fix(to_cpp1): emit template template parameters

Author: JohelEGP

regression-tests/pure2-bugfix-for-template-template-parameter.cpp2

@@ -0,0 +1,5 @@
+t: @struct <T: <_, _: _>> type = { }
+
+u: @struct <T, V: _> type = { }
+
+main: () = { _ = :t<u> = (); }

regression-tests/test-results/gcc-13/pure2-bugfix-for-template-template-parameter.cpp.execution

@@ -0,0 +1,32 @@
+
+#define CPP2_IMPORT_STD          Yes
+
+//=== Cpp2 type declarations ====================================================
+
+
+#include "cpp2util.h"
+
+#line 1 "pure2-bugfix-for-template-template-parameter.cpp2"
+template<template <typename UnnamedTypeParam1, auto> class T> class t;
+#line 2 "pure2-bugfix-for-template-template-parameter.cpp2"
+
+template<typename T, auto V> class u;
+
+
+//=== Cpp2 type definitions and function declarations ===========================
+
+#line 1 "pure2-bugfix-for-template-template-parameter.cpp2"
+template<template <typename UnnamedTypeParam1, auto> class T> class t {};
+#line 2 "pure2-bugfix-for-template-template-parameter.cpp2"
+
+template<typename T, auto V> class u {};
+
+auto main() -> int;
+
+//=== Cpp2 function definitions =================================================
+
+#line 1 "pure2-bugfix-for-template-template-parameter.cpp2"
+
+#line 5 "pure2-bugfix-for-template-template-parameter.cpp2"
+auto main() -> int{static_cast<void>(t<u>{}); }
+

regression-tests/test-results/gcc-13/pure2-bugfix-for-template-template-parameter.cpp.output

@@ -0,0 +1,2 @@
+pure2-bugfix-for-template-template-parameter.cpp2... ok (all Cpp2, passes safety checks)
+

regression-tests/test-results/pure2-bugfix-for-template-template-parameter.cpp

@@ -2853,6 +2853,8 @@ struct declaration_node
 
     auto is_function_expression () const -> bool
         { return is_function() && !identifier;  }
+    auto is_template() const -> bool
+        { return template_parameters != nullptr; }
 
     auto is_polymorphic() const // has base types or virtual functions
         -> bool

regression-tests/test-results/pure2-bugfix-for-template-template-parameter.cpp2.output

@@ -4129,7 +4129,8 @@ class cppfront
     auto emit(
         parameter_declaration_node const& n,
         bool                              is_returns            = false,
-        bool                              is_template_parameter = false
+        bool                              is_template_parameter = false,
+        bool                              emit_identifier       = true
     )
         -> void
     {   STACKINSTR
@@ -4234,13 +4235,27 @@ class cppfront
             if (identifier == "_") {
                 printer.print_cpp2( "UnnamedTypeParam" + std::to_string(n.ordinal), identifier_pos );
             }
-            else {
+            else if (emit_identifier) {
                 printer.print_cpp2( identifier, identifier_pos );
             }
 
             return;
         }
 
+        //-----------------------------------------------------------------------
+        //  Handle template parameters
+
+        if (n.declaration->is_template()) {
+            printer.print_cpp2("template ", identifier_pos);
+            emit(*n.declaration->template_parameters, is_returns, true, false, false);
+            printer.print_cpp2(" class", identifier_pos);
+            if (emit_identifier) {
+                printer.print_cpp2(" ", identifier_pos);
+                printer.print_cpp2( identifier, identifier_pos );
+            }
+            return;
+        }
+
         //-----------------------------------------------------------------------
         //  Else handle template non-type parameters
 
@@ -4249,8 +4264,10 @@ class cppfront
 
         if (is_template_parameter) {
             emit( type_id );
-            printer.print_cpp2(" ", type_id.position());
+            if (emit_identifier) {
+                printer.print_cpp2(" ", type_id.position());
                 printer.print_cpp2( identifier, identifier_pos );
+            }
             return;
         }
 
@@ -4463,7 +4480,8 @@ class cppfront
         parameter_declaration_list_node const& n,
         bool                                   is_returns                 = false,
         bool                                   is_template_parameter      = false,
-        bool                                   generating_postfix_inc_dec = false
+        bool                                   generating_postfix_inc_dec = false,
+        bool                                   emit_identifier            = true
     )
         -> void
     {   STACKINSTR
@@ -4492,7 +4510,7 @@ class cppfront
             }
             prev_pos = x->position();
             assert(x);
-            emit(*x, is_returns, is_template_parameter);
+            emit(*x, is_returns, is_template_parameter, emit_identifier);
             if (!x->declaration->has_name("this")) {
                 first = false;
             }
@@ -4639,7 +4657,7 @@ class cppfront
             );
         }
         else {
-            emit(*n.parameters, false, false, generating_postfix_inc_dec); 
+            emit(*n.parameters, false, false, generating_postfix_inc_dec);
         }
 
         //  For an anonymous function, the emitted lambda is 'constexpr' or 'mutable'