===================================================================
@@ -783,7 +783,14 @@ ocp_convert (tree type, tree expr, int convtype, i
return ignore_overflows (converted, e);
}
if (NULLPTR_TYPE_P (type) && e && null_ptr_cst_p (e))
- return nullptr_node;
+ {
+ if ((complain & tf_warning)
+ && c_inhibit_evaluation_warnings == 0
+ && !NULLPTR_TYPE_P (TREE_TYPE (e)))
+ warning_at (loc, OPT_Wzero_as_null_pointer_constant,
+ "zero as null pointer constant");
+ return nullptr_node;
+ }
if (POINTER_TYPE_P (type) || TYPE_PTRMEM_P (type))
return fold_if_not_in_template (cp_convert_to_pointer (type, e, complain));
if (code == VECTOR_TYPE)
===================================================================
@@ -0,0 +1,14 @@
+// PR c++/56373
+// { dg-options "-std=c++11 -Wzero-as-null-pointer-constant" }
+
+struct shared_ptr
+{
+ shared_ptr(decltype(nullptr));
+};
+
+void f()
+{
+ shared_ptr a = 0; // { dg-warning "zero as null pointer" }
+ shared_ptr b(0); // { dg-warning "zero as null pointer" }
+ shared_ptr c{0}; // { dg-warning "zero as null pointer" }
+}