# DP: Fix PR c++/57211, don't warn about unused parameters of defaulted functions.

/cp
2013-05-22  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/57211
	* method.c (defaultable_fn_check): Avoid do_warn_unused_parameter
	warnings about defaulted functions.

/testsuite
2013-05-22  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/57211
	* g++.dg/cpp0x/Wunused-parm.C: New.

Index: b/src/gcc/cp/method.c
===================================================================
--- a/src/gcc/cp/method.c
+++ b/src/gcc/cp/method.c
@@ -1841,13 +1841,19 @@
     }
   else
     {
-      tree t = FUNCTION_FIRST_USER_PARMTYPE (fn);
-      for (; t && t != void_list_node; t = TREE_CHAIN (t))
+      for (tree t = FUNCTION_FIRST_USER_PARMTYPE (fn);
+	   t && t != void_list_node; t = TREE_CHAIN (t))
 	if (TREE_PURPOSE (t))
 	  {
 	    error ("defaulted function %q+D with default argument", fn);
 	    break;
 	  }
+
+      /* Avoid do_warn_unused_parameter warnings.  */
+      for (tree p = FUNCTION_FIRST_USER_PARM (fn); p; p = DECL_CHAIN (p))
+	if (DECL_NAME (p))
+	  TREE_NO_WARNING (p) = 1;
+
       if (TYPE_BEING_DEFINED (DECL_CONTEXT (fn)))
 	/* Defer checking.  */;
       else if (!processing_template_decl)
Index: b/src/gcc/testsuite/g++.dg/cpp0x/Wunused-parm.C
===================================================================
--- /dev/null
+++ b/src/gcc/testsuite/g++.dg/cpp0x/Wunused-parm.C
@@ -0,0 +1,23 @@
+// PR c++/57211
+// { dg-options "-std=c++11 -Wunused-parameter" }
+
+template <class T> T&& move(T&);
+
+struct A
+{
+  struct B
+  {
+    B& operator=(B&&);
+  };
+
+  B f;
+
+  A& operator=(A&& p) = default;
+};
+
+int main()
+{
+  A a;
+  A b;
+  b = move(a);
+}