1 //===--- ASTWriterDecl.cpp - Declaration Serialization --------------------===//
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 serialization for Declarations.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "ASTCommon.h"
14 #include "clang/AST/DeclCXX.h"
15 #include "clang/AST/DeclContextInternals.h"
16 #include "clang/AST/DeclTemplate.h"
17 #include "clang/AST/DeclVisitor.h"
18 #include "clang/AST/Expr.h"
19 #include "clang/AST/OpenMPClause.h"
20 #include "clang/AST/PrettyDeclStackTrace.h"
21 #include "clang/Basic/SourceManager.h"
22 #include "clang/Serialization/ASTReader.h"
23 #include "clang/Serialization/ASTWriter.h"
24 #include "llvm/Bitcode/BitstreamWriter.h"
25 #include "llvm/Support/ErrorHandling.h"
26 using namespace clang;
27 using namespace serialization;
28 
29 //===----------------------------------------------------------------------===//
30 // Declaration serialization
31 //===----------------------------------------------------------------------===//
32 
33 namespace clang {
34   class ASTDeclWriter : public DeclVisitor<ASTDeclWriter, void> {
35     ASTWriter &Writer;
36     ASTContext &Context;
37     ASTRecordWriter Record;
38 
39     serialization::DeclCode Code;
40     unsigned AbbrevToUse;
41 
42   public:
43     ASTDeclWriter(ASTWriter &Writer, ASTContext &Context,
44                   ASTWriter::RecordDataImpl &Record)
45         : Writer(Writer), Context(Context), Record(Writer, Record),
46           Code((serialization::DeclCode)0), AbbrevToUse(0) {}
47 
48     uint64_t Emit(Decl *D) {
49       if (!Code)
50         llvm::report_fatal_error(StringRef("unexpected declaration kind '") +
51             D->getDeclKindName() + "'");
52       return Record.Emit(Code, AbbrevToUse);
53     }
54 
55     void Visit(Decl *D);
56 
57     void VisitDecl(Decl *D);
58     void VisitPragmaCommentDecl(PragmaCommentDecl *D);
59     void VisitPragmaDetectMismatchDecl(PragmaDetectMismatchDecl *D);
60     void VisitTranslationUnitDecl(TranslationUnitDecl *D);
61     void VisitNamedDecl(NamedDecl *D);
62     void VisitLabelDecl(LabelDecl *LD);
63     void VisitNamespaceDecl(NamespaceDecl *D);
64     void VisitUsingDirectiveDecl(UsingDirectiveDecl *D);
65     void VisitNamespaceAliasDecl(NamespaceAliasDecl *D);
66     void VisitTypeDecl(TypeDecl *D);
67     void VisitTypedefNameDecl(TypedefNameDecl *D);
68     void VisitTypedefDecl(TypedefDecl *D);
69     void VisitTypeAliasDecl(TypeAliasDecl *D);
70     void VisitUnresolvedUsingTypenameDecl(UnresolvedUsingTypenameDecl *D);
71     void VisitTagDecl(TagDecl *D);
72     void VisitEnumDecl(EnumDecl *D);
73     void VisitRecordDecl(RecordDecl *D);
74     void VisitCXXRecordDecl(CXXRecordDecl *D);
75     void VisitClassTemplateSpecializationDecl(
76                                             ClassTemplateSpecializationDecl *D);
77     void VisitClassTemplatePartialSpecializationDecl(
78                                      ClassTemplatePartialSpecializationDecl *D);
79     void VisitVarTemplateSpecializationDecl(VarTemplateSpecializationDecl *D);
80     void VisitVarTemplatePartialSpecializationDecl(
81         VarTemplatePartialSpecializationDecl *D);
82     void VisitClassScopeFunctionSpecializationDecl(
83                                        ClassScopeFunctionSpecializationDecl *D);
84     void VisitTemplateTypeParmDecl(TemplateTypeParmDecl *D);
85     void VisitValueDecl(ValueDecl *D);
86     void VisitEnumConstantDecl(EnumConstantDecl *D);
87     void VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D);
88     void VisitDeclaratorDecl(DeclaratorDecl *D);
89     void VisitFunctionDecl(FunctionDecl *D);
90     void VisitCXXDeductionGuideDecl(CXXDeductionGuideDecl *D);
91     void VisitCXXMethodDecl(CXXMethodDecl *D);
92     void VisitCXXConstructorDecl(CXXConstructorDecl *D);
93     void VisitCXXDestructorDecl(CXXDestructorDecl *D);
94     void VisitCXXConversionDecl(CXXConversionDecl *D);
95     void VisitFieldDecl(FieldDecl *D);
96     void VisitMSPropertyDecl(MSPropertyDecl *D);
97     void VisitIndirectFieldDecl(IndirectFieldDecl *D);
98     void VisitVarDecl(VarDecl *D);
99     void VisitImplicitParamDecl(ImplicitParamDecl *D);
100     void VisitParmVarDecl(ParmVarDecl *D);
101     void VisitDecompositionDecl(DecompositionDecl *D);
102     void VisitBindingDecl(BindingDecl *D);
103     void VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D);
104     void VisitTemplateDecl(TemplateDecl *D);
105     void VisitRedeclarableTemplateDecl(RedeclarableTemplateDecl *D);
106     void VisitClassTemplateDecl(ClassTemplateDecl *D);
107     void VisitVarTemplateDecl(VarTemplateDecl *D);
108     void VisitFunctionTemplateDecl(FunctionTemplateDecl *D);
109     void VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D);
110     void VisitTypeAliasTemplateDecl(TypeAliasTemplateDecl *D);
111     void VisitUsingDecl(UsingDecl *D);
112     void VisitUsingPackDecl(UsingPackDecl *D);
113     void VisitUsingShadowDecl(UsingShadowDecl *D);
114     void VisitConstructorUsingShadowDecl(ConstructorUsingShadowDecl *D);
115     void VisitLinkageSpecDecl(LinkageSpecDecl *D);
116     void VisitExportDecl(ExportDecl *D);
117     void VisitFileScopeAsmDecl(FileScopeAsmDecl *D);
118     void VisitImportDecl(ImportDecl *D);
119     void VisitAccessSpecDecl(AccessSpecDecl *D);
120     void VisitFriendDecl(FriendDecl *D);
121     void VisitFriendTemplateDecl(FriendTemplateDecl *D);
122     void VisitStaticAssertDecl(StaticAssertDecl *D);
123     void VisitBlockDecl(BlockDecl *D);
124     void VisitCapturedDecl(CapturedDecl *D);
125     void VisitEmptyDecl(EmptyDecl *D);
126 
127     void VisitDeclContext(DeclContext *DC);
128     template <typename T> void VisitRedeclarable(Redeclarable<T> *D);
129 
130 
131     // FIXME: Put in the same order is DeclNodes.td?
132     void VisitObjCMethodDecl(ObjCMethodDecl *D);
133     void VisitObjCTypeParamDecl(ObjCTypeParamDecl *D);
134     void VisitObjCContainerDecl(ObjCContainerDecl *D);
135     void VisitObjCInterfaceDecl(ObjCInterfaceDecl *D);
136     void VisitObjCIvarDecl(ObjCIvarDecl *D);
137     void VisitObjCProtocolDecl(ObjCProtocolDecl *D);
138     void VisitObjCAtDefsFieldDecl(ObjCAtDefsFieldDecl *D);
139     void VisitObjCCategoryDecl(ObjCCategoryDecl *D);
140     void VisitObjCImplDecl(ObjCImplDecl *D);
141     void VisitObjCCategoryImplDecl(ObjCCategoryImplDecl *D);
142     void VisitObjCImplementationDecl(ObjCImplementationDecl *D);
143     void VisitObjCCompatibleAliasDecl(ObjCCompatibleAliasDecl *D);
144     void VisitObjCPropertyDecl(ObjCPropertyDecl *D);
145     void VisitObjCPropertyImplDecl(ObjCPropertyImplDecl *D);
146     void VisitOMPThreadPrivateDecl(OMPThreadPrivateDecl *D);
147     void VisitOMPAllocateDecl(OMPAllocateDecl *D);
148     void VisitOMPRequiresDecl(OMPRequiresDecl *D);
149     void VisitOMPDeclareReductionDecl(OMPDeclareReductionDecl *D);
150     void VisitOMPDeclareMapperDecl(OMPDeclareMapperDecl *D);
151     void VisitOMPCapturedExprDecl(OMPCapturedExprDecl *D);
152 
153     /// Add an Objective-C type parameter list to the given record.
154     void AddObjCTypeParamList(ObjCTypeParamList *typeParams) {
155       // Empty type parameter list.
156       if (!typeParams) {
157         Record.push_back(0);
158         return;
159       }
160 
161       Record.push_back(typeParams->size());
162       for (auto typeParam : *typeParams) {
163         Record.AddDeclRef(typeParam);
164       }
165       Record.AddSourceLocation(typeParams->getLAngleLoc());
166       Record.AddSourceLocation(typeParams->getRAngleLoc());
167     }
168 
169     /// Add to the record the first declaration from each module file that
170     /// provides a declaration of D. The intent is to provide a sufficient
171     /// set such that reloading this set will load all current redeclarations.
172     void AddFirstDeclFromEachModule(const Decl *D, bool IncludeLocal) {
173       llvm::MapVector<ModuleFile*, const Decl*> Firsts;
174       // FIXME: We can skip entries that we know are implied by others.
175       for (const Decl *R = D->getMostRecentDecl(); R; R = R->getPreviousDecl()) {
176         if (R->isFromASTFile())
177           Firsts[Writer.Chain->getOwningModuleFile(R)] = R;
178         else if (IncludeLocal)
179           Firsts[nullptr] = R;
180       }
181       for (const auto &F : Firsts)
182         Record.AddDeclRef(F.second);
183     }
184 
185     /// Get the specialization decl from an entry in the specialization list.
186     template <typename EntryType>
187     typename RedeclarableTemplateDecl::SpecEntryTraits<EntryType>::DeclType *
188     getSpecializationDecl(EntryType &T) {
189       return RedeclarableTemplateDecl::SpecEntryTraits<EntryType>::getDecl(&T);
190     }
191 
192     /// Get the list of partial specializations from a template's common ptr.
193     template<typename T>
194     decltype(T::PartialSpecializations) &getPartialSpecializations(T *Common) {
195       return Common->PartialSpecializations;
196     }
197     ArrayRef<Decl> getPartialSpecializations(FunctionTemplateDecl::Common *) {
198       return None;
199     }
200 
201     template<typename DeclTy>
202     void AddTemplateSpecializations(DeclTy *D) {
203       auto *Common = D->getCommonPtr();
204 
205       // If we have any lazy specializations, and the external AST source is
206       // our chained AST reader, we can just write out the DeclIDs. Otherwise,
207       // we need to resolve them to actual declarations.
208       if (Writer.Chain != Writer.Context->getExternalSource() &&
209           Common->LazySpecializations) {
210         D->LoadLazySpecializations();
211         assert(!Common->LazySpecializations);
212       }
213 
214       ArrayRef<DeclID> LazySpecializations;
215       if (auto *LS = Common->LazySpecializations)
216         LazySpecializations = llvm::makeArrayRef(LS + 1, LS[0]);
217 
218       // Add a slot to the record for the number of specializations.
219       unsigned I = Record.size();
220       Record.push_back(0);
221 
222       // AddFirstDeclFromEachModule might trigger deserialization, invalidating
223       // *Specializations iterators.
224       llvm::SmallVector<const Decl*, 16> Specs;
225       for (auto &Entry : Common->Specializations)
226         Specs.push_back(getSpecializationDecl(Entry));
227       for (auto &Entry : getPartialSpecializations(Common))
228         Specs.push_back(getSpecializationDecl(Entry));
229 
230       for (auto *D : Specs) {
231         assert(D->isCanonicalDecl() && "non-canonical decl in set");
232         AddFirstDeclFromEachModule(D, /*IncludeLocal*/true);
233       }
234       Record.append(LazySpecializations.begin(), LazySpecializations.end());
235 
236       // Update the size entry we added earlier.
237       Record[I] = Record.size() - I - 1;
238     }
239 
240     /// Ensure that this template specialization is associated with the specified
241     /// template on reload.
242     void RegisterTemplateSpecialization(const Decl *Template,
243                                         const Decl *Specialization) {
244       Template = Template->getCanonicalDecl();
245 
246       // If the canonical template is local, we'll write out this specialization
247       // when we emit it.
248       // FIXME: We can do the same thing if there is any local declaration of
249       // the template, to avoid emitting an update record.
250       if (!Template->isFromASTFile())
251         return;
252 
253       // We only need to associate the first local declaration of the
254       // specialization. The other declarations will get pulled in by it.
255       if (Writer.getFirstLocalDecl(Specialization) != Specialization)
256         return;
257 
258       Writer.DeclUpdates[Template].push_back(ASTWriter::DeclUpdate(
259           UPD_CXX_ADDED_TEMPLATE_SPECIALIZATION, Specialization));
260     }
261   };
262 }
263 
264 void ASTDeclWriter::Visit(Decl *D) {
265   DeclVisitor<ASTDeclWriter>::Visit(D);
266 
267   // Source locations require array (variable-length) abbreviations.  The
268   // abbreviation infrastructure requires that arrays are encoded last, so
269   // we handle it here in the case of those classes derived from DeclaratorDecl
270   if (DeclaratorDecl *DD = dyn_cast<DeclaratorDecl>(D)) {
271     if (auto *TInfo = DD->getTypeSourceInfo())
272       Record.AddTypeLoc(TInfo->getTypeLoc());
273   }
274 
275   // Handle FunctionDecl's body here and write it after all other Stmts/Exprs
276   // have been written. We want it last because we will not read it back when
277   // retrieving it from the AST, we'll just lazily set the offset.
278   if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
279     Record.push_back(FD->doesThisDeclarationHaveABody());
280     if (FD->doesThisDeclarationHaveABody())
281       Record.AddFunctionDefinition(FD);
282   }
283 
284   // If this declaration is also a DeclContext, write blocks for the
285   // declarations that lexically stored inside its context and those
286   // declarations that are visible from its context.
