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ctf-hash.c revision 1.1
      1 /* Interface to hashtable implementations.
      2    Copyright (C) 2006-2020 Free Software Foundation, Inc.
      3 
      4    This file is part of libctf.
      5 
      6    libctf is free software; you can redistribute it and/or modify it under
      7    the terms of the GNU General Public License as published by the Free
      8    Software Foundation; either version 3, or (at your option) any later
      9    version.
     10 
     11    This program is distributed in the hope that it will be useful, but
     12    WITHOUT ANY WARRANTY; without even the implied warranty of
     13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
     14    See the GNU General Public License for more details.
     15 
     16    You should have received a copy of the GNU General Public License
     17    along with this program; see the file COPYING.  If not see
     18    <http://www.gnu.org/licenses/>.  */
     19 
     20 #include <ctf-impl.h>
     21 #include <string.h>
     22 #include "libiberty.h"
     23 #include "hashtab.h"
     24 
     25 /* We have three hashtable implementations:
     26 
     27    - ctf_hash_* is an interface to a fixed-size hash from const char * ->
     28      ctf_id_t with number of elements specified at creation time, that should
     29      support addition of items but need not support removal.
     30 
     31    - ctf_dynhash_* is an interface to a dynamically-expanding hash with
     32      unknown size that should support addition of large numbers of items, and
     33      removal as well, and is used only at type-insertion time and during
     34      linking.
     35 
     36    - ctf_dynset_* is an interface to a dynamically-expanding hash that contains
     37      only keys: no values.
     38 
     39    These can be implemented by the same underlying hashmap if you wish.  */
     40 
     41 /* The helem is used for general key/value mappings in both the ctf_hash and
     42    ctf_dynhash: the owner may not have space allocated for it, and will be
     43    garbage (not NULL!) in that case.  */
     44 
     45 typedef struct ctf_helem
     46 {
     47   void *key;			 /* Either a pointer, or a coerced ctf_id_t.  */
     48   void *value;			 /* The value (possibly a coerced int).  */
     49   ctf_dynhash_t *owner;          /* The hash that owns us.  */
     50 } ctf_helem_t;
     51 
     52 /* Equally, the key_free and value_free may not exist.  */
     53 
     54 struct ctf_dynhash
     55 {
     56   struct htab *htab;
     57   ctf_hash_free_fun key_free;
     58   ctf_hash_free_fun value_free;
     59 };
     60 
     61 /* Hash and eq functions for the dynhash and hash. */
     62 
     63 unsigned int
     64 ctf_hash_integer (const void *ptr)
     65 {
     66   ctf_helem_t *hep = (ctf_helem_t *) ptr;
     67 
     68   return htab_hash_pointer (hep->key);
     69 }
     70 
     71 int
     72 ctf_hash_eq_integer (const void *a, const void *b)
     73 {
     74   ctf_helem_t *hep_a = (ctf_helem_t *) a;
     75   ctf_helem_t *hep_b = (ctf_helem_t *) b;
     76 
     77   return htab_eq_pointer (hep_a->key, hep_b->key);
     78 }
     79 
     80 unsigned int
     81 ctf_hash_string (const void *ptr)
     82 {
     83   ctf_helem_t *hep = (ctf_helem_t *) ptr;
     84 
     85   return htab_hash_string (hep->key);
     86 }
     87 
     88 int
     89 ctf_hash_eq_string (const void *a, const void *b)
     90 {
     91   ctf_helem_t *hep_a = (ctf_helem_t *) a;
     92   ctf_helem_t *hep_b = (ctf_helem_t *) b;
