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