287   if (DeclContext *DC = dyn_cast<DeclContext>(D))
288     VisitDeclContext(DC);
289 }
290 
291 void ASTDeclWriter::VisitDecl(Decl *D) {
292   Record.AddDeclRef(cast_or_null<Decl>(D->getDeclContext()));
293   if (D->getDeclContext() != D->getLexicalDeclContext())
294     Record.AddDeclRef(cast_or_null<Decl>(D->getLexicalDeclContext()));
295   else
296     Record.push_back(0);
297   Record.push_back(D->isInvalidDecl());
298   Record.push_back(D->hasAttrs());
299   if (D->hasAttrs())
300     Record.AddAttributes(D->getAttrs());
301   Record.push_back(D->isImplicit());
302   Record.push_back(D->isUsed(false));
303   Record.push_back(D->isReferenced());
304   Record.push_back(D->isTopLevelDeclInObjCContainer());
305   Record.push_back(D->getAccess());
306   Record.push_back(D->isModulePrivate());
307   Record.push_back(Writer.getSubmoduleID(D->getOwningModule()));
308 
309   // If this declaration injected a name into a context different from its
310   // lexical context, and that context is an imported namespace, we need to
311   // update its visible declarations to include this name.
312   //
313   // This happens when we instantiate a class with a friend declaration or a
314   // function with a local extern declaration, for instance.
315   //
316   // FIXME: Can we handle this in AddedVisibleDecl instead?
317   if (D->isOutOfLine()) {
318     auto *DC = D->getDeclContext();
319     while (auto *NS = dyn_cast<NamespaceDecl>(DC->getRedeclContext())) {
320       if (!NS->isFromASTFile())
321         break;
322       Writer.UpdatedDeclContexts.insert(NS->getPrimaryContext());
323       if (!NS->isInlineNamespace())
324         break;
325       DC = NS->getParent();
326     }
327   }
328 }
329 
330 void ASTDeclWriter::VisitPragmaCommentDecl(PragmaCommentDecl *D) {
331   StringRef Arg = D->getArg();
332   Record.push_back(Arg.size());
333   VisitDecl(D);
334   Record.AddSourceLocation(D->getBeginLoc());
335   Record.push_back(D->getCommentKind());
336   Record.AddString(Arg);
337   Code = serialization::DECL_PRAGMA_COMMENT;
338 }
339 
340 void ASTDeclWriter::VisitPragmaDetectMismatchDecl(
341     PragmaDetectMismatchDecl *D) {
342   StringRef Name = D->getName();
343   StringRef Value = D->getValue();
344   Record.push_back(Name.size() + 1 + Value.size());
345   VisitDecl(D);
346   Record.AddSourceLocation(D->getBeginLoc());
347   Record.AddString(Name);
348   Record.AddString(Value);
349   Code = serialization::DECL_PRAGMA_DETECT_MISMATCH;
350 }
351 
352 void ASTDeclWriter::VisitTranslationUnitDecl(TranslationUnitDecl *D) {
353   llvm_unreachable("Translation units aren't directly serialized");
354 }
355 
356 void ASTDeclWriter::VisitNamedDecl(NamedDecl *D) {
357   VisitDecl(D);
358   Record.AddDeclarationName(D->getDeclName());
359   Record.push_back(needsAnonymousDeclarationNumber(D)
360                        ? Writer.getAnonymousDeclarationNumber(D)
361                        : 0);
362 }
363 
364 void ASTDeclWriter::VisitTypeDecl(TypeDecl *D) {
365   VisitNamedDecl(D);
366   Record.AddSourceLocation(D->getBeginLoc());
367   Record.AddTypeRef(QualType(D->getTypeForDecl(), 0));
368 }
369 
370 void ASTDeclWriter::VisitTypedefNameDecl(TypedefNameDecl *D) {
371   VisitRedeclarable(D);
372   VisitTypeDecl(D);
373   Record.AddTypeSourceInfo(D->getTypeSourceInfo());
374   Record.push_back(D->isModed());
375   if (D->isModed())
376     Record.AddTypeRef(D->getUnderlyingType());
377   Record.AddDeclRef(D->getAnonDeclWithTypedefName(false));
378 }
379 
380 void ASTDeclWriter::VisitTypedefDecl(TypedefDecl *D) {
381   VisitTypedefNameDecl(D);
382   if (D->getDeclContext() == D->getLexicalDeclContext() &&
383       !D->hasAttrs() &&
384       !D->isImplicit() &&
385       D->getFirstDecl() == D->getMostRecentDecl() &&
386       !D->isInvalidDecl() &&
387       !D->isTopLevelDeclInObjCContainer() &&
388       !D->isModulePrivate() &&
389       !needsAnonymousDeclarationNumber(D) &&
390       D->getDeclName().getNameKind() == DeclarationName::Identifier)
391     AbbrevToUse = Writer.getDeclTypedefAbbrev();
392 
393   Code = serialization::DECL_TYPEDEF;
394 }
395 
396 void ASTDeclWriter::VisitTypeAliasDecl(TypeAliasDecl *D) {
397   VisitTypedefNameDecl(D);
398   Record.AddDeclRef(D->getDescribedAliasTemplate());
399   Code = serialization::DECL_TYPEALIAS;
400 }
401 
402 void ASTDeclWriter::VisitTagDecl(TagDecl *D) {
403   VisitRedeclarable(D);
404   VisitTypeDecl(D);
405   Record.push_back(D->getIdentifierNamespace());
406   Record.push_back((unsigned)D->getTagKind()); // FIXME: stable encoding
407   if (!isa<CXXRecordDecl>(D))
408     Record.push_back(D->isCompleteDefinition());
409   Record.push_back(D->isEmbeddedInDeclarator());
410   Record.push_back(D->isFreeStanding());
411   Record.push_back(D->isCompleteDefinitionRequired());
412   Record.AddSourceRange(D->getBraceRange());
413 
414   if (D->hasExtInfo()) {
415     Record.push_back(1);
416     Record.AddQualifierInfo(*D->getExtInfo());
417   } else if (auto *TD = D->getTypedefNameForAnonDecl()) {
418     Record.push_back(2);
419     Record.AddDeclRef(TD);
420     Record.AddIdentifierRef(TD->getDeclName().getAsIdentifierInfo());
421   } else {
422     Record.push_back(0);
423   }
424 }
425 
426 void ASTDeclWriter::VisitEnumDecl(EnumDecl *D) {
427   VisitTagDecl(D);
428   Record.AddTypeSourceInfo(D->getIntegerTypeSourceInfo());
429   if (!D->getIntegerTypeSourceInfo())
430     Record.AddTypeRef(D->getIntegerType());
431   Record.AddTypeRef(D->getPromotionType());
432   Record.push_back(D->getNumPositiveBits());
433   Record.push_back(D->getNumNegativeBits());
434   Record.push_back(D->isScoped());
435   Record.push_back(D->isScopedUsingClassTag());
436   Record.push_back(D->isFixed());
437   Record.push_back(D->getODRHash());
438 
439   if (MemberSpecializationInfo *MemberInfo = D->getMemberSpecializationInfo()) {
440     Record.AddDeclRef(MemberInfo->getInstantiatedFrom());
441     Record.push_back(MemberInfo->getTemplateSpecializationKind());
442     Record.AddSourceLocation(MemberInfo->getPointOfInstantiation());
443   } else {
444     Record.AddDeclRef(nullptr);
445   }
446 
447   if (D->getDeclContext() == D->getLexicalDeclContext() &&
448       !D->hasAttrs() &&
449       !D->isImplicit() &&
450       !D->isUsed(false) &&
451       !D->hasExtInfo() &&
452       !D->getTypedefNameForAnonDecl() &&
453       D->getFirstDecl() == D->getMostRecentDecl() &&
454       !D->isInvalidDecl() &&
455       !D->isReferenced() &&
456       !D->isTopLevelDeclInObjCContainer() &&
457       D->getAccess() == AS_none &&
458       !D->isModulePrivate() &&
459       !CXXRecordDecl::classofKind(D->getKind()) &&
460       !D->getIntegerTypeSourceInfo() &&
461       !D->getMemberSpecializationInfo() &&
462       !needsAnonymousDeclarationNumber(D) &&
463       D->getDeclName().getNameKind() == DeclarationName::Identifier)
464     AbbrevToUse = Writer.getDeclEnumAbbrev();
465 
466   Code = serialization::DECL_ENUM;
467 }
468 
469 void ASTDeclWriter::VisitRecordDecl(RecordDecl *D) {
470   VisitTagDecl(D);
471   Record.push_back(D->hasFlexibleArrayMember());
472   Record.push_back(D->isAnonymousStructOrUnion());
473   Record.push_back(D->hasObjectMember());
474   Record.push_back(D->hasVolatileMember());
475   Record.push_back(D->isNonTrivialToPrimitiveDefaultInitialize());
476   Record.push_back(D->isNonTrivialToPrimitiveCopy());
477   Record.push_back(D->isNonTrivialToPrimitiveDestroy());
478   Record.push_back(D->isParamDestroyedInCallee());
479   Record.push_back(D->getArgPassingRestrictions());
480 
481   if (D->getDeclContext() == D->getLexicalDeclContext() &&
482       !D->hasAttrs() &&
483       !D->isImplicit() &&
484       !D->isUsed(false) &&
485       !D->hasExtInfo() &&
486       !D->getTypedefNameForAnonDecl() &&
487       D->getFirstDecl() == D->getMostRecentDecl() &&
488       !D->isInvalidDecl() &&
489       !D->isReferenced() &&
490       !D->isTopLevelDeclInObjCContainer() &&
491       D->getAccess() == AS_none &&
492       !D->isModulePrivate() &&
493       !CXXRecordDecl::classofKind(D->getKind()) &&
494       !needsAnonymousDeclarationNumber(D) &&
495       D->getDeclName().getNameKind() == DeclarationName::Identifier)
496     AbbrevToUse = Writer.getDeclRecordAbbrev();
497 
498   Code = serialization::DECL_RECORD;
499 }
500 
501 void ASTDeclWriter::VisitValueDecl(ValueDecl *D) {
502   VisitNamedDecl(D);
503   Record.AddTypeRef(D->getType());
504 }
505 
506 void ASTDeclWriter::VisitEnumConstantDecl(EnumConstantDecl *D) {
507   VisitValueDecl(D);
508   Record.push_back(D->getInitExpr()? 1 : 0);
509   if (D->getInitExpr())
510     Record.AddStmt(D->getInitExpr());
511   Record.AddAPSInt(D->getInitVal());
512 
513   Code = serialization::DECL_ENUM_CONSTANT;
514 }
515 
516 void ASTDeclWriter::VisitDeclaratorDecl(DeclaratorDecl *D) {
517   VisitValueDecl(D);
518   Record.AddSourceLocation(D->getInnerLocStart());
519   Record.push_back(D->hasExtInfo());
520   if (D->hasExtInfo())
521     Record.AddQualifierInfo(*D->getExtInfo());
522   // The location information is deferred until the end of the record.
523   Record.AddTypeRef(D->getTypeSourceInfo() ? D->getTypeSourceInfo()->getType()
524                                            : QualType());
525 }
526 
527 void ASTDeclWriter::VisitFunctionDecl(FunctionDecl *D) {
528   VisitRedeclarable(D);
529   VisitDeclaratorDecl(D);
530   Record.AddDeclarationNameLoc(D->DNLoc, D->getDeclName());
531   Record.push_back(D->getIdentifierNamespace());
532 
533   // FunctionDecl's body is handled last at ASTWriterDecl::Visit,
534   // after everything else is written.
535   Record.push_back(static_cast<int>(D->getStorageClass())); // FIXME: stable encoding
536   Record.push_back(D->isInlineSpecified());
537   Record.push_back(D->isInlined());
538   Record.push_back(D->isVirtualAsWritten());
539   Record.push_back(D->isPure());
540   Record.push_back(D->hasInheritedPrototype());
541   Record.push_back(D->hasWrittenPrototype());
542   Record.push_back(D->isDeletedBit());
543   Record.push_back(D->isTrivial());
544   Record.push_back(D->isTrivialForCall());
545   Record.push_back(D->isDefaulted());
546   Record.push_back(D->isExplicitlyDefaulted());
547   Record.push_back(D->hasImplicitReturnZero());
548   Record.push_back(D->isConstexpr());
549   Record.push_back(D->usesSEHTry());
550   Record.push_back(D->hasSkippedBody());
551   Record.push_back(D->isMultiVersion());
552   Record.push_back(D->isLateTemplateParsed());
553   Record.push_back(D->getLinkageInternal());
554   Record.AddSourceLocation(D->getEndLoc());
555 
556   Record.push_back(D->getODRHash());
557 
558   Record.push_back(D->getTemplatedKind());
559   switch (D->getTemplatedKind()) {
560   case FunctionDecl::TK_NonTemplate:
561     break;
562   case FunctionDecl::TK_FunctionTemplate:
563     Record.AddDeclRef(D->getDescribedFunctionTemplate());
564     break;
565   case FunctionDecl::TK_MemberSpecialization: {
566     MemberSpecializationInfo *MemberInfo = D->getMemberSpecializationInfo();
567     Record.AddDeclRef(MemberInfo->getInstantiatedFrom());
568     Record.push_back(MemberInfo->getTemplateSpecializationKind());
569     Record.AddSourceLocation(MemberInfo->getPointOfInstantiation());
570     break;
571   }
572   case FunctionDecl::TK_FunctionTemplateSpecialization: {
573     FunctionTemplateSpecializationInfo *
574       FTSInfo = D->getTemplateSpecializationInfo();
575 
576     RegisterTemplateSpecialization(FTSInfo->getTemplate(), D);
577 
578     Record.AddDeclRef(FTSInfo->getTemplate());
579     Record.push_back(FTSInfo->getTemplateSpecializationKind());
580 
581     // Template arguments.
