[Bug c++/105202] ICE: defaulted comparison operators for enumerated types segfault

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105202

--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
I don't know.
https://eel.is/c++draft/dcl.fct.def.default#1.1
says that defaulted comparison operator function doesn't have to be a special
member function, but then
https://eel.is/c++draft/class.compare.default#1 says that
"A defaulted comparison operator function ([over.binary]) for some class C" ...
but enums aren't classes...

The reason for the ICE is that the https://wg21.link/p2085 implementation
doesn't take the enums into account.
--- gcc/cp/method.cc.jj 2022-04-02 12:48:32.000000000 +0200
+++ gcc/cp/method.cc    2022-04-08 13:51:00.588337683 +0200
@@ -1205,7 +1205,7 @@ early_check_defaulted_comparison (tree f
   for (; parmnode != void_list_node; parmnode = TREE_CHAIN (parmnode))
     {
       tree parmtype = TREE_VALUE (parmnode);
-      if (CLASS_TYPE_P (parmtype))
+      if (OVERLOAD_TYPE_P (parmtype))
        saw_byval = true;
       else if (TREE_CODE (parmtype) == REFERENCE_TYPE
               && !TYPE_REF_IS_RVALUE (parmtype)
@@ -1224,7 +1224,8 @@ early_check_defaulted_comparison (tree f
          if (!is_friend (ctx, fn))
            error_at (loc, "defaulted %qD is not a friend of %qT", fn, ctx);
        }
-      else if (!same_type_ignoring_top_level_qualifiers_p (parmtype, ctx))
+      else if (ctx
+              && !same_type_ignoring_top_level_qualifiers_p (parmtype, ctx))
        saw_bad = true;
     }

would avoid the ICE, but then it is rejected that it isn't a friend,
which https://eel.is/c++draft/class.compare.default#1.2 requires (for classes)
if it isn't a member function.