From 5a1d8eca5c331edab4e424c2034685433efa4bf5 Mon Sep 17 00:00:00 2001 From: Nick Alcock Date: Tue, 11 Feb 2025 14:32:40 +0000 Subject: libctf: fix slices of slices and of enums 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. --- libctf/ctf-create.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'libctf/ctf-create.c') diff --git a/libctf/ctf-create.c b/libctf/ctf-create.c index 30941fd..1782655 100644 --- a/libctf/ctf-create.c +++ b/libctf/ctf-create.c @@ -1036,7 +1036,7 @@ ctf_add_enumerator (ctf_dict_t *fp, ctf_id_t enid, const char *name, int value) { ctf_dict_t *ofp = fp; - ctf_dtdef_t *dtd = ctf_dtd_lookup (fp, enid); + ctf_dtdef_t *dtd; ctf_enum_t *en; uint32_t kind, vlen, root; @@ -1044,6 +1044,10 @@ ctf_add_enumerator (ctf_dict_t *fp, ctf_id_t enid, const char *name, if (name == NULL) return (ctf_set_errno (fp, EINVAL)); + if ((enid = ctf_type_resolve_unsliced (fp, enid)) == CTF_ERR) + return -1; /* errno is set for us. */ + + dtd = ctf_dtd_lookup (fp, enid); fp = ctf_get_dict (fp, enid); if (enid < fp->ctf_stypes) -- cgit v1.1