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   /// 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 (const CXXMethodDecl *O : CXXMD->overridden_methods()) {
237         Relations.emplace_back((unsigned)SymbolRole::RelationOverrideOf, O);
238       }
239     }
240     gatherTemplatePseudoOverrides(D, Relations);
241     if (const auto *Base = D->getPrimaryTemplate())
242       Relations.push_back(
243           SymbolRelation(SymbolRoleSet(SymbolRole::RelationSpecializationOf),
244                          Base->getTemplatedDecl()));
245 
246     TRY_DECL(D, IndexCtx.handleDecl(D, Roles, Relations));
247     handleDeclarator(D);
248 
249     if (const CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(D)) {
250       IndexCtx.handleReference(Ctor->getParent(), Ctor->getLocation(),
251                                Ctor->getParent(), Ctor->getDeclContext());
252 
253       // Constructor initializers.
254       for (const auto *Init : Ctor->inits()) {
255         if (Init->isWritten()) {
256           IndexCtx.indexTypeSourceInfo(Init->getTypeSourceInfo(), D);
257           if (const FieldDecl *Member = Init->getAnyMember())
258             IndexCtx.handleReference(Member, Init->getMemberLocation(), D, D,
259                                      (unsigned)SymbolRole::Write);
260           IndexCtx.indexBody(Init->getInit(), D, D);
261         }
262       }
263     } else if (const CXXDestructorDecl *Dtor = dyn_cast<CXXDestructorDecl>(D)) {
264       if (auto TypeNameInfo = Dtor->getNameInfo().getNamedTypeInfo()) {
265         IndexCtx.handleReference(Dtor->getParent(),
266                                  TypeNameInfo->getTypeLoc().getBeginLoc(),
267                                  Dtor->getParent(), Dtor->getDeclContext());
268       }
269     } else if (const auto *Guide = dyn_cast<CXXDeductionGuideDecl>(D)) {
270       IndexCtx.handleReference(Guide->getDeducedTemplate()->getTemplatedDecl(),
271                                Guide->getLocation(), Guide,
272                                Guide->getDeclContext());
273     }
274     // Template specialization arguments.
275     if (const ASTTemplateArgumentListInfo *TemplateArgInfo =
276             D->getTemplateSpecializationArgsAsWritten()) {
277       for (const auto &Arg : TemplateArgInfo->arguments())
278         handleTemplateArgumentLoc(Arg, D, D->getLexicalDeclContext());
279     }
280 
281     if (D->isThisDeclarationADefinition()) {
282       const Stmt *Body = D->getBody();
283       if (Body) {
284         IndexCtx.indexBody(Body, D, D);
285       }
286     }
287     return true;
288   }
289 
290   bool VisitVarDecl(const VarDecl *D) {
291     SmallVector<SymbolRelation, 4> Relations;
292     gatherTemplatePseudoOverrides(D, Relations);
293     TRY_DECL(D, IndexCtx.handleDecl(D, SymbolRoleSet(), Relations));
294     handleDeclarator(D);
295     IndexCtx.indexBody(D->getInit(), D);
296     return true;
297   }
298 
299   bool VisitDecompositionDecl(const DecompositionDecl *D) {
300     for (const auto *Binding : D->bindings())
301       TRY_DECL(Binding, IndexCtx.handleDecl(Binding));
302     return Base::VisitDecompositionDecl(D);
303   }
304 
305   bool VisitFieldDecl(const FieldDecl *D) {
306     SmallVector<SymbolRelation, 4> Relations;
307     gatherTemplatePseudoOverrides(D, Relations);
308     TRY_DECL(D, IndexCtx.handleDecl(D, SymbolRoleSet(), Relations));
309     handleDeclarator(D);
310     if (D->isBitField())
311       IndexCtx.indexBody(D->getBitWidth(), D);
312     else if (D->hasInClassInitializer())
313       IndexCtx.indexBody(D->getInClassInitializer(), D);
314     return true;
315   }
316 
317   bool VisitObjCIvarDecl(const ObjCIvarDecl *D) {
318     if (D->getSynthesize()) {
319       // handled in VisitObjCPropertyImplDecl
320       return true;
321     }
322     TRY_DECL(D, IndexCtx.handleDecl(D));
323     handleDeclarator(D);
324     return true;
325   }
326 
327   bool VisitMSPropertyDecl(const MSPropertyDecl *D) {
328     handleDeclarator(D);
329     return true;
330   }
331 
332   bool VisitEnumConstantDecl(const EnumConstantDecl *D) {
333     TRY_DECL(D, IndexCtx.handleDecl(D));
334     IndexCtx.indexBody(D->getInitExpr(), D);
335     return true;
336   }
337 
338   bool VisitTypedefNameDecl(const TypedefNameDecl *D) {
339     if (!D->isTransparentTag()) {
340       SmallVector<SymbolRelation, 4> Relations;
341       gatherTemplatePseudoOverrides(D, Relations);
342       TRY_DECL(D, IndexCtx.handleDecl(D, SymbolRoleSet(), Relations));
343       IndexCtx.indexTypeSourceInfo(D->getTypeSourceInfo(), D);
344     }
345     return true;
346   }
347 
348   bool VisitTagDecl(const TagDecl *D) {
349     // Non-free standing tags are handled in indexTypeSourceInfo.
