecl = VisitTypedefNameDecl(TD);
690  if (auto *Template = readDeclAs<TypeAliasTemplateDecl>())
691    // Merged when we merge the template.
692    TD->setDescribedAliasTemplate(Template);
693  else
694    mergeRedeclarable(TD, Redecl);
695}
696
697ASTDeclReader::RedeclarableResult ASTDeclReader::VisitTagDecl(TagDecl *TD) {
698  RedeclarableResult Redecl = VisitRedeclarable(TD);
699  VisitTypeDecl(TD);
700
701  TD->IdentifierNamespace = Record.readInt();
702  TD->setTagKind((TagDecl::TagKind)Record.readInt());
703  if (!isa<CXXRecordDecl>(TD))
704    TD->setCompleteDefinition(Record.readInt());
705  TD->setEmbeddedInDeclarator(Record.readInt());
706  TD->setFreeStanding(Record.readInt());
707  TD->setCompleteDefinitionRequired(Record.readInt());
708  TD->setBraceRange(readSourceRange());
709
710  switch (Record.readInt()) {
711  case 0:
712    break;
713  case 1: { // ExtInfo
714    auto *Info = new (Reader.getContext()) TagDecl::ExtInfo();
715    Record.readQualifierInfo(*Info);
716    TD->TypedefNameDeclOrQualifier = Info;
717    break;
718  }
719  case 2: // TypedefNameForAnonDecl
720    NamedDeclForTagDecl = readDeclID();
721    TypedefNameForLinkage = Record.readIdentifier();
722    break;
723  default:
724    llvm_unreachable("unexpected tag info kind");
725  }
726
727  if (!isa<CXXRecordDecl>(TD))
728    mergeRedeclarable(TD, Redecl);
729  return Redecl;
730}
731
732void ASTDeclReader::VisitEnumDecl(EnumDecl *ED) {
733  VisitTagDecl(ED);
734  if (TypeSourceInfo *TI = readTypeSourceInfo())
735    ED->setIntegerTypeSourceInfo(TI);
736  else
737    ED->setIntegerType(Record.readType());
738  ED->setPromotionType(Record.readType());
739  ED->setNumPositiveBits(Record.readInt());
740  ED->setNumNegativeBits(Record.readInt());
741  ED->setScoped(Record.readInt());
742  ED->setScopedUsingClassTag(Record.readInt());
743  ED->setFixed(Record.readInt());
744
745  ED->setHasODRHash(true);
746  ED->ODRHash = Record.readInt();
747
748  // If this is a definition subject to the ODR, and we already have a
749  // definition, merge this one into it.
750  if (ED->isCompleteDefinition() &&
751      Reader.getContext().getLangOpts().Modules &&
752      Reader.getContext().getLangOpts().CPlusPlus) {
753    EnumDecl *&OldDef = Reader.EnumDefinitions[ED->getCanonicalDecl()];
754    if (!OldDef) {
755      // This is the first time we've seen an imported definition. Look for a
756      // local definition before deciding that we are the first definition.
757      for (auto *D : merged_redecls(ED->getCanonicalDecl())) {
758        if (!D->isFromASTFile() && D->isCompleteDefinition()) {
759          OldDef = D;
760          break;
761        }
762      }
763    }
764    if (OldDef) {
765      Reader.MergedDeclContexts.insert(std::make_pair(ED, OldDef));
766      ED->setCompleteDefinition(false);
767      Reader.mergeDefinitionVisibility(OldDef, ED);
768      if (OldDef->getODRHash() != ED->getODRHash())
769        Reader.PendingEnumOdrMergeFailures[OldDef].push_back(ED);
770    } else {
771      OldDef = ED;
772    }
773  }
774
775  if (auto *InstED = readDeclAs<EnumDecl>()) {
776    auto TSK = (TemplateSpecializationKind)Record.readInt();
777    SourceLocation POI = readSourceLocation();
778    ED->setInstantiationOfMemberEnum(Reader.getContext(), InstED, TSK);
779    ED->getMemberSpecializationInfo()->setPointOfInstantiation(POI);
780  }
781}
782
783ASTDeclReader::RedeclarableResult
784ASTDeclReader::VisitRecordDeclImpl(RecordDecl *RD) {
785  RedeclarableResult Redecl = VisitTagDecl(RD);
786  RD->setHasFlexibleArrayMember(Record.readInt());
787  RD->setAnonymousStructOrUnion(Record.readInt());
788  RD->setHasObjectMember(Record.readInt());
789  RD->setHasVolatileMember(Record.readInt());
790  RD->setNonTrivialToPrimitiveDefaultInitialize(Record.readInt());
791  RD->setNonTrivialToPrimitiveCopy(Record.readInt());
792  RD->setNonTrivialToPrimitiveDestroy(Record.readInt());
793  RD->setHasNonTrivialToPrimitiveDefaultInitializeCUnion(Record.readInt());
794  RD->setHasNonTrivialToPrimitiveDestructCUnion(Record.readInt());
795  RD->setHasNonTrivialToPrimitiveCopyCUnion(Record.readInt());
796  RD->setParamDestroyedInCallee(Record.readInt());
797  RD->setArgPassingRestrictions((RecordDecl::ArgPassingKind)Record.readInt());
798  return Redecl;
799}
800
801void ASTDeclReader::VisitValueDecl(ValueDecl *VD) {
802  VisitNamedDecl(VD);
803  // For function declarations, defer reading the type in case the function has
804  // a deduced return type that references an entity declared within the
805  // function.
806  if (isa<FunctionDecl>(VD))
807    DeferredTypeID = Record.getGlobalTypeID(Record.readInt());
808  else
809    VD->setType(Record.readType());
810}
811
812void ASTDeclReader::VisitEnumConstantDecl(EnumConstantDecl *ECD) {
813  VisitValueDecl(ECD);
814  if (Record.readInt())
815    ECD->setInitExpr(Record.readExpr());
816  ECD->setInitVal(Record.readAPSInt());
817  mergeMergeable(ECD);
818}
819
820void ASTDeclReader::VisitDeclaratorDecl(DeclaratorDecl *DD) {
821  VisitValueDecl(DD);
822  DD->setInnerLocStart(readSourceLocation());
823  if (Record.readInt()) { // hasExtInfo
824    auto *Info = new (Reader.getContext()) DeclaratorDecl::ExtInfo();
825    Record.readQualifierInfo(*Info);
826    Info->TrailingRequiresClause = Record.readExpr();
827    DD->DeclInfo = Info;
828  }
829  QualType TSIType = Record.readType();
830  DD->setTypeSourceInfo(
831      TSIType.isNull() ? nullptr
832                       : Reader.getContext().CreateTypeSourceInfo(TSIType));
833}
834
835void ASTDeclReader::VisitFunctionDecl(FunctionDecl *FD) {
836  RedeclarableResult Redecl = VisitRedeclarable(FD);
837  VisitDeclaratorDecl(FD);
838
839  // Attach a type to this function. Use the real type if possible, but fall
840  // back to the type as written if it involves a deduced return type.
841  if (FD->getTypeSourceInfo() &&
842      FD->getTypeSourceInfo()->getType()->castAs<FunctionType>()
843                             ->getReturnType()->getContainedAutoType()) {
844    // We'll set up the real type in Visit, once we've finished loading the
845    // function.
846    FD->setType(FD->getTypeSourceInfo()->getType());
847    Reader.PendingFunctionTypes.push_back({FD, DeferredTypeID});
848  } else {
849    FD->setType(Reader.GetType(DeferredTypeID));
850  }
851  DeferredTypeID = 0;
852
853  FD->DNLoc = Record.readDeclarationNameLoc(FD->getDeclName());
854  FD->IdentifierNamespace = Record.readInt();
855
856  // FunctionDecl's body is handled last at ASTDeclReader::Visit,
857  // after everything else is read.
858
859  FD->setStorageClass(static_cast<StorageClass>(Record.readInt()));
860  FD->setInlineSpecified(Record.readInt());
861  FD->setImplicitlyInline(Record.readInt());
862  FD->setVirtualAsWritten(Record.readInt());
863  FD->setPure(Record.readInt());
864  FD->setHasInheritedPrototype(Record.readInt());
865  FD->setHasWrittenPrototype(Record.readInt());
866  FD->setDeletedAsWritten(Record.readInt());
867  FD->setTrivial(Record.readInt());
868  FD->setTrivialForCall(Record.readInt());
869  FD->setDefaulted(Record.readInt());
870  FD->setExplicitlyDefaulted(Record.readInt());
871  FD->setHasImplicitReturnZero(Record.readInt());
872  FD->setConstexprKind(static_cast<ConstexprSpecKind>(Record.readInt()));
873  FD->setUsesSEHTry(Record.readInt());
874  FD->setHasSkippedBody(Record.readInt());
875  FD->setIsMultiVersion(Record.readInt());
876  FD->setLateTemplateParsed(Record.readInt());
877
878  FD->setCachedLinkage(static_cast<Linkage>(Record.readInt()));
879  FD->EndRangeLoc = readSourceLocation();
880
881  FD->ODRHash = Record.readInt();
882  FD->setHasODRHash(true);
883  FD->setUsesFPIntrin(Record.readInt());
884
885  if (FD->isDefaulted()) {
886    if (unsigned NumLookups = Record.readInt()) {
887      SmallVector<DeclAccessPair, 8> Lookups;
888      for (unsigned I = 0; I != NumLookups; ++I) {
889        NamedDecl *ND = Record.readDeclAs<NamedDecl>();
890        AccessSpecifier AS = (AccessSpecifier)Record.readInt();
891        Lookups.push_back(DeclAccessPair::make(ND, AS));
892      }
893      FD->setDefaultedFunctionInfo(FunctionDecl::DefaultedFunctionInfo::Create(
894          Reader.getContext(), Lookups));
895    }
896  }
897
898  switch ((FunctionDecl::TemplatedKind)Record.readInt()) {
899  case FunctionDecl::TK_NonTemplate:
900    mergeRedeclarable(FD, Redecl);
901    break;
902  case FunctionDecl::TK_FunctionTemplate:
903    // Merged when we merge the template.
904    FD->setDescribedFunctionTemplate(readDeclAs<FunctionTemplateDecl>());
905    break;
906  case FunctionDecl::TK_MemberSpecialization: {
907    auto *InstFD = readDeclAs<FunctionDecl>();
908    auto TSK = (TemplateSpecializationKind)Record.readInt();
909    SourceLocation POI = readSourceLocation();
910    FD->setInstantiationOfMemberFunction(Reader.getContext(), InstFD, TSK);
911    FD->getMemberSpecializationInfo()->setPointOfInstantiation(POI);
912    mergeRedeclarable(FD, Redecl);
913    break;
914  }
915  case FunctionDecl::TK_FunctionTemplateSpecialization: {
916    auto *Template = readDeclAs<FunctionTemplateDecl>();
917    auto TSK = (TemplateSpecializationKind)Record.readInt();
918
919    // Template arguments.
920    SmallVector<TemplateArgument, 8> TemplArgs;
921    Record.readTemplateArgumentList(TemplArgs, /*Canonicalize*/ true);
922
923    // Template args as written.
924    SmallVector<TemplateArgumentLoc, 8> TemplArgLocs;
925    SourceLocation LAngleLoc, RAngleLoc;
926    bool HasTemplateArgumentsAsWritten = Record.readInt();
927    if (HasTemplateArgumentsAsWritten) {
928      unsigned NumTemplateArgLocs = Record.readInt();
929      TemplArgLocs.reserve(NumTemplateArgLocs);
930      for (unsigned i = 0; i != NumTemplateArgLocs; ++i)
931        TemplArgLocs.push_back(Record.readTemplateArgumentLoc());
932
933      LAngleLoc = readSourceLocation();
934      RAngleLoc = readSourceLocation();
935    }
936
937    SourceLocation POI = readSourceLocation();
938
939    ASTContext &C = Reader.getContext();
940    TemplateArgumentList *TemplArgList
941      = TemplateArgumentList::CreateCopy(C, TemplArgs);
942    TemplateArgumentListInfo TemplArgsInfo(LAngleLoc, RAngleLoc);
943    for (unsigned i = 0, e = TemplArgLocs.size(); i != e; ++i)
944      TemplArgsInfo.addArgument(TemplArgLocs[i]);
945
946    MemberSpecializationInfo *MSInfo = nullptr;
947    if (Record.readInt()) {
948      auto *FD = readDeclAs<FunctionDecl>();
949      auto TSK = (TemplateSpecializationKind)Record.readInt();
950      SourceLocation POI = readSourceLocation();
951
952      MSInfo = new (C) MemberSpecializationInfo(FD, TSK);
953      MSInfo->setPointOfInstantiation(POI);
954    }
955
956    FunctionTemplateSpecializationInfo *FTInfo =
957        FunctionTemplateSpecializationInfo::Create(
958            C, FD, Template, TSK, TemplArgList,
959            HasTemplateArgumentsAsWritten ? &TemplArgsInfo : nullptr, POI,
960            MSInfo);
961    FD->TemplateOrSpecialization = FTInfo;
962
963    if (FD->isCanonicalDecl()) { // if canonical add to template's set.
964      // The template that contains the specializations set. It's not safe to
965      // use getCanonicalDecl on Template since it may still be initializing.
966      auto *CanonTemplate = readDeclAs<FunctionTemplateDecl>();
967      // Get the InsertPos by FindNodeOrInsertPos() instead of calling
968      // InsertNode(FTInfo) directly to avoid the getASTContext() call in
969      // FunctionTemplateSpecializationInfo's Profile().
970      // We avoid getASTContext because a decl in the parent hierarchy may
971      // be initializing.
972      llvm::FoldingSetNodeID ID;
973      FunctionTemplateSpecializationInfo::Profile(ID, TemplArgs, C);
974      void *InsertPos = nullptr;
975      FunctionTemplateDecl::Common *CommonPtr = CanonTemplate->getCommonPtr();
976      FunctionTemplateSpecializationInfo *ExistingInfo =
977          CommonPtr->Specializations.FindNodeOrInsertPos(ID, InsertPos);
978      if (InsertPos)
979        CommonPtr->Specializations.InsertNode(FTInfo, InsertPos);
980      else {
981        assert(Reader.getContext().getLangOpts().Modules &&
982               "already deserialized this template specialization");
983        mergeRedeclarable(FD, ExistingInfo->getFunction(), Redecl);
984      }
985    }
986    break;
987  }
988  case FunctionDecl::TK_DependentFunctionTemplateSpecialization: {
989    // Templates.
990    UnresolvedSet<8> TemplDecls;
991    unsigned NumTemplates = Record.readInt();
992    while (NumTemplates--)
993      TemplDecls.addDecl(readDeclAs<NamedDecl>());
994
995    // Templates args.
996    TemplateArgumentListInfo TemplArgs;
997    unsigned NumArgs = Record.readInt();
998    while (NumArgs--)
999      TemplArgs.addArgument(Record.readTemplateArgumentLoc());
1000    TemplArgs.setLAngleLoc(readSourceLocation());
1001    TemplArgs.setRAngleLoc(readSourceLocation());
1002
1003    FD->setDependentTemplateSpecialization(Reader.getContext(),
1004                                           TemplDecls, TemplArgs);
1005    // These are not merged; we don't need to merge redeclarations of dependent
1006    // template friends.
1007    break;
1008  }
1009  }
1010
1011  // Read in the parameters.
1012  unsigned NumParams = Record.readInt();
1013  SmallVector<ParmVarDecl *, 16> Params;
1014  Params.reserve(NumParams);
1015  for (unsigned I = 0; I != NumParams; ++I)
1016    Params.push_back(readDeclAs<ParmVarDecl>());
1017  FD->setParams(Reader.getContext(), Params);
1018}
1019
1020void ASTDeclReader::VisitObjCMethodDecl(ObjCMethodDecl *MD) {
1021  VisitNamedDecl(MD);
1022  if (Record.readInt()) {
1023    // Load the body on-demand. Most clients won't care, because method
1024    // definitions rarely show up in headers.
1025    Reader.PendingBodies[MD] = GetCurrentCursorOffset();
1026    HasPendingBody = true;
1027  }
1028  MD->setSelfDecl(readDeclAs<ImplicitParamDecl>());
1029  MD->setCmdDecl(readDeclAs<ImplicitParamDecl>());
1030  MD->setInstanceMethod(Record.readInt());
1031  MD->setVariadic(Record.readInt());
1032  MD->setPropertyAccessor(Record.readInt());
1033  MD->setSynthesizedAccessorStub(Record.readInt());
1034  MD->setDefined(Record.readInt());
1035  MD->setOverriding(Record.readInt());
1036  MD->setHasSkippedBody(Record.readInt());
1037
1038  MD->setIsRedeclaration(Record.readInt());
1039  MD->setHasRedeclaration(Record.readInt());
1040  if (MD->hasRedeclaration())
1041    Reader.getContext().setObjCMethodRedeclaration(MD,
1042                                       readDeclAs<ObjCMethodDecl>());
1043
1044  MD->setDeclImplementation((ObjCMethodDecl::ImplementationControl)Record.readInt());
1045  MD->setObjCDeclQualifier((Decl::ObjCDeclQualifier)Record.readInt());
1046  MD->setRelatedResultType(Record.readInt());
1047  MD->setReturnType(Record.readType());
1048  MD->setReturnTypeSourceInfo(readTypeSourceInfo());
1049  MD->DeclEndLoc = readSourceLocation();
1050  unsigned NumParams = Record.readInt();
1051  SmallVector<ParmVarDecl *, 16> Params;
1052  Params.reserve(NumParams);
1053  for (unsigned I = 0; I != NumParams; ++I)
1054    Params.push_back(readDeclAs<ParmVarDecl>());
1055
1056  MD->setSelLocsKind((SelectorLocationsKind)Record.readInt());
1057  unsigned NumStoredSelLocs = Record.readInt();
1058  SmallVector<SourceLocation, 16> SelLocs;
1059  SelLocs.reserve(NumStoredSelLocs);
1060  for (unsigned i = 0; i != NumStoredSelLocs; ++i)
1061    SelLocs.push_back(readSourceLocation());
1062
1063  MD->setParamsAndSelLocs(Reader.getContext(), Params, SelLocs);
1064}
1065
1066void ASTDeclReader::VisitObjCTypeParamDecl(ObjCTypeParamDecl *D) {
1067  VisitTypedefNameDecl(D);
1068
1069  D->Variance = Record.readInt();
1070  D->Index = Record.readInt();
1071  D->VarianceLoc = readSourceLocation();
1072  D->ColonLoc = readSourceLocation();
1073}
1074
1075void ASTDeclReader::VisitObjCContainerDecl(ObjCContainerDecl *CD) {
1076  VisitNamedDecl(CD);
1077  CD->setAtStartLoc(readSourceLocation());
1078  CD->setAtEndRange(readSourceRange());
1079}
1080
1081ObjCTypeParamList *ASTDeclReader::ReadObjCTypeParamList() {
1082  unsigned numParams = Record.readInt();
1083  if (numParams == 0)
1084    return nullptr;
1085
1086  SmallVector<ObjCTypeParamDecl *, 4> typeParams;
1087  typeParams.reserve(numParams);
1088  for (unsigned i = 0; i != numParams; ++i) {
1089    auto *typeParam = readDeclAs<ObjCTypeParamDecl>();
1090    if (!typeParam)
1091      return nullptr;
1092
1093    typeParams.push_back(typeParam);
1094  }
1095
1096  SourceLocation lAngleLoc = readSourceLocation();
1097  SourceLocation rAngleLoc = readSourceLocation();
1098
1099  return ObjCTypeParamList::create(Reader.getContext(), lAngleLoc,
1100                                   typeParams, rAngleLoc);
1101}
1102
1103void ASTDeclReader::ReadObjCDefinitionData(
1104         struct ObjCInterfaceDecl::DefinitionData &Data) {
1105  // Read the superclass.
1106  Data.SuperClassTInfo = readTypeSourceInfo();
1107
1108  Data.EndLoc = readSourceLocation();
1109  Data.HasDesignatedInitializers = Record.readInt();
1110
1111  // Read the directly referenced protocols and their SourceLocations.
1112  unsigned NumProtocols = Record.readInt();
1113  SmallVector<ObjCProtocolDecl *, 16> Protocols;
1114  Protocols.reserve(NumProtocols);
1115  for (unsigned I = 0; I != NumProtocols; ++I)
1116    Protocols.push_back(readDeclAs<ObjCProtocolDecl>());
1117  SmallVector<SourceLocation, 16> ProtoLocs;
1118  ProtoLocs.reserve(NumProtocols);
1119  for (unsigned I = 0; I != NumProtocols; ++I)
1120    ProtoLocs.push_back(readSourceLocation());
1121  Data.ReferencedProtocols.set(Protocols.data(), NumProtocols, ProtoLocs.data(),
1122                               Reader.getContext());
1123
1124  // Read the transitive closure of protocols referenced by this class.
1125  NumProtocols = Record.readInt();
1126  Protocols.clear();
1127  Protocols.reserve(NumProtocols);
1128  for (unsigned I = 0; I != NumProtocols; ++I)
1129    Protocols.push_back(readDeclAs<ObjCProtocolDecl>());
1130  Data.AllReferencedProtocols.set(Protocols.data(), NumProtocols,
1131                                  Reader.getContext());
1132}
1133
1134void ASTDeclReader::MergeDefinitionData(ObjCInterfaceDecl *D,
1135         struct ObjCInterfaceDecl::DefinitionData &&NewDD) {
1136  // FIXME: odr checking?
1137}
1138
1139void ASTDeclReader::VisitObjCInterfaceDecl(ObjCInterfaceDecl *ID) {
1140  RedeclarableResult Redecl = VisitRedeclarable(ID);
1141  VisitObjCContainerDecl(ID);
1142  DeferredTypeID = Record.getGlobalTypeID(Record.readInt());
1143  mergeRedeclarable(ID, Redecl);
1144
1145  ID->TypeParamList = ReadObjCTypeParamList();
1146  if (Record.readInt()) {
1147    // Read the definition.
1148    ID->allocateDefinitionData();
1149
1150    ReadObjCDefinitionData(ID->data());
1151    ObjCInterfaceDecl *Canon = ID->getCanonicalDecl();
1152    if (Canon->Data.getPointer()) {
1153      // If we already have a definition, keep the definition invariant and
1154      // merge the data.
1155      MergeDefinitionData(Canon, std::move(ID->data()));
1156      ID->Data = Canon->Data;
1157    } else {
1158      // Set the definition data of the canonical declaration, so other
1159      // redeclarations will see it.
1160      ID->getCanonicalDecl()->Data = ID->Data;
1161
1162      // We will rebuild this list lazily.
1163      ID->setIvarList(nullptr);
1164    }
1165
1166    // Note that we have deserialized a definition.
1167    Reader.PendingDefinitions.insert(ID);
1168
1169    // Note that we've loaded this Objective-C class.
1170    Reader.ObjCClassesLoaded.push_back(ID);
1171  } else {
1172    ID->Data = ID->getCanonicalDecl()->Data;
1173  }
1174}
1175
1176void ASTDeclReader::VisitObjCIvarDecl(ObjCIvarDecl *IVD) {
1177  VisitFieldDecl(IVD);
1178  IVD->setAccessControl((ObjCIvarDecl::AccessControl)Record.readInt());
1179  // This field will be built lazily.
