Hi,
On 28/04/2018 18:41, Jason Merrill wrote:
On Fri, Apr 27, 2018 at 7:26 PM, Paolo Carlini <paolo.carl...@oracle.com> wrote:
Hi again,
I'm now pretty sure that we have a latent issue in ocp_convert. The bug
fixed by Jakub shows that we used to not have issues with integer_zero_node.
That's easy to explain: at the beginning of ocp_convert there is code which
handles first some special / simple cases when
same_type_ignoring_top_level_qualifiers_p is true. That code isn't of course
used for integer_zero_node as source expression, which therefore is handled
by:
if (NULLPTR_TYPE_P (type) && e && null_ptr_cst_p (e))
{
if (complain & tf_warning)
maybe_warn_zero_as_null_pointer_constant (e, loc);
return nullptr_node;
}
Maybe we should move this code up, then.
You are totally right. Yesterday I realized that and tested on
x86_64-linux the below, both with and without Jakub's fix.
Thanks!
Paolo.
////////////////////
Index: cvt.c
===================================================================
--- cvt.c (revision 259742)
+++ cvt.c (working copy)
@@ -711,6 +711,14 @@ ocp_convert (tree type, tree expr, int convtype, i
if (error_operand_p (e))
return error_mark_node;
+ if (NULLPTR_TYPE_P (type) && null_ptr_cst_p (e))
+ {
+ if (complain & tf_warning)
+ maybe_warn_zero_as_null_pointer_constant (e, loc);
+ if (!TREE_SIDE_EFFECTS (e))
+ return nullptr_node;
+ }
+
if (MAYBE_CLASS_TYPE_P (type) && (convtype & CONV_FORCE_TEMP))
/* We need a new temporary; don't take this shortcut. */;
else if (same_type_ignoring_top_level_qualifiers_p (type, TREE_TYPE (e)))
@@ -832,12 +840,6 @@ ocp_convert (tree type, tree expr, int convtype, i
/* Ignore any integer overflow caused by the conversion. */
return ignore_overflows (converted, e);
}
- if (NULLPTR_TYPE_P (type) && e && null_ptr_cst_p (e))
- {
- if (complain & tf_warning)
- maybe_warn_zero_as_null_pointer_constant (e, loc);
- return nullptr_node;
- }
if (POINTER_TYPE_P (type) || TYPE_PTRMEM_P (type))
return cp_convert_to_pointer (type, e, dofold, complain);
if (code == VECTOR_TYPE)
