[index] "SpecializationOf" relation should be added even to forward declarations of class template specializations

[arphaman]

Summary

This patch fixes an issue where a forward declaration of a class template specialization was not related to the base template. We need to relate even forward declarations because specializations don't have to be defined.

cfe/trunk/lib/Index/IndexDecl.cpp

return IndexCtx.handleReference(D->getNominatedNamespaceAsWritten(),
                                     D->getLexicalDeclContext(),
                                     SymbolRoleSet());
   }
 
   bool VisitClassTemplateSpecializationDecl(const
                                            ClassTemplateSpecializationDecl *D) {
     // FIXME: Notify subsequent callbacks if info comes from implicit
     // instantiation.
-    if (D->isThisDeclarationADefinition()) {
-      llvm::PointerUnion<ClassTemplateDecl *,
-                         ClassTemplatePartialSpecializationDecl *>
-          Template = D->getSpecializedTemplateOrPartial();
-      const Decl *SpecializationOf =
-          Template.is<ClassTemplateDecl *>()
-              ? (Decl *)Template.get<ClassTemplateDecl *>()
-              : Template.get<ClassTemplatePartialSpecializationDecl *>();
-      IndexCtx.indexTagDecl(
-          D, SymbolRelation(SymbolRoleSet(SymbolRole::RelationSpecializationOf),
-                            SpecializationOf));
-    }
     if (TypeSourceInfo *TSI = D->getTypeAsWritten())
       IndexCtx.indexTypeSourceInfo(TSI, /*Parent=*/nullptr,
                                    D->getLexicalDeclContext());
     return true;
   }
 
   static bool shouldIndexTemplateParameterDefaultValue(const NamedDecl *D) {
     if (!D)

cfe/trunk/test/Index/Core/index-source.cpp

 // CHECK: [[@LINE-1]]:7 | class(Gen)/C++ | SpecializationDecl | c:@ST>1#T@SpecializationDecl | <no-cgname> | Ref | rel: 0
 
 template<typename T>
 class SpecializationDecl { };
 // CHECK: [[@LINE-1]]:7 | class(Gen)/C++ | SpecializationDecl | c:@ST>1#T@SpecializationDecl | <no-cgname> | Def | rel: 0
 
 template<>
 class SpecializationDecl<int>;
-// CHECK: [[@LINE-1]]:7 | class(Gen)/C++ | SpecializationDecl | c:@ST>1#T@SpecializationDecl | <no-cgname> | Ref | rel: 0
+// CHECK: [[@LINE-1]]:7 | class(Gen,TS)/C++ | SpecializationDecl | c:@S@SpecializationDecl>#I | <no-cgname> | Decl,RelSpecialization | rel: 1
+// CHECK-NEXT: RelSpecialization | SpecializationDecl | c:@ST>1#T@SpecializationDecl
+// CHECK: [[@LINE-3]]:7 | class(Gen)/C++ | SpecializationDecl | c:@ST>1#T@SpecializationDecl | <no-cgname> | Ref | rel: 0
 
 template<>
 class SpecializationDecl<int> { };
 // CHECK: [[@LINE-1]]:7 | class(Gen,TS)/C++ | SpecializationDecl | c:@S@SpecializationDecl>#I | <no-cgname> | Def,RelSpecialization | rel: 1
 // CHECK-NEXT: RelSpecialization | SpecializationDecl | c:@ST>1#T@SpecializationDecl
 // CHECK-NEXT: [[@LINE-3]]:7 | class(Gen)/C++ | SpecializationDecl | c:@ST>1#T@SpecializationDecl | <no-cgname> | Ref | rel: 0
 
 template<typename T>
 class PartialSpecilizationClass<Cls, T>;
-// CHECK: [[@LINE-1]]:7 | class(Gen)/C++ | PartialSpecilizationClass | c:@ST>2#T#T@PartialSpecilizationClass | <no-cgname> | Ref | rel: 0
-// CHECK-NEXT: [[@LINE-2]]:33 | class/C++ | Cls | c:@S@Cls | <no-cgname> | Ref | rel: 0
+// CHECK: [[@LINE-1]]:7 | class(Gen,TPS)/C++ | PartialSpecilizationClass | c:@SP>1#T@PartialSpecilizationClass>#$@S@Cls#t0.0 | <no-cgname> | Decl,RelSpecialization | rel: 1
+// CHECK-NEXT: RelSpecialization | PartialSpecilizationClass | c:@ST>2#T#T@PartialSpecilizationClass
+// CHECK: [[@LINE-3]]:7 | class(Gen)/C++ | PartialSpecilizationClass | c:@ST>2#T#T@PartialSpecilizationClass | <no-cgname> | Ref | rel: 0
+// CHECK-NEXT: [[@LINE-4]]:33 | class/C++ | Cls | c:@S@Cls | <no-cgname> | Ref | rel: 0
 
 template<>
 class PartialSpecilizationClass<Cls, Cls> : Cls { };
 // CHECK: [[@LINE-1]]:7 | class(Gen,TS)/C++ | PartialSpecilizationClass | c:@S@PartialSpecilizationClass>#$@S@Cls#S0_ | <no-cgname> | Def,RelSpecialization | rel: 1
 // CHECK-NEXT: RelSpecialization | PartialSpecilizationClass | c:@ST>2#T#T@PartialSpecilizationClass
 // CHECK-NEXT: [[@LINE-3]]:45 | class/C++ | Cls | c:@S@Cls | <no-cgname> | Ref,RelBase,RelCont | rel: 1
 // CHECK-NEXT: RelBase,RelCont | PartialSpecilizationClass | c:@S@PartialSpecilizationClass>#$@S@Cls#S0_
 // CHECK-NEXT: [[@LINE-5]]:7 | class(Gen)/C++ | PartialSpecilizationClass | c:@ST>2#T#T@PartialSpecilizationClass | <no-cgname> | Ref | rel: 0