fatbase

portable OpenBSD tools
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symtab.c (3327B)


      1 /* $OpenBSD: symtab.c,v 1.17 2014/03/13 00:56:39 tedu Exp $	 */
      2 /* $NetBSD: symtab.c,v 1.4 1996/03/19 03:21:48 jtc Exp $	 */
      3 
      4 /*
      5  * Copyright (c) 1989 The Regents of the University of California.
      6  * All rights reserved.
      7  *
      8  * This code is derived from software contributed to Berkeley by
      9  * Robert Paul Corbett.
     10  *
     11  * Redistribution and use in source and binary forms, with or without
     12  * modification, are permitted provided that the following conditions
     13  * are met:
     14  * 1. Redistributions of source code must retain the above copyright
     15  *    notice, this list of conditions and the following disclaimer.
     16  * 2. Redistributions in binary form must reproduce the above copyright
     17  *    notice, this list of conditions and the following disclaimer in the
     18  *    documentation and/or other materials provided with the distribution.
     19  * 3. Neither the name of the University nor the names of its contributors
     20  *    may be used to endorse or promote products derived from this software
     21  *    without specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     33  * SUCH DAMAGE.
     34  */
     35 
     36 #include "defs.h"
     37 
     38 /* TABLE_SIZE is the number of entries in the symbol table. */
     39 /* TABLE_SIZE must be a power of two.			    */
     40 
     41 #define	TABLE_SIZE 1024
     42 
     43 
     44 bucket **symbol_table;
     45 bucket *first_symbol;
     46 bucket *last_symbol;
     47 
     48 int hash(char *);
     49 
     50 
     51 int
     52 hash(char *name)
     53 {
     54 	char *s;
     55 	int c, k;
     56 
     57 	assert(name && *name);
     58 	s = name;
     59 	k = *s;
     60 	while ((c = *++s))
     61 		k = (31 * k + c) & (TABLE_SIZE - 1);
     62 
     63 	return (k);
     64 }
     65 
     66 
     67 bucket *
     68 make_bucket(char *name)
     69 {
     70 	bucket *bp;
     71 
     72 	assert(name);
     73 	bp = malloc(sizeof(bucket));
     74 	if (bp == NULL)
     75 		no_space();
     76 	bp->link = 0;
     77 	bp->next = 0;
     78 	bp->name = strdup(name);
     79 	if (bp->name == NULL)
     80 		no_space();
     81 	bp->tag = 0;
     82 	bp->value = UNDEFINED;
     83 	bp->index = 0;
     84 	bp->prec = 0;
     85 	bp->class = UNKNOWN;
     86 	bp->assoc = TOKEN;
     87 
     88 	return (bp);
     89 }
     90 
     91 
     92 bucket *
     93 lookup(char *name)
     94 {
     95 	bucket *bp, **bpp;
     96 
     97 	bpp = symbol_table + hash(name);
     98 	bp = *bpp;
     99 
    100 	while (bp) {
    101 		if (strcmp(name, bp->name) == 0)
    102 			return (bp);
    103 		bpp = &bp->link;
    104 		bp = *bpp;
    105 	}
    106 
    107 	*bpp = bp = make_bucket(name);
    108 	last_symbol->next = bp;
    109 	last_symbol = bp;
    110 
    111 	return (bp);
    112 }
    113 
    114 
    115 void
    116 create_symbol_table(void)
    117 {
    118 	bucket *bp;
    119 
    120 	symbol_table = calloc(TABLE_SIZE, sizeof(bucket *));
    121 	if (symbol_table == NULL)
    122 		no_space();
    123 
    124 	bp = make_bucket("error");
    125 	bp->index = 1;
    126 	bp->class = TERM;
    127 
    128 	first_symbol = bp;
    129 	last_symbol = bp;
    130 	symbol_table[hash("error")] = bp;
    131 }
    132 
    133 
    134 void
    135 free_symbol_table(void)
    136 {
    137 	free(symbol_table);
    138 	symbol_table = 0;
    139 }
    140 
    141 
    142 void
    143 free_symbols(void)
    144 {
    145 	bucket *p, *q;
    146 
    147 	for (p = first_symbol; p; p = q) {
    148 		q = p->next;
    149 		free(p);
    150 	}
    151 }