582     Record.AddTemplateArgumentList(FTSInfo->TemplateArguments);
583 
584     // Template args as written.
585     Record.push_back(FTSInfo->TemplateArgumentsAsWritten != nullptr);
586     if (FTSInfo->TemplateArgumentsAsWritten) {
587       Record.push_back(FTSInfo->TemplateArgumentsAsWritten->NumTemplateArgs);
588       for (int i=0, e = FTSInfo->TemplateArgumentsAsWritten->NumTemplateArgs;
589              i!=e; ++i)
590         Record.AddTemplateArgumentLoc(
591             (*FTSInfo->TemplateArgumentsAsWritten)[i]);
592       Record.AddSourceLocation(FTSInfo->TemplateArgumentsAsWritten->LAngleLoc);
593       Record.AddSourceLocation(FTSInfo->TemplateArgumentsAsWritten->RAngleLoc);
594     }
595 
596     Record.AddSourceLocation(FTSInfo->getPointOfInstantiation());
597 
598     if (MemberSpecializationInfo *MemberInfo =
599         FTSInfo->getMemberSpecializationInfo()) {
600       Record.push_back(1);
601       Record.AddDeclRef(MemberInfo->getInstantiatedFrom());
602       Record.push_back(MemberInfo->getTemplateSpecializationKind());
603       Record.AddSourceLocation(MemberInfo->getPointOfInstantiation());
604     } else {
605       Record.push_back(0);
606     }
607 
608     if (D->isCanonicalDecl()) {
609       // Write the template that contains the specializations set. We will
610       // add a FunctionTemplateSpecializationInfo to it when reading.
611       Record.AddDeclRef(FTSInfo->getTemplate()->getCanonicalDecl());
612     }
613     break;
614   }
615   case FunctionDecl::TK_DependentFunctionTemplateSpecialization: {
616     DependentFunctionTemplateSpecializationInfo *
617       DFTSInfo = D->getDependentSpecializationInfo();
618 
619     // Templates.
620     Record.push_back(DFTSInfo->getNumTemplates());
621     for (int i=0, e = DFTSInfo->getNumTemplates(); i != e; ++i)
622       Record.AddDeclRef(DFTSInfo->getTemplate(i));
623 
624     // Templates args.
625     Record.push_back(DFTSInfo->getNumTemplateArgs());
626     for (int i=0, e = DFTSInfo->getNumTemplateArgs(); i != e; ++i)
627       Record.AddTemplateArgumentLoc(DFTSInfo->getTemplateArg(i));
628     Record.AddSourceLocation(DFTSInfo->getLAngleLoc());
629     Record.AddSourceLocation(DFTSInfo->getRAngleLoc());
630     break;
631   }
632   }
633 
634   Record.push_back(D->param_size());
635   for (auto P : D->parameters())
636     Record.AddDeclRef(P);
637   Code = serialization::DECL_FUNCTION;
638 }
639 
640 static void addExplicitSpecifier(ExplicitSpecifier ES,
641                                  ASTRecordWriter &Record) {
642   uint64_t Kind = static_cast<uint64_t>(ES.getKind());
643   Kind = Kind << 1 | static_cast<bool>(ES.getExpr());
644   Record.push_back(Kind);
645   if (ES.getExpr()) {
646     Record.AddStmt(ES.getExpr());
647   }
648 }
649 
650 void ASTDeclWriter::VisitCXXDeductionGuideDecl(CXXDeductionGuideDecl *D) {
651   addExplicitSpecifier(D->getExplicitSpecifier(), Record);
652   VisitFunctionDecl(D);
653   Record.push_back(D->isCopyDeductionCandidate());
654   Code = serialization::DECL_CXX_DEDUCTION_GUIDE;
655 }
656 
657 void ASTDeclWriter::VisitObjCMethodDecl(ObjCMethodDecl *D) {
658   VisitNamedDecl(D);
659   // FIXME: convert to LazyStmtPtr?
660   // Unlike C/C++, method bodies will never be in header files.
661   bool HasBodyStuff = D->getBody() != nullptr     ||
662                       D->getSelfDecl() != nullptr || D->getCmdDecl() != nullptr;
663   Record.push_back(HasBodyStuff);
664   if (HasBodyStuff) {
665     Record.AddStmt(D->getBody());
666     Record.AddDeclRef(D->getSelfDecl());
667     Record.AddDeclRef(D->getCmdDecl());
668   }
669   Record.push_back(D->isInstanceMethod());
670   Record.push_back(D->isVariadic());
671   Record.push_back(D->isPropertyAccessor());
672   Record.push_back(D->isDefined());
673   Record.push_back(D->isOverriding());
674   Record.push_back(D->hasSkippedBody());
675 
676   Record.push_back(D->isRedeclaration());
677   Record.push_back(D->hasRedeclaration());
678   if (D->hasRedeclaration()) {
679     assert(Context.getObjCMethodRedeclaration(D));
680     Record.AddDeclRef(Context.getObjCMethodRedeclaration(D));
681   }
682 
683   // FIXME: stable encoding for @required/@optional
684   Record.push_back(D->getImplementationControl());
685   // FIXME: stable encoding for in/out/inout/bycopy/byref/oneway/nullability
686   Record.push_back(D->getObjCDeclQualifier());
687   Record.push_back(D->hasRelatedResultType());
688   Record.AddTypeRef(D->getReturnType());
689   Record.AddTypeSourceInfo(D->getReturnTypeSourceInfo());
690   Record.AddSourceLocation(D->getEndLoc());
691   Record.push_back(D->param_size());
692   for (const auto *P : D->parameters())
693     Record.AddDeclRef(P);
694 
695   Record.push_back(D->getSelLocsKind());
696   unsigned NumStoredSelLocs = D->getNumStoredSelLocs();
697   SourceLocation *SelLocs = D->getStoredSelLocs();
698   Record.push_back(NumStoredSelLocs);
699   for (unsigned i = 0; i != NumStoredSelLocs; ++i)
700     Record.AddSourceLocation(SelLocs[i]);
701 
702   Code = serialization::DECL_OBJC_METHOD;
703 }
704 
705 void ASTDeclWriter::VisitObjCTypeParamDecl(ObjCTypeParamDecl *D) {
706   VisitTypedefNameDecl(D);
707   Record.push_back(D->Variance);
708   Record.push_back(D->Index);
709   Record.AddSourceLocation(D->VarianceLoc);
710   Record.AddSourceLocation(D->ColonLoc);
711 
712   Code = serialization::DECL_OBJC_TYPE_PARAM;
713 }
714 
715 void ASTDeclWriter::VisitObjCContainerDecl(ObjCContainerDecl *D) {
716   VisitNamedDecl(D);
717   Record.AddSourceLocation(D->getAtStartLoc());
718   Record.AddSourceRange(D->getAtEndRange());
719   // Abstract class (no need to define a stable serialization::DECL code).
720 }
721 
722 void ASTDeclWriter::VisitObjCInterfaceDecl(ObjCInterfaceDecl *D) {
723   VisitRedeclarable(D);
724   VisitObjCContainerDecl(D);
725   Record.AddTypeRef(QualType(D->getTypeForDecl(), 0));
726   AddObjCTypeParamList(D->TypeParamList);
727 
728   Record.push_back(D->isThisDeclarationADefinition());
729   if (D->isThisDeclarationADefinition()) {
730     // Write the DefinitionData
731     ObjCInterfaceDecl::DefinitionData &Data = D->data();
732 
733     Record.AddTypeSourceInfo(D->getSuperClassTInfo());
734     Record.AddSourceLocation(D->getEndOfDefinitionLoc());
735     Record.push_back(Data.HasDesignatedInitializers);
736 
737     // Write out the protocols that are directly referenced by the @interface.
738     Record.push_back(Data.ReferencedProtocols.size());
739     for (const auto *P : D->protocols())
740       Record.AddDeclRef(P);
741     for (const auto &PL : D->protocol_locs())
742       Record.AddSourceLocation(PL);
743 
744     // Write out the protocols that are transitively referenced.
745     Record.push_back(Data.AllReferencedProtocols.size());
746     for (ObjCList<ObjCProtocolDecl>::iterator
747               P = Data.AllReferencedProtocols.begin(),
748            PEnd = Data.AllReferencedProtocols.end();
749          P != PEnd; ++P)
750       Record.AddDeclRef(*P);
751 
752 
753     if (ObjCCategoryDecl *Cat = D->getCategoryListRaw()) {
754       // Ensure that we write out the set of categories for this class.
755       Writer.ObjCClassesWithCategories.insert(D);
756 
757       // Make sure that the categories get serialized.
758       for (; Cat; Cat = Cat->getNextClassCategoryRaw())
759         (void)Writer.GetDeclRef(Cat);
760     }
761   }
762 
763   Code = serialization::DECL_OBJC_INTERFACE;
764 }
765 
766 void ASTDeclWriter::VisitObjCIvarDecl(ObjCIvarDecl *D) {
767   VisitFieldDecl(D);
768   // FIXME: stable encoding for @public/@private/@protected/@package
769   Record.push_back(D->getAccessControl());
770   Record.push_back(D->getSynthesize());
771 
772   if (D->getDeclContext() == D->getLexicalDeclContext() &&
773       !D->hasAttrs() &&
774       !D->isImplicit() &&
775       !D->isUsed(false) &&
776       !D->isInvalidDecl() &&
777       !D->isReferenced() &&
778       !D->isModulePrivate() &&
779       !D->getBitWidth() &&
780       !D->hasExtInfo() &&
781       D->getDeclName())
782     AbbrevToUse = Writer.getDeclObjCIvarAbbrev();
783 
784   Code = serialization::DECL_OBJC_IVAR;
785 }
786 
787 void ASTDeclWriter::VisitObjCProtocolDecl(ObjCProtocolDecl *D) {
788   VisitRedeclarable(D);
789   VisitObjCContainerDecl(D);
790 
791   Record.push_back(D->isThisDeclarationADefinition());
792   if (D->isThisDeclarationADefinition()) {
793     Record.push_back(D->protocol_size());
794     for (const auto *I : D->protocols())
795       Record.AddDeclRef(I);
796     for (const auto &PL : D->protocol_locs())
797       Record.AddSourceLocation(PL);
798   }
799 
800   Code = serialization::DECL_OBJC_PROTOCOL;
801 }
802 
803 void ASTDeclWriter::VisitObjCAtDefsFieldDecl(ObjCAtDefsFieldDecl *D) {
804   VisitFieldDecl(D);
805   Code = serialization::DECL_OBJC_AT_DEFS_FIELD;
806 }
807 
808 void ASTDeclWriter::VisitObjCCategoryDecl(ObjCCategoryDecl *D) {
809   VisitObjCContainerDecl(D);
810   Record.AddSourceLocation(D->getCategoryNameLoc());
811   Record.AddSourceLocation(D->getIvarLBraceLoc());
812   Record.AddSourceLocation(D->getIvarRBraceLoc());
813   Record.AddDeclRef(D->getClassInterface());
814   AddObjCTypeParamList(D->TypeParamList);
815   Record.push_back(D->protocol_size());
816   for (const auto *I : D->protocols())
817     Record.AddDeclRef(I);
818   for (const auto &PL : D->protocol_locs())
819     Record.AddSourceLocation(PL);
820   Code = serialization::DECL_OBJC_CATEGORY;
821 }
822 
823 void ASTDeclWriter::VisitObjCCompatibleAliasDecl(ObjCCompatibleAliasDecl *D) {
824   VisitNamedDecl(D);
825   Record.AddDeclRef(D->getClassInterface());
826   Code = serialization::DECL_OBJC_COMPATIBLE_ALIAS;
827 }
828 
829 void ASTDeclWriter::VisitObjCPropertyDecl(ObjCPropertyDecl *D) {
830   VisitNamedDecl(D);
831   Record.AddSourceLocation(D->getAtLoc());
832   Record.AddSourceLocation(D->getLParenLoc());
833   Record.AddTypeRef(D->getType());
834   Record.AddTypeSourceInfo(D->getTypeSourceInfo());
835   // FIXME: stable encoding
836   Record.push_back((unsigned)D->getPropertyAttributes());
837   Record.push_back((unsigned)D->getPropertyAttributesAsWritten());
838   // FIXME: stable encoding
839   Record.push_back((unsigned)D->getPropertyImplementation());
840   Record.AddDeclarationName(D->getGetterName());
841   Record.AddSourceLocation(D->getGetterNameLoc());
842   Record.AddDeclarationName(D->getSetterName());
843   Record.AddSourceLocation(D->getSetterNameLoc());
844   Record.AddDeclRef(D->getGetterMethodDecl());
845   Record.AddDeclRef(D->getSetterMethodDecl());
846   Record.AddDeclRef(D->getPropertyIvarDecl());
847   Code = serialization::DECL_OBJC_PROPERTY;
848 }
849 
850 void ASTDeclWriter::VisitObjCImplDecl(ObjCImplDecl *D) {
851   VisitObjCContainerDecl(D);
852   Record.AddDeclRef(D->getClassInterface());
853   // Abstract class (no need to define a stable serialization::DECL code).
