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 VisitFieldDecl(const FieldDecl *D) {
297     SmallVector<SymbolRelation, 4> Relations;
298     gatherTemplatePseudoOverrides(D, Relations);
299     TRY_DECL(D, IndexCtx.handleDecl(D, SymbolRoleSet(), Relations));
300     handleDeclarator(D);
301     if (D->isBitField())
302       IndexCtx.indexBody(D->getBitWidth(), D);
303     else if (D->hasInClassInitializer())
304       IndexCtx.indexBody(D->getInClassInitializer(), D);
305     return true;
306   }
307 
308   bool VisitObjCIvarDecl(const ObjCIvarDecl *D) {
309     if (D->getSynthesize()) {
310       // handled in VisitObjCPropertyImplDecl
311       return true;
312     }
313     TRY_DECL(D, IndexCtx.handleDecl(D));
314     handleDeclarator(D);
315     return true;
316   }
317 
318   bool VisitMSPropertyDecl(const MSPropertyDecl *D) {
319     handleDeclarator(D);
320     return true;
321   }
322 
323   bool VisitEnumConstantDecl(const EnumConstantDecl *D) {
324     TRY_DECL(D, IndexCtx.handleDecl(D));
325     IndexCtx.indexBody(D->getInitExpr(), D);
326     return true;
327   }
328 
329   bool VisitTypedefNameDecl(const TypedefNameDecl *D) {
330     if (!D->isTransparentTag()) {
331       SmallVector<SymbolRelation, 4> Relations;
332       gatherTemplatePseudoOverrides(D, Relations);
333       TRY_DECL(D, IndexCtx.handleDecl(D, SymbolRoleSet(), Relations));
334       IndexCtx.indexTypeSourceInfo(D->getTypeSourceInfo(), D);
335     }
336     return true;
337   }
338 
339   bool VisitTagDecl(const TagDecl *D) {
340     // Non-free standing tags are handled in indexTypeSourceInfo.
341     if (D->isFreeStanding()) {
342       if (D->isThisDeclarationADefinition()) {
343         SmallVector<SymbolRelation, 4> Relations;
344         gatherTemplatePseudoOverrides(D, Relations);
345         IndexCtx.indexTagDecl(D, Relations);
346       } else {
347         auto *Parent = dyn_cast<NamedDecl>(D->getDeclContext());
348         return IndexCtx.handleReference(D, D->getLocation(), Parent,
349                                         D->getLexicalDeclContext(),
350                                         SymbolRoleSet());
351       }
352     }
353     return true;
354   }
355 
356   bool handleReferencedProtocols(const ObjCProtocolList &ProtList,
357                                  const ObjCContainerDecl *ContD,
358                                  SourceLocation SuperLoc) {
359     ObjCInterfaceDecl::protocol_loc_iterator LI = ProtList.loc_begin();
360     for (ObjCInterfaceDecl::protocol_iterator
361          I = ProtList.begin(), E = ProtList.end(); I != E; ++I, ++LI) {
362       SourceLocation Loc = *LI;
363       ObjCProtocolDecl *PD = *I;
364       SymbolRoleSet roles{};
365       if (Loc == SuperLoc)
366         roles |= (SymbolRoleSet)SymbolRole::Implicit;
367       TRY_TO(IndexCtx.handleReference(PD, Loc, ContD, ContD, roles,
368           SymbolRelation{(unsigned)SymbolRole::RelationBaseOf, ContD}));
369     }
370     return true;
371   }
372 
373   bool VisitObjCInterfaceDecl(const ObjCInterfaceDecl *D) {
374     if (D->isThisDeclarationADefinition()) {
375       TRY_DECL(D, IndexCtx.handleDecl(D));
376       SourceLocation SuperLoc = D->getSuperClassLoc();
377       if (auto *SuperD = D->getSuperClass()) {
378         bool hasSuperTypedef = false;
379         if (auto *TInfo = D->getSuperClassTInfo()) {
380           if (auto *TT = TInfo->getType()->getAs<TypedefType>()) {
381             if (auto *TD = TT->getDecl()) {
382               hasSuperTypedef = true;
383               TRY_TO(IndexCtx.handleReference(TD, SuperLoc, D, D,
384                                               SymbolRoleSet()));
385             }
386           }
387         }
388         SymbolRoleSet superRoles{};
389         if (hasSuperTypedef)
390           superRoles |= (SymbolRoleSet)SymbolRole::Implicit;
