/* Interface to hashtable implementations. Copyright (C) 2006-2023 Free Software Foundation, Inc. This file is part of libctf. libctf is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; see the file COPYING. If not see . */ #include #include #include "libiberty.h" #include "hashtab.h" /* We have three hashtable implementations: - ctf_hash_* is an interface to a fixed-size hash from const char * -> ctf_id_t with number of elements specified at creation time, that should support addition of items but need not support removal. - ctf_dynhash_* is an interface to a dynamically-expanding hash with unknown size that should support addition of large numbers of items, and removal as well, and is used only at type-insertion time and during linking. - ctf_dynset_* is an interface to a dynamically-expanding hash that contains only keys: no values. These can be implemented by the same underlying hashmap if you wish. */ /* The helem is used for general key/value mappings in both the ctf_hash and ctf_dynhash: the owner may not have space allocated for it, and will be garbage (not NULL!) in that case. */ typedef struct ctf_helem { void *key; /* Either a pointer, or a coerced ctf_id_t. */ void *value; /* The value (possibly a coerced int). */ ctf_dynhash_t *owner; /* The hash that owns us. */ } ctf_helem_t; /* Equally, the key_free and value_free may not exist. */ struct ctf_dynhash { struct htab *htab; ctf_hash_free_fun key_free; ctf_hash_free_fun value_free; }; /* Hash and eq functions for the dynhash and hash. */ unsigned int ctf_hash_integer (const void *ptr) { ctf_helem_t *hep = (ctf_helem_t *) ptr; return htab_hash_pointer (hep->key); } int ctf_hash_eq_integer (const void *a, const void *b) { ctf_helem_t *hep_a = (ctf_helem_t *) a; ctf_helem_t *hep_b = (ctf_helem_t *) b; return htab_eq_pointer (hep_a->key, hep_b->key); } unsigned int ctf_hash_string (const void *ptr) { ctf_helem_t *hep = (ctf_helem_t *) ptr; return htab_hash_string (hep->key); } int ctf_hash_eq_string (const void *a, const void *b) { ctf_helem_t *hep_a = (ctf_helem_t *) a; ctf_helem_t *hep_b = (ctf_helem_t *) b; return !strcmp((const char *) hep_a->key, (const char *) hep_b->key); } /* Hash a type_key. */ unsigned int ctf_hash_type_key (const void *ptr) { ctf_helem_t *hep = (ctf_helem_t *) ptr; ctf_link_type_key_t *k = (ctf_link_type_key_t *) hep->key; return htab_hash_pointer (k->cltk_fp) + 59 * htab_hash_pointer ((void *) (uintptr_t) k->cltk_idx); } int ctf_hash_eq_type_key (const void *a, const void *b) { ctf_helem_t *hep_a = (ctf_helem_t *) a; ctf_helem_t *hep_b = (ctf_helem_t *) b; ctf_link_type_key_t *key_a = (ctf_link_type_key_t *) hep_a->key; ctf_link_type_key_t *key_b = (ctf_link_type_key_t *) hep_b->key; return (key_a->cltk_fp == key_b->cltk_fp) && (key_a->cltk_idx == key_b->cltk_idx); } /* Hash a type_id_key. */ unsigned int ctf_hash_type_id_key (const void *ptr) { ctf_helem_t *hep = (ctf_helem_t *) ptr; ctf_type_id_key_t *k = (ctf_type_id_key_t *) hep->key; return htab_hash_pointer ((void *) (uintptr_t) k->ctii_input_num) + 59 * htab_hash_pointer ((void *) (uintptr_t) k->ctii_type); } int ctf_hash_eq_type_id_key (const void *a, const void *b) { ctf_helem_t *hep_a = (ctf_helem_t *) a; ctf_helem_t *hep_b = (ctf_helem_t *) b; ctf_type_id_key_t *key_a = (ctf_type_id_key_t *) hep_a->key; ctf_type_id_key_t *key_b = (ctf_type_id_key_t *) hep_b->key; return (key_a->ctii_input_num == key_b->ctii_input_num) && (key_a->ctii_type == key_b->ctii_type); } /* The dynhash, used for hashes whose size is not known at creation time. */ /* Free a single ctf_helem with arbitrary key/value functions. */ static void ctf_dynhash_item_free (void *item) { ctf_helem_t *helem = item; if (helem->owner->key_free && helem->key) helem->owner->key_free (helem->key); if (helem->owner->value_free && helem->value) helem->owner->value_free (helem->value); free (helem); } ctf_dynhash_t * ctf_dynhash_create (ctf_hash_fun hash_fun, ctf_hash_eq_fun eq_fun, ctf_hash_free_fun key_free, ctf_hash_free_fun value_free) { ctf_dynhash_t *dynhash; htab_del del = ctf_dynhash_item_free; if (key_free || value_free) dynhash = malloc (sizeof (ctf_dynhash_t)); else dynhash = malloc (offsetof (ctf_dynhash_t, key_free)); if (!dynhash) return NULL; if (key_free == NULL && value_free == NULL) del = free; /* 7 is arbitrary and untested for now. */ if ((dynhash->htab = htab_create_alloc (7, (htab_hash) hash_fun, eq_fun, del, xcalloc, free)) == NULL) { free (dynhash); return NULL; } if (key_free || value_free) { dynhash->key_free = key_free; dynhash->value_free = value_free; } return dynhash; } static ctf_helem_t ** ctf_hashtab_lookup (struct htab *htab, const void *key, enum insert_option insert) { ctf_helem_t tmp = { .key = (void *) key }; return (ctf_helem_t **) htab_find_slot (htab, &tmp, insert); } static ctf_helem_t * ctf_hashtab_insert (struct htab *htab, void *key, void *value, ctf_hash_free_fun key_free, ctf_hash_free_fun value_free) { ctf_helem_t **slot; slot = ctf_hashtab_lookup (htab, key, INSERT); if (!slot) { errno = ENOMEM; return NULL; } if (!*slot) { /* Only spend space on the owner if we're going to use it: if there is a key or value freeing function. */ if (key_free || value_free) *slot = malloc (sizeof (ctf_helem_t)); else *slot = malloc (offsetof (ctf_helem_t, owner)); if (!*slot) return NULL; (*slot)->key = key; } else { if (key_free) key_free (key); if (value_free) value_free ((*slot)->value); } (*slot)->value = value; return *slot; } int ctf_dynhash_insert (ctf_dynhash_t *hp, void *key, void *value) { ctf_helem_t *slot; ctf_hash_free_fun key_free = NULL, value_free = NULL; if (hp->htab->del_f == ctf_dynhash_item_free) { key_free = hp->key_free; value_free = hp->value_free; } slot = ctf_hashtab_insert (hp->htab, key, value, key_free, value_free); if (!slot) return errno; /* Keep track of the owner, so that the del function can get at the key_free and value_free functions. Only do this if one of those functions is set: if not, the owner is not even present in the helem. */ if (key_free || value_free) slot->owner = hp; return 0; } void ctf_dynhash_remove (ctf_dynhash_t *hp, const void *key) { ctf_helem_t hep = { (void *) key, NULL, NULL }; htab_remove_elt (hp->htab, &hep); } void ctf_dynhash_empty (ctf_dynhash_t *hp) { htab_empty (hp->htab); } size_t ctf_dynhash_elements (ctf_dynhash_t *hp) { return htab_elements (hp->htab); } void * ctf_dynhash_lookup (ctf_dynhash_t *hp, const void *key) { ctf_helem_t **slot; slot = ctf_hashtab_lookup (hp->htab, key, NO_INSERT); if (slot) return (*slot)->value; return NULL; } /* TRUE/FALSE return. */ int ctf_dynhash_lookup_kv (ctf_dynhash_t *hp, const void *key, const void **orig_key, void **value) { ctf_helem_t **slot; slot = ctf_hashtab_lookup (hp->htab, key, NO_INSERT); if (slot) { if (orig_key) *orig_key = (*slot)->key; if (value) *value = (*slot)->value; return 1; } return 0; } typedef struct ctf_traverse_cb_arg { ctf_hash_iter_f fun; void *arg; } ctf_traverse_cb_arg_t; static int ctf_hashtab_traverse (void **slot, void *arg_) { ctf_helem_t *helem = *((ctf_helem_t **) slot); ctf_traverse_cb_arg_t *arg = (ctf_traverse_cb_arg_t *) arg_; arg->fun (helem->key, helem->value, arg->arg); return 1; } void ctf_dynhash_iter (ctf_dynhash_t *hp, ctf_hash_iter_f fun, void *arg_) { ctf_traverse_cb_arg_t arg = { fun, arg_ }; htab_traverse (hp->htab, ctf_hashtab_traverse, &arg); } typedef struct ctf_traverse_find_cb_arg { ctf_hash_iter_find_f fun; void *arg; void *found_key; } ctf_traverse_find_cb_arg_t; static