fix: Emit refs for class & alias templates (#157)

Author: varungandhi-src

indexer/Indexer.cc

@@ -550,14 +550,25 @@ void TuIndexer::saveTemplateSpecializationTypeLoc(
   using Kind = clang::TemplateName::NameKind;
   switch (templateName.getKind()) {
   case Kind::Template: {
-    if (auto *templateTemplateParmDecl =
-            llvm::dyn_cast<clang::TemplateTemplateParmDecl>(
-                templateName.getAsTemplateDecl())) {
-      if (auto optSymbol = this->symbolFormatter.getTemplateTemplateParmSymbol(
-              *templateTemplateParmDecl)) {
-        this->saveReference(*optSymbol,
-                            templateSpecializationTypeLoc.getTemplateNameLoc());
-      }
+    auto *templateDecl = templateName.getAsTemplateDecl();
+    std::optional<std::string_view> optSymbol;
+    if (auto *classTemplateDecl =
+            llvm::dyn_cast<clang::ClassTemplateDecl>(templateDecl)) {
+      optSymbol = this->symbolFormatter.getRecordSymbol(
+          *classTemplateDecl->getTemplatedDecl());
+    } else if (auto *typeAliasTemplateDecl =
+                   llvm::dyn_cast<clang::TypeAliasTemplateDecl>(templateDecl)) {
+      optSymbol = this->symbolFormatter.getTypedefNameSymbol(
+          *typeAliasTemplateDecl->getTemplatedDecl());
+    } else if (auto *templateTemplateParmDecl =
+                   llvm::dyn_cast<clang::TemplateTemplateParmDecl>(
+                       templateDecl)) {
+      optSymbol = this->symbolFormatter.getTemplateTemplateParmSymbol(
+          *templateTemplateParmDecl);
+    }
+    if (optSymbol.has_value()) {
+      this->saveReference(*optSymbol,
+                          templateSpecializationTypeLoc.getTemplateNameLoc());
     }
     break;
   }

test/index/types/templates.cc

@@ -39,3 +39,13 @@ void specialized(T) {}
 
 template <>
 void specialized<int, int>(int) {}
+
+template <typename T>
+struct Empty {};
+
+void use_empty() {
+  Empty<int> x;
+  Empty<Empty<void>> y;
+  Empty<PointerType<void *>> z;
+  RefPtr<int> w;
+}

test/index/types/templates.snapshot.cc

@@ -70,6 +70,7 @@
 
   using IntRefPtr = RefPtr<int>;
 //      ^^^^^^^^^ definition [..] IntRefPtr#
+//                  ^^^^^^ reference [..] RefPtr#
 
   template <typename T>
 //                   ^ definition local 14
@@ -86,3 +87,26 @@
   template <>
   void specialized<int, int>(int) {}
 //     ^^^^^^^^^^^ definition [..] specialized(d4f767463ce0a6b3).
+  
+  template <typename T>
+//                   ^ definition local 17
+  struct Empty {};
+//       ^^^^^ definition [..] Empty#
+  
+  void use_empty() {
+//     ^^^^^^^^^ definition [..] use_empty(49f6e7a06ebc5aa8).
+    Empty<int> x;
+//  ^^^^^ reference [..] Empty#
+//             ^ definition local 18
+    Empty<Empty<void>> y;
+//  ^^^^^ reference [..] Empty#
+//        ^^^^^ reference [..] Empty#
+//                     ^ definition local 19
+    Empty<PointerType<void *>> z;
+//  ^^^^^ reference [..] Empty#
+//        ^^^^^^^^^^^ reference [..] PointerType#
+//                             ^ definition local 20
+    RefPtr<int> w;
+//  ^^^^^^ reference [..] RefPtr#
+//              ^ definition local 21
+  }

test/index/types/types.snapshot.cc

@@ -146,6 +146,7 @@
 
   void f(GenericClass<E, int(E::E0)>) {
 //     ^ definition [..] f(a9a88f5fb6852c6b).
+//       ^^^^^^^^^^^^ reference [..] GenericClass#
 //                    ^ reference [..] E#
 //                           ^ reference [..] E#
 //                              ^^ reference [..] E#E0.
@@ -194,6 +195,7 @@
   class CRTPChild: CRTPBase<CRTPChild> {
 //      ^^^^^^^^^ definition [..] CRTPChild#
 //      relation implementation [..] CRTPBase#
+//                 ^^^^^^^^ reference [..] CRTPBase#
 //                          ^^^^^^^^^ reference [..] CRTPChild#
     void doStuff() { }
 //       ^^^^^^^ definition [..] CRTPChild#doStuff(49f6e7a06ebc5aa8).