     93 
     94   return !strcmp((const char *) hep_a->key, (const char *) hep_b->key);
     95 }
     96 
     97 /* Hash a type_key.  */
     98 unsigned int
     99 ctf_hash_type_key (const void *ptr)
    100 {
    101   ctf_helem_t *hep = (ctf_helem_t *) ptr;
    102   ctf_link_type_key_t *k = (ctf_link_type_key_t *) hep->key;
    103 
    104   return htab_hash_pointer (k->cltk_fp) + 59
    105     * htab_hash_pointer ((void *) (uintptr_t) k->cltk_idx);
    106 }
    107 
    108 int
    109 ctf_hash_eq_type_key (const void *a, const void *b)
    110 {
    111   ctf_helem_t *hep_a = (ctf_helem_t *) a;
    112   ctf_helem_t *hep_b = (ctf_helem_t *) b;
    113   ctf_link_type_key_t *key_a = (ctf_link_type_key_t *) hep_a->key;
    114   ctf_link_type_key_t *key_b = (ctf_link_type_key_t *) hep_b->key;
    115 
    116   return (key_a->cltk_fp == key_b->cltk_fp)
    117     && (key_a->cltk_idx == key_b->cltk_idx);
    118 }
    119 
    120 /* Hash a type_id_key.  */
    121 unsigned int
    122 ctf_hash_type_id_key (const void *ptr)
    123 {
    124   ctf_helem_t *hep = (ctf_helem_t *) ptr;
    125   ctf_type_id_key_t *k = (ctf_type_id_key_t *) hep->key;
    126 
    127   return htab_hash_pointer ((void *) (uintptr_t) k->ctii_input_num)
    128     + 59 * htab_hash_pointer ((void *) (uintptr_t) k->ctii_type);
    129 }
    130 
    131 int
    132 ctf_hash_eq_type_id_key (const void *a, const void *b)
    133 {
    134   ctf_helem_t *hep_a = (ctf_helem_t *) a;
    135   ctf_helem_t *hep_b = (ctf_helem_t *) b;
    136   ctf_type_id_key_t *key_a = (ctf_type_id_key_t *) hep_a->key;
    137   ctf_type_id_key_t *key_b = (ctf_type_id_key_t *) hep_b->key;
    138 
    139   return (key_a->ctii_input_num == key_b->ctii_input_num)
    140     && (key_a->ctii_type == key_b->ctii_type);
    141 }
    142 
    143 /* Hash and eq functions for the dynset.  Most of these can just use the
    144    underlying hashtab functions directly.   */
    145 
    146 int
    147 ctf_dynset_eq_string (const void *a, const void *b)
    148 {
    149   return !strcmp((const char *) a, (const char *) b);
    150 }
    151 
    152 /* The dynhash, used for hashes whose size is not known at creation time. */
    153 
    154 /* Free a single ctf_helem with arbitrary key/value functions.  */
    155 
    156 static void
    157 ctf_dynhash_item_free (void *item)
    158 {
    159   ctf_helem_t *helem = item;
    160 
    161   if (helem->owner->key_free && helem->key)
    162     helem->owner->key_free (helem->key);
    163   if (helem->owner->value_free && helem->value)
    164     helem->owner->value_free (helem->value);
    165   free (helem);
    166 }
    167 
    168 ctf_dynhash_t *
    169 ctf_dynhash_create (ctf_hash_fun hash_fun, ctf_hash_eq_fun eq_fun,
    170                     ctf_hash_free_fun key_free, ctf_hash_free_fun value_free)
    171 {
    172   ctf_dynhash_t *dynhash;
    173   htab_del del = ctf_dynhash_item_free;
    174 
    175   if (key_free || value_free)
    176     dynhash = malloc (sizeof (ctf_dynhash_t));
    177   else
    178     dynhash = malloc (offsetof (ctf_dynhash_t, key_free));
    179   if (!dynhash)
    180     return NULL;
    181 
    182   if (key_free == NULL && value_free == NULL)
    183     del = free;
    184 
    185   /* 7 is arbitrary and untested for now.  */
    186   if ((dynhash->htab = htab_create_alloc (7, (htab_hash) hash_fun, eq_fun,
    187 					  del, xcalloc, free)) == NULL)
    188     {
    189       free (dynhash);
    190       return NULL;
    191     }
    192 
    193   if (key_free || value_free)
