gas/hash.h

   1 /* hash.h -- header file for gas hash table routines
   2    Copyright (C) 1987-2020 Free Software Foundation, Inc.
   3
   4    This file is part of GAS, the GNU Assembler.
   5
   6    GAS is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3, or (at your option)
   9    any later version.
  10
  11    GAS is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with GAS; see the file COPYING.  If not, write to the Free
  18    Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA
  19    02110-1301, USA.  */
  20
  21 #ifndef HASH_H
  22 #define HASH_H
  23
  24 /* Insert ELEMENT into HTAB.  If REPLACE is non-zero existing elements
  25    are overwritten.  If ELEMENT already exists, a pointer to the slot
  26    is returned.  Otherwise NULL is returned.  */
  27
  28 extern void **htab_insert (htab_t, void * /* element */, int /* replace */);
  29
  30 /* Print statistics about a hash table.  */
  31
  32 extern void htab_print_statistics (FILE *f, const char *name, htab_t table);
  33
  34 /* String hash table functions.  */
  35
  36 struct string_tuple
  37 {
  38   const char *key;
  39   const void *value;
  40 };
  41
  42 typedef struct string_tuple string_tuple_t;
  43
  44 /* Hash function for a string_tuple.  */
  45
  46 static hashval_t
  47 hash_string_tuple (const void *e)
  48 {
  49   string_tuple_t *tuple = (string_tuple_t *) e;
  50   return htab_hash_string (tuple->key);
  51 }
  52
  53 /* Equality function for a string_tuple.  */
  54
  55 static int
  56 eq_string_tuple (const void *a, const void *b)
  57 {
  58   const string_tuple_t *ea = (const string_tuple_t *) a;
  59   const string_tuple_t *eb = (const string_tuple_t *) b;
  60
  61   return strcmp (ea->key, eb->key) == 0;
  62 }
  63
  64 static inline string_tuple_t *
  65 string_tuple_alloc (const char *key, const void *value)
  66 {
  67   string_tuple_t *tuple = XNEW (string_tuple_t);
  68   tuple->key = key;
  69   tuple->value = value;
  70   return tuple;
  71 }
  72
  73 static inline void *
  74 str_hash_find (htab_t table, const char *key)
  75 {
  76   string_tuple_t needle = { key, NULL };
  77   string_tuple_t *tuple = htab_find (table, &needle);
  78   return tuple != NULL ? (void *) tuple->value : NULL;
  79 }
  80
  81 static inline void *
  82 str_hash_find_n (htab_t table, const char *key, size_t n)
  83 {
  84   char *tmp = XNEWVEC (char, n + 1);
  85   memcpy (tmp, key, n);
  86   tmp[n] = '\0';
  87   string_tuple_t needle = { tmp, NULL };
  88   string_tuple_t *tuple = htab_find (table, &needle);
  89   free (tmp);
  90   return tuple != NULL ? (void *) tuple->value : NULL;
  91 }
  92
  93 static inline void
  94 str_hash_delete (htab_t table, const char *key)
  95 {
  96   string_tuple_t needle = { key, NULL };
  97   htab_remove_elt (table, &needle);
  98 }
  99
 100 static inline void **
 101 str_hash_insert (htab_t table, const char *key, const void *value, int replace)
 102 {
 103   string_tuple_t *elt = string_tuple_alloc (key, value);
 104   void **slot = htab_insert (table, elt, replace);
 105   if (slot && !replace)
 106     free (elt);
 107   return slot;
 108 }
 109
 110 static inline htab_t
 111 str_htab_create (void)
 112 {
 113   return htab_create_alloc (16, hash_string_tuple, eq_string_tuple,
 114                             NULL, xcalloc, free);
 115 }
 116
 117 #endif /* HASH_H */