350     if (D->isFreeStanding()) {
351       if (D->isThisDeclarationADefinition()) {
352         SmallVector<SymbolRelation, 4> Relations;
353         gatherTemplatePseudoOverrides(D, Relations);
354         IndexCtx.indexTagDecl(D, Relations);
355       } else {
356         SmallVector<SymbolRelation, 1> Relations;
357         gatherTemplatePseudoOverrides(D, Relations);
358         return IndexCtx.handleDecl(D, D->getLocation(), SymbolRoleSet(),
359                                    Relations, D->getLexicalDeclContext());
360       }
361     }
362     return true;
363   }
364 
365   bool handleReferencedProtocols(const ObjCProtocolList &ProtList,
366                                  const ObjCContainerDecl *ContD,
367                                  SourceLocation SuperLoc) {
368     ObjCInterfaceDecl::protocol_loc_iterator LI = ProtList.loc_begin();
369     for (ObjCInterfaceDecl::protocol_iterator
370          I = ProtList.begin(), E = ProtList.end(); I != E; ++I, ++LI) {
371       SourceLocation Loc = *LI;
372       ObjCProtocolDecl *PD = *I;
373       SymbolRoleSet roles{};
374       if (Loc == SuperLoc)
375         roles |= (SymbolRoleSet)SymbolRole::Implicit;
376       TRY_TO(IndexCtx.handleReference(PD, Loc, ContD, ContD, roles,
377           SymbolRelation{(unsigned)SymbolRole::RelationBaseOf, ContD}));
378     }
379     return true;
380   }
381 
382   bool VisitObjCInterfaceDecl(const ObjCInterfaceDecl *D) {
383     if (D->isThisDeclarationADefinition()) {
384       TRY_DECL(D, IndexCtx.handleDecl(D));
385       SourceLocation SuperLoc = D->getSuperClassLoc();
386       if (auto *SuperD = D->getSuperClass()) {
387         bool hasSuperTypedef = false;
388         if (auto *TInfo = D->getSuperClassTInfo()) {
389           if (auto *TT = TInfo->getType()->getAs<TypedefType>()) {
390             if (auto *TD = TT->getDecl()) {
391               hasSuperTypedef = true;
392               TRY_TO(IndexCtx.handleReference(TD, SuperLoc, D, D,
393                                               SymbolRoleSet()));
394             }
395           }
396         }
397         SymbolRoleSet superRoles{};
398         if (hasSuperTypedef)
399           superRoles |= (SymbolRoleSet)SymbolRole::Implicit;
400         TRY_TO(IndexCtx.handleReference(SuperD, SuperLoc, D, D, superRoles,
401             SymbolRelation{(unsigned)SymbolRole::RelationBaseOf, D}));
402       }
403       TRY_TO(handleReferencedProtocols(D->getReferencedProtocols(), D,
404                                        SuperLoc));
405       TRY_TO(IndexCtx.indexDeclContext(D));
406     } else {
407       return IndexCtx.handleReference(D, D->getLocation(), nullptr,
408                                       D->getDeclContext(), SymbolRoleSet());
409     }
410     return true;
411   }
412 
413   bool VisitObjCProtocolDecl(const ObjCProtocolDecl *D) {
414     if (D->isThisDeclarationADefinition()) {
415       TRY_DECL(D, IndexCtx.handleDecl(D));
416       TRY_TO(handleReferencedProtocols(D->getReferencedProtocols(), D,
417                                        /*superLoc=*/SourceLocation()));
418       TRY_TO(IndexCtx.indexDeclContext(D));
419     } else {
420       return IndexCtx.handleReference(D, D->getLocation(), nullptr,
421                                       D->getDeclContext(), SymbolRoleSet());
422     }
423     return true;
424   }
425 
426   bool VisitObjCImplementationDecl(const ObjCImplementationDecl *D) {
427     const ObjCInterfaceDecl *Class = D->getClassInterface();
428     if (!Class)
429       return true;
430 
431     if (Class->isImplicitInterfaceDecl())
432       IndexCtx.handleDecl(Class);
433 
434     TRY_DECL(D, IndexCtx.handleDecl(D));
435 
436     // Visit implicit @synthesize property implementations first as their
437     // location is reported at the name of the @implementation block. This
438     // serves no purpose other than to simplify the FileCheck-based tests.