854 }
855 
856 void ASTDeclWriter::VisitObjCCategoryImplDecl(ObjCCategoryImplDecl *D) {
857   VisitObjCImplDecl(D);
858   Record.AddSourceLocation(D->getCategoryNameLoc());
859   Code = serialization::DECL_OBJC_CATEGORY_IMPL;
860 }
861 
862 void ASTDeclWriter::VisitObjCImplementationDecl(ObjCImplementationDecl *D) {
863   VisitObjCImplDecl(D);
864   Record.AddDeclRef(D->getSuperClass());
865   Record.AddSourceLocation(D->getSuperClassLoc());
866   Record.AddSourceLocation(D->getIvarLBraceLoc());
867   Record.AddSourceLocation(D->getIvarRBraceLoc());
868   Record.push_back(D->hasNonZeroConstructors());
869   Record.push_back(D->hasDestructors());
870   Record.push_back(D->NumIvarInitializers);
871   if (D->NumIvarInitializers)
872     Record.AddCXXCtorInitializers(
873         llvm::makeArrayRef(D->init_begin(), D->init_end()));
874   Code = serialization::DECL_OBJC_IMPLEMENTATION;
875 }
876 
877 void ASTDeclWriter::VisitObjCPropertyImplDecl(ObjCPropertyImplDecl *D) {
878   VisitDecl(D);
879   Record.AddSourceLocation(D->getBeginLoc());
880   Record.AddDeclRef(D->getPropertyDecl());
881   Record.AddDeclRef(D->getPropertyIvarDecl());
882   Record.AddSourceLocation(D->getPropertyIvarDeclLoc());
883   Record.AddStmt(D->getGetterCXXConstructor());
884   Record.AddStmt(D->getSetterCXXAssignment());
885   Code = serialization::DECL_OBJC_PROPERTY_IMPL;
886 }
887 
888 void ASTDeclWriter::VisitFieldDecl(FieldDecl *D) {
889   VisitDeclaratorDecl(D);
890   Record.push_back(D->isMutable());
891 
892   FieldDecl::InitStorageKind ISK = D->InitStorage.getInt();
893   Record.push_back(ISK);
894   if (ISK == FieldDecl::ISK_CapturedVLAType)
895     Record.AddTypeRef(QualType(D->getCapturedVLAType(), 0));
896   else if (ISK)
897     Record.AddStmt(D->getInClassInitializer());
898 
899   Record.AddStmt(D->getBitWidth());
900 
901   if (!D->getDeclName())
902     Record.AddDeclRef(Context.getInstantiatedFromUnnamedFieldDecl(D));
903 
904   if (D->getDeclContext() == D->getLexicalDeclContext() &&
905       !D->hasAttrs() &&
906       !D->isImplicit() &&
907       !D->isUsed(false) &&
908       !D->isInvalidDecl() &&
909       !D->isReferenced() &&
910       !D->isTopLevelDeclInObjCContainer() &&
911       !D->isModulePrivate() &&
912       !D->getBitWidth() &&
913       !D->hasInClassInitializer() &&
914       !D->hasCapturedVLAType() &&
915       !D->hasExtInfo() &&
916       !ObjCIvarDecl::classofKind(D->getKind()) &&
917       !ObjCAtDefsFieldDecl::classofKind(D->getKind()) &&
918       D->getDeclName())
919     AbbrevToUse = Writer.getDeclFieldAbbrev();
920 
921   Code = serialization::DECL_FIELD;
922 }
923 
924 void ASTDeclWriter::VisitMSPropertyDecl(MSPropertyDecl *D) {
925   VisitDeclaratorDecl(D);
926   Record.AddIdentifierRef(D->getGetterId());
927   Record.AddIdentifierRef(D->getSetterId());
928   Code = serialization::DECL_MS_PROPERTY;
929 }
930 
931 void ASTDeclWriter::VisitIndirectFieldDecl(IndirectFieldDecl *D) {
932   VisitValueDecl(D);
933   Record.push_back(D->getChainingSize());
934 
935   for (const auto *P : D->chain())
936     Record.AddDeclRef(P);
937   Code = serialization::DECL_INDIRECTFIELD;
938 }
939 
940 void ASTDeclWriter::VisitVarDecl(VarDecl *D) {
941   VisitRedeclarable(D);
942   VisitDeclaratorDecl(D);
943   Record.push_back(D->getStorageClass());
944   Record.push_back(D->getTSCSpec());
945   Record.push_back(D->getInitStyle());
946   Record.push_back(D->isARCPseudoStrong());
947   if (!isa<ParmVarDecl>(D)) {
948     Record.push_back(D->isThisDeclarationADemotedDefinition());
949     Record.push_back(D->isExceptionVariable());
950     Record.push_back(D->isNRVOVariable());
951     Record.push_back(D->isCXXForRangeDecl());
952     Record.push_back(D->isObjCForDecl());
953     Record.push_back(D->isInline());
954     Record.push_back(D->isInlineSpecified());
955     Record.push_back(D->isConstexpr());
956     Record.push_back(D->isInitCapture());
957     Record.push_back(D->isPreviousDeclInSameBlockScope());
958     if (const auto *IPD = dyn_cast<ImplicitParamDecl>(D))
959       Record.push_back(static_cast<unsigned>(IPD->getParameterKind()));
960     else
961       Record.push_back(0);
962     Record.push_back(D->isEscapingByref());
963   }
964   Record.push_back(D->getLinkageInternal());
965 
966   if (D->getInit()) {
967     Record.push_back(!D->isInitKnownICE() ? 1 : (D->isInitICE() ? 3 : 2));
968     Record.AddStmt(D->getInit());
969   } else {
970     Record.push_back(0);
971   }
972 
973   if (D->hasAttr<BlocksAttr>() && D->getType()->getAsCXXRecordDecl()) {
974     ASTContext::BlockVarCopyInit Init = Writer.Context->getBlockVarCopyInit(D);
975     Record.AddStmt(Init.getCopyExpr());
976     if (Init.getCopyExpr())
977       Record.push_back(Init.canThrow());
978   }
979 
980   if (D->getStorageDuration() == SD_Static) {
981     bool ModulesCodegen = false;
982     if (Writer.WritingModule &&
983         !D->getDescribedVarTemplate() && !D->getMemberSpecializationInfo() &&
984         !isa<VarTemplateSpecializationDecl>(D)) {
985       // When building a C++ Modules TS module interface unit, a strong
986       // definition in the module interface is provided by the compilation of
987       // that module interface unit, not by its users. (Inline variables are
988       // still emitted in module users.)
989       ModulesCodegen =
990           (Writer.WritingModule->Kind == Module::ModuleInterfaceUnit &&
991            Writer.Context->GetGVALinkageForVariable(D) == GVA_StrongExternal);
992     }
993     Record.push_back(ModulesCodegen);
994     if (ModulesCodegen)
995       Writer.ModularCodegenDecls.push_back(Writer.GetDeclRef(D));
996   }
997 
998   enum {
999     VarNotTemplate = 0, VarTemplate, StaticDataMemberSpecialization
1000   };
1001   if (VarTemplateDecl *TemplD = D->getDescribedVarTemplate()) {
1002     Record.push_back(VarTemplate);
1003     Record.AddDeclRef(TemplD);
1004   } else if (MemberSpecializationInfo *SpecInfo
1005                = D->getMemberSpecializationInfo()) {
1006     Record.push_back(StaticDataMemberSpecialization);
1007     Record.AddDeclRef(SpecInfo->getInstantiatedFrom());
1008     Record.push_back(SpecInfo->getTemplateSpecializationKind());
1009     Record.AddSourceLocation(SpecInfo->getPointOfInstantiation());
1010   } else {
1011     Record.push_back(VarNotTemplate);
1012   }
1013 
1014   if (D->getDeclContext() == D->getLexicalDeclContext() &&
1015       !D->hasAttrs() &&
1016       !D->isImplicit() &&
1017       !D->isUsed(false) &&
1018       !D->isInvalidDecl() &&
1019       !D->isReferenced() &&
1020       !D->isTopLevelDeclInObjCContainer() &&
1021       D->getAccess() == AS_none &&
1022       !D->isModulePrivate() &&
1023       !needsAnonymousDeclarationNumber(D) &&
1024       D->getDeclName().getNameKind() == DeclarationName::Identifier &&
1025       !D->hasExtInfo() &&
1026       D->getFirstDecl() == D->getMostRecentDecl() &&
1027       D->getKind() == Decl::Var &&
1028       !D->isInline() &&
1029       !D->isConstexpr() &&
1030       !D->isInitCapture() &&
1031       !D->isPreviousDeclInSameBlockScope() &&
1032       !(D->hasAttr<BlocksAttr>() && D->getType()->getAsCXXRecordDecl()) &&
1033       !D->isEscapingByref() &&
1034       D->getStorageDuration() != SD_Static &&
1035       !D->getMemberSpecializationInfo())
1036     AbbrevToUse = Writer.getDeclVarAbbrev();
1037 
1038   Code = serialization::DECL_VAR;
1039 }
1040 
1041 void ASTDeclWriter::VisitImplicitParamDecl(ImplicitParamDecl *D) {
1042   VisitVarDecl(D);
1043   Code = serialization::DECL_IMPLICIT_PARAM;
1044 }
1045 
1046 void ASTDeclWriter::VisitParmVarDecl(ParmVarDecl *D) {
1047   VisitVarDecl(D);
1048   Record.push_back(D->isObjCMethodParameter());
1049   Record.push_back(D->getFunctionScopeDepth());
1050   Record.push_back(D->getFunctionScopeIndex());
1051   Record.push_back(D->getObjCDeclQualifier()); // FIXME: stable encoding
1052   Record.push_back(D->isKNRPromoted());
1053   Record.push_back(D->hasInheritedDefaultArg());
1054   Record.push_back(D->hasUninstantiatedDefaultArg());
1055   if (D->hasUninstantiatedDefaultArg())
1056     Record.AddStmt(D->getUninstantiatedDefaultArg());
1057   Code = serialization::DECL_PARM_VAR;
1058 
1059   assert(!D->isARCPseudoStrong()); // can be true of ImplicitParamDecl
1060 
1061   // If the assumptions about the DECL_PARM_VAR abbrev are true, use it.  Here
1062   // we dynamically check for the properties that we optimize for, but don't
1063   // know are true of all PARM_VAR_DECLs.
1064   if (D->getDeclContext() == D->getLexicalDeclContext() &&
1065       !D->hasAttrs() &&
1066       !D->hasExtInfo() &&
1067       !D->isImplicit() &&
1068       !D->isUsed(false) &&
1069       !D->isInvalidDecl() &&
1070       !D->isReferenced() &&
1071       D->getAccess() == AS_none &&
1072       !D->isModulePrivate() &&
1073       D->getStorageClass() == 0 &&
1074       D->getInitStyle() == VarDecl::CInit && // Can params have anything else?
1075       D->getFunctionScopeDepth() == 0 &&
1076       D->getObjCDeclQualifier() == 0 &&
1077       !D->isKNRPromoted() &&
1078       !D->hasInheritedDefaultArg() &&
1079       D->getInit() == nullptr &&
1080       !D->hasUninstantiatedDefaultArg())  // No default expr.
1081     AbbrevToUse = Writer.getDeclParmVarAbbrev();
1082 
1083   // Check things we know are true of *every* PARM_VAR_DECL, which is more than
1084   // just us assuming it.
1085   assert(!D->getTSCSpec() && "PARM_VAR_DECL can't use TLS");
1086   assert(!D->isThisDeclarationADemotedDefinition()
1087          && "PARM_VAR_DECL can't be demoted definition.");
1088   assert(D->getAccess() == AS_none && "PARM_VAR_DECL can't be public/private");
1089   assert(!D->isExceptionVariable() && "PARM_VAR_DECL can't be exception var");
1090   assert(D->getPreviousDecl() == nullptr && "PARM_VAR_DECL can't be redecl");
1091   assert(!D->isStaticDataMember() &&
1092          "PARM_VAR_DECL can't be static data member");
1093 }
1094 
1095 void ASTDeclWriter::VisitDecompositionDecl(DecompositionDecl *D) {
1096   // Record the number of bindings first to simplify deserialization.
1097   Record.push_back(D->bindings().size());
1098 
1099   VisitVarDecl(D);
1100   for (auto *B : D->bindings())
1101     Record.AddDeclRef(B);
1102   Code = serialization::DECL_DECOMPOSITION;
1103 }
1104 
1105 void ASTDeclWriter::VisitBindingDecl(BindingDecl *D) {
1106   VisitValueDecl(D);
1107   Record.AddStmt(D->getBinding());
1108   Code = serialization::DECL_BINDING;
1109 }
1110 
1111 void ASTDeclWriter::VisitFileScopeAsmDecl(FileScopeAsmDecl *D) {
1112   VisitDecl(D);
1113   Record.AddStmt(D->getAsmString());
1114   Record.AddSourceLocation(D->getRParenLoc());
1115   Code = serialization::DECL_FILE_SCOPE_ASM;
1116 }
1117 
1118 void ASTDeclWriter::VisitEmptyDecl(EmptyDecl *D) {
1119   VisitDecl(D);
1120   Code = serialization::DECL_EMPTY;
1121 }
1122 
1123 void ASTDeclWriter::VisitBlockDecl(BlockDecl *D) {
1124   VisitDecl(D);
1125   Record.AddStmt(D->getBody());
1126   Record.AddTypeSourceInfo(D->getSignatureAsWritten());
1127   Record.push_back(D->param_size());
1128   for (ParmVarDecl *P : D->parameters())
1129     Record.AddDeclRef(P);
1130   Record.push_back(D->isVariadic());
1131   Record.push_back(D->blockMissingReturnType());
1132   Record.push_back(D->isConversionFromLambda());
1133   Record.push_back(D->doesNotEscape());
1134   Record.push_back(D->canAvoidCopyToHeap());
1135   Record.push_back(D->capturesCXXThis());
1136   Record.push_back(D->getNumCaptures());
1137   for (const auto &capture : D->captures()) {
1138     Record.AddDeclRef(capture.getVariable());
1139 
1140     unsigned flags = 0;
1141     if (capture.isByRef()) flags |= 1;
1142     if (capture.isNested()) flags |= 2;
1143     if (capture.hasCopyExpr()) flags |= 4;
1144     Record.push_back(flags);
1145 
1146     if (capture.hasCopyExpr()) Record.AddStmt(capture.getCopyExpr());
1147   }
1148 
1149   Code = serialization::DECL_BLOCK;
1150 }
1151 
1152 void ASTDeclWriter::VisitCapturedDecl(CapturedDecl *CD) {
1153   Record.push_back(CD->getNumParams());
1154   VisitDecl(CD);
1155   Record.push_back(CD->getContextParamPosition());
1156   Record.push_back(CD->isNothrow() ? 1 : 0);
1157   // Body is stored by VisitCapturedStmt.
