------- Additional Comments From pinskia at gcc dot gnu dot org 2005-03-10
17:06 -------
>From call.c:
/* Don't pass empty class objects by value. This is useful
for tags in STL, which are used to control overload resolution.
We don't need to handle other cases of copying empty classes. */
if (! decl || ! DECL_BUILT_IN (decl))
for (tmp = parms; tmp; tmp = TREE_CHAIN (tmp))
if (is_empty_class (TREE_TYPE (TREE_VALUE (tmp)))
&& ! TREE_ADDRESSABLE (TREE_TYPE (TREE_VALUE (tmp))))
{
tree t = build0 (EMPTY_CLASS_EXPR, TREE_TYPE (TREE_VALUE (tmp)));
TREE_VALUE (tmp) = build2 (COMPOUND_EXPR, TREE_TYPE (t),
TREE_VALUE (tmp), t);
}
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20408
