1 //===- IndexDecl.cpp - Indexing declarations ------------------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "IndexingContext.h"
11 #include "clang/Index/IndexDataConsumer.h"
12 #include "clang/AST/DeclVisitor.h"
13 
14 using namespace clang;
15 using namespace index;
16 
17 #define TRY_DECL(D,CALL_EXPR)                                                  \
18   do {                                                                         \
19     if (!IndexCtx.shouldIndex(D)) return true;                                 \
20     if (!CALL_EXPR)                                                            \
21       return false;                                                            \
22   } while (0)
23 
24 #define TRY_TO(CALL_EXPR)                                                      \
25   do {                                                                         \
26     if (!CALL_EXPR)                                                            \
27       return false;                                                            \
28   } while (0)
29 
30 namespace {
31 
32 class IndexingDeclVisitor : public ConstDeclVisitor<IndexingDeclVisitor, bool> {
33   IndexingContext &IndexCtx;
34 
35 public:
36   explicit IndexingDeclVisitor(IndexingContext &indexCtx)
37     : IndexCtx(indexCtx) { }
38 
39   bool Handled = true;
40 
41   bool VisitDecl(const Decl *D) {
42     Handled = false;
43     return true;
44   }
45 
46   /// \brief Returns true if the given method has been defined explicitly by the
47   /// user.
48   static bool hasUserDefined(const ObjCMethodDecl *D,
49                              const ObjCImplDecl *Container) {
50     const ObjCMethodDecl *MD = Container->getMethod(D->getSelector(),
51                                                     D->isInstanceMethod());
52     return MD && !MD->isImplicit() && MD->isThisDeclarationADefinition();
53   }
54 
55   void handleTemplateArgumentLoc(const TemplateArgumentLoc &TALoc,
56                                  const NamedDecl *Parent,
57                                  const DeclContext *DC) {
58     const TemplateArgumentLocInfo &LocInfo = TALoc.getLocInfo();
59     switch (TALoc.getArgument().getKind()) {
60     case TemplateArgument::Expression:
61       IndexCtx.indexBody(LocInfo.getAsExpr(), Parent, DC);
62       break;
63     case TemplateArgument::Type:
64       IndexCtx.indexTypeSourceInfo(LocInfo.getAsTypeSourceInfo(), Parent, DC);
65       break;
66     case TemplateArgument::Template:
67     case TemplateArgument::TemplateExpansion:
68       IndexCtx.indexNestedNameSpecifierLoc(TALoc.getTemplateQualifierLoc(),
69                                            Parent, DC);
70       if (const TemplateDecl *TD = TALoc.getArgument()
71                                        .getAsTemplateOrTemplatePattern()
72                                        .getAsTemplateDecl()) {
73         if (const NamedDecl *TTD = TD->getTemplatedDecl())
74           IndexCtx.handleReference(TTD, TALoc.getTemplateNameLoc(), Parent, DC);
75       }
76       break;
77     default:
78       break;
79     }
80   }
81 
82   void handleDeclarator(const DeclaratorDecl *D,
83                         const NamedDecl *Parent = nullptr,
84                         bool isIBType = false) {
85     if (!Parent) Parent = D;
86 
87     IndexCtx.indexTypeSourceInfo(D->getTypeSourceInfo(), Parent,
88                                  Parent->getLexicalDeclContext(),
89                                  /*isBase=*/false, isIBType);
90     IndexCtx.indexNestedNameSpecifierLoc(D->getQualifierLoc(), Parent);
91     if (IndexCtx.shouldIndexFunctionLocalSymbols()) {
92       // Only index parameters in definitions, parameters in declarations are
93       // not useful.
94       if (const ParmVarDecl *Parm = dyn_cast<ParmVarDecl>(D)) {
95         auto *DC = Parm->getDeclContext();
96         if (auto *FD = dyn_cast<FunctionDecl>(DC)) {
97           if (FD->isThisDeclarationADefinition())
98             IndexCtx.handleDecl(Parm);
99         } else if (auto *MD = dyn_cast<ObjCMethodDecl>(DC)) {
100           if (MD->isThisDeclarationADefinition())
101             IndexCtx.handleDecl(Parm);
102         } else {
103           IndexCtx.handleDecl(Parm);
104         }
105       } else if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
106         if (FD->isThisDeclarationADefinition()) {
107           for (auto PI : FD->parameters()) {
108             IndexCtx.handleDecl(PI);
109           }
110         }
111       }
112     } else {
113       // Index the default parameter value for function definitions.