1158   for (unsigned I = 0; I < CD->getNumParams(); ++I)
1159     Record.AddDeclRef(CD->getParam(I));
1160   Code = serialization::DECL_CAPTURED;
1161 }
1162 
1163 void ASTDeclWriter::VisitLinkageSpecDecl(LinkageSpecDecl *D) {
1164   VisitDecl(D);
1165   Record.push_back(D->getLanguage());
1166   Record.AddSourceLocation(D->getExternLoc());
1167   Record.AddSourceLocation(D->getRBraceLoc());
1168   Code = serialization::DECL_LINKAGE_SPEC;
1169 }
1170 
1171 void ASTDeclWriter::VisitExportDecl(ExportDecl *D) {
1172   VisitDecl(D);
1173   Record.AddSourceLocation(D->getRBraceLoc());
1174   Code = serialization::DECL_EXPORT;
1175 }
1176 
1177 void ASTDeclWriter::VisitLabelDecl(LabelDecl *D) {
1178   VisitNamedDecl(D);
1179   Record.AddSourceLocation(D->getBeginLoc());
1180   Code = serialization::DECL_LABEL;
1181 }
1182 
1183 
1184 void ASTDeclWriter::VisitNamespaceDecl(NamespaceDecl *D) {
1185   VisitRedeclarable(D);
1186   VisitNamedDecl(D);
1187   Record.push_back(D->isInline());
1188   Record.AddSourceLocation(D->getBeginLoc());
1189   Record.AddSourceLocation(D->getRBraceLoc());
1190 
1191   if (D->isOriginalNamespace())
1192     Record.AddDeclRef(D->getAnonymousNamespace());
1193   Code = serialization::DECL_NAMESPACE;
1194 
1195   if (Writer.hasChain() && D->isAnonymousNamespace() &&
1196       D == D->getMostRecentDecl()) {
1197     // This is a most recent reopening of the anonymous namespace. If its parent
1198     // is in a previous PCH (or is the TU), mark that parent for update, because
1199     // the original namespace always points to the latest re-opening of its
1200     // anonymous namespace.
1201     Decl *Parent = cast<Decl>(
1202         D->getParent()->getRedeclContext()->getPrimaryContext());
1203     if (Parent->isFromASTFile() || isa<TranslationUnitDecl>(Parent)) {
1204       Writer.DeclUpdates[Parent].push_back(
1205           ASTWriter::DeclUpdate(UPD_CXX_ADDED_ANONYMOUS_NAMESPACE, D));
1206     }
1207   }
1208 }
1209 
1210 void ASTDeclWriter::VisitNamespaceAliasDecl(NamespaceAliasDecl *D) {
1211   VisitRedeclarable(D);
1212   VisitNamedDecl(D);
1213   Record.AddSourceLocation(D->getNamespaceLoc());
1214   Record.AddSourceLocation(D->getTargetNameLoc());
1215   Record.AddNestedNameSpecifierLoc(D->getQualifierLoc());
1216   Record.AddDeclRef(D->getNamespace());
1217   Code = serialization::DECL_NAMESPACE_ALIAS;
1218 }
1219 
1220 void ASTDeclWriter::VisitUsingDecl(UsingDecl *D) {
1221   VisitNamedDecl(D);
1222   Record.AddSourceLocation(D->getUsingLoc());
1223   Record.AddNestedNameSpecifierLoc(D->getQualifierLoc());
1224   Record.AddDeclarationNameLoc(D->DNLoc, D->getDeclName());
1225   Record.AddDeclRef(D->FirstUsingShadow.getPointer());
1226   Record.push_back(D->hasTypename());
1227   Record.AddDeclRef(Context.getInstantiatedFromUsingDecl(D));
1228   Code = serialization::DECL_USING;
1229 }
1230 
1231 void ASTDeclWriter::VisitUsingPackDecl(UsingPackDecl *D) {
1232   Record.push_back(D->NumExpansions);
1233   VisitNamedDecl(D);
1234   Record.AddDeclRef(D->getInstantiatedFromUsingDecl());
1235   for (auto *E : D->expansions())
1236     Record.AddDeclRef(E);
1237   Code = serialization::DECL_USING_PACK;
1238 }
1239 
1240 void ASTDeclWriter::VisitUsingShadowDecl(UsingShadowDecl *D) {
1241   VisitRedeclarable(D);
1242   VisitNamedDecl(D);
1243   Record.AddDeclRef(D->getTargetDecl());
1244   Record.push_back(D->getIdentifierNamespace());
1245   Record.AddDeclRef(D->UsingOrNextShadow);
1246   Record.AddDeclRef(Context.getInstantiatedFromUsingShadowDecl(D));
1247   Code = serialization::DECL_USING_SHADOW;
1248 }
1249 
1250 void ASTDeclWriter::VisitConstructorUsingShadowDecl(
1251     ConstructorUsingShadowDecl *D) {
1252   VisitUsingShadowDecl(D);
1253   Record.AddDeclRef(D->NominatedBaseClassShadowDecl);
1254   Record.AddDeclRef(D->ConstructedBaseClassShadowDecl);
1255   Record.push_back(D->IsVirtual);
1256   Code = serialization::DECL_CONSTRUCTOR_USING_SHADOW;
1257 }
1258 
1259 void ASTDeclWriter::VisitUsingDirectiveDecl(UsingDirectiveDecl *D) {
1260   VisitNamedDecl(D);
1261   Record.AddSourceLocation(D->getUsingLoc());
1262   Record.AddSourceLocation(D->getNamespaceKeyLocation());
1263   Record.AddNestedNameSpecifierLoc(D->getQualifierLoc());
1264   Record.AddDeclRef(D->getNominatedNamespace());
1265   Record.AddDeclRef(dyn_cast<Decl>(D->getCommonAncestor()));
1266   Code = serialization::DECL_USING_DIRECTIVE;
1267 }
1268 
1269 void ASTDeclWriter::VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D) {
1270   VisitValueDecl(D);
1271   Record.AddSourceLocation(D->getUsingLoc());
1272   Record.AddNestedNameSpecifierLoc(D->getQualifierLoc());
1273   Record.AddDeclarationNameLoc(D->DNLoc, D->getDeclName());
1274   Record.AddSourceLocation(D->getEllipsisLoc());
1275   Code = serialization::DECL_UNRESOLVED_USING_VALUE;
1276 }
1277 
1278 void ASTDeclWriter::VisitUnresolvedUsingTypenameDecl(
1279                                                UnresolvedUsingTypenameDecl *D) {
1280   VisitTypeDecl(D);
1281   Record.AddSourceLocation(D->getTypenameLoc());
1282   Record.AddNestedNameSpecifierLoc(D->getQualifierLoc());
1283   Record.AddSourceLocation(D->getEllipsisLoc());
1284   Code = serialization::DECL_UNRESOLVED_USING_TYPENAME;
1285 }
1286 
1287 void ASTDeclWriter::VisitCXXRecordDecl(CXXRecordDecl *D) {
1288   VisitRecordDecl(D);
1289 
1290   enum {
1291     CXXRecNotTemplate = 0, CXXRecTemplate, CXXRecMemberSpecialization
1292   };
1293   if (ClassTemplateDecl *TemplD = D->getDescribedClassTemplate()) {
1294     Record.push_back(CXXRecTemplate);
1295     Record.AddDeclRef(TemplD);
1296   } else if (MemberSpecializationInfo *MSInfo
1297                = D->getMemberSpecializationInfo()) {
1298     Record.push_back(CXXRecMemberSpecialization);
1299     Record.AddDeclRef(MSInfo->getInstantiatedFrom());
1300     Record.push_back(MSInfo->getTemplateSpecializationKind());
1301     Record.AddSourceLocation(MSInfo->getPointOfInstantiation());
1302   } else {
1303     Record.push_back(CXXRecNotTemplate);
1304   }
1305 
1306   Record.push_back(D->isThisDeclarationADefinition());
1307   if (D->isThisDeclarationADefinition())
1308     Record.AddCXXDefinitionData(D);
1309 
1310   // Store (what we currently believe to be) the key function to avoid
1311   // deserializing every method so we can compute it.
1312   if (D->isCompleteDefinition())
1313     Record.AddDeclRef(Context.getCurrentKeyFunction(D));
1314 
1315   Code = serialization::DECL_CXX_RECORD;
1316 }
1317 
1318 void ASTDeclWriter::VisitCXXMethodDecl(CXXMethodDecl *D) {
1319   VisitFunctionDecl(D);
1320   if (D->isCanonicalDecl()) {
1321     Record.push_back(D->size_overridden_methods());
1322     for (const CXXMethodDecl *MD : D->overridden_methods())
1323       Record.AddDeclRef(MD);
1324   } else {
1325     // We only need to record overridden methods once for the canonical decl.
1326     Record.push_back(0);
1327   }
1328 
1329   if (D->getDeclContext() == D->getLexicalDeclContext() &&
1330       D->getFirstDecl() == D->getMostRecentDecl() &&
1331       !D->isInvalidDecl() &&
1332       !D->hasAttrs() &&
1333       !D->isTopLevelDeclInObjCContainer() &&
1334       D->getDeclName().getNameKind() == DeclarationName::Identifier &&
1335       !D->hasExtInfo() &&
1336       !D->hasInheritedPrototype() &&
1337       D->hasWrittenPrototype())
1338     AbbrevToUse = Writer.getDeclCXXMethodAbbrev();
1339 
1340   Code = serialization::DECL_CXX_METHOD;
1341 }
1342 
1343 void ASTDeclWriter::VisitCXXConstructorDecl(CXXConstructorDecl *D) {
1344   Record.push_back(D->getTraillingAllocKind());
1345   addExplicitSpecifier(D->getExplicitSpecifier(), Record);
1346   if (auto Inherited = D->getInheritedConstructor()) {
1347     Record.AddDeclRef(Inherited.getShadowDecl());
1348     Record.AddDeclRef(Inherited.getConstructor());
1349   }
1350 
1351   VisitCXXMethodDecl(D);
1352   Code = serialization::DECL_CXX_CONSTRUCTOR;
1353 }
1354 
1355 void ASTDeclWriter::VisitCXXDestructorDecl(CXXDestructorDecl *D) {
1356   VisitCXXMethodDecl(D);
1357 
1358   Record.AddDeclRef(D->getOperatorDelete());
1359   if (D->getOperatorDelete())
1360     Record.AddStmt(D->getOperatorDeleteThisArg());
1361 
1362   Code = serialization::DECL_CXX_DESTRUCTOR;
1363 }
1364 
1365 void ASTDeclWriter::VisitCXXConversionDecl(CXXConversionDecl *D) {
1366   addExplicitSpecifier(D->getExplicitSpecifier(), Record);
1367   VisitCXXMethodDecl(D);
1368   Code = serialization::DECL_CXX_CONVERSION;
1369 }
1370 
1371 void ASTDeclWriter::VisitImportDecl(ImportDecl *D) {
1372   VisitDecl(D);
1373   Record.push_back(Writer.getSubmoduleID(D->getImportedModule()));
1374   ArrayRef<SourceLocation> IdentifierLocs = D->getIdentifierLocs();
1375   Record.push_back(!IdentifierLocs.empty());
1376   if (IdentifierLocs.empty()) {
1377     Record.AddSourceLocation(D->getEndLoc());
1378     Record.push_back(1);
1379   } else {
1380     for (unsigned I = 0, N = IdentifierLocs.size(); I != N; ++I)
1381       Record.AddSourceLocation(IdentifierLocs[I]);
1382     Record.push_back(IdentifierLocs.size());
1383   }
1384   // Note: the number of source locations must always be the last element in
1385   // the record.
1386   Code = serialization::DECL_IMPORT;
1387 }
1388 
1389 void ASTDeclWriter::VisitAccessSpecDecl(AccessSpecDecl *D) {
1390   VisitDecl(D);
1391   Record.AddSourceLocation(D->getColonLoc());
1392   Code = serialization::DECL_ACCESS_SPEC;
1393 }
1394 
1395 void ASTDeclWriter::VisitFriendDecl(FriendDecl *D) {
1396   // Record the number of friend type template parameter lists here
1397   // so as to simplify memory allocation during deserialization.
1398   Record.push_back(D->NumTPLists);
1399   VisitDecl(D);
1400   bool hasFriendDecl = D->Friend.is<NamedDecl*>();
1401   Record.push_back(hasFriendDecl);
1402   if (hasFriendDecl)
1403     Record.AddDeclRef(D->getFriendDecl());
1404   else
1405     Record.AddTypeSourceInfo(D->getFriendType());
1406   for (unsigned i = 0; i < D->NumTPLists; ++i)
1407     Record.AddTemplateParameterList(D->getFriendTypeTemplateParameterList(i));
1408   Record.AddDeclRef(D->getNextFriend());
1409   Record.push_back(D->UnsupportedFriend);
1410   Record.AddSourceLocation(D->FriendLoc);
1411   Code = serialization::DECL_FRIEND;
1412 }
1413 
1414 void ASTDeclWriter::VisitFriendTemplateDecl(FriendTemplateDecl *D) {
1415   VisitDecl(D);
1416   Record.push_back(D->getNumTemplateParameters());
1417   for (unsigned i = 0, e = D->getNumTemplateParameters(); i != e; ++i)
1418     Record.AddTemplateParameterList(D->getTemplateParameterList(i));
1419   Record.push_back(D->getFriendDecl() != nullptr);
1420   if (D->getFriendDecl())
1421     Record.AddDeclRef(D->getFriendDecl());
1422   else
1423     Record.AddTypeSourceInfo(D->getFriendType());
1424   Record.AddSourceLocation(D->getFriendLoc());
1425   Code = serialization::DECL_FRIEND_TEMPLATE;
1426 }
1427 
1428 void ASTDeclWriter::VisitTemplateDecl(TemplateDecl *D) {
1429   VisitNamedDecl(D);
1430 
1431   Record.AddDeclRef(D->getTemplatedDecl());
1432   Record.AddTemplateParameterList(D->getTemplateParameters());
1433 }
1434 
1435 void ASTDeclWriter::VisitRedeclarableTemplateDecl(RedeclarableTemplateDecl *D) {
1436   VisitRedeclarable(D);
1437 
1438   // Emit data to initialize CommonOrPrev before VisitTemplateDecl so that
1439   // getCommonPtr() can be used while this is still initializing.
