Missing name generation of unamed template types in tempalte parameter list.

Author: MaxSagebaum

regression-tests/test-results/gcc-13/pure2-variadics.cpp.output

@@ -1,16 +0,0 @@
-pure2-variadics.cpp2:17:20: error: declaration of template parameter ‘UnnamedTypeParam1’ shadows template parameter
-pure2-variadics.cpp2:16:10: note: template parameter ‘UnnamedTypeParam1’ declared here
-pure2-variadics.cpp2:27:20: error: declaration of template parameter ‘UnnamedTypeParam1’ shadows template parameter
-pure2-variadics.cpp2:26:10: note: template parameter ‘UnnamedTypeParam1’ declared here
-pure2-variadics.cpp2:17:53: error: declaration of template parameter ‘UnnamedTypeParam1’ shadows template parameter
-pure2-variadics.cpp2:17:13: note: template parameter ‘UnnamedTypeParam1’ declared here
-pure2-variadics.cpp2:17:98: error: ‘_’ was not declared in this scope
-pure2-variadics.cpp2:17:99: error: expected parameter pack before ‘...’
-pure2-variadics.cpp2:17:102: error: template argument 1 is invalid
-pure2-variadics.cpp2:17:95: error: too many template-parameter-lists
-pure2-variadics.cpp2:27:49: error: declaration of template parameter ‘UnnamedTypeParam1’ shadows template parameter
-pure2-variadics.cpp2:27:13: note: template parameter ‘UnnamedTypeParam1’ declared here
-pure2-variadics.cpp2:27:94: error: ‘_’ was not declared in this scope
-pure2-variadics.cpp2:27:95: error: expected parameter pack before ‘...’
-pure2-variadics.cpp2:27:98: error: template argument 1 is invalid
-pure2-variadics.cpp2:27:91: error: too many template-parameter-lists

regression-tests/test-results/pure2-variadics.cpp

@@ -93,13 +93,13 @@ auto main() -> int;
     template <int ...Ts> [[nodiscard]] auto y<Ts...>::func() -> auto { return (0 + ... + Ts);  }
 
 #line 17 "pure2-variadics.cpp2"
-  template <typename ...UnnamedTypeParam1_16_14> template<int UnnamedTypeParam1_17_7> [[nodiscard]] auto t0<_...>::f() -> cpp2::i32 { return 0;  }
+  template <typename ...UnnamedTypeParam1_16_14> template<int UnnamedTypeParam1_17_7> [[nodiscard]] auto t0<UnnamedTypeParam1_16_14...>::f() -> cpp2::i32 { return 0;  }
 
 #line 22 "pure2-variadics.cpp2"
   template <auto ...T> template<int UnnamedTypeParam1_22_7> [[nodiscard]] auto t1<T...>::f() -> cpp2::i32 { return 0;  }
 
 #line 27 "pure2-variadics.cpp2"
-  template <auto ...UnnamedTypeParam1_26_14> template<int UnnamedTypeParam1_27_7> [[nodiscard]] auto t2<_...>::f() -> cpp2::i32 { return 0;  }
+  template <auto ...UnnamedTypeParam1_26_14> template<int UnnamedTypeParam1_27_7> [[nodiscard]] auto t2<UnnamedTypeParam1_26_14...>::f() -> cpp2::i32 { return 0;  }
 
 #line 30 "pure2-variadics.cpp2"
 template<typename ...Args> auto left_fold_print(std::ostream& out, Args const& ...args) -> void{

source/lex.h

@@ -333,6 +333,15 @@ auto labelized_position(token const* t)
     return ret;
 }
 
+auto unnamed_type_param_name(int ordinal, token const* t)
+    -> std::string
+{
+    return "UnnamedTypeParam"
+            + std::to_string(ordinal)
+            + "_"
+            + labelized_position(t);
+}
+
 
 //-----------------------------------------------------------------------
 //

source/to_cpp1.h

@@ -4272,8 +4272,7 @@ class cppfront
             }
 
             if (identifier == "_") {
-                printer.print_cpp2( "UnnamedTypeParam" + std::to_string(n.ordinal) + "_"
-                                    + labelized_position(n.declaration->identifier->get_token()),
+                printer.print_cpp2( unnamed_type_param_name(n.ordinal, n.declaration->identifier->get_token()),
                                     identifier_pos );
             }
             else {
@@ -4929,7 +4928,14 @@ class cppfront
                     auto separator = std::string{"<"};
                     for (auto& tparam : parent->template_parameters->parameters) {
                         assert (tparam->has_name());
-                        list += separator + tparam->name()->to_string();
+                        list += separator;
+                        if ("_" == tparam->name()->to_string()) {
+                            list += unnamed_type_param_name(tparam->ordinal,
+                                                            tparam->declaration->identifier->get_token());
+                        }
+                        else {
+                            list += tparam->name()->to_string();
+                        }
                         if(tparam->declaration->is_variadic) {
                             list += "...";
                         }