Nick Alcock 6da9267482 libctf, include: add ctf_dict_set_flag: less enum dup checking by default ... The recent change to detect duplicate enum values and return ECTF_DUPLICATE when found turns out to perturb a great many callers. In particular, the pahole-created kernel BTF has the same problem we historically did, and gleefully emits duplicated enum constants in profusion. Handling the resulting duplicate errors from BTF -> CTF converters reasonably is unreasonably difficult (it amounts to forcing them to skip some types or reimplement the deduplicator). So let's step back a bit. What we care about mostly is that the deduplicator treat enums with conflicting enumeration constants as conflicting types: programs that want to look up enumeration constant -> value mappings using the new APIs to do so might well want the same checks to apply to any ctf_add_* operations they carry out (and since they're *using* the new APIs, added at the same time as this restriction was imposed, there is likely to be no negative consequence of this). So we want some way to allow processes that know about duplicate detection to opt into it, while allowing everyone else to stay clear of it: but we want ctf_link to get this behaviour even if its caller has opted out. So add a new concept to the API: dict-wide CTF flags, set via ctf_dict_set_flag, obtained via ctf_dict_get_flag. They are not bitflags but simple arbitrary integers and an on/off value, stored in an unspecified manner (the one current flag, we translate into an LCTF_* flag value in the internal ctf_dict ctf_flags word). If you pass in an invalid flag or value you get a new ECTF_BADFLAG error, so the caller can easily tell whether flags added in future are valid with a particular libctf or not. We check this flag in ctf_add_enumerator, and set it around the link (including on child per-CU dicts). The newish enumerator-iteration test is souped up to check the semantics of the flag as well. The fact that the flag can be set and unset at any time has curious consequences. You can unset the flag, insert a pile of duplicates, then set it and expect the new duplicates to be detected, not only by ctf_add_enumerator but also by ctf_lookup_enumerator. This means we now have to maintain the ctf_names and conflicting_enums enum-duplication tracking as new enums are added, not purely as the dict is opened. Move that code out of init_static_types_internal and into a new ctf_track_enumerator function that addition can also call. (None of this affects the file format or serialization machinery, which has to be able to handle duplicate enumeration constants no matter what.) include/ * ctf-api.h (CTF_ERRORS) [ECTF_BADFLAG]: New. (ECTF_NERR): Update. (CTF_STRICT_NO_DUP_ENUMERATORS): New flag. (ctf_dict_set_flag): New function. (ctf_dict_get_flag): Likewise. libctf/ * ctf-impl.h (LCTF_STRICT_NO_DUP_ENUMERATORS): New flag. (ctf_track_enumerator): Declare. * ctf-dedup.c (ctf_dedup_emit_type): Set it. * ctf-link.c (ctf_create_per_cu): Likewise. (ctf_link_deduplicating_per_cu): Likewise. (ctf_link): Likewise. (ctf_link_write): Likewise. * ctf-subr.c (ctf_dict_set_flag): New function. (ctf_dict_get_flag): New function. * ctf-open.c (init_static_types_internal): Move enum tracking to... * ctf-create.c (ctf_track_enumerator): ... this new function. (ctf_add_enumerator): Call it. * libctf.ver: Add the new functions. * testsuite/libctf-lookup/enumerator-iteration.c: Test them.		2024-07-31 21:02:05 +01:00
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config
lib	libctf: suppress spurious failure of malloc-counting tests under valgrind	2024-06-18 13:20:32 +01:00
libctf-lookup	libctf, include: add ctf_dict_set_flag: less enum dup checking by default	2024-07-31 21:02:05 +01:00
libctf-regression	libctf: fix testsuite bugs revealed by -Wall	2024-06-19 15:51:24 +01:00
libctf-writable	libctf: fix CTF dict compression	2024-07-31 21:02:05 +01:00