1440   if (D->isFirstDecl()) {
1441     // This declaration owns the 'common' pointer, so serialize that data now.
1442     Record.AddDeclRef(D->getInstantiatedFromMemberTemplate());
1443     if (D->getInstantiatedFromMemberTemplate())
1444       Record.push_back(D->isMemberSpecialization());
1445   }
1446 
1447   VisitTemplateDecl(D);
1448   Record.push_back(D->getIdentifierNamespace());
1449 }
1450 
1451 void ASTDeclWriter::VisitClassTemplateDecl(ClassTemplateDecl *D) {
1452   VisitRedeclarableTemplateDecl(D);
1453 
1454   if (D->isFirstDecl())
1455     AddTemplateSpecializations(D);
1456   Code = serialization::DECL_CLASS_TEMPLATE;
1457 }
1458 
1459 void ASTDeclWriter::VisitClassTemplateSpecializationDecl(
1460                                            ClassTemplateSpecializationDecl *D) {
1461   RegisterTemplateSpecialization(D->getSpecializedTemplate(), D);
1462 
1463   VisitCXXRecordDecl(D);
1464 
1465   llvm::PointerUnion<ClassTemplateDecl *,
1466                      ClassTemplatePartialSpecializationDecl *> InstFrom
1467     = D->getSpecializedTemplateOrPartial();
1468   if (Decl *InstFromD = InstFrom.dyn_cast<ClassTemplateDecl *>()) {
1469     Record.AddDeclRef(InstFromD);
1470   } else {
1471     Record.AddDeclRef(InstFrom.get<ClassTemplatePartialSpecializationDecl *>());
1472     Record.AddTemplateArgumentList(&D->getTemplateInstantiationArgs());
1473   }
1474 
1475   Record.AddTemplateArgumentList(&D->getTemplateArgs());
1476   Record.AddSourceLocation(D->getPointOfInstantiation());
1477   Record.push_back(D->getSpecializationKind());
1478   Record.push_back(D->isCanonicalDecl());
1479 
1480   if (D->isCanonicalDecl()) {
1481     // When reading, we'll add it to the folding set of the following template.
1482     Record.AddDeclRef(D->getSpecializedTemplate()->getCanonicalDecl());
1483   }
1484 
1485   // Explicit info.
1486   Record.AddTypeSourceInfo(D->getTypeAsWritten());
1487   if (D->getTypeAsWritten()) {
1488     Record.AddSourceLocation(D->getExternLoc());
1489     Record.AddSourceLocation(D->getTemplateKeywordLoc());
1490   }
1491 
1492   Code = serialization::DECL_CLASS_TEMPLATE_SPECIALIZATION;
1493 }
1494 
1495 void ASTDeclWriter::VisitClassTemplatePartialSpecializationDecl(
1496                                     ClassTemplatePartialSpecializationDecl *D) {
1497   VisitClassTemplateSpecializationDecl(D);
1498 
1499   Record.AddTemplateParameterList(D->getTemplateParameters());
1500   Record.AddASTTemplateArgumentListInfo(D->getTemplateArgsAsWritten());
1501 
1502   // These are read/set from/to the first declaration.
1503   if (D->getPreviousDecl() == nullptr) {
1504     Record.AddDeclRef(D->getInstantiatedFromMember());
1505     Record.push_back(D->isMemberSpecialization());
1506   }
1507 
1508   Code = serialization::DECL_CLASS_TEMPLATE_PARTIAL_SPECIALIZATION;
1509 }
1510 
1511 void ASTDeclWriter::VisitVarTemplateDecl(VarTemplateDecl *D) {
1512   VisitRedeclarableTemplateDecl(D);
1513 
1514   if (D->isFirstDecl())
1515     AddTemplateSpecializations(D);
1516   Code = serialization::DECL_VAR_TEMPLATE;
1517 }
1518 
1519 void ASTDeclWriter::VisitVarTemplateSpecializationDecl(
1520     VarTemplateSpecializationDecl *D) {
1521   RegisterTemplateSpecialization(D->getSpecializedTemplate(), D);
1522 
1523   VisitVarDecl(D);
1524 
1525   llvm::PointerUnion<VarTemplateDecl *, VarTemplatePartialSpecializationDecl *>
1526   InstFrom = D->getSpecializedTemplateOrPartial();
1527   if (Decl *InstFromD = InstFrom.dyn_cast<VarTemplateDecl *>()) {
1528     Record.AddDeclRef(InstFromD);
1529   } else {
1530     Record.AddDeclRef(InstFrom.get<VarTemplatePartialSpecializationDecl *>());
1531     Record.AddTemplateArgumentList(&D->getTemplateInstantiationArgs());
1532   }
1533 
1534   // Explicit info.
1535   Record.AddTypeSourceInfo(D->getTypeAsWritten());
1536   if (D->getTypeAsWritten()) {
1537     Record.AddSourceLocation(D->getExternLoc());
1538     Record.AddSourceLocation(D->getTemplateKeywordLoc());
1539   }
1540 
1541   Record.AddTemplateArgumentList(&D->getTemplateArgs());
1542   Record.AddSourceLocation(D->getPointOfInstantiation());
1543   Record.push_back(D->getSpecializationKind());
1544   Record.push_back(D->IsCompleteDefinition);
1545   Record.push_back(D->isCanonicalDecl());
1546 
1547   if (D->isCanonicalDecl()) {
1548     // When reading, we'll add it to the folding set of the following template.
1549     Record.AddDeclRef(D->getSpecializedTemplate()->getCanonicalDecl());
1550   }
1551 
1552   Code = serialization::DECL_VAR_TEMPLATE_SPECIALIZATION;
1553 }
1554 
1555 void ASTDeclWriter::VisitVarTemplatePartialSpecializationDecl(
1556     VarTemplatePartialSpecializationDecl *D) {
1557   VisitVarTemplateSpecializationDecl(D);
1558 
1559   Record.AddTemplateParameterList(D->getTemplateParameters());
1560   Record.AddASTTemplateArgumentListInfo(D->getTemplateArgsAsWritten());
1561 
1562   // These are read/set from/to the first declaration.
1563   if (D->getPreviousDecl() == nullptr) {
1564     Record.AddDeclRef(D->getInstantiatedFromMember());
1565     Record.push_back(D->isMemberSpecialization());
1566   }
1567 
1568   Code = serialization::DECL_VAR_TEMPLATE_PARTIAL_SPECIALIZATION;
1569 }
1570 
1571 void ASTDeclWriter::VisitClassScopeFunctionSpecializationDecl(
1572                                     ClassScopeFunctionSpecializationDecl *D) {
1573   VisitDecl(D);
1574   Record.AddDeclRef(D->getSpecialization());
1575   Record.push_back(D->hasExplicitTemplateArgs());
1576   if (D->hasExplicitTemplateArgs())
1577     Record.AddASTTemplateArgumentListInfo(D->getTemplateArgsAsWritten());
1578   Code = serialization::DECL_CLASS_SCOPE_FUNCTION_SPECIALIZATION;
1579 }
1580 
1581 
1582 void ASTDeclWriter::VisitFunctionTemplateDecl(FunctionTemplateDecl *D) {
1583   VisitRedeclarableTemplateDecl(D);
1584 
1585   if (D->isFirstDecl())
1586     AddTemplateSpecializations(D);
1587   Code = serialization::DECL_FUNCTION_TEMPLATE;
1588 }
1589 
1590 void ASTDeclWriter::VisitTemplateTypeParmDecl(TemplateTypeParmDecl *D) {
1591   VisitTypeDecl(D);
1592 
1593   Record.push_back(D->wasDeclaredWithTypename());
1594 
1595   bool OwnsDefaultArg = D->hasDefaultArgument() &&
1596                         !D->defaultArgumentWasInherited();
1597   Record.push_back(OwnsDefaultArg);
1598   if (OwnsDefaultArg)
1599     Record.AddTypeSourceInfo(D->getDefaultArgumentInfo());
1600 
1601   Code = serialization::DECL_TEMPLATE_TYPE_PARM;
1602 }
1603 
1604 void ASTDeclWriter::VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D) {
1605   // For an expanded parameter pack, record the number of expansion types here
1606   // so that it's easier for deserialization to allocate the right amount of
1607   // memory.
1608   if (D->isExpandedParameterPack())
1609     Record.push_back(D->getNumExpansionTypes());
1610 
1611   VisitDeclaratorDecl(D);
1612   // TemplateParmPosition.
1613   Record.push_back(D->getDepth());
1614   Record.push_back(D->getPosition());
1615 
1616   if (D->isExpandedParameterPack()) {
1617     for (unsigned I = 0, N = D->getNumExpansionTypes(); I != N; ++I) {
1618       Record.AddTypeRef(D->getExpansionType(I));
1619       Record.AddTypeSourceInfo(D->getExpansionTypeSourceInfo(I));
1620     }
1621 
1622     Code = serialization::DECL_EXPANDED_NON_TYPE_TEMPLATE_PARM_PACK;
1623   } else {
1624     // Rest of NonTypeTemplateParmDecl.
1625     Record.push_back(D->isParameterPack());
1626     bool OwnsDefaultArg = D->hasDefaultArgument() &&
1627                           !D->defaultArgumentWasInherited();
1628     Record.push_back(OwnsDefaultArg);
1629     if (OwnsDefaultArg)
1630       Record.AddStmt(D->getDefaultArgument());
1631     Code = serialization::DECL_NON_TYPE_TEMPLATE_PARM;
1632   }
1633 }
1634 
1635 void ASTDeclWriter::VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D) {
1636   // For an expanded parameter pack, record the number of expansion types here
1637   // so that it's easier for deserialization to allocate the right amount of
1638   // memory.
1639   if (D->isExpandedParameterPack())
1640     Record.push_back(D->getNumExpansionTemplateParameters());
1641 
1642   VisitTemplateDecl(D);
1643   // TemplateParmPosition.
1644   Record.push_back(D->getDepth());
1645   Record.push_back(D->getPosition());
1646 
1647   if (D->isExpandedParameterPack()) {
1648     for (unsigned I = 0, N = D->getNumExpansionTemplateParameters();
1649          I != N; ++I)
1650       Record.AddTemplateParameterList(D->getExpansionTemplateParameters(I));
1651     Code = serialization::DECL_EXPANDED_TEMPLATE_TEMPLATE_PARM_PACK;
1652   } else {
1653     // Rest of TemplateTemplateParmDecl.
1654     Record.push_back(D->isParameterPack());
1655     bool OwnsDefaultArg = D->hasDefaultArgument() &&
1656                           !D->defaultArgumentWasInherited();
1657     Record.push_back(OwnsDefaultArg);
1658     if (OwnsDefaultArg)
1659       Record.AddTemplateArgumentLoc(D->getDefaultArgument());
1660     Code = serialization::DECL_TEMPLATE_TEMPLATE_PARM;
1661   }
1662 }
1663 
1664 void ASTDeclWriter::VisitTypeAliasTemplateDecl(TypeAliasTemplateDecl *D) {
1665   VisitRedeclarableTemplateDecl(D);
1666   Code = serialization::DECL_TYPE_ALIAS_TEMPLATE;
1667 }
1668 
1669 void ASTDeclWriter::VisitStaticAssertDecl(StaticAssertDecl *D) {
1670   VisitDecl(D);
1671   Record.AddStmt(D->getAssertExpr());
1672   Record.push_back(D->isFailed());
1673   Record.AddStmt(D->getMessage());
1674   Record.AddSourceLocation(D->getRParenLoc());
1675   Code = serialization::DECL_STATIC_ASSERT;
1676 }
1677 
1678 /// Emit the DeclContext part of a declaration context decl.
1679 void ASTDeclWriter::VisitDeclContext(DeclContext *DC) {
1680   Record.AddOffset(Writer.WriteDeclContextLexicalBlock(Context, DC));
1681   Record.AddOffset(Writer.WriteDeclContextVisibleBlock(Context, DC));
1682 }
1683 
1684 const Decl *ASTWriter::getFirstLocalDecl(const Decl *D) {
1685   assert(IsLocalDecl(D) && "expected a local declaration");
1686 
1687   const Decl *Canon = D->getCanonicalDecl();
1688   if (IsLocalDecl(Canon))
1689     return Canon;
1690 
1691   const Decl *&CacheEntry = FirstLocalDeclCache[Canon];
1692   if (CacheEntry)
1693     return CacheEntry;
1694 
1695   for (const Decl *Redecl = D; Redecl; Redecl = Redecl->getPreviousDecl())
1696     if (IsLocalDecl(Redecl))
1697       D = Redecl;
1698   return CacheEntry = D;
1699 }
1700 
1701 template <typename T>
1702 void ASTDeclWriter::VisitRedeclarable(Redeclarable<T> *D) {
1703   T *First = D->getFirstDecl();
1704   T *MostRecent = First->getMostRecentDecl();
1705   T *DAsT = static_cast<T *>(D);
1706   if (MostRecent != First) {
1707     assert(isRedeclarableDeclKind(DAsT->getKind()) &&
1708            "Not considered redeclarable?");
1709 
1710     Record.AddDeclRef(First);
1711 
1712     // Write out a list of local redeclarations of this declaration if it's the
1713     // first local declaration in the chain.
1714     const Decl *FirstLocal = Writer.getFirstLocalDecl(DAsT);
1715     if (DAsT == FirstLocal) {
1716       // Emit a list of all imported first declarations so that we can be sure
1717       // that all redeclarations visible to this module are before D in the
1718       // redecl chain.
1719       unsigned I = Record.size();
1720       Record.push_back(0);
1721       if (Writer.Chain)
1722         AddFirstDeclFromEachModule(DAsT, /*IncludeLocal*/false);
1723       // This is the number of imported first declarations + 1.