    194     {
    195       dynhash->key_free = key_free;
    196       dynhash->value_free = value_free;
    197     }
    198 
    199   return dynhash;
    200 }
    201 
    202 static ctf_helem_t **
    203 ctf_hashtab_lookup (struct htab *htab, const void *key, enum insert_option insert)
    204 {
    205   ctf_helem_t tmp = { .key = (void *) key };
    206   return (ctf_helem_t **) htab_find_slot (htab, &tmp, insert);
    207 }
    208 
    209 static ctf_helem_t *
    210 ctf_hashtab_insert (struct htab *htab, void *key, void *value,
    211 		    ctf_hash_free_fun key_free,
    212 		    ctf_hash_free_fun value_free)
    213 {
    214   ctf_helem_t **slot;
    215 
    216   slot = ctf_hashtab_lookup (htab, key, INSERT);
    217 
    218   if (!slot)
    219     {
    220       errno = ENOMEM;
    221       return NULL;
    222     }
    223 
    224   if (!*slot)
    225     {
    226       /* Only spend space on the owner if we're going to use it: if there is a
    227 	 key or value freeing function.  */
    228       if (key_free || value_free)
    229 	*slot = malloc (sizeof (ctf_helem_t));
    230       else
    231 	*slot = malloc (offsetof (ctf_helem_t, owner));
    232       if (!*slot)
    233 	return NULL;
    234       (*slot)->key = key;
    235     }
    236   else
    237     {
    238       if (key_free)
    239 	  key_free (key);
    240       if (value_free)
    241 	  value_free ((*slot)->value);
    242     }
    243   (*slot)->value = value;
    244   return *slot;
    245 }
    246 
    247 int
    248 ctf_dynhash_insert (ctf_dynhash_t *hp, void *key, void *value)
    249 {
    250   ctf_helem_t *slot;
    251   ctf_hash_free_fun key_free = NULL, value_free = NULL;
    252 
    253   if (hp->htab->del_f == ctf_dynhash_item_free)
    254     {
    255       key_free = hp->key_free;
    256       value_free = hp->value_free;
    257     }
    258   slot = ctf_hashtab_insert (hp->htab, key, value,
    259 			     key_free, value_free);
    260 
    261   if (!slot)
    262     return errno;
    263 
    264   /* Keep track of the owner, so that the del function can get at the key_free
    265      and value_free functions.  Only do this if one of those functions is set:
    266      if not, the owner is not even present in the helem.  */
    267 
    268   if (key_free || value_free)
    269     slot->owner = hp;
    270 
    271   return 0;
    272 }
    273 
    274 void
    275 ctf_dynhash_remove (ctf_dynhash_t *hp, const void *key)
    276 {
    277   ctf_helem_t hep = { (void *) key, NULL, NULL };
    278   htab_remove_elt (hp->htab, &hep);
    279 }
    280 
    281 void
    282 ctf_dynhash_empty (ctf_dynhash_t *hp)
    283 {
    284   htab_empty (hp->htab);
    285 }
    286 
    287 size_t
    288 ctf_dynhash_elements (ctf_dynhash_t *hp)
    289 {
    290   return htab_elements (hp->htab);
    291 }
    292 
    293 void *
    294 ctf_dynhash_lookup (ctf_dynhash_t *hp, const void *key)
    295 {
    296   ctf_helem_t **slot;
    297 
    298   slot = ctf_hashtab_lookup (hp->htab, key, NO_INSERT);
    299 
    300   if (slot)
    301     return (*slot)->value;
    302 
    303   return NULL;
    304 }
    305 
    306 /* TRUE/FALSE return.  */
    307 int
    308 ctf_dynhash_lookup_kv (ctf_dynhash_t *hp, const void *key,
    309 		       const void **orig_key, void **value)
    310 {
    311   ctf_helem_t **slot;
    312 
    313   slot = ctf_hashtab_lookup (hp->htab, key, NO_INSERT);
    314 
    315   if (slot)
    316     {
    317       if (orig_key)
    318 	*orig_key = (*slot)->key;