439     for (const auto *I : D->property_impls()) {
440       if (I->getLocation().isInvalid())
441         IndexCtx.indexDecl(I);
442     }
443     for (const auto *I : D->decls()) {
444       if (!isa<ObjCPropertyImplDecl>(I) ||
445           cast<ObjCPropertyImplDecl>(I)->getLocation().isValid())
446         IndexCtx.indexDecl(I);
447     }
448 
449     return true;
450   }
451 
452   bool VisitObjCCategoryDecl(const ObjCCategoryDecl *D) {
453     if (!IndexCtx.shouldIndex(D))
454       return true;
455     const ObjCInterfaceDecl *C = D->getClassInterface();
456     if (!C)
457       return true;
458     TRY_TO(IndexCtx.handleReference(C, D->getLocation(), D, D, SymbolRoleSet(),
459                                    SymbolRelation{
460                                      (unsigned)SymbolRole::RelationExtendedBy, D
461                                    }));
462     SourceLocation CategoryLoc = D->getCategoryNameLoc();
463     if (!CategoryLoc.isValid())
464       CategoryLoc = D->getLocation();
465     TRY_TO(IndexCtx.handleDecl(D, CategoryLoc));
466     TRY_TO(handleReferencedProtocols(D->getReferencedProtocols(), D,
467                                      /*superLoc=*/SourceLocation()));
468     TRY_TO(IndexCtx.indexDeclContext(D));
469     return true;
470   }
471 
472   bool VisitObjCCategoryImplDecl(const ObjCCategoryImplDecl *D) {
473     const ObjCCategoryDecl *Cat = D->getCategoryDecl();
474     if (!Cat)
475       return true;
476     const ObjCInterfaceDecl *C = D->getClassInterface();
477     if (C)
478       TRY_TO(IndexCtx.handleReference(C, D->getLocation(), D, D,
479                                       SymbolRoleSet()));
480     SourceLocation CategoryLoc = D->getCategoryNameLoc();
481     if (!CategoryLoc.isValid())
482       CategoryLoc = D->getLocation();
483     TRY_DECL(D, IndexCtx.handleDecl(D, CategoryLoc));
484     IndexCtx.indexDeclContext(D);
485     return true;
486   }
487 
488   bool VisitObjCMethodDecl(const ObjCMethodDecl *D) {
489     // Methods associated with a property, even user-declared ones, are
490     // handled when we handle the property.