391         TRY_TO(IndexCtx.handleReference(SuperD, SuperLoc, D, D, superRoles,
392             SymbolRelation{(unsigned)SymbolRole::RelationBaseOf, D}));
393       }
394       TRY_TO(handleReferencedProtocols(D->getReferencedProtocols(), D,
395                                        SuperLoc));
396       TRY_TO(IndexCtx.indexDeclContext(D));
397     } else {
398       return IndexCtx.handleReference(D, D->getLocation(), nullptr,
399                                       D->getDeclContext(), SymbolRoleSet());
400     }
401     return true;
402   }
403 
404   bool VisitObjCProtocolDecl(const ObjCProtocolDecl *D) {
405     if (D->isThisDeclarationADefinition()) {
406       TRY_DECL(D, IndexCtx.handleDecl(D));
407       TRY_TO(handleReferencedProtocols(D->getReferencedProtocols(), D,
408                                        /*superLoc=*/SourceLocation()));
409       TRY_TO(IndexCtx.indexDeclContext(D));
410     } else {
411       return IndexCtx.handleReference(D, D->getLocation(), nullptr,
412                                       D->getDeclContext(), SymbolRoleSet());
413     }
414     return true;
415   }
416 
417   bool VisitObjCImplementationDecl(const ObjCImplementationDecl *D) {
418     const ObjCInterfaceDecl *Class = D->getClassInterface();
419     if (!Class)
420       return true;
421 
422     if (Class->isImplicitInterfaceDecl())
423       IndexCtx.handleDecl(Class);
424 
425     TRY_DECL(D, IndexCtx.handleDecl(D));
426 
427     // Visit implicit @synthesize property implementations first as their
428     // location is reported at the name of the @implementation block. This
429     // serves no purpose other than to simplify the FileCheck-based tests.
430     for (const auto *I : D->property_impls()) {
431       if (I->getLocation().isInvalid())
432         IndexCtx.indexDecl(I);
433     }
434     for (const auto *I : D->decls()) {
435       if (!isa<ObjCPropertyImplDecl>(I) ||
436           cast<ObjCPropertyImplDecl>(I)->getLocation().isValid())
437         IndexCtx.indexDecl(I);
438     }
439 
440     return true;
441   }
442 
443   bool VisitObjCCategoryDecl(const ObjCCategoryDecl *D) {
444     if (!IndexCtx.shouldIndex(D))
445       return true;
446     const ObjCInterfaceDecl *C = D->getClassInterface();
447     if (!C)
448       return true;
449     TRY_TO(IndexCtx.handleReference(C, D->getLocation(), D, D, SymbolRoleSet(),
450                                    SymbolRelation{
451                                      (unsigned)SymbolRole::RelationExtendedBy, D
452                                    }));
453     SourceLocation CategoryLoc = D->getCategoryNameLoc();
454     if (!CategoryLoc.isValid())
455       CategoryLoc = D->getLocation();
456     TRY_TO(IndexCtx.handleDecl(D, CategoryLoc));
457     TRY_TO(handleReferencedProtocols(D->getReferencedProtocols(), D,
458                                      /*superLoc=*/SourceLocation()));
459     TRY_TO(IndexCtx.indexDeclContext(D));
460     return true;
461   }
462 
463   bool VisitObjCCategoryImplDecl(const ObjCCategoryImplDecl *D) {
464     const ObjCCategoryDecl *Cat = D->getCategoryDecl();
465     if (!Cat)
466       return true;
467     const ObjCInterfaceDecl *C = D->getClassInterface();
468     if (C)
469       TRY_TO(IndexCtx.handleReference(C, D->getLocation(), D, D,
470                                       SymbolRoleSet()));
471     SourceLocation CategoryLoc = D->getCategoryNameLoc();
472     if (!CategoryLoc.isValid())
473       CategoryLoc = D->getLocation();
474     TRY_DECL(D, IndexCtx.handleDecl(D, CategoryLoc));
475     IndexCtx.indexDeclContext(D);
476     return true;
477   }
478 
479   bool VisitObjCMethodDecl(const ObjCMethodDecl *D) {
480     // Methods associated with a property, even user-declared ones, are
481     // handled when we handle the property.
