PR c++/80356 - ICE with reference to function template argument.

	PR c++/79294
	* pt.c (convert_nontype_argument_function): Adjust type even with a
	value-dependent argument.

From-SVN: r246794

gcc/cp/ChangeLog

 2017-04-07  Jason Merrill  <jason@redhat.com>
 
+	PR c++/80356 - ICE with reference to function template argument.
+	PR c++/79294
+	* pt.c (convert_nontype_argument_function): Adjust type even with a
+	value-dependent argument.
+
 	PR c++/80267 - ICE with nested capture of reference
 	PR c++/60992
 	* pt.c (tsubst_copy): Handle lookup finding a capture proxy.

gcc/cp/pt.c

@@ -5981,7 +5981,7 @@ convert_nontype_argument_function (tree type, tree expr,
     return error_mark_node;
 
   if (value_dependent_expression_p (fn))
-    return fn;
+    goto accept;
 
   fn_no_ptr = strip_fnptr_conv (fn);
   if (TREE_CODE (fn_no_ptr) == ADDR_EXPR)
@@ -6030,6 +6030,7 @@ convert_nontype_argument_function (tree type, tree expr,
       return NULL_TREE;
     }
 
+ accept:
   if (TREE_CODE (type) == REFERENCE_TYPE)
     fn = build_address (fn);
   if (!same_type_ignoring_top_level_qualifiers_p (type, TREE_TYPE (fn)))

gcc/testsuite/g++.dg/template/fn-ref1.C

+// PR c++/80356
+
+template <int (&)(int, int)> struct a;
+template <int (&b)(int, int)> a<b> f();