mcs/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 static int
  54 hash (const char *name)
  55 {
  56     const char *s;
  57     register int c, k;
  58
  59     assert(name && *name);
  60     s = name;
  61     k = *s;
  62     while ((c = *++s))
  63         k = (31*k + c) & (TABLE_SIZE - 1);
  64
  65     return (k);
  66 }
  67
  68 bucket *
  69 make_bucket (const char *name)
  70 {
  71     register bucket *bp;
  72
  73     assert(name);
  74     bp = (bucket *) MALLOC(sizeof(bucket));
  75     if (bp == 0) no_space();
  76     bp->link = 0;
  77     bp->next = 0;
  78     bp->name = (char*)MALLOC(strlen(name) + 1);
  79     if (bp->name == 0) no_space();
  80     bp->tag = 0;
  81     bp->value = UNDEFINED;
  82     bp->index = 0;
  83     bp->prec = 0;
  84     bp-> class = UNKNOWN;
  85     bp->assoc = TOKEN;
  86
  87     if (bp->name == 0) no_space();
  88     strcpy(bp->name, name);
  89
  90     return (bp);
  91 }
  92
  93 bucket *
  94 lookup (const char *name)
  95 {
  96     register bucket *bp, **bpp;
  97
  98     bpp = symbol_table + hash(name);
  99     bp = *bpp;
 100
 101     while (bp)
 102     {
 103         if (strcmp(name, bp->name) == 0) return (bp);
 104         bpp = &bp->link;
 105         bp = *bpp;
 106     }
 107
 108     *bpp = bp = make_bucket(name);
 109     last_symbol->next = bp;
 110     last_symbol = bp;
 111
 112     return (bp);
 113 }
 114
 115 void
 116 create_symbol_table (void)
 117 {
 118     register int i;
 119     register bucket *bp;
 120
 121     symbol_table = (bucket **) MALLOC(TABLE_SIZE*sizeof(bucket *));
 122     if (symbol_table == 0) no_space();
 123     for (i = 0; i < TABLE_SIZE; i++)
 124         symbol_table[i] = 0;
 125
 126     bp = make_bucket("error");
 127     bp->index = 1;
 128     bp->class = TERM;
 129
 130     first_symbol = bp;
 131     last_symbol = bp;
 132     symbol_table[hash("error")] = bp;
 133 }
 134
 135 void
 136 free_symbol_table (void)
 137 {
 138     FREE(symbol_table);
 139     symbol_table = 0;
 140 }
 141
 142 void
 143 free_symbols (void)
 144 {
 145     register bucket *p, *q;
 146
 147     for (p = first_symbol; p; p = q)
 148     {
 149         q = p->next;
 150         FREE(p);
 151     }
 152 }