482     if (D->isPropertyAccessor())
483       return true;
484 
485     handleObjCMethod(D);
486     return true;
487   }
488 
489   bool VisitObjCPropertyDecl(const ObjCPropertyDecl *D) {
490     if (ObjCMethodDecl *MD = D->getGetterMethodDecl())
491       if (MD->getLexicalDeclContext() == D->getLexicalDeclContext())
492         handleObjCMethod(MD, D);
493     if (ObjCMethodDecl *MD = D->getSetterMethodDecl())
494       if (MD->getLexicalDeclContext() == D->getLexicalDeclContext())
495         handleObjCMethod(MD, D);
496     TRY_DECL(D, IndexCtx.handleDecl(D));
497     if (IBOutletCollectionAttr *attr = D->getAttr<IBOutletCollectionAttr>())
498       IndexCtx.indexTypeSourceInfo(attr->getInterfaceLoc(), D,
499                                    D->getLexicalDeclContext(), false, true);
500     IndexCtx.indexTypeSourceInfo(D->getTypeSourceInfo(), D);
501     return true;
502   }
503 
504   bool VisitObjCPropertyImplDecl(const ObjCPropertyImplDecl *D) {
505     ObjCPropertyDecl *PD = D->getPropertyDecl();
506     auto *Container = cast<ObjCImplDecl>(D->getDeclContext());
507     SourceLocation Loc = D->getLocation();
508     SymbolRoleSet Roles = 0;
509     SmallVector<SymbolRelation, 1> Relations;
510 
511     if (ObjCIvarDecl *ID = D->getPropertyIvarDecl())
512       Relations.push_back({(SymbolRoleSet)SymbolRole::RelationAccessorOf, ID});
513     if (Loc.isInvalid()) {
514       Loc = Container->getLocation();
515       Roles |= (SymbolRoleSet)SymbolRole::Implicit;
516     }
517     TRY_DECL(D, IndexCtx.handleDecl(D, Loc, Roles, Relations));
518 
519     if (D->getPropertyImplementation() == ObjCPropertyImplDecl::Dynamic)
520       return true;
521 
522     assert(D->getPropertyImplementation() == ObjCPropertyImplDecl::Synthesize);
523     SymbolRoleSet AccessorMethodRoles =
524       SymbolRoleSet(SymbolRole::Dynamic) | SymbolRoleSet(SymbolRole::Implicit);
525     if (ObjCMethodDecl *MD = PD->getGetterMethodDecl()) {
526       if (MD->isPropertyAccessor() &&
527           !hasUserDefined(MD, Container))
528         IndexCtx.handleDecl(MD, Loc, AccessorMethodRoles, {}, Container);
529     }
530     if (ObjCMethodDecl *MD = PD->getSetterMethodDecl()) {
531       if (MD->isPropertyAccessor() &&
532           !hasUserDefined(MD, Container))
533         IndexCtx.handleDecl(MD, Loc, AccessorMethodRoles, {}, Container);
534     }
535     if (ObjCIvarDecl *IvarD = D->getPropertyIvarDecl()) {
536       if (IvarD->getSynthesize()) {
537         // For synthesized ivars, use the location of its name in the
538         // corresponding @synthesize. If there isn't one, use the containing
539         // @implementation's location, rather than the property's location,
540         // otherwise the header file containing the @interface will have different
541         // indexing contents based on whether the @implementation was present or
542         // not in the translation unit.