114       if (const auto *FD = dyn_cast<FunctionDecl>(D)) {
115         if (FD->isThisDeclarationADefinition()) {
116           for (const auto *PV : FD->parameters()) {
117             if (PV->hasDefaultArg() && !PV->hasUninstantiatedDefaultArg() &&
118                 !PV->hasUnparsedDefaultArg())
119               IndexCtx.indexBody(PV->getDefaultArg(), D);
120           }
121         }
122       }
123     }
124   }
125 
126   bool handleObjCMethod(const ObjCMethodDecl *D,
127                         const ObjCPropertyDecl *AssociatedProp = nullptr) {
128     SmallVector<SymbolRelation, 4> Relations;
129     SmallVector<const ObjCMethodDecl*, 4> Overriden;
130 
131     D->getOverriddenMethods(Overriden);
132     for(auto overridden: Overriden) {
133       Relations.emplace_back((unsigned) SymbolRole::RelationOverrideOf,
134                              overridden);
135     }
136     if (AssociatedProp)
137       Relations.emplace_back((unsigned)SymbolRole::RelationAccessorOf,
138                              AssociatedProp);
139 
140     // getLocation() returns beginning token of a method declaration, but for
141     // indexing purposes we want to point to the base name.
142     SourceLocation MethodLoc = D->getSelectorStartLoc();
143     if (MethodLoc.isInvalid())
144       MethodLoc = D->getLocation();
145 
146     SourceLocation AttrLoc;
147 
148     // check for (getter=/setter=)
149     if (AssociatedProp) {
150       bool isGetter = !D->param_size();
151       AttrLoc = isGetter ?
152         AssociatedProp->getGetterNameLoc():
153         AssociatedProp->getSetterNameLoc();
154     }
155 
156     SymbolRoleSet Roles = (SymbolRoleSet)SymbolRole::Dynamic;
157     if (D->isImplicit()) {
158       if (AttrLoc.isValid()) {
159         MethodLoc = AttrLoc;
160       } else {
161         Roles |= (SymbolRoleSet)SymbolRole::Implicit;
162       }
163     } else if (AttrLoc.isValid()) {
164       IndexCtx.handleReference(D, AttrLoc, cast<NamedDecl>(D->getDeclContext()),
165                                D->getDeclContext(), 0);
166     }
167 
168     TRY_DECL(D, IndexCtx.handleDecl(D, MethodLoc, Roles, Relations));
169     IndexCtx.indexTypeSourceInfo(D->getReturnTypeSourceInfo(), D);
170     bool hasIBActionAndFirst = D->hasAttr<IBActionAttr>();
171     for (const auto *I : D->parameters()) {
172       handleDeclarator(I, D, /*isIBType=*/hasIBActionAndFirst);
173       hasIBActionAndFirst = false;
174     }
175 
176     if (D->isThisDeclarationADefinition()) {
177       const Stmt *Body = D->getBody();
178       if (Body) {
179         IndexCtx.indexBody(Body, D, D);
180       }
181     }
182     return true;
183   }
184 
185   /// Gather the declarations which the given declaration \D overrides in a
186   /// pseudo-override manner.
187   ///
188   /// Pseudo-overrides occur when a class template specialization declares
189   /// a declaration that has the same name as a similar declaration in the
190   /// non-specialized template.
191   void
192   gatherTemplatePseudoOverrides(const NamedDecl *D,
193                                 SmallVectorImpl<SymbolRelation> &Relations) {
194     if (!IndexCtx.getLangOpts().CPlusPlus)
195       return;
196     const auto *CTSD =
197         dyn_cast<ClassTemplateSpecializationDecl>(D->getLexicalDeclContext());
198     if (!CTSD)
199       return;
200     llvm::PointerUnion<ClassTemplateDecl *,
201                        ClassTemplatePartialSpecializationDecl *>
202         Template = CTSD->getSpecializedTemplateOrPartial();
203     if (const auto *CTD = Template.dyn_cast<ClassTemplateDecl *>()) {
204       const CXXRecordDecl *Pattern = CTD->getTemplatedDecl();
205       bool TypeOverride = isa<TypeDecl>(D);
206       for (const NamedDecl *ND : Pattern->lookup(D->getDeclName())) {
207         if (const auto *CTD = dyn_cast<ClassTemplateDecl>(ND))
208           ND = CTD->getTemplatedDecl();
209         if (ND->isImplicit())
210           continue;
211         // Types can override other types.
