jay/symtab.c

   1 /*
   2  * Copyright (c) 1989 The Regents of the University of California.
   3  * All rights reserved.
   4  *
   5  * This code is derived from software contributed to Berkeley by
   6  * Robert Paul Corbett.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. All advertising materials mentioning features or use of this software
  17  *    must display the following acknowledgement:
  18  *      This product includes software developed by the University of
  19  *      California, Berkeley and its contributors.
  20  * 4. Neither the name of the University nor the names of its contributors
  21  *    may be used to endorse or promote products derived from this software
  22  *    without specific prior written permission.
  23  *
  24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  34  * SUCH DAMAGE.
  35  */
  36
  37 #ifndef lint
  38 static char sccsid[] = "@(#)symtab.c    5.3 (Berkeley) 6/1/90";
  39 #endif /* not lint */
  40
  41 #include "defs.h"
  42
  43 /* TABLE_SIZE is the number of entries in the symbol table. */
  44 /* TABLE_SIZE must be a power of two.                       */
  45
  46 #define TABLE_SIZE 1024
  47
  48
  49 bucket **symbol_table;
  50 bucket *first_symbol;
  51 bucket *last_symbol;
  52
  53
  54 int
  55 hash(name)
  56 char *name;
  57 {
  58     register char *s;
  59     register int c, k;
  60
  61     assert(name && *name);
  62     s = name;
  63     k = *s;
  64     while (c = *++s)
  65         k = (31*k + c) & (TABLE_SIZE - 1);
  66
  67     return (k);
  68 }
  69
  70
  71 bucket *
  72 make_bucket(name)
  73 char *name;
  74 {
  75     register bucket *bp;
  76
  77     assert(name);
  78     bp = (bucket *) MALLOC(sizeof(bucket));
  79     if (bp == 0) no_space();
  80     bp->link = 0;
  81     bp->next = 0;
  82     bp->name = MALLOC(strlen(name) + 1);
  83     if (bp->name == 0) no_space();
  84     bp->tag = 0;
  85     bp->value = UNDEFINED;
  86     bp->index = 0;
  87     bp->prec = 0;
  88     bp-> class = UNKNOWN;
  89     bp->assoc = TOKEN;
  90
  91     if (bp->name == 0) no_space();
  92     strcpy(bp->name, name);
  93
  94     return (bp);
  95 }
  96
  97
  98 bucket *
  99 lookup(name)
 100 char *name;
 101 {
 102     register bucket *bp, **bpp;
 103
 104     bpp = symbol_table + hash(name);
 105     bp = *bpp;
 106
 107     while (bp)
 108     {
 109         if (strcmp(name, bp->name) == 0) return (bp);
 110         bpp = &bp->link;
 111         bp = *bpp;
 112     }
 113
 114     *bpp = bp = make_bucket(name);
 115     last_symbol->next = bp;
 116     last_symbol = bp;
 117
 118     return (bp);
 119 }
 120
 121
 122 create_symbol_table()
 123 {
 124     register int i;
 125     register bucket *bp;
 126
 127     symbol_table = (bucket **) MALLOC(TABLE_SIZE*sizeof(bucket *));
 128     if (symbol_table == 0) no_space();
 129     for (i = 0; i < TABLE_SIZE; i++)
 130         symbol_table[i] = 0;
 131
 132     bp = make_bucket("error");
 133     bp->index = 1;
 134     bp->class = TERM;
 135
 136     first_symbol = bp;
 137     last_symbol = bp;
 138     symbol_table[hash("error")] = bp;
 139 }
 140
 141
 142 free_symbol_table()
 143 {
 144     FREE(symbol_table);
 145     symbol_table = 0;
 146 }
 147
 148
 149 free_symbols()
 150 {
 151     register bucket *p, *q;
 152
 153     for (p = first_symbol; p; p = q)
 154     {
 155         q = p->next;
 156         FREE(p);
 157     }
 158 }