int ctf_hashtab_traverse_find (void **slot, void *arg_) { ctf_helem_t *helem = *((ctf_helem_t **) slot); ctf_traverse_find_cb_arg_t *arg = (ctf_traverse_find_cb_arg_t *) arg_; if (arg->fun (helem->key, helem->value, arg->arg)) { arg->found_key = helem->key; return 0; } return 1; } void * ctf_dynhash_iter_find (ctf_dynhash_t *hp, ctf_hash_iter_find_f fun, void *arg_) { ctf_traverse_find_cb_arg_t arg = { fun, arg_, NULL }; htab_traverse (hp->htab, ctf_hashtab_traverse_find, &arg); return arg.found_key; } typedef struct ctf_traverse_remove_cb_arg { struct htab *htab; ctf_hash_iter_remove_f fun; void *arg; } ctf_traverse_remove_cb_arg_t; static int ctf_hashtab_traverse_remove (void **slot, void *arg_) { ctf_helem_t *helem = *((ctf_helem_t **) slot); ctf_traverse_remove_cb_arg_t *arg = (ctf_traverse_remove_cb_arg_t *) arg_; if (arg->fun (helem->key, helem->value, arg->arg)) htab_clear_slot (arg->htab, slot); return 1; } void ctf_dynhash_iter_remove (ctf_dynhash_t *hp, ctf_hash_iter_remove_f fun, void *arg_) { ctf_traverse_remove_cb_arg_t arg = { hp->htab, fun, arg_ }; htab_traverse (hp->htab, ctf_hashtab_traverse_remove, &arg); } /* Traverse a dynhash in arbitrary order, in _next iterator form. Mutating the dynhash while iterating is not supported (just as it isn't for htab_traverse). Note: unusually, this returns zero on success and a *positive* value on error, because it does not take an fp, taking an error pointer would be incredibly clunky, and nearly all error-handling ends up stuffing the result of this into some sort of errno or ctf_errno, which is invariably positive. So doing this simplifies essentially all callers. */ int ctf_dynhash_next (ctf_dynhash_t *h, ctf_next_t **it, void **key, void **value) { ctf_next_t *i = *it; ctf_helem_t *slot; if (!i) { size_t size = htab_size (h->htab); /* If the table has too many entries to fit in an ssize_t, just give up. This might be spurious, but if any type-related hashtable has ever been nearly as large as that then something very odd is going on. */ if (((ssize_t) size) < 0) return EDOM; if ((i = ctf_next_create ()) == NULL) return ENOMEM; i->u.ctn_hash_slot = h->htab->entries; i->cu.ctn_h = h; i->ctn_n = 0; i->ctn_size = (ssize_t) size; i->ctn_iter_fun = (void (*) (void)) ctf_dynhash_next; *it = i; } if ((void (*) (void)) ctf_dynhash_next != i->ctn_iter_fun) return ECTF_NEXT_WRONGFUN; if (h != i->cu.ctn_h) return ECTF_NEXT_WRONGFP; if ((ssize_t) i->ctn_n == i->ctn_size) goto hash_end; while ((ssize_t) i->ctn_n < i->ctn_size && (*i->u.ctn_hash_slot == HTAB_EMPTY_ENTRY || *i->u.ctn_hash_slot == HTAB_DELETED_ENTRY)) { i->u.ctn_hash_slot++; i->ctn_n++; } if ((ssize_t) i->ctn_n == i->ctn_size) goto hash_end; slot = *i->u.ctn_hash_slot; if (key) *key = slot->key; if (value) *value = slot->value; i->u.ctn_hash_slot++; i->ctn_n++; return 0; hash_end: ctf_next_destroy (i); *it = NULL; return ECTF_NEXT_END; } int ctf_dynhash_sort_by_name (const ctf_next_hkv_t *one, const ctf_next_hkv_t *two, void *unused _libctf_unused_) { return strcmp ((char *) one->hkv_key, (char *) two->hkv_key); } /* Traverse a sorted dynhash, in _next iterator form. See ctf_dynhash_next for notes on error returns, etc. Sort keys before iterating over them using the SORT_FUN and SORT_ARG. If SORT_FUN is null, thunks to ctf_dynhash_next. */ int ctf_dynhash_next_sorted (ctf_dynhash_t *h, ctf_next_t **it, void **key, void **value, ctf_hash_sort_f sort_fun, void *sort_arg) { ctf_next_t *i = *it; if (sort_fun == NULL) return ctf_dynhash_next (h, it, key, value); if (!i) { size_t els = ctf_dynhash_elements (h); ctf_next_t *accum_i = NULL; void *key, *value; int err; ctf_next_hkv_t *walk; if (((ssize_t) els) < 0) return EDOM; if ((i = ctf_next_create ()) == NULL) return