1180  IVD->setNextIvar(nullptr);
1181  bool synth = Record.readInt();
1182  IVD->setSynthesize(synth);
1183}
1184
1185void ASTDeclReader::ReadObjCDefinitionData(
1186         struct ObjCProtocolDecl::DefinitionData &Data) {
1187    unsigned NumProtoRefs = Record.readInt();
1188    SmallVector<ObjCProtocolDecl *, 16> ProtoRefs;
1189    ProtoRefs.reserve(NumProtoRefs);
1190    for (unsigned I = 0; I != NumProtoRefs; ++I)
1191      ProtoRefs.push_back(readDeclAs<ObjCProtocolDecl>());
1192    SmallVector<SourceLocation, 16> ProtoLocs;
1193    ProtoLocs.reserve(NumProtoRefs);
1194    for (unsigned I = 0; I != NumProtoRefs; ++I)
1195      ProtoLocs.push_back(readSourceLocation());
1196    Data.ReferencedProtocols.set(ProtoRefs.data(), NumProtoRefs,
1197                                 ProtoLocs.data(), Reader.getContext());
1198}
1199
1200void ASTDeclReader::MergeDefinitionData(ObjCProtocolDecl *D,
1201         struct ObjCProtocolDecl::DefinitionData &&NewDD) {
1202  // FIXME: odr checking?
1203}
1204
1205void ASTDeclReader::VisitObjCProtocolDecl(ObjCProtocolDecl *PD) {
1206  RedeclarableResult Redecl = VisitRedeclarable(PD);
1207  VisitObjCContainerDecl(PD);
1208  mergeRedeclarable(PD, Redecl);
1209
1210  if (Record.readInt()) {
1211    // Read the definition.
1212    PD->allocateDefinitionData();
1213
1214    ReadObjCDefinitionData(PD->data());
1215
1216    ObjCProtocolDecl *Canon = PD->getCanonicalDecl();
1217    if (Canon->Data.getPointer()) {
1218      // If we already have a definition, keep the definition invariant and
1219      // merge the data.
1220      MergeDefinitionData(Canon, std::move(PD->data()));
1221      PD->Data = Canon->Data;
1222    } else {
1223      // Set the definition data of the canonical declaration, so other
1224      // redeclarations will see it.
1225      PD->getCanonicalDecl()->Data = PD->Data;
1226    }
1227    // Note that we have deserialized a definition.
1228    Reader.PendingDefinitions.insert(PD);
1229  } else {
1230    PD->Data = PD->getCanonicalDecl()->Data;
1231  }
1232}
1233
1234void ASTDeclReader::VisitObjCAtDefsFieldDecl(ObjCAtDefsFieldDecl *FD) {
1235  VisitFieldDecl(FD);
1236}
1237
1238void ASTDeclReader::VisitObjCCategoryDecl(ObjCCategoryDecl *CD) {
1239  VisitObjCContainerDecl(CD);
1240  CD->setCategoryNameLoc(readSourceLocation());
1241  CD->setIvarLBraceLoc(readSourceLocation());
1242  CD->setIvarRBraceLoc(readSourceLocation());
1243
1244  // Note that this category has been deserialized. We do this before
1245  // deserializing the interface declaration, so that it will consider this
1246  /// category.
1247  Reader.CategoriesDeserialized.insert(CD);
1248
1249  CD->ClassInterface = readDeclAs<ObjCInterfaceDecl>();
1250  CD->TypeParamList = ReadObjCTypeParamList();
1251  unsigned NumProtoRefs = Record.readInt();
1252  SmallVector<ObjCProtocolDecl *, 16> ProtoRefs;
1253  ProtoRefs.reserve(NumProtoRefs);
1254  for (unsigned I = 0; I != NumProtoRefs; ++I)
1255    ProtoRefs.push_back(readDeclAs<ObjCProtocolDecl>());
1256  SmallVector<SourceLocation, 16> ProtoLocs;
1257  ProtoLocs.reserve(NumProtoRefs);
1258  for (unsigned I = 0; I != NumProtoRefs; ++I)
1259    ProtoLocs.push_back(readSourceLocation());
1260  CD->setProtocolList(ProtoRefs.data(), NumProtoRefs, ProtoLocs.data(),
1261                      Reader.getContext());
1262
1263  // Protocols in the class extension belong to the class.
1264  if (NumProtoRefs > 0 && CD->ClassInterface && CD->IsClassExtension())
1265    CD->ClassInterface->mergeClassExtensionProtocolList(
1266        (ObjCProtocolDecl *const *)ProtoRefs.data(), NumProtoRefs,
1267        Reader.getContext());
1268}
1269
1270void ASTDeclReader::VisitObjCCompatibleAliasDecl(ObjCCompatibleAliasDecl *CAD) {
1271  VisitNamedDecl(CAD);
1272  CAD->setClassInterface(readDeclAs<ObjCInterfaceDecl>());
1273}
1274
1275void ASTDeclReader::VisitObjCPropertyDecl(ObjCPropertyDecl *D) {
1276  VisitNamedDecl(D);
1277  D->setAtLoc(readSourceLocation());
1278  D->setLParenLoc(readSourceLocation());
1279  QualType T = Record.readType();
1280  TypeSourceInfo *TSI = readTypeSourceInfo();
1281  D->setType(T, TSI);
1282  D->setPropertyAttributes(
1283      (ObjCPropertyDecl::PropertyAttributeKind)Record.readInt());
1284  D->setPropertyAttributesAsWritten(
1285      (ObjCPropertyDecl::PropertyAttributeKind)Record.readInt());
1286  D->setPropertyImplementation(
1287      (ObjCPropertyDecl::PropertyControl)Record.readInt());
1288  DeclarationName GetterName = Record.readDeclarationName();
1289  SourceLocation GetterLoc = readSourceLocation();
1290  D->setGetterName(GetterName.getObjCSelector(), GetterLoc);
1291  DeclarationName SetterName = Record.readDeclarationName();
1292  SourceLocation SetterLoc = readSourceLocation();
1293  D->setSetterName(SetterName.getObjCSelector(), SetterLoc);
1294  D->setGetterMethodDecl(readDeclAs<ObjCMethodDecl>());
1295  D->setSetterMethodDecl(readDeclAs<ObjCMethodDecl>());
1296  D->setPropertyIvarDecl(readDeclAs<ObjCIvarDecl>());
1297}
1298
1299void ASTDeclReader::VisitObjCImplDecl(ObjCImplDecl *D) {
1300  VisitObjCContainerDecl(D);
1301  D->setClassInterface(readDeclAs<ObjCInterfaceDecl>());
1302}
1303
1304void ASTDeclReader::VisitObjCCategoryImplDecl(ObjCCategoryImplDecl *D) {
1305  VisitObjCImplDecl(D);
1306  D->CategoryNameLoc = readSourceLocation();
1307}
1308
1309void ASTDeclReader::VisitObjCImplementationDecl(ObjCImplementationDecl *D) {
1310  VisitObjCImplDecl(D);
1311  D->setSuperClass(readDeclAs<ObjCInterfaceDecl>());
1312  D->SuperLoc = readSourceLocation();
1313  D->setIvarLBraceLoc(readSourceLocation());
1314  D->setIvarRBraceLoc(readSourceLocation());
1315  D->setHasNonZeroConstructors(Record.readInt());
1316  D->setHasDestructors(Record.readInt());
1317  D->NumIvarInitializers = Record.readInt();
1318  if (D->NumIvarInitializers)
1319    D->IvarInitializers = ReadGlobalOffset();
1320}
1321
1322void ASTDeclReader::VisitObjCPropertyImplDecl(ObjCPropertyImplDecl *D) {
1323  VisitDecl(D);
1324  D->setAtLoc(readSourceLocation());
1325  D->setPropertyDecl(readDeclAs<ObjCPropertyDecl>());
1326  D->PropertyIvarDecl = readDeclAs<ObjCIvarDecl>();
1327  D->IvarLoc = readSourceLocation();
1328  D->setGetterMethodDecl(readDeclAs<ObjCMethodDecl>());
1329  D->setSetterMethodDecl(readDeclAs<ObjCMethodDecl>());
1330  D->setGetterCXXConstructor(Record.readExpr());
1331  D->setSetterCXXAssignment(Record.readExpr());
1332}
1333
1334void ASTDeclReader::VisitFieldDecl(FieldDecl *FD) {
1335  VisitDeclaratorDecl(FD);
1336  FD->Mutable = Record.readInt();
1337
1338  if (auto ISK = static_cast<FieldDecl::InitStorageKind>(Record.readInt())) {
1339    FD->InitStorage.setInt(ISK);
1340    FD->InitStorage.setPointer(ISK == FieldDecl::ISK_CapturedVLAType
1341                                   ? Record.readType().getAsOpaquePtr()
1342                                   : Record.readExpr());
1343  }
1344
1345  if (auto *BW = Record.readExpr())
1346    FD->setBitWidth(BW);
1347
1348  if (!FD->getDeclName()) {
1349    if (auto *Tmpl = readDeclAs<FieldDecl>())
1350      Reader.getContext().setInstantiatedFromUnnamedFieldDecl(FD, Tmpl);
1351  }
1352  mergeMergeable(FD);
1353}
1354
1355void ASTDeclReader::VisitMSPropertyDecl(MSPropertyDecl *PD) {
1356  VisitDeclaratorDecl(PD);
1357  PD->GetterId = Record.readIdentifier();
1358  PD->SetterId = Record.readIdentifier();
1359}
1360
1361void ASTDeclReader::VisitIndirectFieldDecl(IndirectFieldDecl *FD) {
1362  VisitValueDecl(FD);
1363
1364  FD->ChainingSize = Record.readInt();
1365  assert(FD->ChainingSize >= 2 && "Anonymous chaining must be >= 2");
1366  FD->Chaining = new (Reader.getContext())NamedDecl*[FD->ChainingSize];
1367
1368  for (unsigned I = 0; I != FD->ChainingSize; ++I)
1369    FD->Chaining[I] = readDeclAs<NamedDecl>();
1370
1371  mergeMergeable(FD);
1372}
1373
1374ASTDeclReader::RedeclarableResult ASTDeclReader::VisitVarDeclImpl(VarDecl *VD) {
1375  RedeclarableResult Redecl = VisitRedeclarable(VD);
1376  VisitDeclaratorDecl(VD);
1377
1378  VD->VarDeclBits.SClass = (StorageClass)Record.readInt();
1379  VD->VarDeclBits.TSCSpec = Record.readInt();
1380  VD->VarDeclBits.InitStyle = Record.readInt();
1381  VD->VarDeclBits.ARCPseudoStrong = Record.readInt();
1382  if (!isa<ParmVarDecl>(VD)) {
1383    VD->NonParmVarDeclBits.IsThisDeclarationADemotedDefinition =
1384        Record.readInt();
1385    VD->NonParmVarDeclBits.ExceptionVar = Record.readInt();
1386    VD->NonParmVarDeclBits.NRVOVariable = Record.readInt();
1387    VD->NonParmVarDeclBits.CXXForRangeDecl = Record.readInt();
1388    VD->NonParmVarDeclBits.ObjCForDecl = Record.readInt();
1389    VD->NonParmVarDeclBits.IsInline = Record.readInt();
1390    VD->NonParmVarDeclBits.IsInlineSpecified = Record.readInt();
1391    VD->NonParmVarDeclBits.IsConstexpr = Record.readInt();
1392    VD->NonParmVarDeclBits.IsInitCapture = Record.readInt();
1393    VD->NonParmVarDeclBits.PreviousDeclInSameBlockScope = Record.readInt();
1394    VD->NonParmVarDeclBits.ImplicitParamKind = Record.readInt();
1395    VD->NonParmVarDeclBits.EscapingByref = Record.readInt();
1396  }
1397  auto VarLinkage = Linkage(Record.readInt());
1398  VD->setCachedLinkage(VarLinkage);
1399
1400  // Reconstruct the one piece of the IdentifierNamespace that we need.
1401  if (VD->getStorageClass() == SC_Extern && VarLinkage != NoLinkage &&
1402      VD->getLexicalDeclContext()->isFunctionOrMethod())
1403    VD->setLocalExternDecl();
1404
1405  if (uint64_t Val = Record.readInt()) {
1406    VD->setInit(Record.readExpr());
1407    if (Val > 1) {
1408      EvaluatedStmt *Eval = VD->ensureEvaluatedStmt();
1409      Eval->CheckedICE = true;
1410      Eval->IsICE = (Val & 1) != 0;
1411      Eval->HasConstantDestruction = (Val & 4) != 0;
1412    }
1413  }
1414
1415  if (VD->hasAttr<BlocksAttr>() && VD->getType()->getAsCXXRecordDecl()) {
1416    Expr *CopyExpr = Record.readExpr();
1417    if (CopyExpr)
1418      Reader.getContext().setBlockVarCopyInit(VD, CopyExpr, Record.readInt());
1419  }
1420
1421  if (VD->getStorageDuration() == SD_Static && Record.readInt())
1422    Reader.DefinitionSource[VD] = Loc.F->Kind == ModuleKind::MK_MainFile;
1423
1424  enum VarKind {
1425    VarNotTemplate = 0, VarTemplate, StaticDataMemberSpecialization
1426  };
1427  switch ((VarKind)Record.readInt()) {
1428  case VarNotTemplate:
1429    // Only true variables (not parameters or implicit parameters) can be
1430    // merged; the other kinds are not really redeclarable at all.
1431    if (!isa<ParmVarDecl>(VD) && !isa<ImplicitParamDecl>(VD) &&
1432        !isa<VarTemplateSpecializationDecl>(VD))
1433      mergeRedeclarable(VD, Redecl);
1434    break;
1435  case VarTemplate:
1436    // Merged when we merge the template.
1437    VD->setDescribedVarTemplate(readDeclAs<VarTemplateDecl>());
1438    break;
1439  case StaticDataMemberSpecialization: { // HasMemberSpecializationInfo.
1440    auto *Tmpl = readDeclAs<VarDecl>();
1441    auto TSK = (TemplateSpecializationKind)Record.readInt();
1442    SourceLocation POI = readSourceLocation();
1443    Reader.getContext().setInstantiatedFromStaticDataMember(VD, Tmpl, TSK,POI);
1444    mergeRedeclarable(VD, Redecl);
1445    break;
1446  }
1447  }
1448
1449  return Redecl;
1450}
1451
1452void ASTDeclReader::VisitImplicitParamDecl(ImplicitParamDecl *PD) {
1453  VisitVarDecl(PD);
1454}
1455
1456void ASTDeclReader::VisitParmVarDecl(ParmVarDecl *PD) {
1457  VisitVarDecl(PD);
1458  unsigned isObjCMethodParam = Record.readInt();
1459  unsigned scopeDepth = Record.readInt();
1460  unsigned scopeIndex = Record.readInt();
1461  unsigned declQualifier = Record.readInt();
1462  if (isObjCMethodParam) {
1463    assert(scopeDepth == 0);
1464    PD->setObjCMethodScopeInfo(scopeIndex);
1465    PD->ParmVarDeclBits.ScopeDepthOrObjCQuals = declQualifier;
1466  } else {
1467    PD->setScopeInfo(scopeDepth, scopeIndex);
1468  }
1469  PD->ParmVarDeclBits.IsKNRPromoted = Record.readInt();
1470  PD->ParmVarDeclBits.HasInheritedDefaultArg = Record.readInt();
1471  if (Record.readInt()) // hasUninstantiatedDefaultArg.
1472    PD->setUninstantiatedDefaultArg(Record.readExpr());
1473
1474  // FIXME: If this is a redeclaration of a function from another module, handle
1475  // inheritance of default arguments.
1476}
1477
1478void ASTDeclReader::VisitDecompositionDecl(DecompositionDecl *DD) {
1479  VisitVarDecl(DD);
1480  auto **BDs = DD->getTrailingObjects<BindingDecl *>();
1481  for (unsigned I = 0; I != DD->NumBindings; ++I) {
1482    BDs[I] = readDeclAs<BindingDecl>();
1483    BDs[I]->setDecomposedDecl(DD);
1484  }
1485}
1486
1487void ASTDeclReader::VisitBindingDecl(BindingDecl *BD) {
1488  VisitValueDecl(BD);
1489  BD->Binding = Record.readExpr();
1490}
1491
1492void ASTDeclReader::VisitFileScopeAsmDecl(FileScopeAsmDecl *AD) {
1493  VisitDecl(AD);
1494  AD->setAsmString(cast<StringLiteral>(Record.readExpr()));
1495  AD->setRParenLoc(readSourceLocation());
1496}
1497
1498void ASTDeclReader::VisitBlockDecl(BlockDecl *BD) {
1499  VisitDecl(BD);
1500  BD->setBody(cast_or_null<CompoundStmt>(Record.readStmt()));
1501  BD->setSignatureAsWritten(readTypeSourceInfo());
1502  unsigned NumParams = Record.readInt();
1503  SmallVector<ParmVarDecl *, 16> Params;
1504  Params.reserve(NumParams);
1505  for (unsigned I = 0; I != NumParams; ++I)
1506    Params.push_back(readDeclAs<ParmVarDecl>());
1507  BD->setParams(Params);
1508
1509  BD->setIsVariadic(Record.readInt());
1510  BD->setBlockMissingReturnType(Record.readInt());
1511  BD->setIsConversionFromLambda(Record.readInt());
1512  BD->setDoesNotEscape(Record.readInt());
1513  BD->setCanAvoidCopyToHeap(Record.readInt());
1514
1515  bool capturesCXXThis = Record.readInt();
1516  unsigned numCaptures = Record.readInt();
1517  SmallVector<BlockDecl::Capture, 16> captures;
1518  captures.reserve(numCaptures);
1519  for (unsigned i = 0; i != numCaptures; ++i) {
1520    auto *decl = readDeclAs<VarDecl>();
1521    unsigned flags = Record.readInt();
1522    bool byRef = (flags & 1);
1523    bool nested = (flags & 2);
1524    Expr *copyExpr = ((flags & 4) ? Record.readExpr() : nullptr);
1525
1526    captures.push_back(BlockDecl::Capture(decl, byRef, nested, copyExpr));
1527  }
1528  BD->setCaptures(Reader.getContext(), captures, capturesCXXThis);
1529}
1530
1531void ASTDeclReader::VisitCapturedDecl(CapturedDecl *CD) {
1532  VisitDecl(CD);
1533  unsigned ContextParamPos = Record.readInt();
1534  CD->setNothrow(Record.readInt() != 0);
1535  // Body is set by VisitCapturedStmt.
1536  for (unsigned I = 0; I < CD->NumParams; ++I) {
1537    if (I != ContextParamPos)
1538      CD->setParam(I, readDeclAs<ImplicitParamDecl>());
1539    else
1540      CD->setContextParam(I, readDeclAs<ImplicitParamDecl>());
1541  }
1542}
1543
1544void ASTDeclReader::VisitLinkageSpecDecl(LinkageSpecDecl *D) {
1545  VisitDecl(D);
1546  D->setLanguage((LinkageSpecDecl::LanguageIDs)Record.readInt());
1547  D->setExternLoc(readSourceLocation());
1548  D->setRBraceLoc(readSourceLocation());
1549}
1550
1551void ASTDeclReader::VisitExportDecl(ExportDecl *D) {
1552  VisitDecl(D);
1553  D->RBraceLoc = readSourceLocation();
1554}
1555
1556void ASTDeclReader::VisitLabelDecl(LabelDecl *D) {
1557  VisitNamedDecl(D);
1558  D->setLocStart(readSourceLocation());
1559}
1560
1561void ASTDeclReader::VisitNamespaceDecl(NamespaceDecl *D) {
1562  RedeclarableResult Redecl = VisitRedeclarable(D);
1563  VisitNamedDecl(D);
1564  D->setInline(Record.readInt());
1565  D->LocStart = readSourceLocation();
1566  D->RBraceLoc = readSourceLocation();
1567
1568  // Defer loading the anonymous namespace until we've finished merging
1569  // this namespace; loading it might load a later declaration of the
1570  // same namespace, and we have an invariant that older declarations
1571  // get merged before newer ones try to merge.
1572  GlobalDeclID AnonNamespace = 0;
1573  if (Redecl.getFirstID() == ThisDeclID) {
1574    AnonNamespace = readDeclID();
1575  } else {
1576    // Link this namespace back to the first declaration, which has already
1577    // been deserialized.
1578    D->AnonOrFirstNamespaceAndInline.setPointer(D->getFirstDecl());
1579  }
1580
1581  mergeRedeclarable(D, Redecl);
1582
1583  if (AnonNamespace) {
1584    // Each module has its own anonymous namespace, which is disjoint from
1585    // any other module's anonymous namespaces, so don't attach the anonymous
1586    // namespace at all.
1587    auto *Anon = cast<NamespaceDecl>(Reader.GetDecl(AnonNamespace));
1588    if (!Record.isModule())
1589      D->setAnonymousNamespace(Anon);
1590  }
1591}
1592
1593void ASTDeclReader::VisitNamespaceAliasDecl(NamespaceAliasDecl *D) {
1594  RedeclarableResult Redecl = VisitRedeclarable(D);
1595  VisitNamedDecl(D);
1596  D->NamespaceLoc = readSourceLocation();
1597  D->IdentLoc = readSourceLocation();
1598  D->QualifierLoc = Record.readNestedNameSpecifierLoc();
1599  D->Namespace = readDeclAs<NamedDecl>();
1600  mergeRedeclarable(D, Redecl);
1601}
1602
1603void ASTDeclReader::VisitUsingDecl(UsingDecl *D) {
1604  VisitNamedDecl(D);
1605  D->setUsingLoc(readSourceLocation());
1606  D->QualifierLoc = Record.readNestedNameSpecifierLoc();
1607  D->DNLoc = Record.readDeclarationNameLoc(D->getDeclName());
1608  D->FirstUsingShadow.setPointer(readDeclAs<UsingShadowDecl>());
1609  D->setTypename(Record.readInt());
1610  if (auto *Pattern = readDeclAs<NamedDecl>())
1611    Reader.getContext().setInstantiatedFromUsingDecl(D, Pattern);
1612  mergeMergeable(D);
1613}
1614
1615void ASTDeclReader::VisitUsingPackDecl(UsingPackDecl *D) {
1616  VisitNamedDecl(D);
1617  D->InstantiatedFrom = readDeclAs<NamedDecl>();
1618  auto **Expansions = D->getTrailingObjects<NamedDecl *>();
1619  for (unsigned I = 0; I != D->NumExpansions; ++I)
1620    Expansions[I] = readDeclAs<NamedDecl>();
1621  mergeMergeable(D);
1622}
1623
1624void ASTDeclReader::VisitUsingShadowDecl(UsingShadowDecl *D) {
1625  RedeclarableResult Redecl = VisitRedeclarable(D);
1626  VisitNamedDecl(D);
1627  D->Underlying = readDeclAs<NamedDecl>();
1628  D->IdentifierNamespace = Record.readInt();
1629  D->UsingOrNextShadow = readDeclAs<NamedDecl>();
1630  auto *Pattern = readDeclAs<UsingShadowDecl>();
1631  if (Pattern)
1632    Reader.getContext().setInstantiatedFromUsingShadowDecl(D, Pattern);
1633  mergeRedeclarable(D, Redecl);
1634}
1635
1636void ASTDeclReader::VisitConstructorUsingShadowDecl(
1637    ConstructorUsingShadowDecl *D) {
1638  VisitUsingShadowDecl(D);
1639  D->NominatedBaseClassShadowDecl = readDeclAs<ConstructorUsingShadowDecl>();
1640  D->ConstructedBaseClassShadowDecl = readDeclAs<ConstructorUsingShadowDecl>();
1641  D->IsVirtual = Record.readInt();
1642}
1643
1644void ASTDeclReader::VisitUsingDirectiveDecl(UsingDirectiveDecl *D) {
1645  VisitNamedDecl(D);
1646  D->UsingLoc = readSourceLocation();
1647  D->NamespaceLoc = readSourceLocation();
1648  D->QualifierLoc = Record.readNestedNameSpecifierLoc();
1649  D->NominatedNamespace = readDeclAs<NamedDecl>();
1650  D->CommonAncestor = readDeclAs<DeclContext>();
1651}
1652
1653void ASTDeclReader::VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D) {
1654  VisitValueDecl(D);
1655  D->setUsingLoc(readSourceLocation());
1656  D->QualifierLoc = Record.readNestedNameSpecifierLoc();
1657  D->DNLoc = Record.readDeclarationNameLoc(D->getDeclName());
1658  D->EllipsisLoc = readSourceLocation();
1659  mergeMergeable(D);
1660}
1661
1662void ASTDeclReader::VisitUnresolvedUsingTypenameDecl(
1663                                               UnresolvedUsingTypenameDecl *D) {
1664  VisitTypeDecl(D);
1665  D->TypenameLocation = readSourceLocation();
1666  D->QualifierLoc = Record.readNestedNameSpecifierLoc();
1667  D->EllipsisLoc = readSourceLocation();
1668  mergeMergeable(D);
1669}
1670
1671void ASTDeclReader::ReadCXXDefinitionData(
1672    struct CXXRecordDecl::DefinitionData &Data, const CXXRecordDecl *D) {
1673  #define FIELD(Name, Width, Merge) \
1674  Data.Name = Record.readInt();
1675  #include "clang/AST/CXXRecordDeclDefinitionBits.def"
1676
1677  // Note: the caller has deserialized the IsLambda bit already.