    319       if (value)
    320 	*value = (*slot)->value;
    321       return 1;
    322     }
    323   return 0;
    324 }
    325 
    326 typedef struct ctf_traverse_cb_arg
    327 {
    328   ctf_hash_iter_f fun;
    329   void *arg;
    330 } ctf_traverse_cb_arg_t;
    331 
    332 static int
    333 ctf_hashtab_traverse (void **slot, void *arg_)
    334 {
    335   ctf_helem_t *helem = *((ctf_helem_t **) slot);
    336   ctf_traverse_cb_arg_t *arg = (ctf_traverse_cb_arg_t *) arg_;
    337 
    338   arg->fun (helem->key, helem->value, arg->arg);
    339   return 1;
    340 }
    341 
    342 void
    343 ctf_dynhash_iter (ctf_dynhash_t *hp, ctf_hash_iter_f fun, void *arg_)
    344 {
    345   ctf_traverse_cb_arg_t arg = { fun, arg_ };
    346   htab_traverse (hp->htab, ctf_hashtab_traverse, &arg);
    347 }
    348 
    349 typedef struct ctf_traverse_find_cb_arg
    350 {
    351   ctf_hash_iter_find_f fun;
    352   void *arg;
    353   void *found_key;
    354 } ctf_traverse_find_cb_arg_t;
    355 
    356 static int
    357 ctf_hashtab_traverse_find (void **slot, void *arg_)
    358 {
    359   ctf_helem_t *helem = *((ctf_helem_t **) slot);
    360   ctf_traverse_find_cb_arg_t *arg = (ctf_traverse_find_cb_arg_t *) arg_;
    361 
    362   if (arg->fun (helem->key, helem->value, arg->arg))
    363     {
    364       arg->found_key = helem->key;
    365       return 0;
    366     }
    367   return 1;
    368 }
    369 
    370 void *
    371 ctf_dynhash_iter_find (ctf_dynhash_t *hp, ctf_hash_iter_find_f fun, void *arg_)
    372 {
    373   ctf_traverse_find_cb_arg_t arg = { fun, arg_, NULL };
    374   htab_traverse (hp->htab, ctf_hashtab_traverse_find, &arg);
    375   return arg.found_key;
    376 }
    377 
    378 typedef struct ctf_traverse_remove_cb_arg
    379 {
    380   struct htab *htab;
    381   ctf_hash_iter_remove_f fun;
    382   void *arg;
    383 } ctf_traverse_remove_cb_arg_t;
    384 
    385 static int
    386 ctf_hashtab_traverse_remove (void **slot, void *arg_)
    387 {
    388   ctf_helem_t *helem = *((ctf_helem_t **) slot);
    389   ctf_traverse_remove_cb_arg_t *arg = (ctf_traverse_remove_cb_arg_t *) arg_;
    390 
    391   if (arg->fun (helem->key, helem->value, arg->arg))
    392     htab_clear_slot (arg->htab, slot);
    393   return 1;
    394 }
    395 
    396 void
    397 ctf_dynhash_iter_remove (ctf_dynhash_t *hp, ctf_hash_iter_remove_f fun,
    398                          void *arg_)
    399 {
    400   ctf_traverse_remove_cb_arg_t arg = { hp->htab, fun, arg_ };
    401   htab_traverse (hp->htab, ctf_hashtab_traverse_remove, &arg);
    402 }
    403 
    404 /* Traverse a dynhash in arbitrary order, in _next iterator form.
    405 
    406    Mutating the dynhash while iterating is not supported (just as it isn't for
    407    htab_traverse).
    408 
    409    Note: unusually, this returns zero on success and a *positive* value on
    410    error, because it does not take an fp, taking an error pointer would be
    411    incredibly clunky, and nearly all error-handling ends up stuffing the result
    412    of this into some sort of errno or ctf_errno, which is invariably
    413    positive.  So doing this simplifies essentially all callers.  */
    414 int
    415 ctf_dynhash_next (ctf_dynhash_t *h, ctf_next_t **it, void **key, void **value)
    416 {
    417   ctf_next_t *i = *it;
    418   ctf_helem_t *slot;
    419 
    420   if (!i)
    421     {
    422       size_t size = htab_size (h->htab);
    423 
    424       /* If the table has too many entries to fit in an ssize_t, just give up.
