src/mapping.c

   1 /*
   2 ** Splint - annotation-assisted static program checker
   3 ** Copyright (C) 1994-2003 University of Virginia,
   4 **         Massachusetts Institute of Technology
   5 **
   6 ** This program is free software; you can redistribute it and/or modify it
   7 ** under the terms of the GNU General Public License as published by the
   8 ** Free Software Foundation; either version 2 of the License, or (at your
   9 ** option) any later version.
  10 **
  11 ** This program is distributed in the hope that it will be useful, but
  12 ** WITHOUT ANY WARRANTY; without even the implied warranty of
  13 ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 ** General Public License for more details.
  15 **
  16 ** The GNU General Public License is available from http://www.gnu.org/ or
  17 ** the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
  18 ** MA 02111-1307, USA.
  19 **
  20 ** For information on splint: info@splint.org
  21 ** To report a bug: splint-bug@splint.org
  22 ** For more information: http://www.splint.org
  23 */
  24 /*
  25 ** mapping.c
  26 **
  27 ** Module for lsymbol maps.
  28 **
  29 **  AUTHOR:
  30 **      Yang Meng Tan,
  31 **         Massachusetts Institute of Technology
  32 */
  33
  34 # include "splintMacros.nf"
  35 # include "basic.h"
  36
  37 /*@constant int MAPPING_SIZE; @*/
  38 # define MAPPING_SIZE 127
  39
  40 /* use lower-order bits by masking out higher order bits */
  41
  42 /*@-macrofcndecl@*/
  43 # define MMASH(key)  ((unsigned int) ((key) & MAPPING_SIZE))
  44 /*@=macrofcndecl@*/
  45
  46 static void mappair_free (/*@null@*/ /*@only@*/ mappair *p)
  47 {
  48   if (p == NULL)
  49     {
  50       return;
  51     }
  52   else
  53     {
  54       mappair_free (p->next);
  55       sfree (p);
  56     }
  57 }
  58
  59 void mapping_free (/*@only@*/ mapping m)
  60 {
  61   int i;
  62
  63   for (i = 0; i <= MAPPING_SIZE; i++)
  64     {
  65       mappair_free (m->buckets[i]);
  66     }
  67
  68   sfree (m->buckets);
  69   sfree (m);
  70 }
  71
  72 /*@only@*/ mapping
  73 mapping_create (void)
  74 {
  75   int i;
  76   mapping t = (mapping) dmalloc (sizeof (*t));
  77
  78   t->buckets = (mappair **) dmalloc ((MAPPING_SIZE + 1) * sizeof (*t->buckets));
  79   t->count = 0;
  80
  81   for (i = 0; i <= MAPPING_SIZE; i++)
  82     {
  83       t->buckets[i] = (mappair *) 0;
  84     }
  85
  86   return t;
  87 }
  88
  89 lsymbol
  90 mapping_find (mapping t, lsymbol domain)
  91 {
  92   mappair *entry;
  93   unsigned int key;
  94
  95   key = MMASH (domain);
  96   entry = t->buckets[key];
  97   for (; entry != NULL; entry = entry->next)
  98     {
  99       if (entry->domain == domain)
 100         return entry->range;
 101     }
 102
 103   return lsymbol_undefined;
 104 }
 105
 106 void
 107 mapping_bind (mapping t, lsymbol domain, lsymbol range)
 108 {
 109   /* add the binding (domain -> range) to t */
 110   /* can assume that the binding is a new one in m, so no need
 111      to check. */
 112   mappair *entry;
 113   mappair *newentry = (mappair *) dmalloc (sizeof (*newentry));
 114   unsigned int key;
 115
 116   key = MMASH (domain);
 117   /*@-deparrays@*/ entry = t->buckets[key]; /*@=deparrays@*/
 118   newentry->domain = domain;
 119   newentry->range = range;
 120   newentry->next = entry;
 121
 122   t->buckets[key] = newentry;
 123   t->count++;
 124 }