1678  Data.ODRHash = Record.readInt();
1679  Data.HasODRHash = true;
1680
1681  if (Record.readInt())
1682    Reader.DefinitionSource[D] = Loc.F->Kind == ModuleKind::MK_MainFile;
1683
1684  Data.NumBases = Record.readInt();
1685  if (Data.NumBases)
1686    Data.Bases = ReadGlobalOffset();
1687  Data.NumVBases = Record.readInt();
1688  if (Data.NumVBases)
1689    Data.VBases = ReadGlobalOffset();
1690
1691  Record.readUnresolvedSet(Data.Conversions);
1692  Data.ComputedVisibleConversions = Record.readInt();
1693  if (Data.ComputedVisibleConversions)
1694    Record.readUnresolvedSet(Data.VisibleConversions);
1695  assert(Data.Definition && "Data.Definition should be already set!");
1696  Data.FirstFriend = readDeclID();
1697
1698  if (Data.IsLambda) {
1699    using Capture = LambdaCapture;
1700
1701    auto &Lambda = static_cast<CXXRecordDecl::LambdaDefinitionData &>(Data);
1702    Lambda.Dependent = Record.readInt();
1703    Lambda.IsGenericLambda = Record.readInt();
1704    Lambda.CaptureDefault = Record.readInt();
1705    Lambda.NumCaptures = Record.readInt();
1706    Lambda.NumExplicitCaptures = Record.readInt();
1707    Lambda.HasKnownInternalLinkage = Record.readInt();
1708    Lambda.ManglingNumber = Record.readInt();
1709    Lambda.ContextDecl = readDeclID();
1710    Lambda.Captures = (Capture *)Reader.getContext().Allocate(
1711        sizeof(Capture) * Lambda.NumCaptures);
1712    Capture *ToCapture = Lambda.Captures;
1713    Lambda.MethodTyInfo = readTypeSourceInfo();
1714    for (unsigned I = 0, N = Lambda.NumCaptures; I != N; ++I) {
1715      SourceLocation Loc = readSourceLocation();
1716      bool IsImplicit = Record.readInt();
1717      auto Kind = static_cast<LambdaCaptureKind>(Record.readInt());
1718      switch (Kind) {
1719      case LCK_StarThis:
1720      case LCK_This:
1721      case LCK_VLAType:
1722        *ToCapture++ = Capture(Loc, IsImplicit, Kind, nullptr,SourceLocation());
1723        break;
1724      case LCK_ByCopy:
1725      case LCK_ByRef:
1726        auto *Var = readDeclAs<VarDecl>();
1727        SourceLocation EllipsisLoc = readSourceLocation();
1728        *ToCapture++ = Capture(Loc, IsImplicit, Kind, Var, EllipsisLoc);
1729        break;
1730      }
1731    }
1732  }
1733}
1734
1735void ASTDeclReader::MergeDefinitionData(
1736    CXXRecordDecl *D, struct CXXRecordDecl::DefinitionData &&MergeDD) {
1737  assert(D->DefinitionData &&
1738         "merging class definition into non-definition");
1739  auto &DD = *D->DefinitionData;
1740
1741  if (DD.Definition != MergeDD.Definition) {
1742    // Track that we merged the definitions.
1743    Reader.MergedDeclContexts.insert(std::make_pair(MergeDD.Definition,
1744                                                    DD.Definition));
1745    Reader.PendingDefinitions.erase(MergeDD.Definition);
1746    MergeDD.Definition->setCompleteDefinition(false);
1747    Reader.mergeDefinitionVisibility(DD.Definition, MergeDD.Definition);
1748    assert(Reader.Lookups.find(MergeDD.Definition) == Reader.Lookups.end() &&
1749           "already loaded pending lookups for merged definition");
1750  }
1751
1752  auto PFDI = Reader.PendingFakeDefinitionData.find(&DD);
1753  if (PFDI != Reader.PendingFakeDefinitionData.end() &&
1754      PFDI->second == ASTReader::PendingFakeDefinitionKind::Fake) {
1755    // We faked up this definition data because we found a class for which we'd
1756    // not yet loaded the definition. Replace it with the real thing now.
1757    assert(!DD.IsLambda && !MergeDD.IsLambda && "faked up lambda definition?");
1758    PFDI->second = ASTReader::PendingFakeDefinitionKind::FakeLoaded;
1759
1760    // Don't change which declaration is the definition; that is required
1761    // to be invariant once we select it.
1762    auto *Def = DD.Definition;
1763    DD = std::move(MergeDD);
1764    DD.Definition = Def;
1765    return;
1766  }
1767
1768  bool DetectedOdrViolation = false;
1769
1770  #define FIELD(Name, Width, Merge) Merge(Name)
1771  #define MERGE_OR(Field) DD.Field |= MergeDD.Field;
1772  #define NO_MERGE(Field) \
1773    DetectedOdrViolation |= DD.Field != MergeDD.Field; \
1774    MERGE_OR(Field)
1775  #include "clang/AST/CXXRecordDeclDefinitionBits.def"
1776  NO_MERGE(IsLambda)
1777  #undef NO_MERGE
1778  #undef MERGE_OR
1779
1780  if (DD.NumBases != MergeDD.NumBases || DD.NumVBases != MergeDD.NumVBases)
1781    DetectedOdrViolation = true;
1782  // FIXME: Issue a diagnostic if the base classes don't match when we come
1783  // to lazily load them.
1784
1785  // FIXME: Issue a diagnostic if the list of conversion functions doesn't
1786  // match when we come to lazily load them.
1787  if (MergeDD.ComputedVisibleConversions && !DD.ComputedVisibleConversions) {
1788    DD.VisibleConversions = std::move(MergeDD.VisibleConversions);
1789    DD.ComputedVisibleConversions = true;
1790  }
1791
1792  // FIXME: Issue a diagnostic if FirstFriend doesn't match when we come to
1793  // lazily load it.
1794
1795  if (DD.IsLambda) {
1796    // FIXME: ODR-checking for merging lambdas (this happens, for instance,
1797    // when they occur within the body of a function template specialization).
1798  }
1799
1800  if (D->getODRHash() != MergeDD.ODRHash) {
1801    DetectedOdrViolation = true;
1802  }
1803
1804  if (DetectedOdrViolation)
1805    Reader.PendingOdrMergeFailures[DD.Definition].push_back(
1806        {MergeDD.Definition, &MergeDD});
1807}
1808
1809void ASTDeclReader::ReadCXXRecordDefinition(CXXRecordDecl *D, bool Update) {
1810  struct CXXRecordDecl::DefinitionData *DD;
1811  ASTContext &C = Reader.getContext();
1812
1813  // Determine whether this is a lambda closure type, so that we can
1814  // allocate the appropriate DefinitionData structure.
1815  bool IsLambda = Record.readInt();
1816  if (IsLambda)
1817    DD = new (C) CXXRecordDecl::LambdaDefinitionData(D, nullptr, false, false,
1818                                                     LCD_None);
1819  else
1820    DD = new (C) struct CXXRecordDecl::DefinitionData(D);
1821
1822  CXXRecordDecl *Canon = D->getCanonicalDecl();
1823  // Set decl definition data before reading it, so that during deserialization
1824  // when we read CXXRecordDecl, it already has definition data and we don't
1825  // set fake one.
1826  if (!Canon->DefinitionData)
1827    Canon->DefinitionData = DD;
1828  D->DefinitionData = Canon->DefinitionData;
1829  ReadCXXDefinitionData(*DD, D);
1830
1831  // We might already have a different definition for this record. This can
1832  // happen either because we're reading an update record, or because we've
1833  // already done some merging. Either way, just merge into it.
1834  if (Canon->DefinitionData != DD) {
1835    MergeDefinitionData(Canon, std::move(*DD));
1836    return;
1837  }
1838
1839  // Mark this declaration as being a definition.
1840  D->setCompleteDefinition(true);
1841
1842  // If this is not the first declaration or is an update record, we can have
1843  // other redeclarations already. Make a note that we need to propagate the
1844  // DefinitionData pointer onto them.
1845  if (Update || Canon != D)
1846    Reader.PendingDefinitions.insert(D);
1847}
1848
1849ASTDeclReader::RedeclarableResult
1850ASTDeclReader::VisitCXXRecordDeclImpl(CXXRecordDecl *D) {
1851  RedeclarableResult Redecl = VisitRecordDeclImpl(D);
1852
1853  ASTContext &C = Reader.getContext();
1854
1855  enum CXXRecKind {
1856    CXXRecNotTemplate = 0, CXXRecTemplate, CXXRecMemberSpecialization
1857  };
1858  switch ((CXXRecKind)Record.readInt()) {
1859  case CXXRecNotTemplate:
1860    // Merged when we merge the folding set entry in the primary template.
1861    if (!isa<ClassTemplateSpecializationDecl>(D))
1862      mergeRedeclarable(D, Redecl);
1863    break;
1864  case CXXRecTemplate: {
1865    // Merged when we merge the template.
1866    auto *Template = readDeclAs<ClassTemplateDecl>();
1867    D->TemplateOrInstantiation = Template;
1868    if (!Template->getTemplatedDecl()) {
1869      // We've not actually loaded the ClassTemplateDecl yet, because we're
1870      // currently being loaded as its pattern. Rely on it to set up our
1871      // TypeForDecl (see VisitClassTemplateDecl).
1872      //
1873      // Beware: we do not yet know our canonical declaration, and may still
1874      // get merged once the surrounding class template has got off the ground.
1875      DeferredTypeID = 0;
1876    }
1877    break;
1878  }
1879  case CXXRecMemberSpecialization: {
1880    auto *RD = readDeclAs<CXXRecordDecl>();
1881    auto TSK = (TemplateSpecializationKind)Record.readInt();
1882    SourceLocation POI = readSourceLocation();
1883    MemberSpecializationInfo *MSI = new (C) MemberSpecializationInfo(RD, TSK);
1884    MSI->setPointOfInstantiation(POI);
1885    D->TemplateOrInstantiation = MSI;
1886    mergeRedeclarable(D, Redecl);
1887    break;
1888  }
1889  }
1890
1891  bool WasDefinition = Record.readInt();
1892  if (WasDefinition)
1893    ReadCXXRecordDefinition(D, /*Update*/false);
1894  else
1895    // Propagate DefinitionData pointer from the canonical declaration.
1896    D->DefinitionData = D->getCanonicalDecl()->DefinitionData;
1897
1898  // Lazily load the key function to avoid deserializing every method so we can
1899  // compute it.
1900  if (WasDefinition) {
1901    DeclID KeyFn = readDeclID();
1902    if (KeyFn && D->isCompleteDefinition())
1903      // FIXME: This is wrong for the ARM ABI, where some other module may have
1904      // made this function no longer be a key function. We need an update
1905      // record or similar for that case.
1906      C.KeyFunctions[D] = KeyFn;
1907  }
1908
1909  return Redecl;
1910}
1911
1912void ASTDeclReader::VisitCXXDeductionGuideDecl(CXXDeductionGuideDecl *D) {
1913  D->setExplicitSpecifier(Record.readExplicitSpec());
1914  VisitFunctionDecl(D);
1915  D->setIsCopyDeductionCandidate(Record.readInt());
1916}
1917
1918void ASTDeclReader::VisitCXXMethodDecl(CXXMethodDecl *D) {
1919  VisitFunctionDecl(D);
1920
1921  unsigned NumOverridenMethods = Record.readInt();
1922  if (D->isCanonicalDecl()) {
1923    while (NumOverridenMethods--) {
1924      // Avoid invariant checking of CXXMethodDecl::addOverriddenMethod,
1925      // MD may be initializing.
1926      if (auto *MD = readDeclAs<CXXMethodDecl>())
1927        Reader.getContext().addOverriddenMethod(D, MD->getCanonicalDecl());
1928    }
1929  } else {
1930    // We don't care about which declarations this used to override; we get
1931    // the relevant information from the canonical declaration.
1932    Record.skipInts(NumOverridenMethods);
1933  }
1934}
1935
1936void ASTDeclReader::VisitCXXConstructorDecl(CXXConstructorDecl *D) {
1937  // We need the inherited constructor information to merge the declaration,
1938  // so we have to read it before we call VisitCXXMethodDecl.
1939  D->setExplicitSpecifier(Record.readExplicitSpec());
1940  if (D->isInheritingConstructor()) {
1941    auto *Shadow = readDeclAs<ConstructorUsingShadowDecl>();
1942    auto *Ctor = readDeclAs<CXXConstructorDecl>();
1943    *D->getTrailingObjects<InheritedConstructor>() =
1944        InheritedConstructor(Shadow, Ctor);
1945  }
1946
1947  VisitCXXMethodDecl(D);
1948}
1949
1950void ASTDeclReader::VisitCXXDestructorDecl(CXXDestructorDecl *D) {
1951  VisitCXXMethodDecl(D);
1952
1953  if (auto *OperatorDelete = readDeclAs<FunctionDecl>()) {
1954    CXXDestructorDecl *Canon = D->getCanonicalDecl();
1955    auto *ThisArg = Record.readExpr();
1956    // FIXME: Check consistency if we have an old and new operator delete.
1957    if (!Canon->OperatorDelete) {
1958      Canon->OperatorDelete = OperatorDelete;
1959      Canon->OperatorDeleteThisArg = ThisArg;
1960    }
1961  }
1962}
1963
1964void ASTDeclReader::VisitCXXConversionDecl(CXXConversionDecl *D) {
1965  D->setExplicitSpecifier(Record.readExplicitSpec());
1966  VisitCXXMethodDecl(D);
1967}
1968
1969void ASTDeclReader::VisitImportDecl(ImportDecl *D) {
1970  VisitDecl(D);
1971  D->ImportedAndComplete.setPointer(readModule());
1972  D->ImportedAndComplete.setInt(Record.readInt());
1973  auto *StoredLocs = D->getTrailingObjects<SourceLocation>();
1974  for (unsigned I = 0, N = Record.back(); I != N; ++I)
1975    StoredLocs[I] = readSourceLocation();
1976  Record.skipInts(1); // The number of stored source locations.
1977}
1978
1979void ASTDeclReader::VisitAccessSpecDecl(AccessSpecDecl *D) {
1980  VisitDecl(D);
1981  D->setColonLoc(readSourceLocation());
1982}
1983
1984void ASTDeclReader::VisitFriendDecl(FriendDecl *D) {
1985  VisitDecl(D);
1986  if (Record.readInt()) // hasFriendDecl
1987    D->Friend = readDeclAs<NamedDecl>();
1988  else
1989    D->Friend = readTypeSourceInfo();
1990  for (unsigned i = 0; i != D->NumTPLists; ++i)
1991    D->getTrailingObjects<TemplateParameterList *>()[i] =
1992        Record.readTemplateParameterList();
1993  D->NextFriend = readDeclID();
1994  D->UnsupportedFriend = (Record.readInt() != 0);
1995  D->FriendLoc = readSourceLocation();
1996}
1997
1998void ASTDeclReader::VisitFriendTemplateDecl(FriendTemplateDecl *D) {
1999  VisitDecl(D);
2000  unsigned NumParams = Record.readInt();
2001  D->NumParams = NumParams;
2002  D->Params = new TemplateParameterList*[NumParams];
2003  for (unsigned i = 0; i != NumParams; ++i)
2004    D->Params[i] = Record.readTemplateParameterList();
2005  if (Record.readInt()) // HasFriendDecl
2006    D->Friend = readDeclAs<NamedDecl>();
2007  else
2008    D->Friend = readTypeSourceInfo();
2009  D->FriendLoc = readSourceLocation();
2010}
2011
2012DeclID ASTDeclReader::VisitTemplateDecl(TemplateDecl *D) {
2013  VisitNamedDecl(D);
2014
2015  DeclID PatternID = readDeclID();
2016  auto *TemplatedDecl = cast_or_null<NamedDecl>(Reader.GetDecl(PatternID));
2017  TemplateParameterList *TemplateParams = Record.readTemplateParameterList();
2018  D->init(TemplatedDecl, TemplateParams);
2019
2020  return PatternID;
2021}
2022
2023void ASTDeclReader::VisitConceptDecl(ConceptDecl *D) {
2024  VisitTemplateDecl(D);
2025  D->ConstraintExpr = Record.readExpr();
2026  mergeMergeable(D);
2027}
2028
2029void ASTDeclReader::VisitRequiresExprBodyDecl(RequiresExprBodyDecl *D) {
2030}
2031
2032ASTDeclReader::RedeclarableResult
2033ASTDeclReader::VisitRedeclarableTemplateDecl(RedeclarableTemplateDecl *D) {
2034  RedeclarableResult Redecl = VisitRedeclarable(D);
2035
2036  // Make sure we've allocated the Common pointer first. We do this before
2037  // VisitTemplateDecl so that getCommonPtr() can be used during initialization.
2038  RedeclarableTemplateDecl *CanonD = D->getCanonicalDecl();
2039  if (!CanonD->Common) {
2040    CanonD->Common = CanonD->newCommon(Reader.getContext());
2041    Reader.PendingDefinitions.insert(CanonD);
2042  }
2043  D->Common = CanonD->Common;
2044
2045  // If this is the first declaration of the template, fill in the information
2046  // for the 'common' pointer.
2047  if (ThisDeclID == Redecl.getFirstID()) {
2048    if (auto *RTD = readDeclAs<RedeclarableTemplateDecl>()) {
2049      assert(RTD->getKind() == D->getKind() &&
2050             "InstantiatedFromMemberTemplate kind mismatch");
2051      D->setInstantiatedFromMemberTemplate(RTD);
2052      if (Record.readInt())
2053        D->setMemberSpecialization();
2054    }
2055  }
2056
2057  DeclID PatternID = VisitTemplateDecl(D);
2058  D->IdentifierNamespace = Record.readInt();
2059
2060  mergeRedeclarable(D, Redecl, PatternID);
2061
2062  // If we merged the template with a prior declaration chain, merge the common
2063  // pointer.
2064  // FIXME: Actually merge here, don't just overwrite.
2065  D->Common = D->getCanonicalDecl()->Common;
2066
2067  return Redecl;
2068}
2069
2070void ASTDeclReader::VisitClassTemplateDecl(ClassTemplateDecl *D) {
2071  RedeclarableResult Redecl = VisitRedeclarableTemplateDecl(D);
2072
2073  if (ThisDeclID == Redecl.getFirstID()) {
2074    // This ClassTemplateDecl owns a CommonPtr; read it to keep track of all of
2075    // the specializations.
2076    SmallVector<serialization::DeclID, 32> SpecIDs;
2077    readDeclIDList(SpecIDs);
2078    ASTDeclReader::AddLazySpecializations(D, SpecIDs);
2079  }
2080
2081  if (D->getTemplatedDecl()->TemplateOrInstantiation) {
2082    // We were loaded before our templated declaration was. We've not set up
2083    // its corresponding type yet (see VisitCXXRecordDeclImpl), so reconstruct
2084    // it now.
2085    Reader.getContext().getInjectedClassNameType(
2086        D->getTemplatedDecl(), D->getInjectedClassNameSpecialization());
2087  }
2088}
2089
2090void ASTDeclReader::VisitBuiltinTemplateDecl(BuiltinTemplateDecl *D) {
2091  llvm_unreachable("BuiltinTemplates are not serialized");
2092}
2093
2094/// TODO: Unify with ClassTemplateDecl version?
2095///       May require unifying ClassTemplateDecl and
2096///        VarTemplateDecl beyond TemplateDecl...
2097void ASTDeclReader::VisitVarTemplateDecl(VarTemplateDecl *D) {
2098  RedeclarableResult Redecl = VisitRedeclarableTemplateDecl(D);
2099
2100  if (ThisDeclID == Redecl.getFirstID()) {
2101    // This VarTemplateDecl owns a CommonPtr; read it to keep track of all of
2102    // the specializations.
2103    SmallVector<serialization::DeclID, 32> SpecIDs;
2104    readDeclIDList(SpecIDs);
2105    ASTDeclReader::AddLazySpecializations(D, SpecIDs);
2106  }
2107}
2108
2109ASTDeclReader::RedeclarableResult
2110ASTDeclReader::VisitClassTemplateSpecializationDeclImpl(
2111    ClassTemplateSpecializationDecl *D) {
2112  RedeclarableResult Redecl = VisitCXXRecordDeclImpl(D);
2113
2114  ASTContext &C = Reader.getContext();
2115  if (Decl *InstD = readDecl()) {
2116    if (auto *CTD = dyn_cast<ClassTemplateDecl>(InstD)) {
2117      D->SpecializedTemplate = CTD;
2118    } else {
2119      SmallVector<TemplateArgument, 8> TemplArgs;
2120      Record.readTemplateArgumentList(TemplArgs);
2121      TemplateArgumentList *ArgList
2122        = TemplateArgumentList::CreateCopy(C, TemplArgs);
2123      auto *PS =
2124          new (C) ClassTemplateSpecializationDecl::
2125                                             SpecializedPartialSpecialization();
2126      PS->PartialSpecialization
2127          = cast<ClassTemplatePartialSpecializationDecl>(InstD);
2128      PS->TemplateArgs = ArgList;
2129      D->SpecializedTemplate = PS;
2130    }
2131  }
2132
2133  SmallVector<TemplateArgument, 8> TemplArgs;
2134  Record.readTemplateArgumentList(TemplArgs, /*Canonicalize*/ true);
2135  D->TemplateArgs = TemplateArgumentList::CreateCopy(C, TemplArgs);
2136  D->PointOfInstantiation = readSourceLocation();
2137  D->SpecializationKind = (TemplateSpecializationKind)Record.readInt();
2138
2139  bool writtenAsCanonicalDecl = Record.readInt();
2140  if (writtenAsCanonicalDecl) {
2141    auto *CanonPattern = readDeclAs<ClassTemplateDecl>();
2142    if (D->isCanonicalDecl()) { // It's kept in the folding set.
2143      // Set this as, or find, the canonical declaration for this specialization
2144      ClassTemplateSpecializationDecl *CanonSpec;
2145      if (auto *Partial = dyn_cast<ClassTemplatePartialSpecializationDecl>(D)) {
2146        CanonSpec = CanonPattern->getCommonPtr()->PartialSpecializations
2147            .GetOrInsertNode(Partial);
2148      } else {
2149        CanonSpec =
2150            CanonPattern->getCommonPtr()->Specializations.GetOrInsertNode(D);
2151      }
2152      // If there was already a canonical specialization, merge into it.
