PR c++/88184 - ICE when treating name as template-name.

	* pt.c (lookup_template_function): Always build the TEMPLATE_ID_EXPR
	with unknown_type_node.

	* g++.dg/cpp2a/fn-template17.C: New test.
	* g++.dg/cpp2a/fn-template18.C: New test.

From-SVN: r266793

gcc/cp/ChangeLog

+2018-12-04  Marek Polacek  <polacek@redhat.com>
+
+	PR c++/88184 - ICE when treating name as template-name.
+	* pt.c (lookup_template_function): Always build the TEMPLATE_ID_EXPR
+	with unknown_type_node.
+
 2018-12-04  Julian Brown  <julian@codesourcery.com>
 
 	* parser.c (cp_parser_oacc_wait_list): Fix error message and avoid

gcc/cp/pt.c

@@ -9068,8 +9068,6 @@ add_pending_template (tree d)
 tree
 lookup_template_function (tree fns, tree arglist)
 {
-  tree type;
-
   if (fns == error_mark_node || arglist == error_mark_node)
     return error_mark_node;
 
@@ -9090,11 +9088,7 @@ lookup_template_function (tree fns, tree arglist)
       return fns;
     }
 
-  type = TREE_TYPE (fns);
-  if (TREE_CODE (fns) == OVERLOAD || !type)
-    type = unknown_type_node;
-
-  return build2 (TEMPLATE_ID_EXPR, type, fns, arglist);
+  return build2 (TEMPLATE_ID_EXPR, unknown_type_node, fns, arglist);
 }
 
 /* Within the scope of a template class S<T>, the name S gets bound

gcc/testsuite/ChangeLog

+2018-12-04  Marek Polacek  <polacek@redhat.com>
+
+	PR c++/88184 - ICE when treating name as template-name.
+	* g++.dg/cpp2a/fn-template17.C: New test.
+	* g++.dg/cpp2a/fn-template18.C: New test.
+
 2018-12-04  David Edelsohn  <dje.gcc@gmail.com>
 
 	* gcc.dg/live-patching-2.c: Require LTO.

gcc/testsuite/g++.dg/cpp2a/fn-template17.C

+// PR c++/88184
+// { dg-do compile }
+// { dg-options "-std=c++2a -fchecking=2" }
+
+namespace A
+{
+  void f ();
+}
+
+using A::f;
+
+template <typename T> void g ()
+{
+  f<T> (); // { dg-error "no matching function for call" }
+}
+
+void
+fn ()
+{
+  g<int>();
+}

gcc/testsuite/g++.dg/cpp2a/fn-template18.C

+// PR c++/88184
+// { dg-do compile }
+// { dg-options "-std=c++2a -fchecking=2" }
+
+namespace A
+{
+  void f ();
+  void f (int);
+  void f (int, int);
+}
+
+using A::f;
+
+template <typename T> void g ()
+{
+  f<T> (); // { dg-error "no matching function for call" }
+}
+
+void
+fn ()
+{
+  g<int>();
+}