491     if (D->isPropertyAccessor())
492       return true;
493 
494     handleObjCMethod(D);
495     return true;
496   }
497 
498   bool VisitObjCPropertyDecl(const ObjCPropertyDecl *D) {
499     if (ObjCMethodDecl *MD = D->getGetterMethodDecl())
500       if (MD->getLexicalDeclContext() == D->getLexicalDeclContext())
501         handleObjCMethod(MD, D);
502     if (ObjCMethodDecl *MD = D->getSetterMethodDecl())
503       if (MD->getLexicalDeclContext() == D->getLexicalDeclContext())
504         handleObjCMethod(MD, D);
505     TRY_DECL(D, IndexCtx.handleDecl(D));
506     if (IBOutletCollectionAttr *attr = D->getAttr<IBOutletCollectionAttr>())
507       IndexCtx.indexTypeSourceInfo(attr->getInterfaceLoc(), D,
508                                    D->getLexicalDeclContext(), false, true);
509     IndexCtx.indexTypeSourceInfo(D->getTypeSourceInfo(), D);
510     return true;
511   }
512 
513   bool VisitObjCPropertyImplDecl(const ObjCPropertyImplDecl *D) {
514     ObjCPropertyDecl *PD = D->getPropertyDecl();
515     auto *Container = cast<ObjCImplDecl>(D->getDeclContext());
516     SourceLocation Loc = D->getLocation();
517     SymbolRoleSet Roles = 0;
518     SmallVector<SymbolRelation, 1> Relations;
519 
520     if (ObjCIvarDecl *ID = D->getPropertyIvarDecl())
521       Relations.push_back({(SymbolRoleSet)SymbolRole::RelationAccessorOf, ID});
522     if (Loc.isInvalid()) {
523       Loc = Container->getLocation();
524       Roles |= (SymbolRoleSet)SymbolRole::Implicit;
525     }
526     TRY_DECL(D, IndexCtx.handleDecl(D, Loc, Roles, Relations));
527 
528     if (D->getPropertyImplementation() == ObjCPropertyImplDecl::Dynamic)
529       return true;
530 
531     assert(D->getPropertyImplementation() == ObjCPropertyImplDecl::Synthesize);
532     SymbolRoleSet AccessorMethodRoles =
533       SymbolRoleSet(SymbolRole::Dynamic) | SymbolRoleSet(SymbolRole::Implicit);
534     if (ObjCMethodDecl *MD = PD->getGetterMethodDecl()) {
535       if (MD->isPropertyAccessor() &&
536           !hasUserDefined(MD, Container))
537         IndexCtx.handleDecl(MD, Loc, AccessorMethodRoles, {}, Container);
538     }
539     if (ObjCMethodDecl *MD = PD->getSetterMethodDecl()) {
540       if (MD->isPropertyAccessor() &&
541           !hasUserDefined(MD, Container))
542         IndexCtx.handleDecl(MD, Loc, AccessorMethodRoles, {}, Container);
543     }
544     if (ObjCIvarDecl *IvarD = D->getPropertyIvarDecl()) {
545       if (IvarD->getSynthesize()) {
546         // For synthesized ivars, use the location of its name in the
547         // corresponding @synthesize. If there isn't one, use the containing
548         // @implementation's location, rather than the property's location,
549         // otherwise the header file containing the @interface will have different
550         // indexing contents based on whether the @implementation was present or
551         // not in the translation unit.
552         SymbolRoleSet IvarRoles = 0;
553         SourceLocation IvarLoc = D->getPropertyIvarDeclLoc();
554         if (D->getLocation().isInvalid()) {
555           IvarLoc = Container->getLocation();
556           IvarRoles = (SymbolRoleSet)SymbolRole::Implicit;
557         } else if (D->getLocation() == IvarLoc) {
558           IvarRoles = (SymbolRoleSet)SymbolRole::Implicit;
559         }
560         TRY_DECL(IvarD, IndexCtx.handleDecl(IvarD, IvarLoc, IvarRoles));
561       } else {
562         IndexCtx.handleReference(IvarD, D->getPropertyIvarDeclLoc(), nullptr,
563                                  D->getDeclContext(), SymbolRoleSet());
564       }
565     }
566     return true;
567   }
568 
569   bool VisitNamespaceDecl(const NamespaceDecl *D) {
570     TRY_DECL(D, IndexCtx.handleDecl(D));
571     IndexCtx.indexDeclContext(D);
572     return true;
573   }
574 
575   bool VisitNamespaceAliasDecl(const NamespaceAliasDecl *D) {
576     TRY_DECL(D, IndexCtx.handleDecl(D));
577     IndexCtx.indexNestedNameSpecifierLoc(D->getQualifierLoc(), D);
578     IndexCtx.handleReference(D->getAliasedNamespace(), D->getTargetNameLoc(), D,
579                              D->getLexicalDeclContext());
580     return true;
581   }
582 
583   bool VisitUsingDecl(const UsingDecl *D) {
584     const DeclContext *DC = D->getDeclContext()->getRedeclContext();
585     const NamedDecl *Parent = dyn_cast<NamedDecl>(DC);
586 
587     IndexCtx.indexNestedNameSpecifierLoc(D->getQualifierLoc(), Parent,
588                                          D->getLexicalDeclContext());
589     for (const auto *I : D->shadows())
590       IndexCtx.handleReference(I->getUnderlyingDecl(), D->getLocation(), Parent,
591                                D->getLexicalDeclContext(), SymbolRoleSet());
592     return true;
593   }
594 
595   bool VisitUsingDirectiveDecl(const UsingDirectiveDecl *D) {
596     const DeclContext *DC = D->getDeclContext()->getRedeclContext();
597     const NamedDecl *Parent = dyn_cast<NamedDecl>(DC);
598 
599     // NNS for the local 'using namespace' directives is visited by the body
600     // visitor.
