https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92798
Joseph Tilahun <josephttilahun at gmail dot com> changed:
What |Removed |Added
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CC| |josephttilahun at gmail dot com
--- Comment #4 from Joseph Tilahun <josephttilahun at gmail dot com> ---
I encountered this same bug when using -fshort-enums with std::map iterators.
The fact that -fshort-enums breaks std::map iterators implies that there's an
enum somewhere without an explicit underlying type. In
/usr/include/c++/9/bits/stl_tree.h, there's an enum that enumerates the
possible colors of a node of a red-black tree:
enum _Rb_tree_color { _S_red = false, _S_black = true };
struct _Rb_tree_node_base
{
typedef _Rb_tree_node_base* _Base_ptr;
typedef const _Rb_tree_node_base* _Const_Base_ptr;
_Rb_tree_color _M_color;
_Base_ptr _M_parent;
_Base_ptr _M_left;
_Base_ptr _M_right;
// Other code that's not relevant
}
The _Rb_tree_color enum does not have an explicit underlying type. I tried
modifying this to:
enum _Rb_tree_color : int { _S_red = false, _S_black = true };
struct _Rb_tree_node_base
{
typedef _Rb_tree_node_base* _Base_ptr;
typedef const _Rb_tree_node_base* _Const_Base_ptr;
_Rb_tree_color _M_color;
_Base_ptr _M_parent;
_Base_ptr _M_left;
_Base_ptr _M_right;
// Other code that's not relevant
}
and -fshort-enums does not break this. I also tried modifying this to:
enum _Rb_tree_color { _S_red = false, _S_black = true };
struct _Rb_tree_node_base
{
typedef _Rb_tree_node_base* _Base_ptr;
typedef const _Rb_tree_node_base* _Const_Base_ptr;
int _M_color;
_Base_ptr _M_parent;
_Base_ptr _M_left;
_Base_ptr _M_right;
// Other code that's not relevant
}
and -fshort-enums does not break this.
It seems to me that the _Rb_tree_color enum is the real problem. -fshort-enums
simply exposes the fact that the _Rb_tree_color enum does not have an explicit
underlying type. Is there a reason why the _Rb_tree_color enum does not have an
explicit underlying type?