2153      if (CanonSpec != D) {
2154        mergeRedeclarable<TagDecl>(D, CanonSpec, Redecl);
2155
2156        // This declaration might be a definition. Merge with any existing
2157        // definition.
2158        if (auto *DDD = D->DefinitionData) {
2159          if (CanonSpec->DefinitionData)
2160            MergeDefinitionData(CanonSpec, std::move(*DDD));
2161          else
2162            CanonSpec->DefinitionData = D->DefinitionData;
2163        }
2164        D->DefinitionData = CanonSpec->DefinitionData;
2165      }
2166    }
2167  }
2168
2169  // Explicit info.
2170  if (TypeSourceInfo *TyInfo = readTypeSourceInfo()) {
2171    auto *ExplicitInfo =
2172        new (C) ClassTemplateSpecializationDecl::ExplicitSpecializationInfo;
2173    ExplicitInfo->TypeAsWritten = TyInfo;
2174    ExplicitInfo->ExternLoc = readSourceLocation();
2175    ExplicitInfo->TemplateKeywordLoc = readSourceLocation();
2176    D->ExplicitInfo = ExplicitInfo;
2177  }
2178
2179  return Redecl;
2180}
2181
2182void ASTDeclReader::VisitClassTemplatePartialSpecializationDecl(
2183                                    ClassTemplatePartialSpecializationDecl *D) {
2184  // We need to read the template params first because redeclarable is going to
2185  // need them for profiling
2186  TemplateParameterList *Params = Record.readTemplateParameterList();
2187  D->TemplateParams = Params;
2188  D->ArgsAsWritten = Record.readASTTemplateArgumentListInfo();
2189
2190  RedeclarableResult Redecl = VisitClassTemplateSpecializationDeclImpl(D);
2191
2192  // These are read/set from/to the first declaration.
2193  if (ThisDeclID == Redecl.getFirstID()) {
2194    D->InstantiatedFromMember.setPointer(
2195      readDeclAs<ClassTemplatePartialSpecializationDecl>());
2196    D->InstantiatedFromMember.setInt(Record.readInt());
2197  }
2198}
2199
2200void ASTDeclReader::VisitClassScopeFunctionSpecializationDecl(
2201                                    ClassScopeFunctionSpecializationDecl *D) {
2202  VisitDecl(D);
2203  D->Specialization = readDeclAs<CXXMethodDecl>();
2204  if (Record.readInt())
2205    D->TemplateArgs = Record.readASTTemplateArgumentListInfo();
2206}
2207
2208void ASTDeclReader::VisitFunctionTemplateDecl(FunctionTemplateDecl *D) {
2209  RedeclarableResult Redecl = VisitRedeclarableTemplateDecl(D);
2210
2211  if (ThisDeclID == Redecl.getFirstID()) {
2212    // This FunctionTemplateDecl owns a CommonPtr; read it.
2213    SmallVector<serialization::DeclID, 32> SpecIDs;
2214    readDeclIDList(SpecIDs);
2215    ASTDeclReader::AddLazySpecializations(D, SpecIDs);
2216  }
2217}
2218
2219/// TODO: Unify with ClassTemplateSpecializationDecl version?
2220///       May require unifying ClassTemplate(Partial)SpecializationDecl and
2221///        VarTemplate(Partial)SpecializationDecl with a new data
2222///        structure Template(Partial)SpecializationDecl, and
2223///        using Template(Partial)SpecializationDecl as input type.
2224ASTDeclReader::RedeclarableResult
2225ASTDeclReader::VisitVarTemplateSpecializationDeclImpl(
2226    VarTemplateSpecializationDecl *D) {
2227  RedeclarableResult Redecl = VisitVarDeclImpl(D);
2228
2229  ASTContext &C = Reader.getContext();
2230  if (Decl *InstD = readDecl()) {
2231    if (auto *VTD = dyn_cast<VarTemplateDecl>(InstD)) {
2232      D->SpecializedTemplate = VTD;
2233    } else {
2234      SmallVector<TemplateArgument, 8> TemplArgs;
2235      Record.readTemplateArgumentList(TemplArgs);
2236      TemplateArgumentList *ArgList = TemplateArgumentList::CreateCopy(
2237          C, TemplArgs);
2238      auto *PS =
2239          new (C)
2240          VarTemplateSpecializationDecl::SpecializedPartialSpecialization();
2241      PS->PartialSpecialization =
2242          cast<VarTemplatePartialSpecializationDecl>(InstD);
2243      PS->TemplateArgs = ArgList;
2244      D->SpecializedTemplate = PS;
2245    }
2246  }
2247
2248  // Explicit info.
2249  if (TypeSourceInfo *TyInfo = readTypeSourceInfo()) {
2250    auto *ExplicitInfo =
2251        new (C) VarTemplateSpecializationDecl::ExplicitSpecializationInfo;
2252    ExplicitInfo->TypeAsWritten = TyInfo;
2253    ExplicitInfo->ExternLoc = readSourceLocation();
2254    ExplicitInfo->TemplateKeywordLoc = readSourceLocation();
2255    D->ExplicitInfo = ExplicitInfo;
2256  }
2257
2258  SmallVector<TemplateArgument, 8> TemplArgs;
2259  Record.readTemplateArgumentList(TemplArgs, /*Canonicalize*/ true);
2260  D->TemplateArgs = TemplateArgumentList::CreateCopy(C, TemplArgs);
2261  D->PointOfInstantiation = readSourceLocation();
2262  D->SpecializationKind = (TemplateSpecializationKind)Record.readInt();
2263  D->IsCompleteDefinition = Record.readInt();
2264
2265  bool writtenAsCanonicalDecl = Record.readInt();
2266  if (writtenAsCanonicalDecl) {
2267    auto *CanonPattern = readDeclAs<VarTemplateDecl>();
2268    if (D->isCanonicalDecl()) { // It's kept in the folding set.
2269      // FIXME: If it's already present, merge it.
2270      if (auto *Partial = dyn_cast<VarTemplatePartialSpecializationDecl>(D)) {
2271        CanonPattern->getCommonPtr()->PartialSpecializations
2272            .GetOrInsertNode(Partial);
2273      } else {
2274        CanonPattern->getCommonPtr()->Specializations.GetOrInsertNode(D);
2275      }
2276    }
2277  }
2278
2279  return Redecl;
2280}
2281
2282/// TODO: Unify with ClassTemplatePartialSpecializationDecl version?
2283///       May require unifying ClassTemplate(Partial)SpecializationDecl and
2284///        VarTemplate(Partial)SpecializationDecl with a new data
2285///        structure Template(Partial)SpecializationDecl, and
2286///        using Template(Partial)SpecializationDecl as input type.
2287void ASTDeclReader::VisitVarTemplatePartialSpecializationDecl(
2288    VarTemplatePartialSpecializationDecl *D) {
2289  TemplateParameterList *Params = Record.readTemplateParameterList();
2290  D->TemplateParams = Params;
2291  D->ArgsAsWritten = Record.readASTTemplateArgumentListInfo();
2292
2293  RedeclarableResult Redecl = VisitVarTemplateSpecializationDeclImpl(D);
2294
2295  // These are read/set from/to the first declaration.
2296  if (ThisDeclID == Redecl.getFirstID()) {
2297    D->InstantiatedFromMember.setPointer(
2298        readDeclAs<VarTemplatePartialSpecializationDecl>());
2299    D->InstantiatedFromMember.setInt(Record.readInt());
2300  }
2301}
2302
2303void ASTDeclReader::VisitTemplateTypeParmDecl(TemplateTypeParmDecl *D) {
2304  VisitTypeDecl(D);
2305
2306  D->setDeclaredWithTypename(Record.readInt());
2307
2308  if (Record.readBool()) {
2309    NestedNameSpecifierLoc NNS = Record.readNestedNameSpecifierLoc();
2310    DeclarationNameInfo DN = Record.readDeclarationNameInfo();
2311    ConceptDecl *NamedConcept = Record.readDeclAs<ConceptDecl>();
2312    const ASTTemplateArgumentListInfo *ArgsAsWritten = nullptr;
2313    if (Record.readBool())
2314        ArgsAsWritten = Record.readASTTemplateArgumentListInfo();
2315    Expr *ImmediatelyDeclaredConstraint = Record.readExpr();
2316    D->setTypeConstraint(NNS, DN, /*FoundDecl=*/nullptr, NamedConcept,
2317                         ArgsAsWritten, ImmediatelyDeclaredConstraint);
2318    if ((D->ExpandedParameterPack = Record.readInt()))
2319      D->NumExpanded = Record.readInt();
2320  }
2321
2322  if (Record.readInt())
2323    D->setDefaultArgument(readTypeSourceInfo());
2324}
2325
2326void ASTDeclReader::VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D) {
2327  VisitDeclaratorDecl(D);
2328  // TemplateParmPosition.
2329  D->setDepth(Record.readInt());
2330  D->setPosition(Record.readInt());
2331  if (D->hasPlaceholderTypeConstraint())
2332    D->setPlaceholderTypeConstraint(Record.readExpr());
2333  if (D->isExpandedParameterPack()) {
2334    auto TypesAndInfos =
2335        D->getTrailingObjects<std::pair<QualType, TypeSourceInfo *>>();
2336    for (unsigned I = 0, N = D->getNumExpansionTypes(); I != N; ++I) {
2337      new (&TypesAndInfos[I].first) QualType(Record.readType());
2338      TypesAndInfos[I].second = readTypeSourceInfo();
2339    }
2340  } else {
2341    // Rest of NonTypeTemplateParmDecl.
2342    D->ParameterPack = Record.readInt();
2343    if (Record.readInt())
2344      D->setDefaultArgument(Record.readExpr());
2345  }
2346}
2347
2348void ASTDeclReader::VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D) {
2349  VisitTemplateDecl(D);
2350  // TemplateParmPosition.
2351  D->setDepth(Record.readInt());
2352  D->setPosition(Record.readInt());
2353  if (D->isExpandedParameterPack()) {
2354    auto **Data = D->getTrailingObjects<TemplateParameterList *>();
2355    for (unsigned I = 0, N = D->getNumExpansionTemplateParameters();
2356         I != N; ++I)
2357      Data[I] = Record.readTemplateParameterList();
2358  } else {
2359    // Rest of TemplateTemplateParmDecl.
2360    D->ParameterPack = Record.readInt();
2361    if (Record.readInt())
2362      D->setDefaultArgument(Reader.getContext(),
2363                            Record.readTemplateArgumentLoc());
2364  }
2365}
2366
2367void ASTDeclReader::VisitTypeAliasTemplateDecl(TypeAliasTemplateDecl *D) {
2368  VisitRedeclarableTemplateDecl(D);
2369}
2370
2371void ASTDeclReader::VisitStaticAssertDecl(StaticAssertDecl *D) {
2372  VisitDecl(D);
2373  D->AssertExprAndFailed.setPointer(Record.readExpr());
2374  D->AssertExprAndFailed.setInt(Record.readInt());
2375  D->Message = cast_or_null<StringLiteral>(Record.readExpr());
2376  D->RParenLoc = readSourceLocation();
2377}
2378
2379void ASTDeclReader::VisitEmptyDecl(EmptyDecl *D) {
2380  VisitDecl(D);
2381}
2382
2383void ASTDeclReader::VisitLifetimeExtendedTemporaryDecl(
2384    LifetimeExtendedTemporaryDecl *D) {
2385  VisitDecl(D);
2386  D->ExtendingDecl = readDeclAs<ValueDecl>();
2387  D->ExprWithTemporary = Record.readStmt();
2388  if (Record.readInt())
2389    D->Value = new (D->getASTContext()) APValue(Record.readAPValue());
2390  D->ManglingNumber = Record.readInt();
2391  mergeMergeable(D);
2392}
2393
2394std::pair<uint64_t, uint64_t>
2395ASTDeclReader::VisitDeclContext(DeclContext *DC) {
2396  uint64_t LexicalOffset = ReadLocalOffset();
2397  uint64_t VisibleOffset = ReadLocalOffset();
2398  return std::make_pair(LexicalOffset, VisibleOffset);
2399}
2400
2401template <typename T>
2402ASTDeclReader::RedeclarableResult
2403ASTDeclReader::VisitRedeclarable(Redeclarable<T> *D) {
2404  DeclID FirstDeclID = readDeclID();
2405  Decl *MergeWith = nullptr;
2406
2407  bool IsKeyDecl = ThisDeclID == FirstDeclID;
2408  bool IsFirstLocalDecl = false;
2409
2410  uint64_t RedeclOffset = 0;
2411
2412  // 0 indicates that this declaration was the only declaration of its entity,
2413  // and is used for space optimization.
2414  if (FirstDeclID == 0) {
2415    FirstDeclID = ThisDeclID;
2416    IsKeyDecl = true;
2417    IsFirstLocalDecl = true;
2418  } else if (unsigned N = Record.readInt()) {
2419    // This declaration was the first local declaration, but may have imported
2420    // other declarations.
2421    IsKeyDecl = N == 1;
2422    IsFirstLocalDecl = true;
2423
2424    // We have some declarations that must be before us in our redeclaration
2425    // chain. Read them now, and remember that we ought to merge with one of
2426    // them.
2427    // FIXME: Provide a known merge target to the second and subsequent such
2428    // declaration.
2429    for (unsigned I = 0; I != N - 1; ++I)
2430      MergeWith = readDecl();
2431
2432    RedeclOffset = ReadLocalOffset();
2433  } else {
2434    // This declaration was not the first local declaration. Read the first
2435    // local declaration now, to trigger the import of other redeclarations.
2436    (void)readDecl();
2437  }
2438
2439  auto *FirstDecl = cast_or_null<T>(Reader.GetDecl(FirstDeclID));
2440  if (FirstDecl != D) {
2441    // We delay loading of the redeclaration chain to avoid deeply nested calls.
2442    // We temporarily set the first (canonical) declaration as the previous one
2443    // which is the one that matters and mark the real previous DeclID to be
2444    // loaded & attached later on.
2445    D->RedeclLink = Redeclarable<T>::PreviousDeclLink(FirstDecl);
2446    D->First = FirstDecl->getCanonicalDecl();
2447  }
2448
2449  auto *DAsT = static_cast<T *>(D);
2450
2451  // Note that we need to load local redeclarations of this decl and build a
2452  // decl chain for them. This must happen *after* we perform the preloading
2453  // above; this ensures that the redeclaration chain is built in the correct
2454  // order.
2455  if (IsFirstLocalDecl)
2456    Reader.PendingDeclChains.push_back(std::make_pair(DAsT, RedeclOffset));
2457
2458  return RedeclarableResult(MergeWith, FirstDeclID, IsKeyDecl);
2459}
2460
2461/// Attempts to merge the given declaration (D) with another declaration
2462/// of the same entity.
2463template<typename T>
2464void ASTDeclReader::mergeRedeclarable(Redeclarable<T> *DBase,
2465                                      RedeclarableResult &Redecl,
2466                                      DeclID TemplatePatternID) {
2467  // If modules are not available, there is no reason to perform this merge.
2468  if (!Reader.getContext().getLangOpts().Modules)
2469    return;
2470
2471  // If we're not the canonical declaration, we don't need to merge.
2472  if (!DBase->isFirstDecl())
2473    return;
2474
2475  auto *D = static_cast<T *>(DBase);
2476
2477  if (auto *Existing = Redecl.getKnownMergeTarget())
2478    // We already know of an existing declaration we should merge with.
2479    mergeRedeclarable(D, cast<T>(Existing), Redecl, TemplatePatternID);
2480  else if (FindExistingResult ExistingRes = findExisting(D))
2481    if (T *Existing = ExistingRes)
2482      mergeRedeclarable(D, Existing, Redecl, TemplatePatternID);
2483}
2484
2485/// "Cast" to type T, asserting if we don't have an implicit conversion.
2486/// We use this to put code in a template that will only be valid for certain
2487/// instantiations.
2488template<typename T> static T assert_cast(T t) { return t; }
2489template<typename T> static T assert_cast(...) {
2490  llvm_unreachable("bad assert_cast");
2491}
2492
2493/// Merge together the pattern declarations from two template
2494/// declarations.
2495void ASTDeclReader::mergeTemplatePattern(RedeclarableTemplateDecl *D,
2496                                         RedeclarableTemplateDecl *Existing,
2497                                         DeclID DsID, bool IsKeyDecl) {
2498  auto *DPattern = D->getTemplatedDecl();
2499  auto *ExistingPattern = Existing->getTemplatedDecl();
2500  RedeclarableResult Result(/*MergeWith*/ ExistingPattern,
2501                            DPattern->getCanonicalDecl()->getGlobalID(),
2502                            IsKeyDecl);
2503
2504  if (auto *DClass = dyn_cast<CXXRecordDecl>(DPattern)) {
2505    // Merge with any existing definition.
2506    // FIXME: This is duplicated in several places. Refactor.
2507    auto *ExistingClass =
2508        cast<CXXRecordDecl>(ExistingPattern)->getCanonicalDecl();
2509    if (auto *DDD = DClass->DefinitionData) {
2510      if (ExistingClass->DefinitionData) {
2511        MergeDefinitionData(ExistingClass, std::move(*DDD));
2512      } else {
2513        ExistingClass->DefinitionData = DClass->DefinitionData;
2514        // We may have skipped this before because we thought that DClass
2515        // was the canonical declaration.
2516        Reader.PendingDefinitions.insert(DClass);
2517      }
2518    }
2519    DClass->DefinitionData = ExistingClass->DefinitionData;
2520
2521    return mergeRedeclarable(DClass, cast<TagDecl>(ExistingPattern),
2522                             Result);
2523  }
2524  if (auto *DFunction = dyn_cast<FunctionDecl>(DPattern))
2525    return mergeRedeclarable(DFunction, cast<FunctionDecl>(ExistingPattern),
2526                             Result);
2527  if (auto *DVar = dyn_cast<VarDecl>(DPattern))
2528    return mergeRedeclarable(DVar, cast<VarDecl>(ExistingPattern), Result);
2529  if (auto *DAlias = dyn_cast<TypeAliasDecl>(DPattern))
2530    return mergeRedeclarable(DAlias, cast<TypedefNameDecl>(ExistingPattern),
2531                             Result);
2532  llvm_unreachable("merged an unknown kind of redeclarable template");
2533}
2534
2535/// Attempts to merge the given declaration (D) with another declaration
2536/// of the same entity.
2537template<typename T>
2538void ASTDeclReader::mergeRedeclarable(Redeclarable<T> *DBase, T *Existing,
2539                                      RedeclarableResult &Redecl,
2540                                      DeclID TemplatePatternID) {
2541  auto *D = static_cast<T *>(DBase);
2542  T *ExistingCanon = Existing->getCanonicalDecl();
2543  T *DCanon = D->getCanonicalDecl();
2544  if (ExistingCanon != DCanon) {
2545    assert(DCanon->getGlobalID() == Redecl.getFirstID() &&
2546           "already merged this declaration");
2547
2548    // Have our redeclaration link point back at the canonical declaration
2549    // of the existing declaration, so that this declaration has the
2550    // appropriate canonical declaration.
2551    D->RedeclLink = Redeclarable<T>::PreviousDeclLink(ExistingCanon);
2552    D->First = ExistingCanon;
2553    ExistingCanon->Used |= D->Used;
2554    D->Used = false;
2555
2556    // When we merge a namespace, update its pointer to the first namespace.
2557    // We cannot have loaded any redeclarations of this declaration yet, so
2558    // there's nothing else that needs to be updated.
2559    if (auto *Namespace = dyn_cast<NamespaceDecl>(D))
2560      Namespace->AnonOrFirstNamespaceAndInline.setPointer(
2561          assert_cast<NamespaceDecl*>(ExistingCanon));
2562
2563    // When we merge a template, merge its pattern.
2564    if (auto *DTemplate = dyn_cast<RedeclarableTemplateDecl>(D))
2565      mergeTemplatePattern(
2566          DTemplate, assert_cast<RedeclarableTemplateDecl*>(ExistingCanon),
2567          TemplatePatternID, Redecl.isKeyDecl());
2568
2569    // If this declaration is a key declaration, make a note of that.
2570    if (Redecl.isKeyDecl())
2571      Reader.KeyDecls[ExistingCanon].push_back(Redecl.getFirstID());
2572  }
2573}
2574
2575/// ODR-like semantics for C/ObjC allow us to merge tag types and a structural
2576/// check in Sema guarantees the types can be merged (see C11 6.2.7/1 or C89
2577/// 6.1.2.6/1). Although most merging is done in Sema, we need to guarantee
2578/// that some types are mergeable during deserialization, otherwise name
2579/// lookup fails. This is the case for EnumConstantDecl.
2580static bool allowODRLikeMergeInC(NamedDecl *ND) {
2581  if (!ND)
2582    return false;
2583  // TODO: implement merge for other necessary decls.
2584  if (isa<EnumConstantDecl>(ND))
2585    return true;
2586  return false;
2587}
2588
2589/// Attempts to merge LifetimeExtendedTemporaryDecl with
2590/// identical class definitions from two different modules.
2591void ASTDeclReader::mergeMergeable(LifetimeExtendedTemporaryDecl *D) {
2592  // If modules are not available, there is no reason to perform this merge.
2593  if (!Reader.getContext().getLangOpts().Modules)
2594    return;
2595
2596  LifetimeExtendedTemporaryDecl *LETDecl = D;
2597
2598  LifetimeExtendedTemporaryDecl *&LookupResult =
2599      Reader.LETemporaryForMerging[std::make_pair(
2600          LETDecl->getExtendingDecl(), LETDecl->getManglingNumber())];
2601  if (LookupResult)
2602    Reader.getContext().setPrimaryMergedDecl(LETDecl,
2603                                             LookupResult->getCanonicalDecl());
2604  else
2605    LookupResult = LETDecl;
2606}
2607
2608/// Attempts to merge the given declaration (D) with another declaration
2609/// of the same entity, for the case where the entity is not actually
2610/// redeclarable. This happens, for instance, when merging the fields of
2611/// identical class definitions from two different modules.
2612template<typename T>
2613void ASTDeclReader::mergeMergeable(Mergeable<T> *D) {
2614  // If modules are not available, there is no reason to perform this merge.
2615  if (!Reader.getContext().getLangOpts().Modules)
2616    return;
2617
2618  // ODR-based merging is performed in C++ and in some cases (tag types) in C.
2619  // Note that C identically-named things in different translation units are
2620  // not redeclarations, but may still have compatible types, where ODR-like
2621  // semantics may apply.