1724       Record[I] = Record.size() - I;
1725 
1726       // Collect the set of local redeclarations of this declaration, from
1727       // newest to oldest.
1728       ASTWriter::RecordData LocalRedecls;
1729       ASTRecordWriter LocalRedeclWriter(Record, LocalRedecls);
1730       for (const Decl *Prev = FirstLocal->getMostRecentDecl();
1731            Prev != FirstLocal; Prev = Prev->getPreviousDecl())
1732         if (!Prev->isFromASTFile())
1733           LocalRedeclWriter.AddDeclRef(Prev);
1734 
1735       // If we have any redecls, write them now as a separate record preceding
1736       // the declaration itself.
1737       if (LocalRedecls.empty())
1738         Record.push_back(0);
1739       else
1740         Record.AddOffset(LocalRedeclWriter.Emit(LOCAL_REDECLARATIONS));
1741     } else {
1742       Record.push_back(0);
1743       Record.AddDeclRef(FirstLocal);
1744     }
1745 
1746     // Make sure that we serialize both the previous and the most-recent
1747     // declarations, which (transitively) ensures that all declarations in the
1748     // chain get serialized.
1749     //
1750     // FIXME: This is not correct; when we reach an imported declaration we
1751     // won't emit its previous declaration.
1752     (void)Writer.GetDeclRef(D->getPreviousDecl());
1753     (void)Writer.GetDeclRef(MostRecent);
1754   } else {
1755     // We use the sentinel value 0 to indicate an only declaration.
1756     Record.push_back(0);
1757   }
1758 }
1759 
1760 void ASTDeclWriter::VisitOMPThreadPrivateDecl(OMPThreadPrivateDecl *D) {
1761   Record.push_back(D->varlist_size());
1762   VisitDecl(D);
1763   for (auto *I : D->varlists())
1764     Record.AddStmt(I);
1765   Code = serialization::DECL_OMP_THREADPRIVATE;
1766 }
1767 
1768 void ASTDeclWriter::VisitOMPAllocateDecl(OMPAllocateDecl *D) {
1769   Record.push_back(D->varlist_size());
1770   Record.push_back(D->clauselist_size());
1771   VisitDecl(D);
1772   for (auto *I : D->varlists())
1773     Record.AddStmt(I);
1774   OMPClauseWriter ClauseWriter(Record);
1775   for (OMPClause *C : D->clauselists())
1776     ClauseWriter.writeClause(C);
1777   Code = serialization::DECL_OMP_ALLOCATE;
1778 }
1779 
1780 void ASTDeclWriter::VisitOMPRequiresDecl(OMPRequiresDecl *D) {
1781   Record.push_back(D->clauselist_size());
1782   VisitDecl(D);
1783   OMPClauseWriter ClauseWriter(Record);
1784   for (OMPClause *C : D->clauselists())
1785     ClauseWriter.writeClause(C);
1786   Code = serialization::DECL_OMP_REQUIRES;
1787 }
1788 
1789 void ASTDeclWriter::VisitOMPDeclareReductionDecl(OMPDeclareReductionDecl *D) {
1790   VisitValueDecl(D);
1791   Record.AddSourceLocation(D->getBeginLoc());
1792   Record.AddStmt(D->getCombinerIn());
1793   Record.AddStmt(D->getCombinerOut());
1794   Record.AddStmt(D->getCombiner());
1795   Record.AddStmt(D->getInitOrig());
1796   Record.AddStmt(D->getInitPriv());
1797   Record.AddStmt(D->getInitializer());
1798   Record.push_back(D->getInitializerKind());
1799   Record.AddDeclRef(D->getPrevDeclInScope());
1800   Code = serialization::DECL_OMP_DECLARE_REDUCTION;
1801 }
1802 
1803 void ASTDeclWriter::VisitOMPDeclareMapperDecl(OMPDeclareMapperDecl *D) {
1804   Record.push_back(D->clauselist_size());
1805   VisitValueDecl(D);
1806   Record.AddSourceLocation(D->getBeginLoc());
1807   Record.AddStmt(D->getMapperVarRef());
1808   Record.AddDeclarationName(D->getVarName());
1809   Record.AddDeclRef(D->getPrevDeclInScope());
1810   OMPClauseWriter ClauseWriter(Record);
1811   for (OMPClause *C : D->clauselists())
1812     ClauseWriter.writeClause(C);
1813   Code = serialization::DECL_OMP_DECLARE_MAPPER;
1814 }
1815 
1816 void ASTDeclWriter::VisitOMPCapturedExprDecl(OMPCapturedExprDecl *D) {
1817   VisitVarDecl(D);
1818   Code = serialization::DECL_OMP_CAPTUREDEXPR;
1819 }
1820 
1821 //===----------------------------------------------------------------------===//
1822 // ASTWriter Implementation
1823 //===----------------------------------------------------------------------===//
1824 
1825 void ASTWriter::WriteDeclAbbrevs() {
1826   using namespace llvm;
1827 
1828   std::shared_ptr<BitCodeAbbrev> Abv;
1829 
1830   // Abbreviation for DECL_FIELD
1831   Abv = std::make_shared<BitCodeAbbrev>();
1832   Abv->Add(BitCodeAbbrevOp(serialization::DECL_FIELD));
1833   // Decl
1834   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1835   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
1836   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1837   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1838   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1839   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
1840   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
1841   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1842   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2));  // AccessSpecifier
1843   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
1844   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1845   // NamedDecl
1846   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1847   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1848   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
1849   // ValueDecl
1850   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
1851   // DeclaratorDecl
1852   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // InnerStartLoc
1853   Abv->Add(BitCodeAbbrevOp(0));                       // hasExtInfo
1854   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TSIType
1855   // FieldDecl
1856   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isMutable
1857   Abv->Add(BitCodeAbbrevOp(0));                       // InitStyle
1858   // Type Source Info
1859   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1860   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
1861   DeclFieldAbbrev = Stream.EmitAbbrev(std::move(Abv));
1862 
1863   // Abbreviation for DECL_OBJC_IVAR
1864   Abv = std::make_shared<BitCodeAbbrev>();
1865   Abv->Add(BitCodeAbbrevOp(serialization::DECL_OBJC_IVAR));
1866   // Decl
1867   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1868   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
1869   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1870   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1871   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1872   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
1873   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
1874   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1875   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2));  // AccessSpecifier
1876   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
1877   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1878   // NamedDecl
1879   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1880   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1881   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
1882   // ValueDecl
1883   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
1884   // DeclaratorDecl
1885   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // InnerStartLoc
1886   Abv->Add(BitCodeAbbrevOp(0));                       // hasExtInfo
1887   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TSIType
1888   // FieldDecl
1889   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isMutable
1890   Abv->Add(BitCodeAbbrevOp(0));                       // InitStyle
1891   // ObjC Ivar
1892   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // getAccessControl
1893   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // getSynthesize
1894   // Type Source Info
1895   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1896   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
1897   DeclObjCIvarAbbrev = Stream.EmitAbbrev(std::move(Abv));
1898 
1899   // Abbreviation for DECL_ENUM
1900   Abv = std::make_shared<BitCodeAbbrev>();
1901   Abv->Add(BitCodeAbbrevOp(serialization::DECL_ENUM));
1902   // Redeclarable
1903   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
1904   // Decl
1905   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1906   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
1907   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1908   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1909   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1910   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
1911   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
1912   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1913   Abv->Add(BitCodeAbbrevOp(AS_none));                 // C++ AccessSpecifier
1914   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
1915   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1916   // NamedDecl
1917   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1918   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1919   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
1920   // TypeDecl
1921   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Source Location
1922   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type Ref
1923   // TagDecl
1924   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // IdentifierNamespace
1925   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getTagKind
1926   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isCompleteDefinition
1927   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // EmbeddedInDeclarator
1928   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsFreeStanding
1929   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsCompleteDefinitionRequired
1930   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // SourceLocation
1931   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // SourceLocation
1932   Abv->Add(BitCodeAbbrevOp(0));                         // ExtInfoKind
1933   // EnumDecl
1934   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // AddTypeRef
1935   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // IntegerType
1936   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getPromotionType
1937   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getNumPositiveBits
1938   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getNumNegativeBits
1939   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isScoped
1940   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isScopedUsingClassTag
1941   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isFixed
1942   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));// ODRHash
1943   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // InstantiatedMembEnum
1944   // DC
1945   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // LexicalOffset
1946   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // VisibleOffset
1947   DeclEnumAbbrev = Stream.EmitAbbrev(std::move(Abv));
1948 
1949   // Abbreviation for DECL_RECORD
1950   Abv = std::make_shared<BitCodeAbbrev>();
1951   Abv->Add(BitCodeAbbrevOp(serialization::DECL_RECORD));
1952   // Redeclarable
1953   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
1954   // Decl
1955   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
1956   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
1957   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
1958   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
1959   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
1960   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
1961   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
1962   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
1963   Abv->Add(BitCodeAbbrevOp(AS_none));                 // C++ AccessSpecifier
1964   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
1965   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
1966   // NamedDecl
1967   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
1968   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
1969   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
1970   // TypeDecl
1971   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Source Location
1972   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type Ref
1973   // TagDecl
1974   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // IdentifierNamespace
1975   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // getTagKind
1976   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isCompleteDefinition
1977   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // EmbeddedInDeclarator
1978   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsFreeStanding
1979   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsCompleteDefinitionRequired
1980   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // SourceLocation
1981   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // SourceLocation
1982   Abv->Add(BitCodeAbbrevOp(0));                         // ExtInfoKind
1983   // RecordDecl
1984   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // FlexibleArrayMember
1985   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // AnonymousStructUnion
1986   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // hasObjectMember
1987   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // hasVolatileMember
1988 
1989   // isNonTrivialToPrimitiveDefaultInitialize
1990   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1991   // isNonTrivialToPrimitiveCopy
1992   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1993   // isNonTrivialToPrimitiveDestroy
1994   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1995   // isParamDestroyedInCallee
1996   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1997   // getArgPassingRestrictions
1998   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2));
1999 
2000   // DC
2001   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // LexicalOffset
2002   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // VisibleOffset
2003   DeclRecordAbbrev = Stream.EmitAbbrev(std::move(Abv));
2004 
2005   // Abbreviation for DECL_PARM_VAR
2006   Abv = std::make_shared<BitCodeAbbrev>();
2007   Abv->Add(BitCodeAbbrevOp(serialization::DECL_PARM_VAR));
2008   // Redeclarable
2009   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
2010   // Decl
2011   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
2012   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
2013   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
2014   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
2015   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
2016   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
2017   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
2018   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
2019   Abv->Add(BitCodeAbbrevOp(AS_none));                 // C++ AccessSpecifier
2020   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
2021   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
2022   // NamedDecl
2023   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
2024   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
2025   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
2026   // ValueDecl
2027   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
2028   // DeclaratorDecl
2029   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // InnerStartLoc
2030   Abv->Add(BitCodeAbbrevOp(0));                       // hasExtInfo
2031   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TSIType
2032   // VarDecl
2033   Abv->Add(BitCodeAbbrevOp(0));                       // SClass
2034   Abv->Add(BitCodeAbbrevOp(0));                       // TSCSpec
2035   Abv->Add(BitCodeAbbrevOp(0));                       // InitStyle
2036   Abv->Add(BitCodeAbbrevOp(0));                       // ARCPseudoStrong
2037   Abv->Add(BitCodeAbbrevOp(0));                       // Linkage
2038   Abv->Add(BitCodeAbbrevOp(0));                       // HasInit
2039   Abv->Add(BitCodeAbbrevOp(0));                   // HasMemberSpecializationInfo
2040   // ParmVarDecl
2041   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsObjCMethodParameter
2042   Abv->Add(BitCodeAbbrevOp(0));                       // ScopeDepth
2043   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ScopeIndex
2044   Abv->Add(BitCodeAbbrevOp(0));                       // ObjCDeclQualifier
2045   Abv->Add(BitCodeAbbrevOp(0));                       // KNRPromoted
2046   Abv->Add(BitCodeAbbrevOp(0));                       // HasInheritedDefaultArg
2047   Abv->Add(BitCodeAbbrevOp(0));                   // HasUninstantiatedDefaultArg
2048   // Type Source Info
2049   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2050   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
2051   DeclParmVarAbbrev = Stream.EmitAbbrev(std::move(Abv));
2052 
2053   // Abbreviation for DECL_TYPEDEF
2054   Abv = std::make_shared<BitCodeAbbrev>();
2055   Abv->Add(BitCodeAbbrevOp(serialization::DECL_TYPEDEF));
2056   // Redeclarable
2057   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
2058   // Decl
2059   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
2060   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
2061   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
2062   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
2063   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
2064   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isUsed
2065   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isReferenced
2066   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
2067   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // C++ AccessSpecifier
2068   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
2069   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
2070   // NamedDecl
2071   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
2072   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
2073   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
2074   // TypeDecl
2075   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Source Location
2076   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type Ref