212         if (!TypeOverride) {
213           if (ND->getKind() != D->getKind())
214             continue;
215         } else if (!isa<TypeDecl>(ND))
216           continue;
217         if (const auto *FD = dyn_cast<FunctionDecl>(ND)) {
218           const auto *DFD = cast<FunctionDecl>(D);
219           // Function overrides are approximated using the number of parameters.
220           if (FD->getStorageClass() != DFD->getStorageClass() ||
221               FD->getNumParams() != DFD->getNumParams())
222             continue;
223         }
224         Relations.emplace_back(
225             SymbolRoleSet(SymbolRole::RelationSpecializationOf), ND);
226       }
227     }
228   }
229 
230   bool VisitFunctionDecl(const FunctionDecl *D) {
231     SymbolRoleSet Roles{};
232     SmallVector<SymbolRelation, 4> Relations;
233     if (auto *CXXMD = dyn_cast<CXXMethodDecl>(D)) {
234       if (CXXMD->isVirtual())
235         Roles |= (unsigned)SymbolRole::Dynamic;
236       for (auto I = CXXMD->begin_overridden_methods(),
237            E = CXXMD->end_overridden_methods(); I != E; ++I) {
238         Relations.emplace_back((unsigned)SymbolRole::RelationOverrideOf, *I);
239       }
240     }
241     gatherTemplatePseudoOverrides(D, Relations);
242     if (const auto *Base = D->getPrimaryTemplate())
243       Relations.push_back(
244           SymbolRelation(SymbolRoleSet(SymbolRole::RelationSpecializationOf),
245                          Base->getTemplatedDecl()));
246 
247     TRY_DECL(D, IndexCtx.handleDecl(D, Roles, Relations));
248     handleDeclarator(D);
249 
250     if (const CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(D)) {
251       IndexCtx.handleReference(Ctor->getParent(), Ctor->getLocation(),
252                                Ctor->getParent(), Ctor->getDeclContext());
253 
254       // Constructor initializers.
255       for (const auto *Init : Ctor->inits()) {
256         if (Init->isWritten()) {
257           IndexCtx.indexTypeSourceInfo(Init->getTypeSourceInfo(), D);
258           if (const FieldDecl *Member = Init->getAnyMember())
259             IndexCtx.handleReference(Member, Init->getMemberLocation(), D, D,
260                                      (unsigned)SymbolRole::Write);
261           IndexCtx.indexBody(Init->getInit(), D, D);
262         }
263       }
264     } else if (const CXXDestructorDecl *Dtor = dyn_cast<CXXDestructorDecl>(D)) {
265       if (auto TypeNameInfo = Dtor->getNameInfo().getNamedTypeInfo()) {
266         IndexCtx.handleReference(Dtor->getParent(),
267                                  TypeNameInfo->getTypeLoc().getLocStart(),
268                                  Dtor->getParent(), Dtor->getDeclContext());
269       }
270     }
271     // Template specialization arguments.
