PR c++/82664 - ICE with reference to function template parm.

	* pt.c (convert_nontype_argument_function): Avoid obfuscationg
	NOP_EXPRs.

From-SVN: r257753

gcc/cp/ChangeLog

 2018-02-16  Jason Merrill  <jason@redhat.com>
 
+	PR c++/82664 - ICE with reference to function template parm.
+	* pt.c (convert_nontype_argument_function): Avoid obfuscationg
+	NOP_EXPRs.
+
 	PR c++/82764 - C++17 ICE with empty base
 	* class.c (build_base_field_1): Set DECL_SIZE to zero for empty base.
 

gcc/cp/pt.c

@@ -6143,7 +6143,12 @@ convert_nontype_argument_function (tree type, tree expr,
 
  accept:
   if (TREE_CODE (type) == REFERENCE_TYPE)
-    fn = build_address (fn);
+    {
+      if (REFERENCE_REF_P (fn))
+	fn = TREE_OPERAND (fn, 0);
+      else
+	fn = build_address (fn);
+    }
   if (!same_type_ignoring_top_level_qualifiers_p (type, TREE_TYPE (fn)))
     fn = build_nop (type, fn);
 

gcc/testsuite/g++.dg/template/nontype-fn1.C

+// PR c++/82664
+
+template < typename > struct target_disambiguator;
+template < typename R, typename A1 > struct target_disambiguator< R(A1) > {
+  typedef A1 type;
+  template < R (&)() > struct layout;
+};
+
+int main() {
+  typedef target_disambiguator< void (int) > ::type target_type ;
+}