2622  if (!Reader.getContext().getLangOpts().CPlusPlus &&
2623      !allowODRLikeMergeInC(dyn_cast<NamedDecl>(static_cast<T*>(D))))
2624    return;
2625
2626  if (FindExistingResult ExistingRes = findExisting(static_cast<T*>(D)))
2627    if (T *Existing = ExistingRes)
2628      Reader.getContext().setPrimaryMergedDecl(static_cast<T *>(D),
2629                                               Existing->getCanonicalDecl());
2630}
2631
2632void ASTDeclReader::VisitOMPThreadPrivateDecl(OMPThreadPrivateDecl *D) {
2633  VisitDecl(D);
2634  unsigned NumVars = D->varlist_size();
2635  SmallVector<Expr *, 16> Vars;
2636  Vars.reserve(NumVars);
2637  for (unsigned i = 0; i != NumVars; ++i) {
2638    Vars.push_back(Record.readExpr());
2639  }
2640  D->setVars(Vars);
2641}
2642
2643void ASTDeclReader::VisitOMPAllocateDecl(OMPAllocateDecl *D) {
2644  VisitDecl(D);
2645  unsigned NumVars = D->varlist_size();
2646  unsigned NumClauses = D->clauselist_size();
2647  SmallVector<Expr *, 16> Vars;
2648  Vars.reserve(NumVars);
2649  for (unsigned i = 0; i != NumVars; ++i) {
2650    Vars.push_back(Record.readExpr());
2651  }
2652  D->setVars(Vars);
2653  SmallVector<OMPClause *, 8> Clauses;
2654  Clauses.reserve(NumClauses);
2655  for (unsigned I = 0; I != NumClauses; ++I)
2656    Clauses.push_back(Record.readOMPClause());
2657  D->setClauses(Clauses);
2658}
2659
2660void ASTDeclReader::VisitOMPRequiresDecl(OMPRequiresDecl * D) {
2661  VisitDecl(D);
2662  unsigned NumClauses = D->clauselist_size();
2663  SmallVector<OMPClause *, 8> Clauses;
2664  Clauses.reserve(NumClauses);
2665  for (unsigned I = 0; I != NumClauses; ++I)
2666    Clauses.push_back(Record.readOMPClause());
2667  D->setClauses(Clauses);
2668}
2669
2670void ASTDeclReader::VisitOMPDeclareReductionDecl(OMPDeclareReductionDecl *D) {
2671  VisitValueDecl(D);
2672  D->setLocation(readSourceLocation());
2673  Expr *In = Record.readExpr();
2674  Expr *Out = Record.readExpr();
2675  D->setCombinerData(In, Out);
2676  Expr *Combiner = Record.readExpr();
2677  D->setCombiner(Combiner);
2678  Expr *Orig = Record.readExpr();
2679  Expr *Priv = Record.readExpr();
2680  D->setInitializerData(Orig, Priv);
2681  Expr *Init = Record.readExpr();
2682  auto IK = static_cast<OMPDeclareReductionDecl::InitKind>(Record.readInt());
2683  D->setInitializer(Init, IK);
2684  D->PrevDeclInScope = readDeclID();
2685}
2686
2687void ASTDeclReader::VisitOMPDeclareMapperDecl(OMPDeclareMapperDecl *D) {
2688  VisitValueDecl(D);
2689  D->setLocation(readSourceLocation());
2690  Expr *MapperVarRefE = Record.readExpr();
2691  D->setMapperVarRef(MapperVarRefE);
2692  D->VarName = Record.readDeclarationName();
2693  D->PrevDeclInScope = readDeclID();
2694  unsigned NumClauses = D->clauselist_size();
2695  SmallVector<OMPClause *, 8> Clauses;
2696  Clauses.reserve(NumClauses);
2697  for (unsigned I = 0; I != NumClauses; ++I)
2698    Clauses.push_back(Record.readOMPClause());
2699  D->setClauses(Clauses);
2700}
2701
2702void ASTDeclReader::VisitOMPCapturedExprDecl(OMPCapturedExprDecl *D) {
2703  VisitVarDecl(D);
2704}
2705
2706//===----------------------------------------------------------------------===//
2707// Attribute Reading
2708//===----------------------------------------------------------------------===//
2709
2710namespace {
2711class AttrReader {
2712  ASTRecordReader &Reader;
2713
2714public:
2715  AttrReader(ASTRecordReader &Reader) : Reader(Reader) {}
2716
2717  uint64_t readInt() {
2718    return Reader.readInt();
2719  }
2720
2721  SourceRange readSourceRange() {
2722    return Reader.readSourceRange();
2723  }
2724
2725  SourceLocation readSourceLocation() {
2726    return Reader.readSourceLocation();
2727  }
2728
2729  Expr *readExpr() { return Reader.readExpr(); }
2730
2731  std::string readString() {
2732    return Reader.readString();
2733  }
2734
2735  TypeSourceInfo *readTypeSourceInfo() {
2736    return Reader.readTypeSourceInfo();
2737  }
2738
2739  IdentifierInfo *readIdentifier() {
2740    return Reader.readIdentifier();
2741  }
2742
2743  VersionTuple readVersionTuple() {
2744    return Reader.readVersionTuple();
2745  }
2746
2747  template <typename T> T *GetLocalDeclAs(uint32_t LocalID) {
2748    return Reader.GetLocalDeclAs<T>(LocalID);
2749  }
2750};
2751}
2752
2753Attr *ASTRecordReader::readAttr() {
2754  AttrReader Record(*this);
2755  auto V = Record.readInt();
2756  if (!V)
2757    return nullptr;
2758
2759  Attr *New = nullptr;
2760  // Kind is stored as a 1-based integer because 0 is used to indicate a null
2761  // Attr pointer.
2762  auto Kind = static_cast<attr::Kind>(V - 1);
2763  ASTContext &Context = getContext();
2764
2765  IdentifierInfo *AttrName = Record.readIdentifier();
2766  IdentifierInfo *ScopeName = Record.readIdentifier();
2767  SourceRange AttrRange = Record.readSourceRange();
2768  SourceLocation ScopeLoc = Record.readSourceLocation();
2769  unsigned ParsedKind = Record.readInt();
2770  unsigned Syntax = Record.readInt();
2771  unsigned SpellingIndex = Record.readInt();
2772
2773  AttributeCommonInfo Info(AttrName, ScopeName, AttrRange, ScopeLoc,
2774                           AttributeCommonInfo::Kind(ParsedKind),
2775                           AttributeCommonInfo::Syntax(Syntax), SpellingIndex);
2776
2777#include "clang/Serialization/AttrPCHRead.inc"
2778
2779  assert(New && "Unable to decode attribute?");
2780  return New;
2781}
2782
2783/// Reads attributes from the current stream position.
2784void ASTRecordReader::readAttributes(AttrVec &Attrs) {
2785  for (unsigned I = 0, E = readInt(); I != E; ++I)
2786    Attrs.push_back(readAttr());
2787}
2788
2789//===----------------------------------------------------------------------===//
2790// ASTReader Implementation
2791//===----------------------------------------------------------------------===//
2792
2793/// Note that we have loaded the declaration with the given
2794/// Index.
2795///
2796/// This routine notes that this declaration has already been loaded,
2797/// so that future GetDecl calls will return this declaration rather
2798/// than trying to load a new declaration.
2799inline void ASTReader::LoadedDecl(unsigned Index, Decl *D) {
2800  assert(!DeclsLoaded[Index] && "Decl loaded twice?");
2801  DeclsLoaded[Index] = D;
2802}
2803
2804/// Determine whether the consumer will be interested in seeing
2805/// this declaration (via HandleTopLevelDecl).
2806///
2807/// This routine should return true for anything that might affect
2808/// code generation, e.g., inline function definitions, Objective-C
2809/// declarations with metadata, etc.
2810static bool isConsumerInterestedIn(ASTContext &Ctx, Decl *D, bool HasBody) {
2811  // An ObjCMethodDecl is never considered as "interesting" because its
2812  // implementation container always is.
2813
2814  // An ImportDecl or VarDecl imported from a module map module will get
2815  // emitted when we import the relevant module.
2816  if (isPartOfPerModuleInitializer(D)) {
2817    auto *M = D->getImportedOwningModule();
2818    if (M && M->Kind == Module::ModuleMapModule &&
2819        Ctx.DeclMustBeEmitted(D))
2820      return false;
2821  }
2822
2823  if (isa<FileScopeAsmDecl>(D) ||
2824      isa<ObjCProtocolDecl>(D) ||
2825      isa<ObjCImplDecl>(D) ||
2826      isa<ImportDecl>(D) ||
2827      isa<PragmaCommentDecl>(D) ||
2828      isa<PragmaDetectMismatchDecl>(D))
2829    return true;
2830  if (isa<OMPThreadPrivateDecl>(D) || isa<OMPDeclareReductionDecl>(D) ||
2831      isa<OMPDeclareMapperDecl>(D) || isa<OMPAllocateDecl>(D))
2832    return !D->getDeclContext()->isFunctionOrMethod();
2833  if (const auto *Var = dyn_cast<VarDecl>(D))
2834    return Var->isFileVarDecl() &&
2835           (Var->isThisDeclarationADefinition() == VarDecl::Definition ||
2836            OMPDeclareTargetDeclAttr::isDeclareTargetDeclaration(Var));
2837  if (const auto *Func = dyn_cast<FunctionDecl>(D))
2838    return Func->doesThisDeclarationHaveABody() || HasBody;
2839
2840  if (auto *ES = D->getASTContext().getExternalSource())
2841    if (ES->hasExternalDefinitions(D) == ExternalASTSource::EK_Never)
2842      return true;
2843
2844  return false;
2845}
2846
2847/// Get the correct cursor and offset for loading a declaration.
2848ASTReader::RecordLocation
2849ASTReader::DeclCursorForID(DeclID ID, SourceLocation &Loc) {
2850  GlobalDeclMapType::iterator I = GlobalDeclMap.find(ID);
2851  assert(I != GlobalDeclMap.end() && "Corrupted global declaration map");
2852  ModuleFile *M = I->second;
2853  const DeclOffset &DOffs =
2854      M->DeclOffsets[ID - M->BaseDeclID - NUM_PREDEF_DECL_IDS];
2855  Loc = TranslateSourceLocation(*M, DOffs.getLocation());
2856  return RecordLocation(M, DOffs.BitOffset);
2857}
2858
2859ASTReader::RecordLocation ASTReader::getLocalBitOffset(uint64_t GlobalOffset) {
2860  auto I = GlobalBitOffsetsMap.find(GlobalOffset);
2861
2862  assert(I != GlobalBitOffsetsMap.end() && "Corrupted global bit offsets map");
2863  return RecordLocation(I->second, GlobalOffset - I->second->GlobalBitOffset);
2864}
2865
2866uint64_t ASTReader::getGlobalBitOffset(ModuleFile &M, uint32_t LocalOffset) {
2867  return LocalOffset + M.GlobalBitOffset;
2868}
2869
2870static bool isSameTemplateParameterList(const ASTContext &C,
2871                                        const TemplateParameterList *X,
2872                                        const TemplateParameterList *Y);
2873
2874/// Determine whether two template parameters are similar enough
2875/// that they may be used in declarations of the same template.
2876static bool isSameTemplateParameter(const NamedDecl *X,
2877                                    const NamedDecl *Y) {
2878  if (X->getKind() != Y->getKind())
2879    return false;
2880
2881  if (const auto *TX = dyn_cast<TemplateTypeParmDecl>(X)) {
2882    const auto *TY = cast<TemplateTypeParmDecl>(Y);
2883    if (TX->isParameterPack() != TY->isParameterPack())
2884      return false;
2885    if (TX->hasTypeConstraint() != TY->hasTypeConstraint())
2886      return false;
2887    if (TX->hasTypeConstraint()) {
2888      const TypeConstraint *TXTC = TX->getTypeConstraint();
2889      const TypeConstraint *TYTC = TY->getTypeConstraint();
2890      if (TXTC->getNamedConcept() != TYTC->getNamedConcept())
2891        return false;
2892      if (TXTC->hasExplicitTemplateArgs() != TYTC->hasExplicitTemplateArgs())
2893        return false;
2894      if (TXTC->hasExplicitTemplateArgs()) {
2895        const auto *TXTCArgs = TXTC->getTemplateArgsAsWritten();
2896        const auto *TYTCArgs = TYTC->getTemplateArgsAsWritten();
2897        if (TXTCArgs->NumTemplateArgs != TYTCArgs->NumTemplateArgs)
2898          return false;
2899        llvm::FoldingSetNodeID XID, YID;
2900        for (const auto &ArgLoc : TXTCArgs->arguments())
2901          ArgLoc.getArgument().Profile(XID, X->getASTContext());
2902        for (const auto &ArgLoc : TYTCArgs->arguments())
2903          ArgLoc.getArgument().Profile(YID, Y->getASTContext());
2904        if (XID != YID)
2905          return false;
2906      }
2907    }
2908    return true;
2909  }
2910
2911  if (const auto *TX = dyn_cast<NonTypeTemplateParmDecl>(X)) {
2912    const auto *TY = cast<NonTypeTemplateParmDecl>(Y);
2913    return TX->isParameterPack() == TY->isParameterPack() &&
2914           TX->getASTContext().hasSameType(TX->getType(), TY->getType());
2915  }
2916
2917  const auto *TX = cast<TemplateTemplateParmDecl>(X);
2918  const auto *TY = cast<TemplateTemplateParmDecl>(Y);
2919  return TX->isParameterPack() == TY->isParameterPack() &&
2920         isSameTemplateParameterList(TX->getASTContext(),
2921                                     TX->getTemplateParameters(),
2922                                     TY->getTemplateParameters());
2923}
2924
2925static NamespaceDecl *getNamespace(const NestedNameSpecifier *X) {
2926  if (auto *NS = X->getAsNamespace())
2927    return NS;
2928  if (auto *NAS = X->getAsNamespaceAlias())
2929    return NAS->getNamespace();
2930  return nullptr;
2931}
2932
2933static bool isSameQualifier(const NestedNameSpecifier *X,
2934                            const NestedNameSpecifier *Y) {
2935  if (auto *NSX = getNamespace(X)) {
2936    auto *NSY = getNamespace(Y);
2937    if (!NSY || NSX->getCanonicalDecl() != NSY->getCanonicalDecl())
2938      return false;
2939  } else if (X->getKind() != Y->getKind())
2940    return false;
2941
2942  // FIXME: For namespaces and types, we're permitted to check that the entity
2943  // is named via the same tokens. We should probably do so.
2944  switch (X->getKind()) {
2945  case NestedNameSpecifier::Identifier:
2946    if (X->getAsIdentifier() != Y->getAsIdentifier())
2947      return false;
2948    break;
2949  case NestedNameSpecifier::Namespace:
2950  case NestedNameSpecifier::NamespaceAlias:
2951    // We've already checked that we named the same namespace.
2952    break;
2953  case NestedNameSpecifier::TypeSpec:
2954  case NestedNameSpecifier::TypeSpecWithTemplate:
2955    if (X->getAsType()->getCanonicalTypeInternal() !=
2956        Y->getAsType()->getCanonicalTypeInternal())
2957      return false;
2958    break;
2959  case NestedNameSpecifier::Global:
2960  case NestedNameSpecifier::Super:
2961    return true;
2962  }
2963
2964  // Recurse into earlier portion of NNS, if any.
2965  auto *PX = X->getPrefix();
2966  auto *PY = Y->getPrefix();
2967  if (PX && PY)
2968    return isSameQualifier(PX, PY);
2969  return !PX && !PY;
2970}
2971
2972/// Determine whether two template parameter lists are similar enough
2973/// that they may be used in declarations of the same template.
2974static bool isSameTemplateParameterList(const ASTContext &C,
2975                                        const TemplateParameterList *X,
2976                                        const TemplateParameterList *Y) {
2977  if (X->size() != Y->size())
2978    return false;
2979
2980  for (unsigned I = 0, N = X->size(); I != N; ++I)
2981    if (!isSameTemplateParameter(X->getParam(I), Y->getParam(I)))
2982      return false;
2983
2984  const Expr *XRC = X->getRequiresClause();
2985  const Expr *YRC = Y->getRequiresClause();
2986  if (!XRC != !YRC)
2987    return false;
2988  if (XRC) {
2989    llvm::FoldingSetNodeID XRCID, YRCID;
2990    XRC->Profile(XRCID, C, /*Canonical=*/true);
2991    YRC->Profile(YRCID, C, /*Canonical=*/true);
2992    if (XRCID != YRCID)
2993      return false;
2994  }
2995
2996  return true;
2997}
2998
2999/// Determine whether the attributes we can overload on are identical for A and
3000/// B. Will ignore any overloadable attrs represented in the type of A and B.
3001static bool hasSameOverloadableAttrs(const FunctionDecl *A,
3002                                     const FunctionDecl *B) {
3003  // Note that pass_object_size attributes are represented in the function's
3004  // ExtParameterInfo, so we don't need to check them here.
3005
3006  llvm::FoldingSetNodeID Cand1ID, Cand2ID;
3007  auto AEnableIfAttrs = A->specific_attrs<EnableIfAttr>();
3008  auto BEnableIfAttrs = B->specific_attrs<EnableIfAttr>();
3009
3010  for (auto Pair : zip_longest(AEnableIfAttrs, BEnableIfAttrs)) {
3011    Optional<EnableIfAttr *> Cand1A = std::get<0>(Pair);
3012    Optional<EnableIfAttr *> Cand2A = std::get<1>(Pair);
3013
3014    // Return false if the number of enable_if attributes is different.
3015    if (!Cand1A || !Cand2A)
3016      return false;
3017
3018    Cand1ID.clear();
3019    Cand2ID.clear();
3020
3021    (*Cand1A)->getCond()->Profile(Cand1ID, A->getASTContext(), true);
3022    (*Cand2A)->getCond()->Profile(Cand2ID, B->getASTContext(), true);
3023
3024    // Return false if any of the enable_if expressions of A and B are
3025    // different.
3026    if (Cand1ID != Cand2ID)
3027      return false;
3028  }
3029  return true;
3030}
3031
3032/// Determine whether the two declarations refer to the same entity.pr
3033static bool isSameEntity(NamedDecl *X, NamedDecl *Y) {
3034  assert(X->getDeclName() == Y->getDeclName() && "Declaration name mismatch!");
3035
3036  if (X == Y)
3037    return true;
3038
3039  // Must be in the same context.
3040  //
3041  // Note that we can't use DeclContext::Equals here, because the DeclContexts
3042  // could be two different declarations of the same function. (We will fix the
3043  // semantic DC to refer to the primary definition after merging.)
3044  if (!declaresSameEntity(cast<Decl>(X->getDeclContext()->getRedeclContext()),
3045                          cast<Decl>(Y->getDeclContext()->getRedeclContext())))
3046    return false;
3047
3048  // Two typedefs refer to the same entity if they have the same underlying
3049  // type.
3050  if (const auto *TypedefX = dyn_cast<TypedefNameDecl>(X))
3051    if (const auto *TypedefY = dyn_cast<TypedefNameDecl>(Y))
3052      return X->getASTContext().hasSameType(TypedefX->getUnderlyingType(),
3053                                            TypedefY->getUnderlyingType());
3054
3055  // Must have the same kind.
3056  if (X->getKind() != Y->getKind())
3057    return false;
3058
3059  // Objective-C classes and protocols with the same name always match.
3060  if (isa<ObjCInterfaceDecl>(X) || isa<ObjCProtocolDecl>(X))
3061    return true;
3062
3063  if (isa<ClassTemplateSpecializationDecl>(X)) {
3064    // No need to handle these here: we merge them when adding them to the
3065    // template.
3066    return false;
3067  }
3068
3069  // Compatible tags match.
3070  if (const auto *TagX = dyn_cast<TagDecl>(X)) {
3071    const auto *TagY = cast<TagDecl>(Y);
3072    return (TagX->getTagKind() == TagY->getTagKind()) ||
3073      ((TagX->getTagKind() == TTK_Struct || TagX->getTagKind() == TTK_Class ||
3074        TagX->getTagKind() == TTK_Interface) &&
3075       (TagY->getTagKind() == TTK_Struct || TagY->getTagKind() == TTK_Class ||
3076        TagY->getTagKind() == TTK_Interface));
3077  }
3078
3079  // Functions with the same type and linkage match.
3080  // FIXME: This needs to cope with merging of prototyped/non-prototyped
3081  // functions, etc.
3082  if (const auto *FuncX = dyn_cast<FunctionDecl>(X)) {
3083    const auto *FuncY = cast<FunctionDecl>(Y);
3084    if (const auto *CtorX = dyn_cast<CXXConstructorDecl>(X)) {
3085      const auto *CtorY = cast<CXXConstructorDecl>(Y);
3086      if (CtorX->getInheritedConstructor() &&
3087          !isSameEntity(CtorX->getInheritedConstructor().getConstructor(),
3088                        CtorY->getInheritedConstructor().getConstructor()))
3089        return false;
3090    }
3091
3092    if (FuncX->isMultiVersion() != FuncY->isMultiVersion())
3093      return false;
3094
3095    // Multiversioned functions with different feature strings are represented
3096    // as separate declarations.
3097    if (FuncX->isMultiVersion()) {
3098      const auto *TAX = FuncX->getAttr<TargetAttr>();
3099      const auto *TAY = FuncY->getAttr<TargetAttr>();
3100      assert(TAX && TAY && "Multiversion Function without target attribute");
3101
3102      if (TAX->getFeaturesStr() != TAY->getFeaturesStr())
3103        return false;
3104    }
3105
3106    ASTContext &C = FuncX->getASTContext();
3107
3108    const Expr *XRC = FuncX->getTrailingRequiresClause();
3109    const Expr *YRC = FuncY->getTrailingRequiresClause();
3110    if (!XRC != !YRC)
3111      return false;
3112    if (XRC) {
3113      llvm::FoldingSetNodeID XRCID, YRCID;
3114      XRC->Profile(XRCID, C, /*Canonical=*/true);
3115      YRC->Profile(YRCID, C, /*Canonical=*/true);
3116      if (XRCID != YRCID)
3117        return false;
3118    }
3119
3120    auto GetTypeAsWritten = [](const FunctionDecl *FD) {
3121      // Map to the first declaration that we've already merged into this one.
3122      // The TSI of redeclarations might not match (due to calling conventions
3123      // being inherited onto the type but not the TSI), but the TSI type of
3124      // the first declaration of the function should match across modules.
3125      FD = FD->getCanonicalDecl();
3126      return FD->getTypeSourceInfo() ? FD->getTypeSourceInfo()->getType()
3127                                     : FD->getType();
3128    };
3129    QualType XT = GetTypeAsWritten(FuncX), YT = GetTypeAsWritten(FuncY);
3130    if (!C.hasSameType(XT, YT)) {
3131      // We can get functions with different types on the redecl chain in C++17
3132      // if they have differing exception specifications and at least one of
3133      // the excpetion specs is unresolved.
3134      auto *XFPT = XT->getAs<FunctionProtoType>();
3135      auto *YFPT = YT->getAs<FunctionProtoType>();
3136      if (C.getLangOpts().CPlusPlus17 && XFPT && YFPT &&
3137          (isUnresolvedExceptionSpec(XFPT->getExceptionSpecType()) ||
3138           isUnresolvedExceptionSpec(YFPT->getExceptionSpecType())) &&
3139          C.hasSameFunctionTypeIgnoringExceptionSpec(XT, YT))
3140        return true;
3141      return false;
3142    }
3143
3144    return FuncX->getLinkageInternal() == FuncY->getLinkageInternal() &&
3145           hasSameOverloadableAttrs(FuncX, FuncY);
3146  }
3147
3148  // Variables with the same type and linkage match.
3149  if (const auto *VarX = dyn_cast<VarDecl>(X)) {
3150    const auto *VarY = cast<VarDecl>(Y);
3151    if (VarX->getLinkageInternal() == VarY->getLinkageInternal()) {
3152      ASTContext &C = VarX->getASTContext();
3153      if (C.hasSameType(VarX->getType(), VarY->getType()))
3154        return true;
3155
3156      // We can get decls with different types on the redecl chain. Eg.
3157      // template <typename T> struct S { static T Var[]; }; // #1
3158      // template <typename T> T S<T>::Var[sizeof(T)]; // #2
3159      // Only? happens when completing an incomplete array type. In this case
3160      // when comparing #1 and #2 we should go through their element type.