272     if (const ASTTemplateArgumentListInfo *TemplateArgInfo =
273             D->getTemplateSpecializationArgsAsWritten()) {
274       for (const auto &Arg : TemplateArgInfo->arguments())
275         handleTemplateArgumentLoc(Arg, D, D->getLexicalDeclContext());
276     }
277 
278     if (D->isThisDeclarationADefinition()) {
279       const Stmt *Body = D->getBody();
280       if (Body) {
281         IndexCtx.indexBody(Body, D, D);
282       }
283     }
284     return true;
285   }
286 
287   bool VisitVarDecl(const VarDecl *D) {
288     SmallVector<SymbolRelation, 4> Relations;
289     gatherTemplatePseudoOverrides(D, Relations);
290     TRY_DECL(D, IndexCtx.handleDecl(D, SymbolRoleSet(), Relations));
291     handleDeclarator(D);
292     IndexCtx.indexBody(D->getInit(), D);
293     return true;
294   }
295 
296   bool VisitDecompositionDecl(const DecompositionDecl *D) {
297     for (const auto *Binding : D->bindings())
298       TRY_DECL(Binding, IndexCtx.handleDecl(Binding));
299     return Base::VisitDecompositionDecl(D);
300   }
301 
302   bool VisitFieldDecl(const FieldDecl *D) {
303     SmallVector<SymbolRelation, 4> Relations;
304     gatherTemplatePseudoOverrides(D, Relations);
305     TRY_DECL(D, IndexCtx.handleDecl(D, SymbolRoleSet(), Relations));
306     handleDeclarator(D);
307     if (D->isBitField())
308       IndexCtx.indexBody(D->getBitWidth(), D);
309     else if (D->hasInClassInitializer())
310       IndexCtx.indexBody(D->getInClassInitializer(), D);
311     return true;
312   }
313 
314   bool VisitObjCIvarDecl(const ObjCIvarDecl *D) {
315     if (D->getSynthesize()) {
316       // handled in VisitObjCPropertyImplDecl
317       return true;
318     }
319     TRY_DECL(D, IndexCtx.handleDecl(D));
320     handleDeclarator(D);
321     return true;
322   }
323 
324   bool VisitMSPropertyDecl(const MSPropertyDecl *D) {
325     handleDeclarator(D);
326     return true;
327   }
328 
329   bool VisitEnumConstantDecl(const EnumConstantDecl *D) {
330     TRY_DECL(D, IndexCtx.handleDecl(D));
331     IndexCtx.indexBody(D->getInitExpr(), D);
332     return true;
333   }
334 
335   bool VisitTypedefNameDecl(const TypedefNameDecl *D) {
336     if (!D->isTransparentTag()) {
337       SmallVector<SymbolRelation, 4> Relations;
338       gatherTemplatePseudoOverrides(D, Relations);
339       TRY_DECL(D, IndexCtx.handleDecl(D, SymbolRoleSet(), Relations));
340       IndexCtx.indexTypeSourceInfo(D->getTypeSourceInfo(), D);
341     }
342     return true;
343   }
344 
345   bool VisitTagDecl(const TagDecl *D) {
346     // Non-free standing tags are handled in indexTypeSourceInfo.
347     if (D->isFreeStanding()) {
348       if (D->isThisDeclarationADefinition()) {
349         SmallVector<SymbolRelation, 4> Relations;
350         gatherTemplatePseudoOverrides(D, Relations);
351         IndexCtx.indexTagDecl(D, Relations);
352       } else {
353         auto *Parent = dyn_cast<NamedDecl>(D->getDeclContext());
354         SmallVector<SymbolRelation, 1> Relations;
355         gatherTemplatePseudoOverrides(D, Relations);
356         return IndexCtx.handleReference(D, D->getLocation(), Parent,
357                                         D->getLexicalDeclContext(),
358                                         SymbolRoleSet(), Relations);
359       }
360     }
361     return true;
362   }
363 
364   bool handleReferencedProtocols(const ObjCProtocolList &ProtList,
365                                  const ObjCContainerDecl *ContD,
366                                  SourceLocation SuperLoc) {
367     ObjCInterfaceDecl::protocol_loc_iterator LI = ProtList.loc_begin();
368     for (ObjCInterfaceDecl::protocol_iterator
369          I = ProtList.begin(), E = ProtList.end(); I != E; ++I, ++LI) {
370       SourceLocation Loc = *LI;
371       ObjCProtocolDecl *PD = *I;
372       SymbolRoleSet roles{};
373       if (Loc == SuperLoc)
374         roles |= (SymbolRoleSet)SymbolRole::Implicit;
375       TRY_TO(IndexCtx.handleReference(PD, Loc, ContD, ContD, roles,
376           SymbolRelation{(unsigned)SymbolRole::RelationBaseOf, ContD}));
377     }
378     return true;
379   }
380 
381   bool VisitObjCInterfaceDecl(const ObjCInterfaceDecl *D) {
382     if (D->isThisDeclarationADefinition()) {
383       TRY_DECL(D, IndexCtx.handleDecl(D));
384       SourceLocation SuperLoc = D->getSuperClassLoc();
385       if (auto *SuperD = D->getSuperClass()) {