    425 	 This might be spurious, but if any type-related hashtable has ever been
    426 	 nearly as large as that then something very odd is going on.  */
    427       if (((ssize_t) size) < 0)
    428 	return EDOM;
    429 
    430       if ((i = ctf_next_create ()) == NULL)
    431 	return ENOMEM;
    432 
    433       i->u.ctn_hash_slot = h->htab->entries;
    434       i->cu.ctn_h = h;
    435       i->ctn_n = 0;
    436       i->ctn_size = (ssize_t) size;
    437       i->ctn_iter_fun = (void (*) (void)) ctf_dynhash_next;
    438       *it = i;
    439     }
    440 
    441   if ((void (*) (void)) ctf_dynhash_next != i->ctn_iter_fun)
    442     return ECTF_NEXT_WRONGFUN;
    443 
    444   if (h != i->cu.ctn_h)
    445     return ECTF_NEXT_WRONGFP;
    446 
    447   if ((ssize_t) i->ctn_n == i->ctn_size)
    448     goto hash_end;
    449 
    450   while ((ssize_t) i->ctn_n < i->ctn_size
    451 	 && (*i->u.ctn_hash_slot == HTAB_EMPTY_ENTRY
    452 	     || *i->u.ctn_hash_slot == HTAB_DELETED_ENTRY))
    453     {
    454       i->u.ctn_hash_slot++;
    455       i->ctn_n++;
    456     }
    457 
    458   if ((ssize_t) i->ctn_n == i->ctn_size)
    459     goto hash_end;
    460 
    461   slot = *i->u.ctn_hash_slot;
    462 
    463   if (key)
    464     *key = slot->key;
    465   if (value)
    466     *value = slot->value;
    467 
    468   i->u.ctn_hash_slot++;
    469   i->ctn_n++;
    470 
    471   return 0;
    472 
    473  hash_end:
    474   ctf_next_destroy (i);
    475   *it = NULL;
    476   return ECTF_NEXT_END;
    477 }
    478 
    479 /* Traverse a sorted dynhash, in _next iterator form.
    480 
    481    See ctf_dynhash_next for notes on error returns, etc.
    482 
    483    Sort keys before iterating over them using the SORT_FUN and SORT_ARG.
    484 
    485    If SORT_FUN is null, thunks to ctf_dynhash_next.  */
    486 int
    487 ctf_dynhash_next_sorted (ctf_dynhash_t *h, ctf_next_t **it, void **key,
    488 			 void **value, ctf_hash_sort_f sort_fun, void *sort_arg)
    489 {
    490   ctf_next_t *i = *it;
    491 
    492   if (sort_fun == NULL)
    493     return ctf_dynhash_next (h, it, key, value);
    494 
    495   if (!i)
    496     {
    497       size_t els = ctf_dynhash_elements (h);
    498       ctf_next_t *accum_i = NULL;
    499       void *key, *value;
    500       int err;
    501       ctf_next_hkv_t *walk;
    502 
    503       if (((ssize_t) els) < 0)
    504 	return EDOM;
    505 
    506       if ((i = ctf_next_create ()) == NULL)
    507 	return ENOMEM;
    508 
    509       if ((i->u.ctn_sorted_hkv = calloc (els, sizeof (ctf_next_hkv_t))) == NULL)
    510 	{
    511 	  ctf_next_destroy (i);
    512 	  return ENOMEM;
    513 	}
    514       walk = i->u.ctn_sorted_hkv;
    515 
    516       i->cu.ctn_h = h;
    517 
    518       while ((err = ctf_dynhash_next (h, &accum_i, &key, &value)) == 0)
    519 	{
    520 	  walk->hkv_key = key;
    521 	  walk->hkv_value = value;
    522 	  walk++;
    523 	}
    524       if (err != ECTF_NEXT_END)
    525 	{
    526 	  ctf_next_destroy (i);