543         SymbolRoleSet IvarRoles = 0;
544         SourceLocation IvarLoc = D->getPropertyIvarDeclLoc();
545         if (D->getLocation().isInvalid()) {
546           IvarLoc = Container->getLocation();
547           IvarRoles = (SymbolRoleSet)SymbolRole::Implicit;
548         } else if (D->getLocation() == IvarLoc) {
549           IvarRoles = (SymbolRoleSet)SymbolRole::Implicit;
550         }
551         TRY_DECL(IvarD, IndexCtx.handleDecl(IvarD, IvarLoc, IvarRoles));
552       } else {
553         IndexCtx.handleReference(IvarD, D->getPropertyIvarDeclLoc(), nullptr,
554                                  D->getDeclContext(), SymbolRoleSet());
555       }
556     }
557     return true;
558   }
559 
560   bool VisitNamespaceDecl(const NamespaceDecl *D) {
561     TRY_DECL(D, IndexCtx.handleDecl(D));
562     IndexCtx.indexDeclContext(D);
563     return true;
564   }
565 
566   bool VisitNamespaceAliasDecl(const NamespaceAliasDecl *D) {
567     TRY_DECL(D, IndexCtx.handleDecl(D));
568     IndexCtx.indexNestedNameSpecifierLoc(D->getQualifierLoc(), D);
569     IndexCtx.handleReference(D->getAliasedNamespace(), D->getTargetNameLoc(), D,
570                              D->getLexicalDeclContext());
571     return true;
572   }
573 
574   bool VisitUsingDecl(const UsingDecl *D) {
575     const DeclContext *DC = D->getDeclContext()->getRedeclContext();
576     const NamedDecl *Parent = dyn_cast<NamedDecl>(DC);
577 
578     IndexCtx.indexNestedNameSpecifierLoc(D->getQualifierLoc(), Parent,
579                                          D->getLexicalDeclContext());
580     for (const auto *I : D->shadows())
581       IndexCtx.handleReference(I->getUnderlyingDecl(), D->getLocation(), Parent,
582                                D->getLexicalDeclContext(), SymbolRoleSet());
583     return true;
584   }
585 
586   bool VisitUsingDirectiveDecl(const UsingDirectiveDecl *D) {
587     const DeclContext *DC = D->getDeclContext()->getRedeclContext();
588     const NamedDecl *Parent = dyn_cast<NamedDecl>(DC);
589 
590     // NNS for the local 'using namespace' directives is visited by the body
591     // visitor.
592     if (!D->getParentFunctionOrMethod())
593       IndexCtx.indexNestedNameSpecifierLoc(D->getQualifierLoc(), Parent,
594                                            D->getLexicalDeclContext());
595 
596     return IndexCtx.handleReference(D->getNominatedNamespaceAsWritten(),
597                                     D->getLocation(), Parent,
598                                     D->getLexicalDeclContext(),
599                                     SymbolRoleSet());
600   }
601 
602   bool VisitClassTemplateSpecializationDecl(const
603                                            ClassTemplateSpecializationDecl *D) {
604     // FIXME: Notify subsequent callbacks if info comes from implicit
605     // instantiation.
606     if (D->isThisDeclarationADefinition()) {
607       llvm::PointerUnion<ClassTemplateDecl *,
608                          ClassTemplatePartialSpecializationDecl *>
609           Template = D->getSpecializedTemplateOrPartial();
610       const Decl *SpecializationOf =
611           Template.is<ClassTemplateDecl *>()
612               ? (Decl *)Template.get<ClassTemplateDecl *>()
613               : Template.get<ClassTemplatePartialSpecializationDecl *>();
614       IndexCtx.indexTagDecl(
615           D, SymbolRelation(SymbolRoleSet(SymbolRole::RelationSpecializationOf),
616                             SpecializationOf));
617     }
618     if (TypeSourceInfo *TSI = D->getTypeAsWritten())
619       IndexCtx.indexTypeSourceInfo(TSI, /*Parent=*/nullptr,
620                                    D->getLexicalDeclContext());
621     return true;
622   }
623 
624   static bool shouldIndexTemplateParameterDefaultValue(const NamedDecl *D) {
625     if (!D)
626       return false;
627     // We want to index the template parameters only once when indexing the
628     // canonical declaration.
