src/uniqstr.c

   1 /* Keep a unique copy of strings.
   2
   3    Copyright (C) 2002-2005, 2009-2015, 2018-2021 Free Software
   4    Foundation, Inc.
   5
   6    This file is part of Bison, the GNU Compiler Compiler.
   7
   8    This program is free software: you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation, either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  20
  21 #include <config.h>
  22 #include "system.h"
  23
  24 #include <attribute.h>
  25 #include <error.h>
  26 #include <hash.h>
  27 #include <quotearg.h>
  28 #include <stdarg.h>
  29
  30 #include "uniqstr.h"
  31
  32 /*-----------------------.
  33 | A uniqstr hash table.  |
  34 `-----------------------*/
  35
  36 /* Initial capacity of uniqstr hash table.  */
  37 #define HT_INITIAL_CAPACITY 257
  38
  39 static struct hash_table *uniqstrs_table = NULL;
  40
  41 /*-------------------------------------.
  42 | Create the uniqstr for S if needed.  |
  43 `-------------------------------------*/
  44
  45 uniqstr
  46 uniqstr_new (char const *str)
  47 {
  48   uniqstr res = hash_lookup (uniqstrs_table, str);
  49   if (!res)
  50     {
  51       /* First insertion in the hash. */
  52       res = xstrdup (str);
  53       hash_xinsert (uniqstrs_table, res);
  54     }
  55   return res;
  56 }
  57
  58 uniqstr
  59 uniqstr_concat (int nargs, ...)
  60 {
  61   va_list args;
  62
  63   va_start (args, nargs);
  64   size_t reslen = 0;
  65   for (int i = 0; i < nargs; i++)
  66     reslen += strlen (va_arg (args, char const *));
  67   va_end (args);
  68
  69   char *str = xmalloc (reslen + 1);
  70   char *p = str;
  71
  72   va_start (args, nargs);
  73   for (int i = 0; i < nargs; i++)
  74     {
  75       char const *arg = va_arg (args, char const *);
  76       size_t arglen = strlen (arg);
  77       memcpy (p, arg, arglen);
  78       p += arglen;
  79     }
  80   va_end (args);
  81
  82   *p = '\0';
  83   uniqstr res = hash_xinsert (uniqstrs_table, str);
  84   if (res != str)
  85     free (str);
  86   return res;
  87 }
  88
  89 /*------------------------------.
  90 | Abort if S is not a uniqstr.  |
  91 `------------------------------*/
  92
  93 void
  94 uniqstr_assert (char const *str)
  95 {
  96   uniqstr s = hash_lookup (uniqstrs_table, str);
  97   if (!s || s != str)
  98     {
  99       error (0, 0,
 100              "not a uniqstr: %s", quotearg (str));
 101       abort ();
 102     }
 103 }
 104
 105
 106 /*--------------------.
 107 | Print the uniqstr.  |
 108 `--------------------*/
 109
 110 static inline bool
 111 uniqstr_print (uniqstr ustr)
 112 {
 113   fprintf (stderr, "%s\n", ustr);
 114   return true;
 115 }
 116
 117 static bool
 118 uniqstr_print_processor (void *ustr, void *null MAYBE_UNUSED)
 119 {
 120   return uniqstr_print (ustr);
 121 }
 122
 123 int
 124 uniqstr_cmp (uniqstr l, uniqstr r)
 125 {
 126   return (l == r ? 0
 127           : !l ? -1
 128           : !r ? +1
 129           : strcmp (l, r));
 130 }
 131
 132
 133 /*-----------------------.
 134 | A uniqstr hash table.  |
 135 `-----------------------*/
 136
 137 static bool
 138 hash_compare_uniqstr (void const *m1, void const *m2)
 139 {
 140   return STREQ (m1, m2);
 141 }
 142
 143 static size_t
 144 hash_uniqstr (void const *m, size_t tablesize)
 145 {
 146   return hash_string (m, tablesize);
 147 }
 148
 149
 150 /*----------------------------.
 151 | Create the uniqstrs table.  |
 152 `----------------------------*/
 153
 154 void
 155 uniqstrs_new (void)
 156 {
 157   uniqstrs_table = hash_xinitialize (HT_INITIAL_CAPACITY,
 158                                      NULL,
 159                                      hash_uniqstr,
 160                                      hash_compare_uniqstr,
 161                                      free);
 162 }
 163
 164
 165 /*-------------------------------------.
 166 | Perform a task on all the uniqstrs.  |
 167 `-------------------------------------*/
 168
 169 static void
 170 uniqstrs_do (Hash_processor processor, void *processor_data)
 171 {
 172   hash_do_for_each (uniqstrs_table, processor, processor_data);
 173 }
 174
 175
 176 /*-----------------.
 177 | Print them all.  |
 178 `-----------------*/
 179
 180 void
 181 uniqstrs_print (void)
 182 {
 183   uniqstrs_do (uniqstr_print_processor, NULL);
 184 }
 185
 186
 187 /*--------------------.
 188 | Free the uniqstrs.  |
 189 `--------------------*/
 190
 191 void
 192 uniqstrs_free (void)
 193 {
 194   hash_free (uniqstrs_table);
 195 }