386         bool hasSuperTypedef = false;
387         if (auto *TInfo = D->getSuperClassTInfo()) {
388           if (auto *TT = TInfo->getType()->getAs<TypedefType>()) {
389             if (auto *TD = TT->getDecl()) {
390               hasSuperTypedef = true;
391               TRY_TO(IndexCtx.handleReference(TD, SuperLoc, D, D,
392                                               SymbolRoleSet()));
393             }
394           }
395         }
396         SymbolRoleSet superRoles{};
397         if (hasSuperTypedef)
398           superRoles |= (SymbolRoleSet)SymbolRole::Implicit;
399         TRY_TO(IndexCtx.handleReference(SuperD, SuperLoc, D, D, superRoles,
400             SymbolRelation{(unsigned)SymbolRole::RelationBaseOf, D}));
401       }
402       TRY_TO(handleReferencedProtocols(D->getReferencedProtocols(), D,
403                                        SuperLoc));
404       TRY_TO(IndexCtx.indexDeclContext(D));
405     } else {
406       return IndexCtx.handleReference(D, D->getLocation(), nullptr,
407                                       D->getDeclContext(), SymbolRoleSet());
408     }
409     return true;
410   }
411 
412   bool VisitObjCProtocolDecl(const ObjCProtocolDecl *D) {
413     if (D->isThisDeclarationADefinition()) {
414       TRY_DECL(D, IndexCtx.handleDecl(D));
415       TRY_TO(handleReferencedProtocols(D->getReferencedProtocols(), D,
416                                        /*superLoc=*/SourceLocation()));
417       TRY_TO(IndexCtx.indexDeclContext(D));
418     } else {
419       return IndexCtx.handleReference(D, D->getLocation(), nullptr,
420                                       D->getDeclContext(), SymbolRoleSet());
421     }
422     return true;
423   }
424 
425   bool VisitObjCImplementationDecl(const ObjCImplementationDecl *D) {
426     const ObjCInterfaceDecl *Class = D->getClassInterface();
427     if (!Class)
428       return true;
429 
430     if (Class->isImplicitInterfaceDecl())
431       IndexCtx.handleDecl(Class);
432 
433     TRY_DECL(D, IndexCtx.handleDecl(D));
434 
435     // Visit implicit @synthesize property implementations first as their
436     // location is reported at the name of the @implementation block. This
437     // serves no purpose other than to simplify the FileCheck-based tests.
438     for (const auto *I : D->property_impls()) {
439       if (I->getLocation().isInvalid())
440         IndexCtx.indexDecl(I);
441     }
442     for (const auto *I : D->decls()) {
443       if (!isa<ObjCPropertyImplDecl>(I) ||
444           cast<ObjCPropertyImplDecl>(I)->getLocation().isValid())
445         IndexCtx.indexDecl(I);
446     }
447 
448     return true;
449   }
450 
451   bool VisitObjCCategoryDecl(const ObjCCategoryDecl *D) {
452     if (!IndexCtx.shouldIndex(D))
453       return true;
454     const ObjCInterfaceDecl *C = D->getClassInterface();
455     if (!C)
456       return true;
457     TRY_TO(IndexCtx.handleReference(C, D->getLocation(), D, D, SymbolRoleSet(),
458                                    SymbolRelation{
459                                      (unsigned)SymbolRole::RelationExtendedBy, D
460                                    }));
461     SourceLocation CategoryLoc = D->getCategoryNameLoc();
462     if (!CategoryLoc.isValid())
463       CategoryLoc = D->getLocation();
464     TRY_TO(IndexCtx.handleDecl(D, CategoryLoc));
465     TRY_TO(handleReferencedProtocols(D->getReferencedProtocols(), D,
466                                      /*superLoc=*/SourceLocation()));
467     TRY_TO(IndexCtx.indexDeclContext(D));
468     return true;
469   }
470 
471   bool VisitObjCCategoryImplDecl(const ObjCCategoryImplDecl *D) {
472     const ObjCCategoryDecl *Cat = D->getCategoryDecl();
473     if (!Cat)
474       return true;
475     const ObjCInterfaceDecl *C = D->getClassInterface();
476     if (C)
477       TRY_TO(IndexCtx.handleReference(C, D->getLocation(), D, D,
478                                       SymbolRoleSet()));
479     SourceLocation CategoryLoc = D->getCategoryNameLoc();
480     if (!CategoryLoc.isValid())
481       CategoryLoc = D->getLocation();
482     TRY_DECL(D, IndexCtx.handleDecl(D, CategoryLoc));
483     IndexCtx.indexDeclContext(D);
484     return true;
485   }
486 
487   bool VisitObjCMethodDecl(const ObjCMethodDecl *D) {
488     // Methods associated with a property, even user-declared ones, are
489     // handled when we handle the property.