3161      const ArrayType *VarXTy = C.getAsArrayType(VarX->getType());
3162      const ArrayType *VarYTy = C.getAsArrayType(VarY->getType());
3163      if (!VarXTy || !VarYTy)
3164        return false;
3165      if (VarXTy->isIncompleteArrayType() || VarYTy->isIncompleteArrayType())
3166        return C.hasSameType(VarXTy->getElementType(), VarYTy->getElementType());
3167    }
3168    return false;
3169  }
3170
3171  // Namespaces with the same name and inlinedness match.
3172  if (const auto *NamespaceX = dyn_cast<NamespaceDecl>(X)) {
3173    const auto *NamespaceY = cast<NamespaceDecl>(Y);
3174    return NamespaceX->isInline() == NamespaceY->isInline();
3175  }
3176
3177  // Identical template names and kinds match if their template parameter lists
3178  // and patterns match.
3179  if (const auto *TemplateX = dyn_cast<TemplateDecl>(X)) {
3180    const auto *TemplateY = cast<TemplateDecl>(Y);
3181    return isSameEntity(TemplateX->getTemplatedDecl(),
3182                        TemplateY->getTemplatedDecl()) &&
3183           isSameTemplateParameterList(TemplateX->getASTContext(),
3184                                       TemplateX->getTemplateParameters(),
3185                                       TemplateY->getTemplateParameters());
3186  }
3187
3188  // Fields with the same name and the same type match.
3189  if (const auto *FDX = dyn_cast<FieldDecl>(X)) {
3190    const auto *FDY = cast<FieldDecl>(Y);
3191    // FIXME: Also check the bitwidth is odr-equivalent, if any.
3192    return X->getASTContext().hasSameType(FDX->getType(), FDY->getType());
3193  }
3194
3195  // Indirect fields with the same target field match.
3196  if (const auto *IFDX = dyn_cast<IndirectFieldDecl>(X)) {
3197    const auto *IFDY = cast<IndirectFieldDecl>(Y);
3198    return IFDX->getAnonField()->getCanonicalDecl() ==
3199           IFDY->getAnonField()->getCanonicalDecl();
3200  }
3201
3202  // Enumerators with the same name match.
3203  if (isa<EnumConstantDecl>(X))
3204    // FIXME: Also check the value is odr-equivalent.
3205    return true;
3206
3207  // Using shadow declarations with the same target match.
3208  if (const auto *USX = dyn_cast<UsingShadowDecl>(X)) {
3209    const auto *USY = cast<UsingShadowDecl>(Y);
3210    return USX->getTargetDecl() == USY->getTargetDecl();
3211  }
3212
3213  // Using declarations with the same qualifier match. (We already know that
3214  // the name matches.)
3215  if (const auto *UX = dyn_cast<UsingDecl>(X)) {
3216    const auto *UY = cast<UsingDecl>(Y);
3217    return isSameQualifier(UX->getQualifier(), UY->getQualifier()) &&
3218           UX->hasTypename() == UY->hasTypename() &&
3219           UX->isAccessDeclaration() == UY->isAccessDeclaration();
3220  }
3221  if (const auto *UX = dyn_cast<UnresolvedUsingValueDecl>(X)) {
3222    const auto *UY = cast<UnresolvedUsingValueDecl>(Y);
3223    return isSameQualifier(UX->getQualifier(), UY->getQualifier()) &&
3224           UX->isAccessDeclaration() == UY->isAccessDeclaration();
3225  }
3226  if (const auto *UX = dyn_cast<UnresolvedUsingTypenameDecl>(X))
3227    return isSameQualifier(
3228        UX->getQualifier(),
3229        cast<UnresolvedUsingTypenameDecl>(Y)->getQualifier());
3230
3231  // Namespace alias definitions with the same target match.
3232  if (const auto *NAX = dyn_cast<NamespaceAliasDecl>(X)) {
3233    const auto *NAY = cast<NamespaceAliasDecl>(Y);
3234    return NAX->getNamespace()->Equals(NAY->getNamespace());
3235  }
3236
3237  return false;
3238}
3239
3240/// Find the context in which we should search for previous declarations when
3241/// looking for declarations to merge.
3242DeclContext *ASTDeclReader::getPrimaryContextForMerging(ASTReader &Reader,
3243                                                        DeclContext *DC) {
3244  if (auto *ND = dyn_cast<NamespaceDecl>(DC))
3245    return ND->getOriginalNamespace();
3246
3247  if (auto *RD = dyn_cast<CXXRecordDecl>(DC)) {
3248    // Try to dig out the definition.
3249    auto *DD = RD->DefinitionData;
3250    if (!DD)
3251      DD = RD->getCanonicalDecl()->DefinitionData;
3252
3253    // If there's no definition yet, then DC's definition is added by an update
3254    // record, but we've not yet loaded that update record. In this case, we
3255    // commit to DC being the canonical definition now, and will fix this when
3256    // we load the update record.
3257    if (!DD) {
3258      DD = new (Reader.getContext()) struct CXXRecordDecl::DefinitionData(RD);
3259      RD->setCompleteDefinition(true);
3260      RD->DefinitionData = DD;
3261      RD->getCanonicalDecl()->DefinitionData = DD;
3262
3263      // Track that we did this horrible thing so that we can fix it later.
3264      Reader.PendingFakeDefinitionData.insert(
3265          std::make_pair(DD, ASTReader::PendingFakeDefinitionKind::Fake));
3266    }
3267
3268    return DD->Definition;
3269  }
3270
3271  if (auto *ED = dyn_cast<EnumDecl>(DC))
3272    return ED->getASTContext().getLangOpts().CPlusPlus? ED->getDefinition()
3273                                                      : nullptr;
3274
3275  // We can see the TU here only if we have no Sema object. In that case,
3276  // there's no TU scope to look in, so using the DC alone is sufficient.
3277  if (auto *TU = dyn_cast<TranslationUnitDecl>(DC))
3278    return TU;
3279
3280  return nullptr;
3281}
3282
3283ASTDeclReader::FindExistingResult::~FindExistingResult() {
3284  // Record that we had a typedef name for linkage whether or not we merge
3285  // with that declaration.
3286  if (TypedefNameForLinkage) {
3287    DeclContext *DC = New->getDeclContext()->getRedeclContext();
3288    Reader.ImportedTypedefNamesForLinkage.insert(
3289        std::make_pair(std::make_pair(DC, TypedefNameForLinkage), New));
3290    return;
3291  }
3292
3293  if (!AddResult || Existing)
3294    return;
3295
3296  DeclarationName Name = New->getDeclName();
3297  DeclContext *DC = New->getDeclContext()->getRedeclContext();
3298  if (needsAnonymousDeclarationNumber(New)) {
3299    setAnonymousDeclForMerging(Reader, New->getLexicalDeclContext(),
3300                               AnonymousDeclNumber, New);
3301  } else if (DC->isTranslationUnit() &&
3302             !Reader.getContext().getLangOpts().CPlusPlus) {
3303    if (Reader.getIdResolver().tryAddTopLevelDecl(New, Name))
3304      Reader.PendingFakeLookupResults[Name.getAsIdentifierInfo()]
3305            .push_back(New);
3306  } else if (DeclContext *MergeDC = getPrimaryContextForMerging(Reader, DC)) {
3307    // Add the declaration to its redeclaration context so later merging
3308    // lookups will find it.
3309    MergeDC->makeDeclVisibleInContextImpl(New, /*Internal*/true);
3310  }
3311}
3312
3313/// Find the declaration that should be merged into, given the declaration found
3314/// by name lookup. If we're merging an anonymous declaration within a typedef,
3315/// we need a matching typedef, and we merge with the type inside it.
3316static NamedDecl *getDeclForMerging(NamedDecl *Found,
3317                                    bool IsTypedefNameForLinkage) {
3318  if (!IsTypedefNameForLinkage)
3319    return Found;
3320
3321  // If we found a typedef declaration that gives a name to some other
3322  // declaration, then we want that inner declaration. Declarations from
3323  // AST files are handled via ImportedTypedefNamesForLinkage.
3324  if (Found->isFromASTFile())
3325    return nullptr;
3326
3327  if (auto *TND = dyn_cast<TypedefNameDecl>(Found))
3328    return TND->getAnonDeclWithTypedefName(/*AnyRedecl*/true);
3329
3330  return nullptr;
3331}
3332
3333/// Find the declaration to use to populate the anonymous declaration table
3334/// for the given lexical DeclContext. We only care about finding local
3335/// definitions of the context; we'll merge imported ones as we go.
3336DeclContext *
3337ASTDeclReader::getPrimaryDCForAnonymousDecl(DeclContext *LexicalDC) {
3338  // For classes, we track the definition as we merge.
3339  if (auto *RD = dyn_cast<CXXRecordDecl>(LexicalDC)) {
3340    auto *DD = RD->getCanonicalDecl()->DefinitionData;
3341    return DD ? DD->Definition : nullptr;
3342  }
3343
3344  // For anything else, walk its merged redeclarations looking for a definition.
3345  // Note that we can't just call getDefinition here because the redeclaration
3346  // chain isn't wired up.
3347  for (auto *D : merged_redecls(cast<Decl>(LexicalDC))) {
3348    if (auto *FD = dyn_cast<FunctionDecl>(D))
3349      if (FD->isThisDeclarationADefinition())
3350        return FD;
3351    if (auto *MD = dyn_cast<ObjCMethodDecl>(D))
3352      if (MD->isThisDeclarationADefinition())
3353        return MD;
3354  }
3355
3356  // No merged definition yet.
3357  return nullptr;
3358}
3359
3360NamedDecl *ASTDeclReader::getAnonymousDeclForMerging(ASTReader &Reader,
3361                                                     DeclContext *DC,
3362                                                     unsigned Index) {
3363  // If the lexical context has been merged, look into the now-canonical
3364  // definition.
3365  auto *CanonDC = cast<Decl>(DC)->getCanonicalDecl();
3366
3367  // If we've seen this before, return the canonical declaration.
3368  auto &Previous = Reader.AnonymousDeclarationsForMerging[CanonDC];
3369  if (Index < Previous.size() && Previous[Index])
3370    return Previous[Index];
3371
3372  // If this is the first time, but we have parsed a declaration of the context,
3373  // build the anonymous declaration list from the parsed declaration.
3374  auto *PrimaryDC = getPrimaryDCForAnonymousDecl(DC);
3375  if (PrimaryDC && !cast<Decl>(PrimaryDC)->isFromASTFile()) {
3376    numberAnonymousDeclsWithin(PrimaryDC, [&](NamedDecl *ND, unsigned Number) {
3377      if (Previous.size() == Number)
3378        Previous.push_back(cast<NamedDecl>(ND->getCanonicalDecl()));
3379      else
3380        Previous[Number] = cast<NamedDecl>(ND->getCanonicalDecl());
3381    });
3382  }
3383
3384  return Index < Previous.size() ? Previous[Index] : nullptr;
3385}
3386
3387void ASTDeclReader::setAnonymousDeclForMerging(ASTReader &Reader,
3388                                               DeclContext *DC, unsigned Index,
3389                                               NamedDecl *D) {
3390  auto *CanonDC = cast<Decl>(DC)->getCanonicalDecl();
3391
3392  auto &Previous = Reader.AnonymousDeclarationsForMerging[CanonDC];
3393  if (Index >= Previous.size())
3394    Previous.resize(Index + 1);
3395  if (!Previous[Index])
3396    Previous[Index] = D;
3397}
3398
3399ASTDeclReader::FindExistingResult ASTDeclReader::findExisting(NamedDecl *D) {
3400  DeclarationName Name = TypedefNameForLinkage ? TypedefNameForLinkage
3401                                               : D->getDeclName();
3402
3403  if (!Name && !needsAnonymousDeclarationNumber(D)) {
3404    // Don't bother trying to find unnamed declarations that are in
3405    // unmergeable contexts.
3406    FindExistingResult Result(Reader, D, /*Existing=*/nullptr,
3407                              AnonymousDeclNumber, TypedefNameForLinkage);
3408    Result.suppress();
3409    return Result;
3410  }
3411
3412  DeclContext *DC = D->getDeclContext()->getRedeclContext();
3413  if (TypedefNameForLinkage) {
3414    auto It = Reader.ImportedTypedefNamesForLinkage.find(
3415        std::make_pair(DC, TypedefNameForLinkage));
3416    if (It != Reader.ImportedTypedefNamesForLinkage.end())
3417      if (isSameEntity(It->second, D))
3418        return FindExistingResult(Reader, D, It->second, AnonymousDeclNumber,
3419                                  TypedefNameForLinkage);
3420    // Go on to check in other places in case an existing typedef name
3421    // was not imported.
3422  }
3423
3424  if (needsAnonymousDeclarationNumber(D)) {
3425    // This is an anonymous declaration that we may need to merge. Look it up
3426    // in its context by number.
3427    if (auto *Existing = getAnonymousDeclForMerging(
3428            Reader, D->getLexicalDeclContext(), AnonymousDeclNumber))
3429      if (isSameEntity(Existing, D))
3430        return FindExistingResult(Reader, D, Existing, AnonymousDeclNumber,
3431                                  TypedefNameForLinkage);
3432  } else if (DC->isTranslationUnit() &&
3433             !Reader.getContext().getLangOpts().CPlusPlus) {
3434    IdentifierResolver &IdResolver = Reader.getIdResolver();
3435
3436    // Temporarily consider the identifier to be up-to-date. We don't want to
3437    // cause additional lookups here.
3438    class UpToDateIdentifierRAII {
3439      IdentifierInfo *II;
3440      bool WasOutToDate = false;
3441
3442    public:
3443      explicit UpToDateIdentifierRAII(IdentifierInfo *II) : II(II) {
3444        if (II) {
3445          WasOutToDate = II->isOutOfDate();
3446          if (WasOutToDate)
3447            II->setOutOfDate(false);
3448        }
3449      }
3450
3451      ~UpToDateIdentifierRAII() {
3452        if (WasOutToDate)
3453          II->setOutOfDate(true);
3454      }
3455    } UpToDate(Name.getAsIdentifierInfo());
3456
3457    for (IdentifierResolver::iterator I = IdResolver.begin(Name),
3458                                   IEnd = IdResolver.end();
3459         I != IEnd; ++I) {
3460      if (NamedDecl *Existing = getDeclForMerging(*I, TypedefNameForLinkage))
3461        if (isSameEntity(Existing, D))
3462          return FindExistingResult(Reader, D, Existing, AnonymousDeclNumber,
3463                                    TypedefNameForLinkage);
3464    }
3465  } else if (DeclContext *MergeDC = getPrimaryContextForMerging(Reader, DC)) {
3466    DeclContext::lookup_result R = MergeDC->noload_lookup(Name);
3467    for (DeclContext::lookup_iterator I = R.begin(), E = R.end(); I != E; ++I) {
3468      if (NamedDecl *Existing = getDeclForMerging(*I, TypedefNameForLinkage))
3469        if (isSameEntity(Existing, D))
3470          return FindExistingResult(Reader, D, Existing, AnonymousDeclNumber,
3471                                    TypedefNameForLinkage);
3472    }
3473  } else {
3474    // Not in a mergeable context.
3475    return FindExistingResult(Reader);
3476  }
3477
3478  // If this declaration is from a merged context, make a note that we need to
3479  // check that the canonical definition of that context contains the decl.
3480  //
3481  // FIXME: We should do something similar if we merge two definitions of the
3482  // same template specialization into the same CXXRecordDecl.
3483  auto MergedDCIt = Reader.MergedDeclContexts.find(D->getLexicalDeclContext());
3484  if (MergedDCIt != Reader.MergedDeclContexts.end() &&
3485      MergedDCIt->second == D->getDeclContext())
3486    Reader.PendingOdrMergeChecks.push_back(D);
3487
3488  return FindExistingResult(Reader, D, /*Existing=*/nullptr,
3489                            AnonymousDeclNumber, TypedefNameForLinkage);
3490}
3491
3492template<typename DeclT>
3493Decl *ASTDeclReader::getMostRecentDeclImpl(Redeclarable<DeclT> *D) {
3494  return D->RedeclLink.getLatestNotUpdated();
3495}
3496
3497Decl *ASTDeclReader::getMostRecentDeclImpl(...) {
3498  llvm_unreachable("getMostRecentDecl on non-redeclarable declaration");
3499}
3500
3501Decl *ASTDeclReader::getMostRecentDecl(Decl *D) {
3502  assert(D);
3503
3504  switch (D->getKind()) {
3505#define ABSTRACT_DECL(TYPE)
3506#define DECL(TYPE, BASE)                               \
3507  case Decl::TYPE:                                     \
3508    return getMostRecentDeclImpl(cast<TYPE##Decl>(D));
3509#include "clang/AST/DeclNodes.inc"
3510  }
3511  llvm_unreachable("unknown decl kind");
3512}
3513
3514Decl *ASTReader::getMostRecentExistingDecl(Decl *D) {
3515  return ASTDeclReader::getMostRecentDecl(D->getCanonicalDecl());
3516}
3517
3518template<typename DeclT>
3519void ASTDeclReader::attachPreviousDeclImpl(ASTReader &Reader,
3520                                           Redeclarable<DeclT> *D,
3521                                           Decl *Previous, Decl *Canon) {
3522  D->RedeclLink.setPrevious(cast<DeclT>(Previous));
3523  D->First = cast<DeclT>(Previous)->First;
3524}
3525
3526namespace clang {
3527
3528template<>
3529void ASTDeclReader::attachPreviousDeclImpl(ASTReader &Reader,
3530                                           Redeclarable<VarDecl> *D,
3531                                           Decl *Previous, Decl *Canon) {
3532  auto *VD = static_cast<VarDecl *>(D);
3533  auto *PrevVD = cast<VarDecl>(Previous);
3534  D->RedeclLink.setPrevious(PrevVD);
3535  D->First = PrevVD->First;
3536
3537  // We should keep at most one definition on the chain.
3538  // FIXME: Cache the definition once we've found it. Building a chain with
3539  // N definitions currently takes O(N^2) time here.
3540  if (VD->isThisDeclarationADefinition() == VarDecl::Definition) {
3541    for (VarDecl *CurD = PrevVD; CurD; CurD = CurD->getPreviousDecl()) {
3542      if (CurD->isThisDeclarationADefinition() == VarDecl::Definition) {
3543        Reader.mergeDefinitionVisibility(CurD, VD);
3544        VD->demoteThisDefinitionToDeclaration();
3545        break;
3546      }
3547    }
3548  }
3549}
3550
3551static bool isUndeducedReturnType(QualType T) {
3552  auto *DT = T->getContainedDeducedType();
3553  return DT && !DT->isDeduced();
3554}
3555
3556template<>
3557void ASTDeclReader::attachPreviousDeclImpl(ASTReader &Reader,
3558                                           Redeclarable<FunctionDecl> *D,
3559                                           Decl *Previous, Decl *Canon) {
3560  auto *FD = static_cast<FunctionDecl *>(D);
3561  auto *PrevFD = cast<FunctionDecl>(Previous);
3562
3563  FD->RedeclLink.setPrevious(PrevFD);
3564  FD->First = PrevFD->First;
3565
3566  // If the previous declaration is an inline function declaration, then this
3567  // declaration is too.
3568  if (PrevFD->isInlined() != FD->isInlined()) {
3569    // FIXME: [dcl.fct.spec]p4:
3570    //   If a function with external linkage is declared inline in one
3571    //   translation unit, it shall be declared inline in all translation
3572    //   units in which it appears.
3573    //
3574    // Be careful of this case:
3575    //
3576    // module A:
3577    //   template<typename T> struct X { void f(); };
3578    //   template<typename T> inline void X<T>::f() {}
3579    //
3580    // module B instantiates the declaration of X<int>::f
3581    // module C instantiates the definition of X<int>::f
3582    //
3583    // If module B and C are merged, we do not have a violation of this rule.
3584    FD->setImplicitlyInline(true);
3585  }
3586
3587  auto *FPT = FD->getType()->getAs<FunctionProtoType>();
3588  auto *PrevFPT = PrevFD->getType()->getAs<FunctionProtoType>();
3589  if (FPT && PrevFPT) {
3590    // If we need to propagate an exception specification along the redecl
3591    // chain, make a note of that so that we can do so later.
3592    bool IsUnresolved = isUnresolvedExceptionSpec(FPT->getExceptionSpecType());
3593    bool WasUnresolved =
3594        isUnresolvedExceptionSpec(PrevFPT->getExceptionSpecType());
3595    if (IsUnresolved != WasUnresolved)
3596      Reader.PendingExceptionSpecUpdates.insert(
3597          {Canon, IsUnresolved ? PrevFD : FD});
3598
3599    // If we need to propagate a deduced return type along the redecl chain,
3600    // make a note of that so that we can do it later.
3601    bool IsUndeduced = isUndeducedReturnType(FPT->getReturnType());
3602    bool WasUndeduced = isUndeducedReturnType(PrevFPT->getReturnType());
3603    if (IsUndeduced != WasUndeduced)
3604      Reader.PendingDeducedTypeUpdates.insert(
3605          {cast<FunctionDecl>(Canon),
3606           (IsUndeduced ? PrevFPT : FPT)->getReturnType()});
3607  }
3608}
3609
3610} // namespace clang
3611
3612void ASTDeclReader::attachPreviousDeclImpl(ASTReader &Reader, ...) {
3613  llvm_unreachable("attachPreviousDecl on non-redeclarable declaration");
3614}
3615
3616/// Inherit the default template argument from \p From to \p To. Returns
3617/// \c false if there is no default template for \p From.
3618template <typename ParmDecl>
3619static bool inheritDefaultTemplateArgument(ASTContext &Context, ParmDecl *From,
3620                                           Decl *ToD) {
3621  auto *To = cast<ParmDecl>(ToD);
3622  if (!From->hasDefaultArgument())
3623    return false;
3624  To->setInheritedDefaultArgument(Context, From);
3625  return true;
3626}
3627
3628static void inheritDefaultTemplateArguments(ASTContext &Context,
3629                                            TemplateDecl *From,
3630                                            TemplateDecl *To) {
3631  auto *FromTP = From->getTemplateParameters();
3632  auto *ToTP = To->getTemplateParameters();
3633  assert(FromTP->size() == ToTP->size() && "merged mismatched templates?");
3634
3635  for (unsigned I = 0, N = FromTP->size(); I != N; ++I) {
3636    NamedDecl *FromParam = FromTP->getParam(I);
3637    NamedDecl *ToParam = ToTP->getParam(I);
3638
3639    if (auto *FTTP = dyn_cast<TemplateTypeParmDecl>(FromParam))
3640      inheritDefaultTemplateArgument(Context, FTTP, ToParam);
3641    else if (auto *FNTTP = dyn_cast<NonTypeTemplateParmDecl>(FromParam))
3642      inheritDefaultTemplateArgument(Context, FNTTP, ToParam);
3643    else
3644      inheritDefaultTemplateArgument(
3645              Context, cast<TemplateTemplateParmDecl>(FromParam), ToParam);
3646  }
3647}
3648
3649void ASTDeclReader::attachPreviousDecl(ASTReader &Reader, Decl *D,
3650                                       Decl *Previous, Decl *Canon) {
3651  assert(D && Previous);
3652
3653  switch (D->getKind()) {
3654#define ABSTRACT_DECL(TYPE)
3655#define DECL(TYPE, BASE)                                                  \
3656  case Decl::TYPE:                                                        \
3657    attachPreviousDeclImpl(Reader, cast<TYPE##Decl>(D), Previous, Canon); \
3658    break;
3659#include "clang/AST/DeclNodes.inc"
3660  }
3661
3662  // If the declaration was visible in one module, a redeclaration of it in
3663  // another module remains visible even if it wouldn't be visible by itself.