    527 	  return err;
    528 	}
    529 
    530       if (sort_fun)
    531 	  ctf_qsort_r (i->u.ctn_sorted_hkv, els, sizeof (ctf_next_hkv_t),
    532 		       (int (*) (const void *, const void *, void *)) sort_fun,
    533 		       sort_arg);
    534       i->ctn_n = 0;
    535       i->ctn_size = (ssize_t) els;
    536       i->ctn_iter_fun = (void (*) (void)) ctf_dynhash_next_sorted;
    537       *it = i;
    538     }
    539 
    540   if ((void (*) (void)) ctf_dynhash_next_sorted != i->ctn_iter_fun)
    541     return ECTF_NEXT_WRONGFUN;
    542 
    543   if (h != i->cu.ctn_h)
    544     return ECTF_NEXT_WRONGFP;
    545 
    546   if ((ssize_t) i->ctn_n == i->ctn_size)
    547     {
    548       ctf_next_destroy (i);
    549       *it = NULL;
    550       return ECTF_NEXT_END;
    551     }
    552 
    553   if (key)
    554     *key = i->u.ctn_sorted_hkv[i->ctn_n].hkv_key;
    555   if (value)
    556     *value = i->u.ctn_sorted_hkv[i->ctn_n].hkv_value;
    557   i->ctn_n++;
    558   return 0;
    559 }
    560 
    561 void
    562 ctf_dynhash_destroy (ctf_dynhash_t *hp)
    563 {
    564   if (hp != NULL)
    565     htab_delete (hp->htab);
    566   free (hp);
    567 }
    568 
    569 /* The dynset, used for sets of keys with no value.  The implementation of this
    570    can be much simpler, because without a value the slot can simply be the
    571    stored key, which means we don't need to store the freeing functions and the
    572    dynset itself is just a htab.  */
    573 
    574 ctf_dynset_t *
    575 ctf_dynset_create (htab_hash hash_fun, htab_eq eq_fun,
    576 		   ctf_hash_free_fun key_free)
    577 {
    578   /* 7 is arbitrary and untested for now.  */
    579   return (ctf_dynset_t *) htab_create_alloc (7, (htab_hash) hash_fun, eq_fun,
    580 					     key_free, xcalloc, free);
    581 }
    582 
    583 /* The dynset has one complexity: the underlying implementation reserves two
    584    values for internal hash table implementation details (empty versus deleted
    585    entries).  These values are otherwise very useful for pointers cast to ints,
    586    so transform the ctf_dynset_inserted value to allow for it.  (This
    587    introduces an ambiguity in that one can no longer store these two values in
    588    the dynset, but if we pick high enough values this is very unlikely to be a
    589    problem.)
    590 
    591    We leak this implementation detail to the freeing functions on the grounds
    592    that any use of these functions is overwhelmingly likely to be in sets using
    593    real pointers, which will be unaffected.  */
    594 
    595 #define DYNSET_EMPTY_ENTRY_REPLACEMENT ((void *) (uintptr_t) -64)
    596 #define DYNSET_DELETED_ENTRY_REPLACEMENT ((void *) (uintptr_t) -63)
    597 
    598 static void *
    599 key_to_internal (const void *key)
    600 {
    601   if (key == HTAB_EMPTY_ENTRY)
    602     return DYNSET_EMPTY_ENTRY_REPLACEMENT;
    603   else if (key == HTAB_DELETED_ENTRY)
    604     return DYNSET_DELETED_ENTRY_REPLACEMENT;
    605 
