src/struniq.c

   1 /* Keeping a unique copy of strings.
   2    Copyright (C) 2002 Free Software Foundation, Inc.
   3
   4    This file is part of Bison, the GNU Compiler Compiler.
   5
   6    Bison 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 2, or (at your option)
   9    any later version.
  10
  11    Bison 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 Bison; see the file COPYING.  If not, write to
  18    the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  19    Boston, MA 02111-1307, USA.  */
  20
  21 #include "system.h"
  22 #include "quotearg.h"
  23 #include "error.h"
  24 #include "hash.h"
  25 #include "struniq.h"
  26
  27 /*-----------------------.
  28 | A struniq hash table.  |
  29 `-----------------------*/
  30
  31 /* Initial capacity of struniq hash table.  */
  32 #define HT_INITIAL_CAPACITY 257
  33
  34 static struct hash_table *struniqs_table = NULL;
  35
  36 /*-------------------------------------.
  37 | Create the struniq for S if needed.  |
  38 `-------------------------------------*/
  39
  40 struniq_t
  41 struniq_new (const char *s)
  42 {
  43   struniq_t res = hash_lookup (struniqs_table, s);
  44   if (!res)
  45     {
  46       /* First insertion in the hash. */
  47       res = xstrdup (s);
  48       hash_insert (struniqs_table, res);
  49     }
  50   return res;
  51 }
  52
  53
  54 /*------------------------------.
  55 | Abort if S is not a struniq.  |
  56 `------------------------------*/
  57
  58 void
  59 struniq_assert (const char *s)
  60 {
  61   if (!hash_lookup (struniqs_table, s))
  62     {
  63       error (0, 0, "not a struniq: %s", quotearg (s));
  64       abort ();
  65     }
  66 }
  67
  68
  69 /*--------------------.
  70 | Print the struniq.  |
  71 `--------------------*/
  72
  73 static bool
  74 struniq_print (const struniq_t s)
  75 {
  76   fprintf (stderr, "%s\n", s);
  77   return true;
  78 }
  79
  80 \f
  81 /*-----------------------.
  82 | A struniq hash table.  |
  83 `-----------------------*/
  84
  85 static bool
  86 hash_compare_struniq_t (const struniq_t m1, const struniq_t m2)
  87 {
  88   return strcmp (m1, m2) == 0;
  89 }
  90
  91 static unsigned int
  92 hash_struniq_t (const struniq_t m, unsigned int tablesize)
  93 {
  94   return hash_string (m, tablesize);
  95 }
  96
  97 /* A function to apply to each symbol. */
  98 typedef bool (*struniq_processor_t) (const struniq_t);
  99
 100 /*----------------------------.
 101 | Create the struniqs table.  |
 102 `----------------------------*/
 103
 104 void
 105 struniqs_new (void)
 106 {
 107   struniqs_table = hash_initialize (HT_INITIAL_CAPACITY,
 108                                     NULL,
 109                                     (Hash_hasher) hash_struniq_t,
 110                                     (Hash_comparator) hash_compare_struniq_t,
 111                                     (Hash_data_freer) free);
 112 }
 113
 114
 115 /*-------------------------------------.
 116 | Perform a task on all the struniqs.  |
 117 `-------------------------------------*/
 118
 119 static void
 120 struniqs_do (struniq_processor_t processor, void *processor_data)
 121 {
 122   hash_do_for_each (struniqs_table,
 123                     (Hash_processor) processor,
 124                     processor_data);
 125 }
 126
 127
 128 /*-----------------.
 129 | Print them all.  |
 130 `-----------------*/
 131
 132 void
 133 struniqs_print (void)
 134 {
 135   struniqs_do (struniq_print, NULL);
 136 }
 137
 138
 139 /*--------------------.
 140 | Free the struniqs.  |
 141 `--------------------*/
 142
 143 void
 144 struniqs_free (void)
 145 {
 146   hash_free (struniqs_table);
 147 }