3664  //
3665  // FIXME: In this case, the declaration should only be visible if a module
3666  //        that makes it visible has been imported.
3667  D->IdentifierNamespace |=
3668      Previous->IdentifierNamespace &
3669      (Decl::IDNS_Ordinary | Decl::IDNS_Tag | Decl::IDNS_Type);
3670
3671  // If the declaration declares a template, it may inherit default arguments
3672  // from the previous declaration.
3673  if (auto *TD = dyn_cast<TemplateDecl>(D))
3674    inheritDefaultTemplateArguments(Reader.getContext(),
3675                                    cast<TemplateDecl>(Previous), TD);
3676}
3677
3678template<typename DeclT>
3679void ASTDeclReader::attachLatestDeclImpl(Redeclarable<DeclT> *D, Decl *Latest) {
3680  D->RedeclLink.setLatest(cast<DeclT>(Latest));
3681}
3682
3683void ASTDeclReader::attachLatestDeclImpl(...) {
3684  llvm_unreachable("attachLatestDecl on non-redeclarable declaration");
3685}
3686
3687void ASTDeclReader::attachLatestDecl(Decl *D, Decl *Latest) {
3688  assert(D && Latest);
3689
3690  switch (D->getKind()) {
3691#define ABSTRACT_DECL(TYPE)
3692#define DECL(TYPE, BASE)                                  \
3693  case Decl::TYPE:                                        \
3694    attachLatestDeclImpl(cast<TYPE##Decl>(D), Latest); \
3695    break;
3696#include "clang/AST/DeclNodes.inc"
3697  }
3698}
3699
3700template<typename DeclT>
3701void ASTDeclReader::markIncompleteDeclChainImpl(Redeclarable<DeclT> *D) {
3702  D->RedeclLink.markIncomplete();
3703}
3704
3705void ASTDeclReader::markIncompleteDeclChainImpl(...) {
3706  llvm_unreachable("markIncompleteDeclChain on non-redeclarable declaration");
3707}
3708
3709void ASTReader::markIncompleteDeclChain(Decl *D) {
3710  switch (D->getKind()) {
3711#define ABSTRACT_DECL(TYPE)
3712#define DECL(TYPE, BASE)                                             \
3713  case Decl::TYPE:                                                   \
3714    ASTDeclReader::markIncompleteDeclChainImpl(cast<TYPE##Decl>(D)); \
3715    break;
3716#include "clang/AST/DeclNodes.inc"
3717  }
3718}
3719
3720/// Read the declaration at the given offset from the AST file.
3721Decl *ASTReader::ReadDeclRecord(DeclID ID) {
3722  unsigned Index = ID - NUM_PREDEF_DECL_IDS;
3723  SourceLocation DeclLoc;
3724  RecordLocation Loc = DeclCursorForID(ID, DeclLoc);
3725  llvm::BitstreamCursor &DeclsCursor = Loc.F->DeclsCursor;
3726  // Keep track of where we are in the stream, then jump back there
3727  // after reading this declaration.
3728  SavedStreamPosition SavedPosition(DeclsCursor);
3729
3730  ReadingKindTracker ReadingKind(Read_Decl, *this);
3731
3732  // Note that we are loading a declaration record.
3733  Deserializing ADecl(this);
3734
3735  auto Fail = [](const char *what, llvm::Error &&Err) {
3736    llvm::report_fatal_error(Twine("ASTReader::readDeclRecord failed ") + what +
3737                             ": " + toString(std::move(Err)));
3738  };
3739
3740  if (llvm::Error JumpFailed = DeclsCursor.JumpToBit(Loc.Offset))
3741    Fail("jumping", std::move(JumpFailed));
3742  ASTRecordReader Record(*this, *Loc.F);
3743  ASTDeclReader Reader(*this, Record, Loc, ID, DeclLoc);
3744  Expected<unsigned> MaybeCode = DeclsCursor.ReadCode();
3745  if (!MaybeCode)
3746    Fail("reading code", MaybeCode.takeError());
3747  unsigned Code = MaybeCode.get();
3748
3749  ASTContext &Context = getContext();
3750  Decl *D = nullptr;
3751  Expected<unsigned> MaybeDeclCode = Record.readRecord(DeclsCursor, Code);
3752  if (!MaybeDeclCode)
3753    llvm::report_fatal_error(
3754        "ASTReader::readDeclRecord failed reading decl code: " +
3755        toString(MaybeDeclCode.takeError()));
3756  switch ((DeclCode)MaybeDeclCode.get()) {
3757  case DECL_CONTEXT_LEXICAL:
3758  case DECL_CONTEXT_VISIBLE:
3759    llvm_unreachable("Record cannot be de-serialized with readDeclRecord");
3760  case DECL_TYPEDEF:
3761    D = TypedefDecl::CreateDeserialized(Context, ID);
3762    break;
3763  case DECL_TYPEALIAS:
3764    D = TypeAliasDecl::CreateDeserialized(Context, ID);
3765    break;
3766  case DECL_ENUM:
3767    D = EnumDecl::CreateDeserialized(Context, ID);
3768    break;
3769  case DECL_RECORD:
3770    D = RecordDecl::CreateDeserialized(Context, ID);
3771    break;
3772  case DECL_ENUM_CONSTANT:
3773    D = EnumConstantDecl::CreateDeserialized(Context, ID);
3774    break;
3775  case DECL_FUNCTION:
3776    D = FunctionDecl::CreateDeserialized(Context, ID);
3777    break;
3778  case DECL_LINKAGE_SPEC:
3779    D = LinkageSpecDecl::CreateDeserialized(Context, ID);
3780    break;
3781  case DECL_EXPORT:
3782    D = ExportDecl::CreateDeserialized(Context, ID);
3783    break;
3784  case DECL_LABEL:
3785    D = LabelDecl::CreateDeserialized(Context, ID);
3786    break;
3787  case DECL_NAMESPACE:
3788    D = NamespaceDecl::CreateDeserialized(Context, ID);
3789    break;
3790  case DECL_NAMESPACE_ALIAS:
3791    D = NamespaceAliasDecl::CreateDeserialized(Context, ID);
3792    break;
3793  case DECL_USING:
3794    D = UsingDecl::CreateDeserialized(Context, ID);
3795    break;
3796  case DECL_USING_PACK:
3797    D = UsingPackDecl::CreateDeserialized(Context, ID, Record.readInt());
3798    break;
3799  case DECL_USING_SHADOW:
3800    D = UsingShadowDecl::CreateDeserialized(Context, ID);
3801    break;
3802  case DECL_CONSTRUCTOR_USING_SHADOW:
3803    D = ConstructorUsingShadowDecl::CreateDeserialized(Context, ID);
3804    break;
3805  case DECL_USING_DIRECTIVE:
3806    D = UsingDirectiveDecl::CreateDeserialized(Context, ID);
3807    break;
3808  case DECL_UNRESOLVED_USING_VALUE:
3809    D = UnresolvedUsingValueDecl::CreateDeserialized(Context, ID);
3810    break;
3811  case DECL_UNRESOLVED_USING_TYPENAME:
3812    D = UnresolvedUsingTypenameDecl::CreateDeserialized(Context, ID);
3813    break;
3814  case DECL_CXX_RECORD:
3815    D = CXXRecordDecl::CreateDeserialized(Context, ID);
3816    break;
3817  case DECL_CXX_DEDUCTION_GUIDE:
3818    D = CXXDeductionGuideDecl::CreateDeserialized(Context, ID);
3819    break;
3820  case DECL_CXX_METHOD:
3821    D = CXXMethodDecl::CreateDeserialized(Context, ID);
3822    break;
3823  case DECL_CXX_CONSTRUCTOR:
3824    D = CXXConstructorDecl::CreateDeserialized(Context, ID, Record.readInt());
3825    break;
3826  case DECL_CXX_DESTRUCTOR:
3827    D = CXXDestructorDecl::CreateDeserialized(Context, ID);
3828    break;
3829  case DECL_CXX_CONVERSION:
3830    D = CXXConversionDecl::CreateDeserialized(Context, ID);
3831    break;
3832  case DECL_ACCESS_SPEC:
3833    D = AccessSpecDecl::CreateDeserialized(Context, ID);
3834    break;
3835  case DECL_FRIEND:
3836    D = FriendDecl::CreateDeserialized(Context, ID, Record.readInt());
3837    break;
3838  case DECL_FRIEND_TEMPLATE:
3839    D = FriendTemplateDecl::CreateDeserialized(Context, ID);
3840    break;
3841  case DECL_CLASS_TEMPLATE:
3842    D = ClassTemplateDecl::CreateDeserialized(Context, ID);
3843    break;
3844  case DECL_CLASS_TEMPLATE_SPECIALIZATION:
3845    D = ClassTemplateSpecializationDecl::CreateDeserialized(Context, ID);
3846    break;
3847  case DECL_CLASS_TEMPLATE_PARTIAL_SPECIALIZATION:
3848    D = ClassTemplatePartialSpecializationDecl::CreateDeserialized(Context, ID);
3849    break;
3850  case DECL_VAR_TEMPLATE:
3851    D = VarTemplateDecl::CreateDeserialized(Context, ID);
3852    break;
3853  case DECL_VAR_TEMPLATE_SPECIALIZATION:
3854    D = VarTemplateSpecializationDecl::CreateDeserialized(Context, ID);
3855    break;
3856  case DECL_VAR_TEMPLATE_PARTIAL_SPECIALIZATION:
3857    D = VarTemplatePartialSpecializationDecl::CreateDeserialized(Context, ID);
3858    break;
3859  case DECL_CLASS_SCOPE_FUNCTION_SPECIALIZATION:
3860    D = ClassScopeFunctionSpecializationDecl::CreateDeserialized(Context, ID);
3861    break;
3862  case DECL_FUNCTION_TEMPLATE:
3863    D = FunctionTemplateDecl::CreateDeserialized(Context, ID);
3864    break;
3865  case DECL_TEMPLATE_TYPE_PARM: {
3866    bool HasTypeConstraint = Record.readInt();
3867    D = TemplateTypeParmDecl::CreateDeserialized(Context, ID,
3868                                                 HasTypeConstraint);
3869    break;
3870  }
3871  case DECL_NON_TYPE_TEMPLATE_PARM: {
3872    bool HasTypeConstraint = Record.readInt();
3873    D = NonTypeTemplateParmDecl::CreateDeserialized(Context, ID,
3874                                                    HasTypeConstraint);
3875    break;
3876  }
3877  case DECL_EXPANDED_NON_TYPE_TEMPLATE_PARM_PACK: {
3878    bool HasTypeConstraint = Record.readInt();
3879    D = NonTypeTemplateParmDecl::CreateDeserialized(Context, ID,
3880                                                    Record.readInt(),
3881                                                    HasTypeConstraint);
3882    break;
3883  }
3884  case DECL_TEMPLATE_TEMPLATE_PARM:
3885    D = TemplateTemplateParmDecl::CreateDeserialized(Context, ID);
3886    break;
3887  case DECL_EXPANDED_TEMPLATE_TEMPLATE_PARM_PACK:
3888    D = TemplateTemplateParmDecl::CreateDeserialized(Context, ID,
3889                                                     Record.readInt());
3890    break;
3891  case DECL_TYPE_ALIAS_TEMPLATE:
3892    D = TypeAliasTemplateDecl::CreateDeserialized(Context, ID);
3893    break;
3894  case DECL_CONCEPT:
3895    D = ConceptDecl::CreateDeserialized(Context, ID);
3896    break;
3897  case DECL_REQUIRES_EXPR_BODY:
3898    D = RequiresExprBodyDecl::CreateDeserialized(Context, ID);
3899    break;
3900  case DECL_STATIC_ASSERT:
3901    D = StaticAssertDecl::CreateDeserialized(Context, ID);
3902    break;
3903  case DECL_OBJC_METHOD:
3904    D = ObjCMethodDecl::CreateDeserialized(Context, ID);
3905    break;
3906  case DECL_OBJC_INTERFACE:
3907    D = ObjCInterfaceDecl::CreateDeserialized(Context, ID);
3908    break;
3909  case DECL_OBJC_IVAR:
3910    D = ObjCIvarDecl::CreateDeserialized(Context, ID);
3911    break;
3912  case DECL_OBJC_PROTOCOL:
3913    D = ObjCProtocolDecl::CreateDeserialized(Context, ID);
3914    break;
3915  case DECL_OBJC_AT_DEFS_FIELD:
3916    D = ObjCAtDefsFieldDecl::CreateDeserialized(Context, ID);
3917    break;
3918  case DECL_OBJC_CATEGORY:
3919    D = ObjCCategoryDecl::CreateDeserialized(Context, ID);
3920    break;
3921  case DECL_OBJC_CATEGORY_IMPL:
3922    D = ObjCCategoryImplDecl::CreateDeserialized(Context, ID);
3923    break;
3924  case DECL_OBJC_IMPLEMENTATION:
3925    D = ObjCImplementationDecl::CreateDeserialized(Context, ID);
3926    break;
3927  case DECL_OBJC_COMPATIBLE_ALIAS:
3928    D = ObjCCompatibleAliasDecl::CreateDeserialized(Context, ID);
3929    break;
3930  case DECL_OBJC_PROPERTY:
3931    D = ObjCPropertyDecl::CreateDeserialized(Context, ID);
3932    break;
3933  case DECL_OBJC_PROPERTY_IMPL:
3934    D = ObjCPropertyImplDecl::CreateDeserialized(Context, ID);
3935    break;
3936  case DECL_FIELD:
3937    D = FieldDecl::CreateDeserialized(Context, ID);
3938    break;
3939  case DECL_INDIRECTFIELD:
3940    D = IndirectFieldDecl::CreateDeserialized(Context, ID);
3941    break;
3942  case DECL_VAR:
3943    D = VarDecl::CreateDeserialized(Context, ID);
3944    break;
3945  case DECL_IMPLICIT_PARAM:
3946    D = ImplicitParamDecl::CreateDeserialized(Context, ID);
3947    break;
3948  case DECL_PARM_VAR:
3949    D = ParmVarDecl::CreateDeserialized(Context, ID);
3950    break;
3951  case DECL_DECOMPOSITION:
3952    D = DecompositionDecl::CreateDeserialized(Context, ID, Record.readInt());
3953    break;
3954  case DECL_BINDING:
3955    D = BindingDecl::CreateDeserialized(Context, ID);
3956    break;
3957  case DECL_FILE_SCOPE_ASM:
3958    D = FileScopeAsmDecl::CreateDeserialized(Context, ID);
3959    break;
3960  case DECL_BLOCK:
3961    D = BlockDecl::CreateDeserialized(Context, ID);
3962    break;
3963  case DECL_MS_PROPERTY:
3964    D = MSPropertyDecl::CreateDeserialized(Context, ID);
3965    break;
3966  case DECL_CAPTURED:
3967    D = CapturedDecl::CreateDeserialized(Context, ID, Record.readInt());
3968    break;
3969  case DECL_CXX_BASE_SPECIFIERS:
3970    Error("attempt to read a C++ base-specifier record as a declaration");
3971    return nullptr;
3972  case DECL_CXX_CTOR_INITIALIZERS:
3973    Error("attempt to read a C++ ctor initializer record as a declaration");
3974    return nullptr;
3975  case DECL_IMPORT:
3976    // Note: last entry of the ImportDecl record is the number of stored source
3977    // locations.
3978    D = ImportDecl::CreateDeserialized(Context, ID, Record.back());
3979    break;
3980  case DECL_OMP_THREADPRIVATE:
3981    D = OMPThreadPrivateDecl::CreateDeserialized(Context, ID, Record.readInt());
3982    break;
3983  case DECL_OMP_ALLOCATE: {
3984    unsigned NumVars = Record.readInt();
3985    unsigned NumClauses = Record.readInt();
3986    D = OMPAllocateDecl::CreateDeserialized(Context, ID, NumVars, NumClauses);
3987    break;
3988  }
3989  case DECL_OMP_REQUIRES:
3990    D = OMPRequiresDecl::CreateDeserialized(Context, ID, Record.readInt());
3991    break;
3992  case DECL_OMP_DECLARE_REDUCTION:
3993    D = OMPDeclareReductionDecl::CreateDeserialized(Context, ID);
3994    break;
3995  case DECL_OMP_DECLARE_MAPPER:
3996    D = OMPDeclareMapperDecl::CreateDeserialized(Context, ID, Record.readInt());
3997    break;
3998  case DECL_OMP_CAPTUREDEXPR:
3999    D = OMPCapturedExprDecl::CreateDeserialized(Context, ID);
4000    break;
4001  case DECL_PRAGMA_COMMENT:
4002    D = PragmaCommentDecl::CreateDeserialized(Context, ID, Record.readInt());
4003    break;
4004  case DECL_PRAGMA_DETECT_MISMATCH:
4005    D = PragmaDetectMismatchDecl::CreateDeserialized(Context, ID,
4006                                                     Record.readInt());
4007    break;
4008  case DECL_EMPTY:
4009    D = EmptyDecl::CreateDeserialized(Context, ID);
4010    break;
4011  case DECL_LIFETIME_EXTENDED_TEMPORARY:
4012    D = LifetimeExtendedTemporaryDecl::CreateDeserialized(Context, ID);
4013    break;
4014  case DECL_OBJC_TYPE_PARAM:
4015    D = ObjCTypeParamDecl::CreateDeserialized(Context, ID);
4016    break;
4017  }
4018
4019  assert(D && "Unknown declaration reading AST file");
4020  LoadedDecl(Index, D);
4021  // Set the DeclContext before doing any deserialization, to make sure internal
4022  // calls to Decl::getASTContext() by Decl's methods will find the
4023  // TranslationUnitDecl without crashing.
4024  D->setDeclContext(Context.getTranslationUnitDecl());
4025  Reader.Visit(D);
4026
4027  // If this declaration is also a declaration context, get the
4028  // offsets for its tables of lexical and visible declarations.
4029  if (auto *DC = dyn_cast<DeclContext>(D)) {
4030    std::pair<uint64_t, uint64_t> Offsets = Reader.VisitDeclContext(DC);
4031    if (Offsets.first &&
4032        ReadLexicalDeclContextStorage(*Loc.F, DeclsCursor, Offsets.first, DC))
4033      return nullptr;
4034    if (Offsets.second &&
4035        ReadVisibleDeclContextStorage(*Loc.F, DeclsCursor, Offsets.second, ID))
4036      return nullptr;
4037  }
4038  assert(Record.getIdx() == Record.size());
4039
4040  // Load any relevant update records.
4041  PendingUpdateRecords.push_back(
4042      PendingUpdateRecord(ID, D, /*JustLoaded=*/true));
4043
4044  // Load the categories after recursive loading is finished.
4045  if (auto *Class = dyn_cast<ObjCInterfaceDecl>(D))
4046    // If we already have a definition when deserializing the ObjCInterfaceDecl,
4047    // we put the Decl in PendingDefinitions so we can pull the categories here.
4048    if (Class->isThisDeclarationADefinition() ||
4049        PendingDefinitions.count(Class))
4050      loadObjCCategories(ID, Class);
4051
4052  // If we have deserialized a declaration that has a definition the
4053  // AST consumer might need to know about, queue it.
4054  // We don't pass it to the consumer immediately because we may be in recursive
4055  // loading, and some declarations may still be initializing.
4056  PotentiallyInterestingDecls.push_back(
4057      InterestingDecl(D, Reader.hasPendingBody()));
4058
4059  return D;
4060}
4061
4062void ASTReader::PassInterestingDeclsToConsumer() {
4063  assert(Consumer);
4064
4065  if (PassingDeclsToConsumer)
4066    return;
4067
4068  // Guard variable to avoid recursively redoing the process of passing
4069  // decls to consumer.
4070  SaveAndRestore<bool> GuardPassingDeclsToConsumer(PassingDeclsToConsumer,
4071                                                   true);
4072
4073  // Ensure that we've loaded all potentially-interesting declarations
4074  // that need to be eagerly loaded.
4075  for (auto ID : EagerlyDeserializedDecls)
4076    GetDecl(ID);
4077  EagerlyDeserializedDecls.clear();
4078
4079  while (!PotentiallyInterestingDecls.empty()) {
4080    InterestingDecl D = PotentiallyInterestingDecls.front();
4081    PotentiallyInterestingDecls.pop_front();
4082    if (isConsumerInterestedIn(getContext(), D.getDecl(), D.hasPendingBody()))
4083      PassInterestingDeclToConsumer(D.getDecl());
4084  }
4085}
4086
4087void ASTReader::loadDeclUpdateRecords(PendingUpdateRecord &Record) {
4088  // The declaration may have been modified by files later in the chain.
4089  // If this is the case, read the record containing the updates from each file
4090  // and pass it to ASTDeclReader to make the modifications.
4091  serialization::GlobalDeclID ID = Record.ID;
4092  Decl *D = Record.D;
4093  ProcessingUpdatesRAIIObj ProcessingUpdates(*this);
4094  DeclUpdateOffsetsMap::iterator UpdI = DeclUpdateOffsets.find(ID);
4095
4096  SmallVector<serialization::DeclID, 8> PendingLazySpecializationIDs;
4097
4098  if (UpdI != DeclUpdateOffsets.end()) {
4099    auto UpdateOffsets = std::move(UpdI->second);
4100    DeclUpdateOffsets.erase(UpdI);
4101
4102    // Check if this decl was interesting to the consumer. If we just loaded
4103    // the declaration, then we know it was interesting and we skip the call
4104    // to isConsumerInterestedIn because it is unsafe to call in the
4105    // current ASTReader state.
4106    bool WasInteresting =
4107        Record.JustLoaded || isConsumerInterestedIn(getContext(), D, false);
4108    for (auto &FileAndOffset : UpdateOffsets) {
4109      ModuleFile *F = FileAndOffset.first;
4110      uint64_t Offset = FileAndOffset.second;
4111      llvm::BitstreamCursor &Cursor = F->DeclsCursor;
4112      SavedStreamPosition SavedPosition(Cursor);
4113      if (llvm::Error JumpFailed = Cursor.JumpToBit(Offset))
4114        // FIXME don't do a fatal error.
4115        llvm::report_fatal_error(
4116            "ASTReader::loadDeclUpdateRecords failed jumping: " +
4117            toString(std::move(JumpFailed)));
4118      Expected<unsigned> MaybeCode = Cursor.ReadCode();
4119      if (!MaybeCode)
4120        llvm::report_fatal_error(
4121            "ASTReader::loadDeclUpdateRecords failed reading code: " +
4122            toString(MaybeCode.takeError()));
4123      unsigned Code = MaybeCode.get();
4124      ASTRecordReader Record(*this, *F);
4125      if (Expected<unsigned> MaybeRecCode = Record.readRecord(Cursor, Code))
4126        assert(MaybeRecCode.get() == DECL_UPDATES &&
4127               "Expected DECL_UPDATES record!");
4128      else
4129        llvm::report_fatal_error(
4130            "ASTReader::loadDeclUpdateRecords failed reading rec code: " +
4131            toString(MaybeCode.takeError()));
4132
4133      ASTDeclReader Reader(*this, Record, RecordLocation(F, Offset), ID,
4134                           SourceLocation());
4135      Reader.UpdateDecl(D, PendingLazySpecializationIDs);
4136
4137      // We might have made this declaration interesting. If so, remember that
4138      // we need to hand it off to the consumer.
4139      if (!WasInteresting &&
4140          isConsumerInterestedIn(getContext(), D, Reader.hasPendingBody())) {
4141        PotentiallyInterestingDecls.push_back(
4142            InterestingDecl(D, Reader.hasPendingBody()));
4143        WasInteresting = true;
4144      }
4145    }
4146  }
4147  // Add the lazy specializations to the template.