601     if (!D->getParentFunctionOrMethod())
602       IndexCtx.indexNestedNameSpecifierLoc(D->getQualifierLoc(), Parent,
603                                            D->getLexicalDeclContext());
604 
605     return IndexCtx.handleReference(D->getNominatedNamespaceAsWritten(),
606                                     D->getLocation(), Parent,
607                                     D->getLexicalDeclContext(),
608                                     SymbolRoleSet());
609   }
610 
611   bool VisitUnresolvedUsingValueDecl(const UnresolvedUsingValueDecl *D) {
612     TRY_DECL(D, IndexCtx.handleDecl(D));
613     const DeclContext *DC = D->getDeclContext()->getRedeclContext();
614     const NamedDecl *Parent = dyn_cast<NamedDecl>(DC);
615     IndexCtx.indexNestedNameSpecifierLoc(D->getQualifierLoc(), Parent,
616                                          D->getLexicalDeclContext());
617     return true;
618   }
619 
620   bool VisitUnresolvedUsingTypenameDecl(const UnresolvedUsingTypenameDecl *D) {
621     TRY_DECL(D, IndexCtx.handleDecl(D));
622     const DeclContext *DC = D->getDeclContext()->getRedeclContext();
623     const NamedDecl *Parent = dyn_cast<NamedDecl>(DC);
624     IndexCtx.indexNestedNameSpecifierLoc(D->getQualifierLoc(), Parent,
625                                          D->getLexicalDeclContext());
626     return true;
627   }
628 
629   bool VisitClassTemplateSpecializationDecl(const
630                                            ClassTemplateSpecializationDecl *D) {
631     // FIXME: Notify subsequent callbacks if info comes from implicit
632     // instantiation.
633     llvm::PointerUnion<ClassTemplateDecl *,
634                        ClassTemplatePartialSpecializationDecl *>
635         Template = D->getSpecializedTemplateOrPartial();
636     const Decl *SpecializationOf =
637         Template.is<ClassTemplateDecl *>()
638             ? (Decl *)Template.get<ClassTemplateDecl *>()
639             : Template.get<ClassTemplatePartialSpecializationDecl *>();
640     if (!D->isThisDeclarationADefinition())
641       IndexCtx.indexNestedNameSpecifierLoc(D->getQualifierLoc(), D);
642     IndexCtx.indexTagDecl(
643         D, SymbolRelation(SymbolRoleSet(SymbolRole::RelationSpecializationOf),
644                           SpecializationOf));
645     if (TypeSourceInfo *TSI = D->getTypeAsWritten())
646       IndexCtx.indexTypeSourceInfo(TSI, /*Parent=*/nullptr,
647                                    D->getLexicalDeclContext());
648     return true;
649   }
650 
651   static bool shouldIndexTemplateParameterDefaultValue(const NamedDecl *D) {
652     if (!D)
653       return false;
654     // We want to index the template parameters only once when indexing the
655     // canonical declaration.