490     if (D->isPropertyAccessor())
491       return true;
492 
493     handleObjCMethod(D);
494     return true;
495   }
496 
497   bool VisitObjCPropertyDecl(const ObjCPropertyDecl *D) {
498     if (ObjCMethodDecl *MD = D->getGetterMethodDecl())
499       if (MD->getLexicalDeclContext() == D->getLexicalDeclContext())
500         handleObjCMethod(MD, D);
501     if (ObjCMethodDecl *MD = D->getSetterMethodDecl())
502       if (MD->getLexicalDeclContext() == D->getLexicalDeclContext())
503         handleObjCMethod(MD, D);
504     TRY_DECL(D, IndexCtx.handleDecl(D));
505     if (IBOutletCollectionAttr *attr = D->getAttr<IBOutletCollectionAttr>())
506       IndexCtx.indexTypeSourceInfo(attr->getInterfaceLoc(), D,
507                                    D->getLexicalDeclContext(), false, true);
508     IndexCtx.indexTypeSourceInfo(D->getTypeSourceInfo(), D);
509     return true;
510   }
511 
512   bool VisitObjCPropertyImplDecl(const ObjCPropertyImplDecl *D) {
513     ObjCPropertyDecl *PD = D->getPropertyDecl();
514     auto *Container = cast<ObjCImplDecl>(D->getDeclContext());
515     SourceLocation Loc = D->getLocation();
516     SymbolRoleSet Roles = 0;
517     SmallVector<SymbolRelation, 1> Relations;
518 
519     if (ObjCIvarDecl *ID = D->getPropertyIvarDecl())
520       Relations.push_back({(SymbolRoleSet)SymbolRole::RelationAccessorOf, ID});
521     if (Loc.isInvalid()) {
522       Loc = Container->getLocation();
523       Roles |= (SymbolRoleSet)SymbolRole::Implicit;
524     }
525     TRY_DECL(D, IndexCtx.handleDecl(D, Loc, Roles, Relations));
526 
527     if (D->getPropertyImplementation() == ObjCPropertyImplDecl::Dynamic)
528       return true;
529 
530     assert(D->getPropertyImplementation() == ObjCPropertyImplDecl::Synthesize);
531     SymbolRoleSet AccessorMethodRoles =
532       SymbolRoleSet(SymbolRole::Dynamic) | SymbolRoleSet(SymbolRole::Implicit);
533     if (ObjCMethodDecl *MD = PD->getGetterMethodDecl()) {
534       if (MD->isPropertyAccessor() &&
535           !hasUserDefined(MD, Container))
536         IndexCtx.handleDecl(MD, Loc, AccessorMethodRoles, {}, Container);
537     }
538     if (ObjCMethodDecl *MD = PD->getSetterMethodDecl()) {
539       if (MD->isPropertyAccessor() &&
540           !hasUserDefined(MD, Container))
541         IndexCtx.handleDecl(MD, Loc, AccessorMethodRoles, {}, Container);
542     }
543     if (ObjCIvarDecl *IvarD = D->getPropertyIvarDecl()) {
544       if (IvarD->getSynthesize()) {
545         // For synthesized ivars, use the location of its name in the
546         // corresponding @synthesize. If there isn't one, use the containing
547         // @implementation's location, rather than the property's location,
548         // otherwise the header file containing the @interface will have different
549         // indexing contents based on whether the @implementation was present or
550         // not in the translation unit.
