Hi,
this is a regression about duplicate warnings with
-Wzero-as-null-pointer-constant. The regression is rather old, affects
4_8-branch too, and started when check_default_argument got a
perform_implicit_conversion_flags call which warns a first time, then
maybe_warn_zero_as_null_pointer_constant as called by
check_default_argument itself warns a second time. The latter call is
even older, dates back to c++/52718, I think we can now safely remove it
and keep on returning nullptr_node to avoid warning later still at the
call sites (that was the point of c++/52718). Tested x86_64-linux.
Thanks,
Paolo.
///////////////////
Index: decl.c
===================================================================
--- decl.c (revision 221230)
+++ decl.c (working copy)
@@ -11227,11 +11227,9 @@ check_default_argument (tree decl, tree arg, tsubs
LOOKUP_IMPLICIT);
--cp_unevaluated_operand;
- if (warn_zero_as_null_pointer_constant
- && TYPE_PTR_OR_PTRMEM_P (decl_type)
+ if (TYPE_PTR_OR_PTRMEM_P (decl_type)
&& null_ptr_cst_p (arg)
- && (complain & tf_warning)
- && maybe_warn_zero_as_null_pointer_constant (arg, input_location))
+ && !NULLPTR_TYPE_P (TREE_TYPE (arg)))
return nullptr_node;
/* [dcl.fct.default]