    606   return (void *) key;
    607 }
    608 
    609 static void *
    610 internal_to_key (const void *internal)
    611 {
    612   if (internal == DYNSET_EMPTY_ENTRY_REPLACEMENT)
    613     return HTAB_EMPTY_ENTRY;
    614   else if (internal == DYNSET_DELETED_ENTRY_REPLACEMENT)
    615     return HTAB_DELETED_ENTRY;
    616   return (void *) internal;
    617 }
    618 
    619 int
    620 ctf_dynset_insert (ctf_dynset_t *hp, void *key)
    621 {
    622   struct htab *htab = (struct htab *) hp;
    623   void **slot;
    624 
    625   slot = htab_find_slot (htab, key, INSERT);
    626 
    627   if (!slot)
    628     {
    629       errno = ENOMEM;
    630       return -errno;
    631     }
    632 
    633   if (*slot)
    634     {
    635       if (htab->del_f)
    636 	(*htab->del_f) (*slot);
    637     }
    638 
    639   *slot = key_to_internal (key);
    640 
    641   return 0;
    642 }
    643 
    644 void
    645 ctf_dynset_remove (ctf_dynset_t *hp, const void *key)
    646 {
    647   htab_remove_elt ((struct htab *) hp, key_to_internal (key));
    648 }
    649 
    650 void
    651 ctf_dynset_destroy (ctf_dynset_t *hp)
    652 {
    653   if (hp != NULL)
    654     htab_delete ((struct htab *) hp);
    655 }
    656 
    657 void *
    658 ctf_dynset_lookup (ctf_dynset_t *hp, const void *key)
    659 {
    660   void **slot = htab_find_slot ((struct htab *) hp,
    661 				key_to_internal (key), NO_INSERT);
    662 
    663   if (slot)
    664     return internal_to_key (*slot);
    665   return NULL;
    666 }
    667 
    668 /* TRUE/FALSE return.  */
    669 int
    670 ctf_dynset_exists (ctf_dynset_t *hp, const void *key, const void **orig_key)
    671 {
    672   void **slot = htab_find_slot ((struct htab *) hp,
    673 				key_to_internal (key), NO_INSERT);
    674 
    675   if (orig_key && slot)
    676     *orig_key = internal_to_key (*slot);
    677   return (slot != NULL);
    678 }
    679 
    680 /* Look up a completely random value from the set, if any exist.
    681    Keys with value zero cannot be distinguished from a nonexistent key.  */
    682 void *
    683 ctf_dynset_lookup_any (ctf_dynset_t *hp)
    684 {
    685   struct htab *htab = (struct htab *) hp;
    686   void **slot = htab->entries;
    687   void **limit = slot + htab_size (htab);
    688 
    689   while (slot < limit
    690 	 && (*slot == HTAB_EMPTY_ENTRY || *slot == HTAB_DELETED_ENTRY))
    691       slot++;
    692 
    693   if (slot < limit)
    694     return internal_to_key (*slot);
    695   return NULL;
    696 }
    697 
    698 /* Traverse a dynset in arbitrary order, in _next iterator form.
    699 
    700    Otherwise, just like ctf_dynhash_next.  */
    701 int
    702 ctf_dynset_next (ctf_dynset_t *hp, ctf_next_t **it, void **key)
    703 {
    704   struct htab *htab = (struct htab *) hp;
    705   ctf_next_t *i = *it;
    706   void *slot;
    707 
    708   if (!i)
    709     {
    710       size_t size = htab_size (htab);
    711 
    712       /* If the table has too many entries to fit in an ssize_t, just give up.
