Slices had a bunch of horrible usability problems. In particular, while towers of cv-quals are resolved away by functions that need to do it, towers of cv-quals with slices in the middle are not resolved away by functions like ctf_enum_value that can see through slices: resolving volatile -> slice -> const -> enum will leave it with a 'const', which will error pointlessly, annoying callers, who reasonably expect slices to be more invisible than this. (The user-callable ctf_type_resolve still does not resolve away slices, because this is the only way users can see that the slices are there at all.) This is induced by a fix for another wart: ctf_add_enumerator does not resolve anything away at all, so you can't even add enumerators to const or volatile enums -- and more problematically, you can't add enumerators to enums with an explicit encoding without resolving away the types by hand, since ctf_add_enum_encoded works by returning a slice! ctf_add_enumerator now resolves away all of those, so any cvr-or-typedef-or-slice-qual terminating in an enum can be added to, exactly as callers likely expect. (New tests added.) libctf/ * ctf-create.c (ctf_add_enumerator): Resolve away cvr-qualness. * ctf-types.c (ctf_type_resolve_unsliced): Don't terminate at the first slice. * testsuite/libctf-writable/slice-of-slice.*: New test.