[Bug ada/38331] New: Illegal program not detected, "=" not predefined for class-wide types, ARM 4.5.2(6) and AI05-71

["ludovic at ludovic-brenta dot org" <gcc-bugzilla at gcc dot gnu dot org>]

generic
   type Item (<>) is private;
   with function "=" (L, R : Item) return Boolean is <>;
package pak1 is
end pak1;


with pak1;
package pak2 is
   type T is tagged null record;
   package new_pak1a is new pak1 (Item => T'Class);    --OK by AI05-71
   package new_pak1b is new pak1 (Item => T'Class, "=" => "=");       --ERROR:
   package new_pak1c is new pak1 (Item => T'Class, "=" => pak2."=");  --ERROR:
end pak2;

The compiler accepts this program; it should reject new_pak1b and new_pak1c
because function "=" (L, R : T'Class) does not exist.  The equality operator is
defined only for "specific type T that is not limited, and not an anonymous
access type" (ARM 4.5.2(6)); class-wide types are not "specific" per ARM
3.9(3).

The reason why new_pak1a is legal is because of the special rule in AI05-71
which only applies when _not_ specifying an actual for the generic formal "=".


-- 
           Summary: Illegal program not detected, "=" not predefined for
                    class-wide types, ARM 4.5.2(6) and AI05-71
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: ada
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: ludovic at ludovic-brenta dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38331