    713 	 This might be spurious, but if any type-related hashtable has ever been
    714 	 nearly as large as that then somthing very odd is going on.  */
    715 
    716       if (((ssize_t) size) < 0)
    717 	return EDOM;
    718 
    719       if ((i = ctf_next_create ()) == NULL)
    720 	return ENOMEM;
    721 
    722       i->u.ctn_hash_slot = htab->entries;
    723       i->cu.ctn_s = hp;
    724       i->ctn_n = 0;
    725       i->ctn_size = (ssize_t) size;
    726       i->ctn_iter_fun = (void (*) (void)) ctf_dynset_next;
    727       *it = i;
    728     }
    729 
    730   if ((void (*) (void)) ctf_dynset_next != i->ctn_iter_fun)
    731     return ECTF_NEXT_WRONGFUN;
    732 
    733   if (hp != i->cu.ctn_s)
    734     return ECTF_NEXT_WRONGFP;
    735 
    736   if ((ssize_t) i->ctn_n == i->ctn_size)
    737     goto set_end;
    738 
    739   while ((ssize_t) i->ctn_n < i->ctn_size
    740 	 && (*i->u.ctn_hash_slot == HTAB_EMPTY_ENTRY
    741 	     || *i->u.ctn_hash_slot == HTAB_DELETED_ENTRY))
    742     {
    743       i->u.ctn_hash_slot++;
    744       i->ctn_n++;
    745     }
    746 
    747   if ((ssize_t) i->ctn_n == i->ctn_size)
    748     goto set_end;
    749 
    750   slot = *i->u.ctn_hash_slot;
    751 
    752   if (key)
    753     *key = internal_to_key (slot);
    754 
    755   i->u.ctn_hash_slot++;
    756   i->ctn_n++;
    757 
    758   return 0;
    759 
    760  set_end:
    761   ctf_next_destroy (i);
    762   *it = NULL;
    763   return ECTF_NEXT_END;
    764 }
    765 
    766 /* ctf_hash, used for fixed-size maps from const char * -> ctf_id_t without
    767    removal.  This is a straight cast of a hashtab.  */
    768 
    769 ctf_hash_t *
    770 ctf_hash_create (unsigned long nelems, ctf_hash_fun hash_fun,
    771 		 ctf_hash_eq_fun eq_fun)
    772 {
    773   return (ctf_hash_t *) htab_create_alloc (nelems, (htab_hash) hash_fun,
    774 					   eq_fun, free, xcalloc, free);
    775 }
    776 
    777 uint32_t
    778 ctf_hash_size (const ctf_hash_t *hp)
    779 {
    780   return htab_elements ((struct htab *) hp);
    781 }
    782 
    783 int
    784 ctf_hash_insert_type (ctf_hash_t *hp, ctf_file_t *fp, uint32_t type,
    785 		      uint32_t name)
    786 {
    787   const char *str = ctf_strraw (fp, name);
    788 
    789   if (type == 0)
    790     return EINVAL;
    791 
    792   if (str == NULL
    793       && CTF_NAME_STID (name) == CTF_STRTAB_1
    794       && fp->ctf_syn_ext_strtab == NULL
    795       && fp->ctf_str[CTF_NAME_STID (name)].cts_strs == NULL)
    796     return ECTF_STRTAB;
    797 
    798   if (str == NULL)
    799     return ECTF_BADNAME;
    800 
    801   if (str[0] == '\0')
    802     return 0;		   /* Just ignore empty strings on behalf of caller.  */
    803 
    804   if (ctf_hashtab_insert ((struct htab *) hp, (char *) str,
    805 			  (void *) (ptrdiff_t) type, NULL, NULL) != NULL)
    806     return 0;
    807   return errno;
    808 }
    809 
    810 /* if the key is already in the hash, override the previous definition with
    811    this new official definition. If the key is not present, then call
    812    ctf_hash_insert_type and hash it in.  */
    813 int
    814 ctf_hash_define_type (ctf_hash_t *hp, ctf_file_t *fp, uint32_t type,
    815                       uint32_t name)
    816 {
    817   /* This matches the semantics of ctf_hash_insert_type in this
    818      implementation anyway.  */
    819 
    820   return ctf_hash_insert_type (hp, fp, type, name);
    821 }
    822 
    823 ctf_id_t
    824 ctf_hash_lookup_type (ctf_hash_t *hp, ctf_file_t *fp __attribute__ ((__unused__)),
    825 		      const char *key)
    826 {
    827   ctf_helem_t **slot;
    828 
    829   slot = ctf_hashtab_lookup ((struct htab *) hp, key, NO_INSERT);
    830 
    831   if (slot)
    832     return (ctf_id_t) (uintptr_t) ((*slot)->value);
    833 
    834   return 0;
    835 }
    836 
    837 void
    838 ctf_hash_destroy (ctf_hash_t *hp)
    839 {
    840   if (hp != NULL)
    841     htab_delete ((struct htab *) hp);
    842 }
    843