551         SymbolRoleSet IvarRoles = 0;
552         SourceLocation IvarLoc = D->getPropertyIvarDeclLoc();
553         if (D->getLocation().isInvalid()) {
554           IvarLoc = Container->getLocation();
555           IvarRoles = (SymbolRoleSet)SymbolRole::Implicit;
556         } else if (D->getLocation() == IvarLoc) {
557           IvarRoles = (SymbolRoleSet)SymbolRole::Implicit;
558         }
559         TRY_DECL(IvarD, IndexCtx.handleDecl(IvarD, IvarLoc, IvarRoles));
560       } else {
561         IndexCtx.handleReference(IvarD, D->getPropertyIvarDeclLoc(), nullptr,
562                                  D->getDeclContext(), SymbolRoleSet());
563       }
564     }
565     return true;
566   }
567 
568   bool VisitNamespaceDecl(const NamespaceDecl *D) {
569     TRY_DECL(D, IndexCtx.handleDecl(D));
570     IndexCtx.indexDeclContext(D);
571     return true;
572   }
573 
574   bool VisitNamespaceAliasDecl(const NamespaceAliasDecl *D) {
575     TRY_DECL(D, IndexCtx.handleDecl(D));
576     IndexCtx.indexNestedNameSpecifierLoc(D->getQualifierLoc(), D);
577     IndexCtx.handleReference(D->getAliasedNamespace(), D->getTargetNameLoc(), D,
578                              D->getLexicalDeclContext());
579     return true;
580   }
581 
582   bool VisitUsingDecl(const UsingDecl *D) {
583     const DeclContext *DC = D->getDeclContext()->getRedeclContext();
584     const NamedDecl *Parent = dyn_cast<NamedDecl>(DC);
585 
586     IndexCtx.indexNestedNameSpecifierLoc(D->getQualifierLoc(), Parent,
587                                          D->getLexicalDeclContext());
588     for (const auto *I : D->shadows())
589       IndexCtx.handleReference(I->getUnderlyingDecl(), D->getLocation(), Parent,
590                                D->getLexicalDeclContext(), SymbolRoleSet());
591     return true;
592   }
593 
594   bool VisitUsingDirectiveDecl(const UsingDirectiveDecl *D) {
595     const DeclContext *DC = D->getDeclContext()->getRedeclContext();
596     const NamedDecl *Parent = dyn_cast<NamedDecl>(DC);
597 
598     // NNS for the local 'using namespace' directives is visited by the body
599     // visitor.
600     if (!D->getParentFunctionOrMethod())
601       IndexCtx.indexNestedNameSpecifierLoc(D->getQualifierLoc(), Parent,
602                                            D->getLexicalDeclContext());
603 
604     return IndexCtx.handleReference(D->getNominatedNamespaceAsWritten(),
605                                     D->getLocation(), Parent,
606                                     D->getLexicalDeclContext(),
607                                     SymbolRoleSet());
608   }
609 
610   bool VisitClassTemplateSpecializationDecl(const
611                                            ClassTemplateSpecializationDecl *D) {
612     // FIXME: Notify subsequent callbacks if info comes from implicit
613     // instantiation.
614     llvm::PointerUnion<ClassTemplateDecl *,
615                        ClassTemplatePartialSpecializationDecl *>
616         Template = D->getSpecializedTemplateOrPartial();
617     const Decl *SpecializationOf =
618         Template.is<ClassTemplateDecl *>()
619             ? (Decl *)Template.get<ClassTemplateDecl *>()
620             : Template.get<ClassTemplatePartialSpecializationDecl *>();
621     IndexCtx.indexTagDecl(
622         D, SymbolRelation(SymbolRoleSet(SymbolRole::RelationSpecializationOf),
623                           SpecializationOf));
624     if (TypeSourceInfo *TSI = D->getTypeAsWritten())
625       IndexCtx.indexTypeSourceInfo(TSI, /*Parent=*/nullptr,
626                                    D->getLexicalDeclContext());
627     return true;
628   }
629 
630   static bool shouldIndexTemplateParameterDefaultValue(const NamedDecl *D) {
631     if (!D)
632       return false;
633     // We want to index the template parameters only once when indexing the
634     // canonical declaration.
