[clang-tidy] Fix false positive in readability-redundant-typename (#170034)

Closes #169166

---------

Co-authored-by: Victor Chernyakin <chernyakin.victor.j@outlook.com>

Author: zeyi2

clang-tools-extra/clang-tidy/readability/RedundantTypenameCheck.cpp

@@ -47,6 +47,9 @@ void RedundantTypenameCheck::check(const MatchFinder::MatchResult &Result) {
   const SourceLocation ElaboratedKeywordLoc = [&] {
     if (const auto *NonDependentTypeLoc =
             Result.Nodes.getNodeAs<TypeLoc>("nonDependentTypeLoc")) {
+      if (NonDependentTypeLoc->getType()->isDependentType())
+        return SourceLocation();
+
       if (const auto TL = NonDependentTypeLoc->getAs<TypedefTypeLoc>())
         return TL.getElaboratedKeywordLoc();
 
@@ -59,8 +62,7 @@ void RedundantTypenameCheck::check(const MatchFinder::MatchResult &Result) {
 
       if (const auto TL =
               NonDependentTypeLoc->getAs<TemplateSpecializationTypeLoc>())
-        if (!TL.getType()->isDependentType())
-          return TL.getElaboratedKeywordLoc();
+        return TL.getElaboratedKeywordLoc();
     } else {
       TypeLoc InnermostTypeLoc =
           *Result.Nodes.getNodeAs<TypeLoc>("dependentTypeLoc");

clang-tools-extra/test/clang-tidy/checkers/readability/redundant-typename.cpp

@@ -267,3 +267,27 @@ WHOLE_TYPE_IN_MACRO Macro2;
 
 #define WHOLE_DECLARATION_IN_MACRO typename NotDependent::R Macro3
 WHOLE_DECLARATION_IN_MACRO;
+
+template <typename T> struct Wrapper {};
+template <typename T>
+struct ClassWrapper {
+    using R = T;
+    Wrapper<R> f();
+};
+
+template <typename T>
+Wrapper<typename ClassWrapper<T>::R> ClassWrapper<T>::f() {
+    return {};
+}
+
+template <typename T> struct StructWrapper {};
+template <typename T>
+class ClassWithNestedStruct {
+  struct Nested {};
+  StructWrapper<Nested> f();
+};
+
+template <typename T>
+StructWrapper<typename ClassWithNestedStruct<T>::Nested> ClassWithNestedStruct<T>::f() {
+  return {};
+}