PR libstdc++/85843 - warning in logic_error copy constructor.

	* class.c (type_has_user_nondefault_constructor): Check for a
	user-provided ctor, not user-declared.

From-SVN: r260432

gcc/cp/ChangeLog

+2018-05-20  Jason Merrill  <jason@redhat.com>
+
+	PR libstdc++/85843 - warning in logic_error copy constructor.
+	* class.c (type_has_user_nondefault_constructor): Check for a
+	user-provided ctor, not user-declared.
+
 2018-05-19  Jason Merrill  <jason@redhat.com>
 
 	* pt.c (tsubst_pack_expansion): Sorry rather than abort

gcc/cp/class.c

@@ -4884,7 +4884,7 @@ default_ctor_p (tree fn)
 	  && sufficient_parms_p (FUNCTION_FIRST_USER_PARMTYPE (fn)));
 }
 
-/* Returns true iff class T has a user-defined constructor that can be called
+/* Returns true iff class T has a user-provided constructor that can be called
    with more than zero arguments.  */
 
 bool
@@ -4896,7 +4896,7 @@ type_has_user_nondefault_constructor (tree t)
   for (ovl_iterator iter (CLASSTYPE_CONSTRUCTORS (t)); iter; ++iter)
     {
       tree fn = *iter;
-      if (!DECL_ARTIFICIAL (fn)
+      if (user_provided_p (fn)
 	  && (TREE_CODE (fn) == TEMPLATE_DECL
 	      || (skip_artificial_parms_for (fn, DECL_ARGUMENTS (fn))
 		  != NULL_TREE)))

gcc/testsuite/g++.dg/warn/Wextra-4.C

+// PR libstdc++/85843
+// { dg-do compile { target c++11 } }
+// { dg-additional-options -Wextra }
+
+struct A
+{
+  A();
+  A(const A&) = default;
+};
+
+struct B : A
+{
+  B(): A() { }
+  B(const B&) { }
+};