629     if (const auto *FD = dyn_cast<FunctionDecl>(D))
630       return FD->getCanonicalDecl() == FD;
631     else if (const auto *TD = dyn_cast<TagDecl>(D))
632       return TD->getCanonicalDecl() == TD;
633     else if (const auto *VD = dyn_cast<VarDecl>(D))
634       return VD->getCanonicalDecl() == VD;
635     return true;
636   }
637 
638   bool VisitTemplateDecl(const TemplateDecl *D) {
639     // FIXME: Template parameters.
640 
641     // Index the default values for the template parameters.
642     const NamedDecl *Parent = D->getTemplatedDecl();
643     if (D->getTemplateParameters() &&
644         shouldIndexTemplateParameterDefaultValue(Parent)) {
645       const TemplateParameterList *Params = D->getTemplateParameters();
646       for (const NamedDecl *TP : *Params) {
647         if (const auto *TTP = dyn_cast<TemplateTypeParmDecl>(TP)) {
648           if (TTP->hasDefaultArgument())
649             IndexCtx.indexTypeSourceInfo(TTP->getDefaultArgumentInfo(), Parent);
650         } else if (const auto *NTTP = dyn_cast<NonTypeTemplateParmDecl>(TP)) {
651           if (NTTP->hasDefaultArgument())
652             IndexCtx.indexBody(NTTP->getDefaultArgument(), Parent);
653         } else if (const auto *TTPD = dyn_cast<TemplateTemplateParmDecl>(TP)) {
654           if (TTPD->hasDefaultArgument())
655             handleTemplateArgumentLoc(TTPD->getDefaultArgument(), Parent,
656                                       /*DC=*/nullptr);
657         }
658       }
659     }
660 
661     return Visit(D->getTemplatedDecl());
662   }
663 
664   bool VisitFriendDecl(const FriendDecl *D) {
665     if (auto ND = D->getFriendDecl()) {
666       // FIXME: Ignore a class template in a dependent context, these are not
667       // linked properly with their redeclarations, ending up with duplicate
668       // USRs.
669       // See comment "Friend templates are visible in fairly strange ways." in
670       // SemaTemplate.cpp which precedes code that prevents the friend template
671       // from becoming visible from the enclosing context.
672       if (isa<ClassTemplateDecl>(ND) && D->getDeclContext()->isDependentContext())
673         return true;
674       return Visit(ND);
675     }
676     if (auto Ty = D->getFriendType()) {
677       IndexCtx.indexTypeSourceInfo(Ty, cast<NamedDecl>(D->getDeclContext()));
678     }
679     return true;
680   }
681 
682   bool VisitImportDecl(const ImportDecl *D) {
683     return IndexCtx.importedModule(D);
684   }
685 };
686 
687 } // anonymous namespace
688 
689 bool IndexingContext::indexDecl(const Decl *D) {
690   if (D->isImplicit() && shouldIgnoreIfImplicit(D))
691     return true;
692 
693   if (isTemplateImplicitInstantiation(D))
694     return true;
695 
696   IndexingDeclVisitor Visitor(*this);
697   bool ShouldContinue = Visitor.Visit(D);
698   if (!ShouldContinue)
699     return false;
700 
701   if (!Visitor.Handled && isa<DeclContext>(D))
702     return indexDeclContext(cast<DeclContext>(D));
703 
704   return true;
705 }
706 
707 bool IndexingContext::indexDeclContext(const DeclContext *DC) {
708   for (const auto *I : DC->decls())
709     if (!indexDecl(I))
710       return false;
711   return true;
712 }
713 
714 bool IndexingContext::indexTopLevelDecl(const Decl *D) {
715   if (D->getLocation().isInvalid())
716     return true;
717 
718   if (isa<ObjCMethodDecl>(D))
719     return true; // Wait for the objc container.
720 
721   return indexDecl(D);
722 }
723 
724 bool IndexingContext::indexDeclGroupRef(DeclGroupRef DG) {
725   for (DeclGroupRef::iterator I = DG.begin(), E = DG.end(); I != E; ++I)
726     if (!indexTopLevelDecl(*I))
727       return false;
728   return true;
729 }
730