2077   // TypedefDecl
2078   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2079   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
2080   DeclTypedefAbbrev = Stream.EmitAbbrev(std::move(Abv));
2081 
2082   // Abbreviation for DECL_VAR
2083   Abv = std::make_shared<BitCodeAbbrev>();
2084   Abv->Add(BitCodeAbbrevOp(serialization::DECL_VAR));
2085   // Redeclarable
2086   Abv->Add(BitCodeAbbrevOp(0));                       // No redeclaration
2087   // Decl
2088   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclContext
2089   Abv->Add(BitCodeAbbrevOp(0));                       // LexicalDeclContext
2090   Abv->Add(BitCodeAbbrevOp(0));                       // isInvalidDecl
2091   Abv->Add(BitCodeAbbrevOp(0));                       // HasAttrs
2092   Abv->Add(BitCodeAbbrevOp(0));                       // isImplicit
2093   Abv->Add(BitCodeAbbrevOp(0));                       // isUsed
2094   Abv->Add(BitCodeAbbrevOp(0));                       // isReferenced
2095   Abv->Add(BitCodeAbbrevOp(0));                   // TopLevelDeclInObjCContainer
2096   Abv->Add(BitCodeAbbrevOp(AS_none));                 // C++ AccessSpecifier
2097   Abv->Add(BitCodeAbbrevOp(0));                       // ModulePrivate
2098   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // SubmoduleID
2099   // NamedDecl
2100   Abv->Add(BitCodeAbbrevOp(0));                       // NameKind = Identifier
2101   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Name
2102   Abv->Add(BitCodeAbbrevOp(0));                       // AnonDeclNumber
2103   // ValueDecl
2104   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
2105   // DeclaratorDecl
2106   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // InnerStartLoc
2107   Abv->Add(BitCodeAbbrevOp(0));                       // hasExtInfo
2108   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TSIType
2109   // VarDecl
2110   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // SClass
2111   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // TSCSpec
2112   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // InitStyle
2113   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isARCPseudoStrong
2114   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsThisDeclarationADemotedDefinition
2115   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isExceptionVariable
2116   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isNRVOVariable
2117   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isCXXForRangeDecl
2118   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // isObjCForDecl
2119   Abv->Add(BitCodeAbbrevOp(0));                         // isInline
2120   Abv->Add(BitCodeAbbrevOp(0));                         // isInlineSpecified
2121   Abv->Add(BitCodeAbbrevOp(0));                         // isConstexpr
2122   Abv->Add(BitCodeAbbrevOp(0));                         // isInitCapture
2123   Abv->Add(BitCodeAbbrevOp(0));                         // isPrevDeclInSameScope
2124   Abv->Add(BitCodeAbbrevOp(0));                         // ImplicitParamKind
2125   Abv->Add(BitCodeAbbrevOp(0));                         // EscapingByref
2126   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // Linkage
2127   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // IsInitICE (local)
2128   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // VarKind (local enum)
2129   // Type Source Info
2130   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2131   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // TypeLoc
2132   DeclVarAbbrev = Stream.EmitAbbrev(std::move(Abv));
2133 
2134   // Abbreviation for DECL_CXX_METHOD
2135   Abv = std::make_shared<BitCodeAbbrev>();
2136   Abv->Add(BitCodeAbbrevOp(serialization::DECL_CXX_METHOD));
2137   // RedeclarableDecl
2138   Abv->Add(BitCodeAbbrevOp(0));                         // CanonicalDecl
2139   // Decl
2140   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // DeclContext
2141   Abv->Add(BitCodeAbbrevOp(0));                         // LexicalDeclContext
2142   Abv->Add(BitCodeAbbrevOp(0));                         // Invalid
2143   Abv->Add(BitCodeAbbrevOp(0));                         // HasAttrs
2144   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Implicit
2145   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Used
2146   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Referenced
2147   Abv->Add(BitCodeAbbrevOp(0));                         // InObjCContainer
2148   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2)); // Access
2149   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // ModulePrivate
2150   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // SubmoduleID
2151   // NamedDecl
2152   Abv->Add(BitCodeAbbrevOp(DeclarationName::Identifier)); // NameKind
2153   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // Identifier
2154   Abv->Add(BitCodeAbbrevOp(0));                         // AnonDeclNumber
2155   // ValueDecl
2156   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // Type
2157   // DeclaratorDecl
2158   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // InnerLocStart
2159   Abv->Add(BitCodeAbbrevOp(0));                         // HasExtInfo
2160   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // TSIType
2161   // FunctionDecl
2162   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 11)); // IDNS
2163   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // StorageClass
2164   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Inline
2165   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // InlineSpecified
2166   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // VirtualAsWritten
2167   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Pure
2168   Abv->Add(BitCodeAbbrevOp(0));                         // HasInheritedProto
2169   Abv->Add(BitCodeAbbrevOp(1));                         // HasWrittenProto
2170   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Deleted
2171   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Trivial
2172   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // TrivialForCall
2173   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Defaulted
2174   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // ExplicitlyDefaulted
2175   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // ImplicitReturnZero
2176   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // Constexpr
2177   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // UsesSEHTry
2178   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // SkippedBody
2179   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // MultiVersion
2180   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // LateParsed
2181   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // Linkage
2182   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // LocEnd
2183   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32)); // ODRHash
2184   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // TemplateKind
2185   // This Array slurps the rest of the record. Fortunately we want to encode
2186   // (nearly) all the remaining (variable number of) fields in the same way.
2187   //
2188   // This is the function template information if any, then
2189   //         NumParams and Params[] from FunctionDecl, and
2190   //         NumOverriddenMethods, OverriddenMethods[] from CXXMethodDecl.
2191   //
2192   //  Add an AbbrevOp for 'size then elements' and use it here.
2193   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2194   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
2195   DeclCXXMethodAbbrev = Stream.EmitAbbrev(std::move(Abv));
2196 
2197   // Abbreviation for EXPR_DECL_REF
2198   Abv = std::make_shared<BitCodeAbbrev>();
2199   Abv->Add(BitCodeAbbrevOp(serialization::EXPR_DECL_REF));
2200   //Stmt
2201   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsOMPStructuredBlock
2202   // Expr
2203   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
2204   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //TypeDependent
2205   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ValueDependent
2206   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //InstantiationDependent
2207   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //UnexpandedParamPack
2208   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetValueKind
2209   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetObjectKind
2210   //DeclRefExpr
2211   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //HasQualifier
2212   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //GetDeclFound
2213   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ExplicitTemplateArgs
2214   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //HadMultipleCandidates
2215   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
2216                            1)); // RefersToEnclosingVariableOrCapture
2217   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // DeclRef
2218   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Location
2219   DeclRefExprAbbrev = Stream.EmitAbbrev(std::move(Abv));
2220 
2221   // Abbreviation for EXPR_INTEGER_LITERAL
2222   Abv = std::make_shared<BitCodeAbbrev>();
2223   Abv->Add(BitCodeAbbrevOp(serialization::EXPR_INTEGER_LITERAL));
2224   //Stmt
2225   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsOMPStructuredBlock
2226   // Expr
2227   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
2228   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //TypeDependent
2229   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ValueDependent
2230   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //InstantiationDependent
2231   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //UnexpandedParamPack
2232   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetValueKind
2233   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetObjectKind
2234   //Integer Literal
2235   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Location
2236   Abv->Add(BitCodeAbbrevOp(32));                      // Bit Width
2237   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Value
2238   IntegerLiteralAbbrev = Stream.EmitAbbrev(std::move(Abv));
2239 
2240   // Abbreviation for EXPR_CHARACTER_LITERAL
2241   Abv = std::make_shared<BitCodeAbbrev>();
2242   Abv->Add(BitCodeAbbrevOp(serialization::EXPR_CHARACTER_LITERAL));
2243   //Stmt
2244   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsOMPStructuredBlock
2245   // Expr
2246   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
2247   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //TypeDependent
2248   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ValueDependent
2249   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //InstantiationDependent
2250   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //UnexpandedParamPack
2251   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetValueKind
2252   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetObjectKind
2253   //Character Literal
2254   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // getValue
2255   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Location
2256   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // getKind
2257   CharacterLiteralAbbrev = Stream.EmitAbbrev(std::move(Abv));
2258 
2259   // Abbreviation for EXPR_IMPLICIT_CAST
2260   Abv = std::make_shared<BitCodeAbbrev>();
2261   Abv->Add(BitCodeAbbrevOp(serialization::EXPR_IMPLICIT_CAST));
2262   // Stmt
2263   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // IsOMPStructuredBlock
2264   // Expr
2265   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Type
2266   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //TypeDependent
2267   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //ValueDependent
2268   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //InstantiationDependent
2269   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); //UnexpandedParamPack
2270   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetValueKind
2271   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); //GetObjectKind
2272   // CastExpr
2273   Abv->Add(BitCodeAbbrevOp(0)); // PathSize
2274   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 6)); // CastKind
2275   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // PartOfExplicitCast
2276   // ImplicitCastExpr
2277   ExprImplicitCastAbbrev = Stream.EmitAbbrev(std::move(Abv));
2278 
2279   Abv = std::make_shared<BitCodeAbbrev>();
2280   Abv->Add(BitCodeAbbrevOp(serialization::DECL_CONTEXT_LEXICAL));
2281   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2282   DeclContextLexicalAbbrev = Stream.EmitAbbrev(std::move(Abv));
2283 
2284   Abv = std::make_shared<BitCodeAbbrev>();
2285   Abv->Add(BitCodeAbbrevOp(serialization::DECL_CONTEXT_VISIBLE));
2286   Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Blob));
2287   DeclContextVisibleLookupAbbrev = Stream.EmitAbbrev(std::move(Abv));
2288 }
2289 
2290 /// isRequiredDecl - Check if this is a "required" Decl, which must be seen by
2291 /// consumers of the AST.
2292 ///
2293 /// Such decls will always be deserialized from the AST file, so we would like
2294 /// this to be as restrictive as possible. Currently the predicate is driven by
2295 /// code generation requirements, if other clients have a different notion of
2296 /// what is "required" then we may have to consider an alternate scheme where
2297 /// clients can iterate over the top-level decls and get information on them,
2298 /// without necessary deserializing them. We could explicitly require such
2299 /// clients to use a separate API call to "realize" the decl. This should be
2300 /// relatively painless since they would presumably only do it for top-level
2301 /// decls.
2302 static bool isRequiredDecl(const Decl *D, ASTContext &Context,
2303                            bool WritingModule) {
2304   // An ObjCMethodDecl is never considered as "required" because its
2305   // implementation container always is.
2306 
2307   // File scoped assembly or obj-c or OMP declare target implementation must be
2308   // seen.
2309   if (isa<FileScopeAsmDecl>(D) || isa<ObjCImplDecl>(D))
2310     return true;
2311 
2312   if (WritingModule && isPartOfPerModuleInitializer(D)) {
2313     // These declarations are part of the module initializer, and are emitted
2314     // if and when the module is imported, rather than being emitted eagerly.
2315     return false;
2316   }
2317 
2318   return Context.DeclMustBeEmitted(D);
2319 }
2320 
2321 void ASTWriter::WriteDecl(ASTContext &Context, Decl *D) {
2322   PrettyDeclStackTraceEntry CrashInfo(Context, D, SourceLocation(),
2323                                       "serializing");
2324 
2325   // Determine the ID for this declaration.
2326   serialization::DeclID ID;
2327   assert(!D->isFromASTFile() && "should not be emitting imported decl");
2328   serialization::DeclID &IDR = DeclIDs[D];
2329   if (IDR == 0)
2330     IDR = NextDeclID++;
2331 
2332   ID = IDR;
2333 
2334   assert(ID >= FirstDeclID && "invalid decl ID");
2335 
2336   RecordData Record;
2337   ASTDeclWriter W(*this, Context, Record);
2338 
2339   // Build a record for this declaration
2340   W.Visit(D);
2341 
2342   // Emit this declaration to the bitstream.
2343   uint64_t Offset = W.Emit(D);
2344 
2345   // Record the offset for this declaration
2346   SourceLocation Loc = D->getLocation();
2347   unsigned Index = ID - FirstDeclID;
2348   if (DeclOffsets.size() == Index)
2349     DeclOffsets.push_back(DeclOffset(Loc, Offset));
2350   else if (DeclOffsets.size() < Index) {
2351     // FIXME: Can/should this happen?
2352     DeclOffsets.resize(Index+1);
2353     DeclOffsets[Index].setLocation(Loc);
2354     DeclOffsets[Index].BitOffset = Offset;
2355   } else {
2356     llvm_unreachable("declarations should be emitted in ID order");
2357   }
2358 
2359   SourceManager &SM = Context.getSourceManager();
2360   if (Loc.isValid() && SM.isLocalSourceLocation(Loc))
2361     associateDeclWithFile(D, ID);
2362 
2363   // Note declarations that should be deserialized eagerly so that we can add
2364   // them to a record in the AST file later.
2365   if (isRequiredDecl(D, Context, WritingModule))
2366     EagerlyDeserializedDecls.push_back(ID);
2367 }
2368 
2369 void ASTRecordWriter::AddFunctionDefinition(const FunctionDecl *FD) {
2370   // Switch case IDs are per function body.
2371   Writer->ClearSwitchCaseIDs();
2372 
2373   assert(FD->doesThisDeclarationHaveABody());
2374   bool ModulesCodegen = false;
2375   if (Writer->WritingModule && !FD->isDependentContext()) {
2376     Optional<GVALinkage> Linkage;
2377     if (Writer->WritingModule->Kind == Module::ModuleInterfaceUnit) {
2378       // When building a C++ Modules TS module interface unit, a strong
2379       // definition in the module interface is provided by the compilation of
2380       // that module interface unit, not by its users. (Inline functions are
2381       // still emitted in module users.)
2382       Linkage = Writer->Context->GetGVALinkageForFunction(FD);
2383       ModulesCodegen = *Linkage == GVA_StrongExternal;
2384     }
2385     if (Writer->Context->getLangOpts().ModulesCodegen) {
2386       // Under -fmodules-codegen, codegen is performed for all non-internal,
2387       // non-always_inline functions.
2388       if (!FD->hasAttr<AlwaysInlineAttr>()) {
2389         if (!Linkage)
2390           Linkage = Writer->Context->GetGVALinkageForFunction(FD);
2391         ModulesCodegen = *Linkage != GVA_Internal;
2392       }
2393     }
2394   }
2395   Record->push_back(ModulesCodegen);
2396   if (ModulesCodegen)
2397     Writer->ModularCodegenDecls.push_back(Writer->GetDeclRef(FD));
2398   if (auto *CD = dyn_cast<CXXConstructorDecl>(FD)) {
2399     Record->push_back(CD->getNumCtorInitializers());
2400     if (CD->getNumCtorInitializers())
2401       AddCXXCtorInitializers(
2402           llvm::makeArrayRef(CD->init_begin(), CD->init_end()));
2403   }
2404   AddStmt(FD->getBody());
2405 }
2406