635     if (const auto *FD = dyn_cast<FunctionDecl>(D))
636       return FD->getCanonicalDecl() == FD;
637     else if (const auto *TD = dyn_cast<TagDecl>(D))
638       return TD->getCanonicalDecl() == TD;
639     else if (const auto *VD = dyn_cast<VarDecl>(D))
640       return VD->getCanonicalDecl() == VD;
641     return true;
642   }
643 
644   bool VisitTemplateDecl(const TemplateDecl *D) {
645     // FIXME: Template parameters.
646 
647     // Index the default values for the template parameters.
648     const NamedDecl *Parent = D->getTemplatedDecl();
649     if (D->getTemplateParameters() &&
650         shouldIndexTemplateParameterDefaultValue(Parent)) {
651       const TemplateParameterList *Params = D->getTemplateParameters();
652       for (const NamedDecl *TP : *Params) {
653         if (const auto *TTP = dyn_cast<TemplateTypeParmDecl>(TP)) {
654           if (TTP->hasDefaultArgument())
655             IndexCtx.indexTypeSourceInfo(TTP->getDefaultArgumentInfo(), Parent);
656         } else if (const auto *NTTP = dyn_cast<NonTypeTemplateParmDecl>(TP)) {
657           if (NTTP->hasDefaultArgument())
658             IndexCtx.indexBody(NTTP->getDefaultArgument(), Parent);
659         } else if (const auto *TTPD = dyn_cast<TemplateTemplateParmDecl>(TP)) {
660           if (TTPD->hasDefaultArgument())
661             handleTemplateArgumentLoc(TTPD->getDefaultArgument(), Parent,
662                                       /*DC=*/nullptr);
663         }
664       }
665     }
666 
667     return Visit(D->getTemplatedDecl());
668   }
669 
670   bool VisitFriendDecl(const FriendDecl *D) {
671     if (auto ND = D->getFriendDecl()) {
672       // FIXME: Ignore a class template in a dependent context, these are not
673       // linked properly with their redeclarations, ending up with duplicate
674       // USRs.
675       // See comment "Friend templates are visible in fairly strange ways." in
676       // SemaTemplate.cpp which precedes code that prevents the friend template
677       // from becoming visible from the enclosing context.
678       if (isa<ClassTemplateDecl>(ND) && D->getDeclContext()->isDependentContext())
679         return true;
680       return Visit(ND);
681     }
682     if (auto Ty = D->getFriendType()) {
683       IndexCtx.indexTypeSourceInfo(Ty, cast<NamedDecl>(D->getDeclContext()));
684     }
685     return true;
686   }
687 
688   bool VisitImportDecl(const ImportDecl *D) {
689     return IndexCtx.importedModule(D);
690   }
691 
692   bool VisitStaticAssertDecl(const StaticAssertDecl *D) {
693     IndexCtx.indexBody(D->getAssertExpr(),
694                        dyn_cast<NamedDecl>(D->getDeclContext()),
695                        D->getLexicalDeclContext());
696     return true;
697   }
698 };
699 
700 } // anonymous namespace
701 
702 bool IndexingContext::indexDecl(const Decl *D) {
703   if (D->isImplicit() && shouldIgnoreIfImplicit(D))
704     return true;
705 
706   if (isTemplateImplicitInstantiation(D))
707     return true;
708 
709   IndexingDeclVisitor Visitor(*this);
710   bool ShouldContinue = Visitor.Visit(D);
711   if (!ShouldContinue)
712     return false;
713 
714   if (!Visitor.Handled && isa<DeclContext>(D))
715     return indexDeclContext(cast<DeclContext>(D));
716 
717   return true;
718 }
719 
720 bool IndexingContext::indexDeclContext(const DeclContext *DC) {
721   for (const auto *I : DC->decls())
722     if (!indexDecl(I))
723       return false;
724   return true;
725 }
726 
727 bool IndexingContext::indexTopLevelDecl(const Decl *D) {
728   if (D->getLocation().isInvalid())
729     return true;
730 
731   if (isa<ObjCMethodDecl>(D))
732     return true; // Wait for the objc container.
733 
734   return indexDecl(D);
735 }
736 
737 bool IndexingContext::indexDeclGroupRef(DeclGroupRef DG) {
738   for (DeclGroupRef::iterator I = DG.begin(), E = DG.end(); I != E; ++I)
739     if (!indexTopLevelDecl(*I))
740       return false;
741   return true;
742 }
743