656     if (const auto *FD = dyn_cast<FunctionDecl>(D))
657       return FD->getCanonicalDecl() == FD;
658     else if (const auto *TD = dyn_cast<TagDecl>(D))
659       return TD->getCanonicalDecl() == TD;
660     else if (const auto *VD = dyn_cast<VarDecl>(D))
661       return VD->getCanonicalDecl() == VD;
662     return true;
663   }
664 
665   bool VisitTemplateDecl(const TemplateDecl *D) {
666 
667     const NamedDecl *Parent = D->getTemplatedDecl();
668     if (!Parent)
669       return true;
670 
671     // Index the default values for the template parameters.
672     if (D->getTemplateParameters() &&
673         shouldIndexTemplateParameterDefaultValue(Parent)) {
674       const TemplateParameterList *Params = D->getTemplateParameters();
675       for (const NamedDecl *TP : *Params) {
676         if (const auto *TTP = dyn_cast<TemplateTypeParmDecl>(TP)) {
677           if (TTP->hasDefaultArgument())
678             IndexCtx.indexTypeSourceInfo(TTP->getDefaultArgumentInfo(), Parent);
679         } else if (const auto *NTTP = dyn_cast<NonTypeTemplateParmDecl>(TP)) {
680           if (NTTP->hasDefaultArgument())
681             IndexCtx.indexBody(NTTP->getDefaultArgument(), Parent);
682         } else if (const auto *TTPD = dyn_cast<TemplateTemplateParmDecl>(TP)) {
683           if (TTPD->hasDefaultArgument())
684             handleTemplateArgumentLoc(TTPD->getDefaultArgument(), Parent,
685                                       TP->getLexicalDeclContext());
686         }
687       }
688     }
689 
690     return Visit(Parent);
691   }
692 
693   bool VisitFriendDecl(const FriendDecl *D) {
694     if (auto ND = D->getFriendDecl()) {
695       // FIXME: Ignore a class template in a dependent context, these are not
696       // linked properly with their redeclarations, ending up with duplicate
697       // USRs.
698       // See comment "Friend templates are visible in fairly strange ways." in
699       // SemaTemplate.cpp which precedes code that prevents the friend template
700       // from becoming visible from the enclosing context.
701       if (isa<ClassTemplateDecl>(ND) && D->getDeclContext()->isDependentContext())
702         return true;
703       return Visit(ND);
704     }
705     if (auto Ty = D->getFriendType()) {
706       IndexCtx.indexTypeSourceInfo(Ty, cast<NamedDecl>(D->getDeclContext()));
707     }
708     return true;
709   }
710 
711   bool VisitImportDecl(const ImportDecl *D) {
712     return IndexCtx.importedModule(D);
713   }
714 
715   bool VisitStaticAssertDecl(const StaticAssertDecl *D) {
716     IndexCtx.indexBody(D->getAssertExpr(),
717                        dyn_cast<NamedDecl>(D->getDeclContext()),
718                        D->getLexicalDeclContext());
719     return true;
720   }
721 };
722 
723 } // anonymous namespace
724 
725 bool IndexingContext::indexDecl(const Decl *D) {
726   if (D->isImplicit() && shouldIgnoreIfImplicit(D))
727     return true;
728 
729   if (isTemplateImplicitInstantiation(D) && !shouldIndexImplicitInstantiation())
730     return true;
731 
732   IndexingDeclVisitor Visitor(*this);
733   bool ShouldContinue = Visitor.Visit(D);
734   if (!ShouldContinue)
735     return false;
736 
737   if (!Visitor.Handled && isa<DeclContext>(D))
738     return indexDeclContext(cast<DeclContext>(D));
739 
740   return true;
741 }
742 
743 bool IndexingContext::indexDeclContext(const DeclContext *DC) {
744   for (const auto *I : DC->decls())
745     if (!indexDecl(I))
746       return false;
747   return true;
748 }
749 
750 bool IndexingContext::indexTopLevelDecl(const Decl *D) {
751   if (D->getLocation().isInvalid())
752     return true;
753 
754   if (isa<ObjCMethodDecl>(D))
755     return true; // Wait for the objc container.
756 
757   return indexDecl(D);
758 }
759 
760 bool IndexingContext::indexDeclGroupRef(DeclGroupRef DG) {
761   for (DeclGroupRef::iterator I = DG.begin(), E = DG.end(); I != E; ++I)
762     if (!indexTopLevelDecl(*I))
763       return false;
764   return true;
765 }
766