src/uniqstr.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
  23 #include <error.h>
  24 #include <hash.h>
  25 #include <quotearg.h>
  26
  27 #include "uniqstr.h"
  28
  29 /*-----------------------.
  30 | A uniqstr hash table.  |
  31 `-----------------------*/
  32
  33 /* Initial capacity of uniqstr hash table.  */
  34 #define HT_INITIAL_CAPACITY 257
  35
  36 static struct hash_table *uniqstrs_table = NULL;
  37
  38 /*-------------------------------------.
  39 | Create the uniqstr for S if needed.  |
  40 `-------------------------------------*/
  41
  42 uniqstr
  43 uniqstr_new (const char *s)
  44 {
  45   uniqstr res = hash_lookup (uniqstrs_table, s);
  46   if (!res)
  47     {
  48       /* First insertion in the hash. */
  49       res = xstrdup (s);
  50       hash_insert (uniqstrs_table, res);
  51     }
  52   return res;
  53 }
  54
  55
  56 /*------------------------------.
  57 | Abort if S is not a uniqstr.  |
  58 `------------------------------*/
  59
  60 void
  61 uniqstr_assert (const char *s)
  62 {
  63   if (!hash_lookup (uniqstrs_table, s))
  64     {
  65       error (0, 0, "not a uniqstr: %s", quotearg (s));
  66       abort ();
  67     }
  68 }
  69
  70
  71 /*--------------------.
  72 | Print the uniqstr.  |
  73 `--------------------*/
  74
  75 static bool
  76 uniqstr_print (const uniqstr s)
  77 {
  78   fprintf (stderr, "%s\n", s);
  79   return true;
  80 }
  81
  82 \f
  83 /*-----------------------.
  84 | A uniqstr hash table.  |
  85 `-----------------------*/
  86
  87 static bool
  88 hash_compare_uniqstr (const uniqstr m1, const uniqstr m2)
  89 {
  90   return strcmp (m1, m2) == 0;
  91 }
  92
  93 static unsigned int
  94 hash_uniqstr (const uniqstr m, unsigned int tablesize)
  95 {
  96   return hash_string (m, tablesize);
  97 }
  98
  99 /* A function to apply to each symbol. */
 100 typedef bool (*uniqstr_processor) (const uniqstr);
 101
 102 /*----------------------------.
 103 | Create the uniqstrs table.  |
 104 `----------------------------*/
 105
 106 void
 107 uniqstrs_new (void)
 108 {
 109   uniqstrs_table = hash_initialize (HT_INITIAL_CAPACITY,
 110                                     NULL,
 111                                     (Hash_hasher) hash_uniqstr,
 112                                     (Hash_comparator) hash_compare_uniqstr,
 113                                     (Hash_data_freer) free);
 114 }
 115
 116
 117 /*-------------------------------------.
 118 | Perform a task on all the uniqstrs.  |
 119 `-------------------------------------*/
 120
 121 static void
 122 uniqstrs_do (uniqstr_processor processor, void *processor_data)
 123 {
 124   hash_do_for_each (uniqstrs_table,
 125                     (Hash_processor) processor,
 126                     processor_data);
 127 }
 128
 129
 130 /*-----------------.
 131 | Print them all.  |
 132 `-----------------*/
 133
 134 void
 135 uniqstrs_print (void)
 136 {
 137   uniqstrs_do (uniqstr_print, NULL);
 138 }
 139
 140
 141 /*--------------------.
 142 | Free the uniqstrs.  |
 143 `--------------------*/
 144
 145 void
 146 uniqstrs_free (void)
 147 {
 148   hash_free (uniqstrs_table);
 149 }