4148  assert((PendingLazySpecializationIDs.empty() || isa<ClassTemplateDecl>(D) ||
4149          isa<FunctionTemplateDecl>(D) || isa<VarTemplateDecl>(D)) &&
4150         "Must not have pending specializations");
4151  if (auto *CTD = dyn_cast<ClassTemplateDecl>(D))
4152    ASTDeclReader::AddLazySpecializations(CTD, PendingLazySpecializationIDs);
4153  else if (auto *FTD = dyn_cast<FunctionTemplateDecl>(D))
4154    ASTDeclReader::AddLazySpecializations(FTD, PendingLazySpecializationIDs);
4155  else if (auto *VTD = dyn_cast<VarTemplateDecl>(D))
4156    ASTDeclReader::AddLazySpecializations(VTD, PendingLazySpecializationIDs);
4157  PendingLazySpecializationIDs.clear();
4158
4159  // Load the pending visible updates for this decl context, if it has any.
4160  auto I = PendingVisibleUpdates.find(ID);
4161  if (I != PendingVisibleUpdates.end()) {
4162    auto VisibleUpdates = std::move(I->second);
4163    PendingVisibleUpdates.erase(I);
4164
4165    auto *DC = cast<DeclContext>(D)->getPrimaryContext();
4166    for (const auto &Update : VisibleUpdates)
4167      Lookups[DC].Table.add(
4168          Update.Mod, Update.Data,
4169          reader::ASTDeclContextNameLookupTrait(*this, *Update.Mod));
4170    DC->setHasExternalVisibleStorage(true);
4171  }
4172}
4173
4174void ASTReader::loadPendingDeclChain(Decl *FirstLocal, uint64_t LocalOffset) {
4175  // Attach FirstLocal to the end of the decl chain.
4176  Decl *CanonDecl = FirstLocal->getCanonicalDecl();
4177  if (FirstLocal != CanonDecl) {
4178    Decl *PrevMostRecent = ASTDeclReader::getMostRecentDecl(CanonDecl);
4179    ASTDeclReader::attachPreviousDecl(
4180        *this, FirstLocal, PrevMostRecent ? PrevMostRecent : CanonDecl,
4181        CanonDecl);
4182  }
4183
4184  if (!LocalOffset) {
4185    ASTDeclReader::attachLatestDecl(CanonDecl, FirstLocal);
4186    return;
4187  }
4188
4189  // Load the list of other redeclarations from this module file.
4190  ModuleFile *M = getOwningModuleFile(FirstLocal);
4191  assert(M && "imported decl from no module file");
4192
4193  llvm::BitstreamCursor &Cursor = M->DeclsCursor;
4194  SavedStreamPosition SavedPosition(Cursor);
4195  if (llvm::Error JumpFailed = Cursor.JumpToBit(LocalOffset))
4196    llvm::report_fatal_error(
4197        "ASTReader::loadPendingDeclChain failed jumping: " +
4198        toString(std::move(JumpFailed)));
4199
4200  RecordData Record;
4201  Expected<unsigned> MaybeCode = Cursor.ReadCode();
4202  if (!MaybeCode)
4203    llvm::report_fatal_error(
4204        "ASTReader::loadPendingDeclChain failed reading code: " +
4205        toString(MaybeCode.takeError()));
4206  unsigned Code = MaybeCode.get();
4207  if (Expected<unsigned> MaybeRecCode = Cursor.readRecord(Code, Record))
4208    assert(MaybeRecCode.get() == LOCAL_REDECLARATIONS &&
4209           "expected LOCAL_REDECLARATIONS record!");
4210  else
4211    llvm::report_fatal_error(
4212        "ASTReader::loadPendingDeclChain failed reading rec code: " +
4213        toString(MaybeCode.takeError()));
4214
4215  // FIXME: We have several different dispatches on decl kind here; maybe
4216  // we should instead generate one loop per kind and dispatch up-front?
4217  Decl *MostRecent = FirstLocal;
4218  for (unsigned I = 0, N = Record.size(); I != N; ++I) {
4219    auto *D = GetLocalDecl(*M, Record[N - I - 1]);
4220    ASTDeclReader::attachPreviousDecl(*this, D, MostRecent, CanonDecl);
4221    MostRecent = D;
4222  }
4223  ASTDeclReader::attachLatestDecl(CanonDecl, MostRecent);
4224}
4225
4226namespace {
4227
4228  /// Given an ObjC interface, goes through the modules and links to the
4229  /// interface all the categories for it.
4230  class ObjCCategoriesVisitor {
4231    ASTReader &Reader;
4232    ObjCInterfaceDecl *Interface;
4233    llvm::SmallPtrSetImpl<ObjCCategoryDecl *> &Deserialized;
4234    ObjCCategoryDecl *Tail = nullptr;
4235    llvm::DenseMap<DeclarationName, ObjCCategoryDecl *> NameCategoryMap;
4236    serialization::GlobalDeclID InterfaceID;
4237    unsigned PreviousGeneration;
4238
4239    void add(ObjCCategoryDecl *Cat) {
4240      // Only process each category once.
4241      if (!Deserialized.erase(Cat))
4242        return;
4243
4244      // Check for duplicate categories.
4245      if (Cat->getDeclName()) {
4246        ObjCCategoryDecl *&Existing = NameCategoryMap[Cat->getDeclName()];
4247        if (Existing &&
4248            Reader.getOwningModuleFile(Existing)
4249                                          != Reader.getOwningModuleFile(Cat)) {
4250          // FIXME: We should not warn for duplicates in diamond:
4251          //
4252          //   MT     //
4253          //  /  \    //
4254          // ML  MR   //
4255          //  \  /    //
4256          //   MB     //
4257          //
4258          // If there are duplicates in ML/MR, there will be warning when
4259          // creating MB *and* when importing MB. We should not warn when
4260          // importing.
4261          Reader.Diag(Cat->getLocation(), diag::warn_dup_category_def)
4262            << Interface->getDeclName() << Cat->getDeclName();
4263          Reader.Diag(Existing->getLocation(), diag::note_previous_definition);
4264        } else if (!Existing) {
4265          // Record this category.
4266          Existing = Cat;
4267        }
4268      }
4269
4270      // Add this category to the end of the chain.
4271      if (Tail)
4272        ASTDeclReader::setNextObjCCategory(Tail, Cat);
4273      else
4274        Interface->setCategoryListRaw(Cat);
4275      Tail = Cat;
4276    }
4277
4278  public:
4279    ObjCCategoriesVisitor(ASTReader &Reader,
4280                          ObjCInterfaceDecl *Interface,
4281                          llvm::SmallPtrSetImpl<ObjCCategoryDecl *> &Deserialized,
4282                          serialization::GlobalDeclID InterfaceID,
4283                          unsigned PreviousGeneration)
4284        : Reader(Reader), Interface(Interface), Deserialized(Deserialized),
4285          InterfaceID(InterfaceID), PreviousGeneration(PreviousGeneration) {
4286      // Populate the name -> category map with the set of known categories.
4287      for (auto *Cat : Interface->known_categories()) {
4288        if (Cat->getDeclName())
4289          NameCategoryMap[Cat->getDeclName()] = Cat;
4290
4291        // Keep track of the tail of the category list.
4292        Tail = Cat;
4293      }
4294    }
4295
4296    bool operator()(ModuleFile &M) {
4297      // If we've loaded all of the category information we care about from
4298      // this module file, we're done.
4299      if (M.Generation <= PreviousGeneration)
4300        return true;
4301
4302      // Map global ID of the definition down to the local ID used in this
4303      // module file. If there is no such mapping, we'll find nothing here
4304      // (or in any module it imports).
4305      DeclID LocalID = Reader.mapGlobalIDToModuleFileGlobalID(M, InterfaceID);
4306      if (!LocalID)
4307        return true;
4308
4309      // Perform a binary search to find the local redeclarations for this
4310      // declaration (if any).
4311      const ObjCCategoriesInfo Compare = { LocalID, 0 };
4312      const ObjCCategoriesInfo *Result
4313        = std::lower_bound(M.ObjCCategoriesMap,
4314                           M.ObjCCategoriesMap + M.LocalNumObjCCategoriesInMap,
4315                           Compare);
4316      if (Result == M.ObjCCategoriesMap + M.LocalNumObjCCategoriesInMap ||
4317          Result->DefinitionID != LocalID) {
4318        // We didn't find anything. If the class definition is in this module
4319        // file, then the module files it depends on cannot have any categories,
4320        // so suppress further lookup.
4321        return Reader.isDeclIDFromModule(InterfaceID, M);
4322      }
4323
4324      // We found something. Dig out all of the categories.
4325      unsigned Offset = Result->Offset;
4326      unsigned N = M.ObjCCategories[Offset];
4327      M.ObjCCategories[Offset++] = 0; // Don't try to deserialize again
4328      for (unsigned I = 0; I != N; ++I)
4329        add(cast_or_null<ObjCCategoryDecl>(
4330              Reader.GetLocalDecl(M, M.ObjCCategories[Offset++])));
4331      return true;
4332    }
4333  };
4334
4335} // namespace
4336
4337void ASTReader::loadObjCCategories(serialization::GlobalDeclID ID,
4338                                   ObjCInterfaceDecl *D,
4339                                   unsigned PreviousGeneration) {
4340  ObjCCategoriesVisitor Visitor(*this, D, CategoriesDeserialized, ID,
4341                                PreviousGeneration);
4342  ModuleMgr.visit(Visitor);
4343}
4344
4345template<typename DeclT, typename Fn>
4346static void forAllLaterRedecls(DeclT *D, Fn F) {
4347  F(D);
4348
4349  // Check whether we've already merged D into its redeclaration chain.
4350  // MostRecent may or may not be nullptr if D has not been merged. If
4351  // not, walk the merged redecl chain and see if it's there.
4352  auto *MostRecent = D->getMostRecentDecl();
4353  bool Found = false;
4354  for (auto *Redecl = MostRecent; Redecl && !Found;
4355       Redecl = Redecl->getPreviousDecl())
4356    Found = (Redecl == D);
4357
4358  // If this declaration is merged, apply the functor to all later decls.
4359  if (Found) {
4360    for (auto *Redecl = MostRecent; Redecl != D;
4361         Redecl = Redecl->getPreviousDecl())
4362      F(Redecl);
4363  }
4364}
4365
4366void ASTDeclReader::UpdateDecl(Decl *D,
4367   llvm::SmallVectorImpl<serialization::DeclID> &PendingLazySpecializationIDs) {
4368  while (Record.getIdx() < Record.size()) {
4369    switch ((DeclUpdateKind)Record.readInt()) {
4370    case UPD_CXX_ADDED_IMPLICIT_MEMBER: {
4371      auto *RD = cast<CXXRecordDecl>(D);
4372      // FIXME: If we also have an update record for instantiating the
4373      // definition of D, we need that to happen before we get here.
4374      Decl *MD = Record.readDecl();
4375      assert(MD && "couldn't read decl from update record");
4376      // FIXME: We should call addHiddenDecl instead, to add the member
4377      // to its DeclContext.
4378      RD->addedMember(MD);
4379      break;
4380    }
4381
4382    case UPD_CXX_ADDED_TEMPLATE_SPECIALIZATION:
4383      // It will be added to the template's lazy specialization set.
4384      PendingLazySpecializationIDs.push_back(readDeclID());
4385      break;
4386
4387    case UPD_CXX_ADDED_ANONYMOUS_NAMESPACE: {
4388      auto *Anon = readDeclAs<NamespaceDecl>();
4389
4390      // Each module has its own anonymous namespace, which is disjoint from
4391      // any other module's anonymous namespaces, so don't attach the anonymous
4392      // namespace at all.
4393      if (!Record.isModule()) {
4394        if (auto *TU = dyn_cast<TranslationUnitDecl>(D))
4395          TU->setAnonymousNamespace(Anon);
4396        else
4397          cast<NamespaceDecl>(D)->setAnonymousNamespace(Anon);
4398      }
4399      break;
4400    }
4401
4402    case UPD_CXX_ADDED_VAR_DEFINITION: {
4403      auto *VD = cast<VarDecl>(D);
4404      VD->NonParmVarDeclBits.IsInline = Record.readInt();
4405      VD->NonParmVarDeclBits.IsInlineSpecified = Record.readInt();
4406      uint64_t Val = Record.readInt();
4407      if (Val && !VD->getInit()) {
4408        VD->setInit(Record.readExpr());
4409        if (Val > 1) { // IsInitKnownICE = 1, IsInitNotICE = 2, IsInitICE = 3
4410          EvaluatedStmt *Eval = VD->ensureEvaluatedStmt();
4411          Eval->CheckedICE = true;
4412          Eval->IsICE = Val == 3;
4413        }
4414      }
4415      break;
4416    }
4417
4418    case UPD_CXX_POINT_OF_INSTANTIATION: {
4419      SourceLocation POI = Record.readSourceLocation();
4420      if (auto *VTSD = dyn_cast<VarTemplateSpecializationDecl>(D)) {
4421        VTSD->setPointOfInstantiation(POI);
4422      } else if (auto *VD = dyn_cast<VarDecl>(D)) {
4423        VD->getMemberSpecializationInfo()->setPointOfInstantiation(POI);
4424      } else {
4425        auto *FD = cast<FunctionDecl>(D);
4426        if (auto *FTSInfo = FD->TemplateOrSpecialization
4427                    .dyn_cast<FunctionTemplateSpecializationInfo *>())
4428          FTSInfo->setPointOfInstantiation(POI);
4429        else
4430          FD->TemplateOrSpecialization.get<MemberSpecializationInfo *>()
4431              ->setPointOfInstantiation(POI);
4432      }
4433      break;
4434    }
4435
4436    case UPD_CXX_INSTANTIATED_DEFAULT_ARGUMENT: {
4437      auto *Param = cast<ParmVarDecl>(D);
4438
4439      // We have to read the default argument regardless of whether we use it
4440      // so that hypothetical further update records aren't messed up.
4441      // TODO: Add a function to skip over the next expr record.
4442      auto *DefaultArg = Record.readExpr();
4443
4444      // Only apply the update if the parameter still has an uninstantiated
4445      // default argument.
4446      if (Param->hasUninstantiatedDefaultArg())
4447        Param->setDefaultArg(DefaultArg);
4448      break;
4449    }
4450
4451    case UPD_CXX_INSTANTIATED_DEFAULT_MEMBER_INITIALIZER: {
4452      auto *FD = cast<FieldDecl>(D);
4453      auto *DefaultInit = Record.readExpr();
4454
4455      // Only apply the update if the field still has an uninstantiated
4456      // default member initializer.
4457      if (FD->hasInClassInitializer() && !FD->getInClassInitializer()) {
4458        if (DefaultInit)
4459          FD->setInClassInitializer(DefaultInit);
4460        else
4461          // Instantiation failed. We can get here if we serialized an AST for
4462          // an invalid program.
4463          FD->removeInClassInitializer();
4464      }
4465      break;
4466    }
4467
4468    case UPD_CXX_ADDED_FUNCTION_DEFINITION: {
4469      auto *FD = cast<FunctionDecl>(D);
4470      if (Reader.PendingBodies[FD]) {
4471        // FIXME: Maybe check for ODR violations.
4472        // It's safe to stop now because this update record is always last.
4473        return;
4474      }
4475
4476      if (Record.readInt()) {
4477        // Maintain AST consistency: any later redeclarations of this function
4478        // are inline if this one is. (We might have merged another declaration
4479        // into this one.)
4480        forAllLaterRedecls(FD, [](FunctionDecl *FD) {
4481          FD->setImplicitlyInline();
4482        });
4483      }
4484      FD->setInnerLocStart(readSourceLocation());
4485      ReadFunctionDefinition(FD);
4486      assert(Record.getIdx() == Record.size() && "lazy body must be last");
4487      break;
4488    }
4489
4490    case UPD_CXX_INSTANTIATED_CLASS_DEFINITION: {
4491      auto *RD = cast<CXXRecordDecl>(D);
4492      auto *OldDD = RD->getCanonicalDecl()->DefinitionData;
4493      bool HadRealDefinition =
4494          OldDD && (OldDD->Definition != RD ||
4495                    !Reader.PendingFakeDefinitionData.count(OldDD));
4496      RD->setParamDestroyedInCallee(Record.readInt());
4497      RD->setArgPassingRestrictions(
4498          (RecordDecl::ArgPassingKind)Record.readInt());
4499      ReadCXXRecordDefinition(RD, /*Update*/true);
4500
4501      // Visible update is handled separately.
4502      uint64_t LexicalOffset = ReadLocalOffset();
4503      if (!HadRealDefinition && LexicalOffset) {
4504        Record.readLexicalDeclContextStorage(LexicalOffset, RD);
4505        Reader.PendingFakeDefinitionData.erase(OldDD);
4506      }
4507
4508      auto TSK = (TemplateSpecializationKind)Record.readInt();
4509      SourceLocation POI = readSourceLocation();
4510      if (MemberSpecializationInfo *MSInfo =
4511              RD->getMemberSpecializationInfo()) {
4512        MSInfo->setTemplateSpecializationKind(TSK);
4513        MSInfo->setPointOfInstantiation(POI);
4514      } else {
4515        auto *Spec = cast<ClassTemplateSpecializationDecl>(RD);
4516        Spec->setTemplateSpecializationKind(TSK);
4517        Spec->setPointOfInstantiation(POI);
4518
4519        if (Record.readInt()) {
4520          auto *PartialSpec =
4521              readDeclAs<ClassTemplatePartialSpecializationDecl>();
4522          SmallVector<TemplateArgument, 8> TemplArgs;
4523          Record.readTemplateArgumentList(TemplArgs);
4524          auto *TemplArgList = TemplateArgumentList::CreateCopy(
4525              Reader.getContext(), TemplArgs);
4526
4527          // FIXME: If we already have a partial specialization set,
4528          // check that it matches.
4529          if (!Spec->getSpecializedTemplateOrPartial()
4530                   .is<ClassTemplatePartialSpecializationDecl *>())
4531            Spec->setInstantiationOf(PartialSpec, TemplArgList);
4532        }
4533      }
4534
4535      RD->setTagKind((TagTypeKind)Record.readInt());
4536      RD->setLocation(readSourceLocation());
4537      RD->setLocStart(readSourceLocation());
4538      RD->setBraceRange(readSourceRange());
4539
4540      if (Record.readInt()) {
4541        AttrVec Attrs;
4542        Record.readAttributes(Attrs);
4543        // If the declaration already has attributes, we assume that some other
4544        // AST file already loaded them.
4545        if (!D->hasAttrs())
4546          D->setAttrsImpl(Attrs, Reader.getContext());
4547      }
4548      break;
4549    }
4550
4551    case UPD_CXX_RESOLVED_DTOR_DELETE: {
4552      // Set the 'operator delete' directly to avoid emitting another update
4553      // record.
4554      auto *Del = readDeclAs<FunctionDecl>();
4555      auto *First = cast<CXXDestructorDecl>(D->getCanonicalDecl());
4556      auto *ThisArg = Record.readExpr();
4557      // FIXME: Check consistency if we have an old and new operator delete.
4558      if (!First->OperatorDelete) {
4559        First->OperatorDelete = Del;
4560        First->OperatorDeleteThisArg = ThisArg;
4561      }
4562      break;
4563    }
4564
4565    case UPD_CXX_RESOLVED_EXCEPTION_SPEC: {
4566      SmallVector<QualType, 8> ExceptionStorage;
4567      auto ESI = Record.readExceptionSpecInfo(ExceptionStorage);
4568
4569      // Update this declaration's exception specification, if needed.
4570      auto *FD = cast<FunctionDecl>(D);
4571      auto *FPT = FD->getType()->castAs<FunctionProtoType>();
4572      // FIXME: If the exception specification is already present, check that it
4573      // matches.
4574      if (isUnresolvedExceptionSpec(FPT->getExceptionSpecType())) {
4575        FD->setType(Reader.getContext().getFunctionType(
4576            FPT->getReturnType(), FPT->getParamTypes(),
4577            FPT->getExtProtoInfo().withExceptionSpec(ESI)));
4578
4579        // When we get to the end of deserializing, see if there are other decls
4580        // that we need to propagate this exception specification onto.
4581        Reader.PendingExceptionSpecUpdates.insert(
4582            std::make_pair(FD->getCanonicalDecl(), FD));
4583      }
4584      break;
4585    }
4586
4587    case UPD_CXX_DEDUCED_RETURN_TYPE: {
4588      auto *FD = cast<FunctionDecl>(D);
4589      QualType DeducedResultType = Record.readType();
4590      Reader.PendingDeducedTypeUpdates.insert(
4591          {FD->getCanonicalDecl(), DeducedResultType});
4592      break;
4593    }
4594
4595    case UPD_DECL_MARKED_USED:
4596      // Maintain AST consistency: any later redeclarations are used too.
4597      D->markUsed(Reader.getContext());
4598      break;
4599
4600    case UPD_MANGLING_NUMBER:
4601      Reader.getContext().setManglingNumber(cast<NamedDecl>(D),
4602                                            Record.readInt());
4603      break;
4604
4605    case UPD_STATIC_LOCAL_NUMBER:
4606      Reader.getContext().setStaticLocalNumber(cast<VarDecl>(D),
4607                                               Record.readInt());
4608      break;
4609
4610    case UPD_DECL_MARKED_OPENMP_THREADPRIVATE:
4611      D->addAttr(OMPThreadPrivateDeclAttr::CreateImplicit(
4612          Reader.getContext(), readSourceRange(),
4613          AttributeCommonInfo::AS_Pragma));
4614      break;
4615
4616    case UPD_DECL_MARKED_OPENMP_ALLOCATE: {
4617      auto AllocatorKind =
4618          static_cast<OMPAllocateDeclAttr::AllocatorTypeTy>(Record.readInt());
4619      Expr *Allocator = Record.readExpr();
4620      SourceRange SR = readSourceRange();
4621      D->addAttr(OMPAllocateDeclAttr::CreateImplicit(
4622          Reader.getContext(), AllocatorKind, Allocator, SR,
4623          AttributeCommonInfo::AS_Pragma));
4624      break;
4625    }
4626
4627    case UPD_DECL_EXPORTED: {
4628      unsigned SubmoduleID = readSubmoduleID();
4629      auto *Exported = cast<NamedDecl>(D);
4630      Module *Owner = SubmoduleID ? Reader.getSubmodule(SubmoduleID) : nullptr;
4631      Reader.getContext().mergeDefinitionIntoModule(Exported, Owner);
4632      Reader.PendingMergedDefinitionsToDeduplicate.insert(Exported);
4633      break;
4634    }
4635
4636    case UPD_DECL_MARKED_OPENMP_DECLARETARGET: {
4637      OMPDeclareTargetDeclAttr::MapTypeTy MapType =
4638          static_cast<OMPDeclareTargetDeclAttr::MapTypeTy>(Record.readInt());
4639      OMPDeclareTargetDeclAttr::DevTypeTy DevType =
4640          static_cast<OMPDeclareTargetDeclAttr::DevTypeTy>(Record.readInt());
4641      D->addAttr(OMPDeclareTargetDeclAttr::CreateImplicit(
4642          Reader.getContext(), MapType, DevType, readSourceRange(),
4643          AttributeCommonInfo::AS_Pragma));
4644      break;
4645    }
4646
4647    case UPD_ADDED_ATTR_TO_RECORD:
4648      AttrVec Attrs;
4649      Record.readAttributes(Attrs);
4650      assert(Attrs.size() == 1);
4651      D->addAttr(Attrs[0]);
4652      break;
4653    }
4654  }
4655}
4656