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 | Return TRUE iff S is a struniq.  |
  56 `---------------------------------*/
  57
  58 bool
  59 struniq_assert_p (const char *s)
  60 {
  61   if (!hash_lookup (struniqs_table, s))
  62     {
  63       error (0, 0, "not a struniq: %s", quotearg (s));
  64       return false;
  65     }
  66   else
  67     {
  68       return true;
  69     }
  70 }
  71
  72
  73 /*--------------------.
  74 | Print the struniq.  |
  75 `--------------------*/
  76
  77 static bool
  78 struniq_print (const struniq_t s)
  79 {
  80   fprintf (stderr, "%s\n", s);
  81   return true;
  82 }
  83
  84 \f
  85 /*-----------------------.
  86 | A struniq hash table.  |
  87 `-----------------------*/
  88
  89 static bool
  90 hash_compare_struniq_t (const struniq_t m1, const struniq_t m2)
  91 {
  92   return strcmp (m1, m2) == 0;
  93 }
  94
  95 static unsigned int
  96 hash_struniq_t (const struniq_t m, unsigned int tablesize)
  97 {
  98   return hash_string (m, tablesize);
  99 }
 100
 101 /* A function to apply to each symbol. */
 102 typedef bool (*struniq_processor_t) (const struniq_t);
 103
 104 /*----------------------------.
 105 | Create the struniqs table.  |
 106 `----------------------------*/
 107
 108 void
 109 struniqs_new (void)
 110 {
 111   struniqs_table = hash_initialize (HT_INITIAL_CAPACITY,
 112                                     NULL,
 113                                     (Hash_hasher) hash_struniq_t,
 114                                     (Hash_comparator) hash_compare_struniq_t,
 115                                     (Hash_data_freer) free);
 116 }
 117
 118
 119 /*-------------------------------------.
 120 | Perform a task on all the struniqs.  |
 121 `-------------------------------------*/
 122
 123 static void
 124 struniqs_do (struniq_processor_t processor, void *processor_data)
 125 {
 126   hash_do_for_each (struniqs_table,
 127                     (Hash_processor) processor,
 128                     processor_data);
 129 }
 130
 131
 132 /*-----------------.
 133 | Print them all.  |
 134 `-----------------*/
 135
 136 void
 137 struniqs_print (void)
 138 {
 139   struniqs_do (struniq_print, NULL);
 140 }
 141
 142
 143 /*--------------------.
 144 | Free the struniqs.  |
 145 `--------------------*/
 146
 147 void
 148 struniqs_free (void)
 149 {
 150   hash_free (struniqs_table);
 151 }