ENOMEM; if ((i->u.ctn_sorted_hkv = calloc (els, sizeof (ctf_next_hkv_t))) == NULL) { ctf_next_destroy (i); return ENOMEM; } walk = i->u.ctn_sorted_hkv; i->cu.ctn_h = h; while ((err = ctf_dynhash_next (h, &accum_i, &key, &value)) == 0) { walk->hkv_key = key; walk->hkv_value = value; walk++; } if (err != ECTF_NEXT_END) { ctf_next_destroy (i); return err; } if (sort_fun) ctf_qsort_r (i->u.ctn_sorted_hkv, els, sizeof (ctf_next_hkv_t), (int (*) (const void *, const void *, void *)) sort_fun, sort_arg); i->ctn_n = 0; i->ctn_size = (ssize_t) els; i->ctn_iter_fun = (void (*) (void)) ctf_dynhash_next_sorted; *it = i; } if ((void (*) (void)) ctf_dynhash_next_sorted != i->ctn_iter_fun) return ECTF_NEXT_WRONGFUN; if (h != i->cu.ctn_h) return ECTF_NEXT_WRONGFP; if ((ssize_t) i->ctn_n == i->ctn_size) { ctf_next_destroy (i); *it = NULL; return ECTF_NEXT_END; } if (key) *key = i->u.ctn_sorted_hkv[i->ctn_n].hkv_key; if (value) *value = i->u.ctn_sorted_hkv[i->ctn_n].hkv_value; i->ctn_n++; return 0; } void ctf_dynhash_destroy (ctf_dynhash_t *hp) { if (hp != NULL) htab_delete (hp->htab); free (hp); } /* The dynset, used for sets of keys with no value. The implementation of this can be much simpler, because without a value the slot can simply be the stored key, which means we don't need to store the freeing functions and the dynset itself is just a htab. */ ctf_dynset_t * ctf_dynset_create (htab_hash hash_fun, htab_eq eq_fun, ctf_hash_free_fun key_free) { /* 7 is arbitrary and untested for now. */ return (ctf_dynset_t *) htab_create_alloc (7, (htab_hash) hash_fun, eq_fun, key_free, xcalloc, free); } /* The dynset has one complexity: the underlying implementation reserves two values for internal hash table implementation details (empty versus deleted entries). These values are otherwise very useful for pointers cast to ints, so transform the ctf_dynset_inserted value to allow for it. (This introduces an ambiguity in that one can no longer store these two values in the dynset, but if we pick high enough values this is very unlikely to be a problem.) We leak this implementation detail to the freeing functions on the grounds that any use of these functions is overwhelmingly likely to be in sets using real pointers, which will be unaffected. */ #define DYNSET_EMPTY_ENTRY_REPLACEMENT ((void *) (uintptr_t) -64) #define DYNSET_DELETED_ENTRY_REPLACEMENT ((void *) (uintptr_t) -63) static void * key_to_internal (const void *key) { if (key == HTAB_EMPTY_ENTRY) return DYNSET_EMPTY_ENTRY_REPLACEMENT; else if (key == HTAB_DELETED_ENTRY) return DYNSET_DELETED_ENTRY_REPLACEMENT; return (void *) key; } static void * internal_to_key (const void *internal) { if (internal == DYNSET_EMPTY_ENTRY_REPLACEMENT) return HTAB_EMPTY_ENTRY; else if (internal == DYNSET_DELETED_ENTRY_REPLACEMENT) return HTAB_DELETED_ENTRY; return (void *) internal; } int ctf_dynset_insert (ctf_dynset_t *hp, void *key) { struct htab *htab = (struct htab *) hp; void **slot; slot = htab_find_slot (htab, key, INSERT); if (!slot) { errno = ENOMEM; return -errno; } if (*slot) { if (htab->del_f) (*htab->del_f) (*slot); } *slot = key_to_internal (key); return 0; } void ctf_dynset_remove (ctf_dynset_t *hp, const void *key) { htab_remove_elt ((struct htab *) hp, key_to_internal (key)); } void ctf_dynset_destroy (ctf_dynset_t *hp) { if (hp != NULL) htab_delete ((struct htab *) hp); } void * ctf_dynset_lookup (ctf_dynset_t *hp, const void *key) { void **slot = htab_find_slot ((struct htab *) hp, key_to_internal (key), NO_INSERT); if (slot) return internal_to_key (*slot); return NULL; } size_t ctf_dynset_elements (ctf_dynset_t *hp) { return htab_elements ((struct htab *) hp); } /* TRUE/FALSE return. */ int ctf_dynset_exists (ctf_dynset_t *hp, const void *key, const void **orig_key) { void **slot = htab_find_slot ((struct htab *) hp, key_to_internal (key), NO_INSERT); if (orig_key && slot) *orig_key = internal_to_key (*slot); return (slot != NULL); } /* Look up a completely random value from the set, if any exist. Keys with value zero cannot be distinguished from a nonexistent key. */ void * ctf_dynset_lookup_any (ctf_dynset_t *hp) { struct htab *htab = (struct htab *) hp; void **slot = htab->entries; void **limit = slot + htab_size (htab); while (slot < limit && (*slot == HTAB_EMPTY_ENTRY || *slot == HTAB_DELETED_ENTRY)) slot++; if (slot < limit) return internal_to_key (*slot); return NULL; } /* Traverse a dynset in arbitrary order, in _next iterator form. Otherwise, just like ctf_dynhash_next. */ int ctf_dynset_next (ctf_dynset_t *hp, ctf_next_t **it, void **key) { struct htab *htab = (struct htab *) hp; ctf_next_t *i = *it; void *slot; if (!i) { size_t size = htab_size (htab); /* If the table has too many entries to fit in an ssize_t, just give up. This might be spurious, but if any type-related hashtable has ever been nearly as large as that then somthing very odd is going on. */ if (((ssize_t) size) < 0) return EDOM; if ((i = ctf_next_create ()) == NULL) return ENOMEM; i->u.ctn_hash_slot = htab->entries; i->cu.ctn_s = hp; i->ctn_n = 0; i->ctn_size = (ssize_t) size; i->ctn_iter_fun = (void (*) (void)) ctf_dynset_next; *it = i; } if ((void (*) (void)) ctf_dynset_next != i->ctn_iter_fun) return ECTF_NEXT_WRONGFUN; if (hp != i->cu.ctn_s) return ECTF_NEXT_WRONGFP; if ((ssize_t) i->ctn_n == i->ctn_size) goto set_end; while ((ssize_t) i->ctn_n < i->ctn_size && (*i->u.ctn_hash_slot == HTAB_EMPTY_ENTRY || *i->u.ctn_hash_slot == HTAB_DELETED_ENTRY)) { i->u.ctn_hash_slot++; i->ctn_n++; } if ((ssize_t) i->ctn_n == i->ctn_size) goto set_end; slot = *i->u.ctn_hash_slot; if (key) *key = internal_to_key (slot); i->u.ctn_hash_slot++; i->ctn_n++; return 0; set_end: ctf_next_destroy (i); *it = NULL; return ECTF_NEXT_END; } /* ctf_hash, used for fixed-size maps from const char * -> ctf_id_t without removal. This is a straight cast of a hashtab. */ ctf_hash_t * ctf_hash_create (unsigned long nelems, ctf_hash_fun hash_fun, ctf_hash_eq_fun eq_fun) { return (ctf_hash_t *) htab_create_alloc (nelems, (htab_hash) hash_fun, eq_fun, free, xcalloc, free); } uint32_t ctf_hash_size (const ctf_hash_t *hp) { return htab_elements ((struct htab *) hp); } int ctf_hash_insert_type (ctf_hash_t *hp, ctf_dict_t *fp, uint32_t type, uint32_t name) { const char *str = ctf_strraw (fp, name); if (type == 0) return EINVAL; if (str == NULL && CTF_NAME_STID (name) == CTF_STRTAB_1 && fp->ctf_syn_ext_strtab == NULL && fp->ctf_str[CTF_NAME_STID (name)].cts_strs == NULL) return ECTF_STRTAB; if (str == NULL) return ECTF_BADNAME; if (str[0] == '\0') return 0; /* Just ignore empty strings on behalf of caller. */ if (ctf_hashtab_insert ((struct htab *) hp, (char *) str, (void *) (ptrdiff_t) type, NULL, NULL) != NULL) return 0; return errno; } /* if the key is already in the hash, override the previous definition with this new official definition. If the key is not present, then call ctf_hash_insert_type and hash it in. */ int ctf_hash_define_type (ctf_hash_t *hp, ctf_dict_t *fp, uint32_t type, uint32_t name) { /* This matches the semantics of ctf_hash_insert_type in this implementation anyway. */ return ctf_hash_insert_type (hp, fp, type, name); } ctf_id_t ctf_hash_lookup_type (ctf_hash_t *hp, ctf_dict_t *fp __attribute__ ((__unused__)), const char *key) { ctf_helem_t **slot; slot = ctf_hashtab_lookup ((struct htab *) hp, key, NO_INSERT); if (slot) return (ctf_id_t) (uintptr_t) ((*slot)->value); return 0; } void ctf_hash_destroy (ctf_hash_t *hp) { if (hp != NULL) htab_delete ((struct htab *) hp); }