xref: /openbsd-src/usr.bin/yacc/symtab.c (revision b2ea75c1b17e1a9a339660e7ed45cd24946b230e)
1 /*	$OpenBSD: symtab.c,v 1.4 2001/07/16 06:29:45 pvalchev 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. All advertising materials mentioning features or use of this software
20  *    must display the following acknowledgement:
21  *	This product includes software developed by the University of
22  *	California, Berkeley and its contributors.
23  * 4. Neither the name of the University nor the names of its contributors
24  *    may be used to endorse or promote products derived from this software
25  *    without specific prior written permission.
26  *
27  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
28  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
31  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
33  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37  * SUCH DAMAGE.
38  */
39 
40 #ifndef lint
41 #if 0
42 static char sccsid[] = "@(#)symtab.c	5.3 (Berkeley) 6/1/90";
43 #else
44 static char rcsid[] = "$OpenBSD: symtab.c,v 1.4 2001/07/16 06:29:45 pvalchev Exp $";
45 #endif
46 #endif /* not lint */
47 
48 #include "defs.h"
49 
50 /* TABLE_SIZE is the number of entries in the symbol table. */
51 /* TABLE_SIZE must be a power of two.			    */
52 
53 #define	TABLE_SIZE 1024
54 
55 
56 bucket **symbol_table;
57 bucket *first_symbol;
58 bucket *last_symbol;
59 
60 int hash __P((char *));
61 
62 
63 int
64 hash(name)
65 char *name;
66 {
67     register char *s;
68     register int c, k;
69 
70     assert(name && *name);
71     s = name;
72     k = *s;
73     while (c = *++s)
74 	k = (31*k + c) & (TABLE_SIZE - 1);
75 
76     return (k);
77 }
78 
79 
80 bucket *
81 make_bucket(name)
82 char *name;
83 {
84     register bucket *bp;
85 
86     assert(name);
87     bp = (bucket *) MALLOC(sizeof(bucket));
88     if (bp == 0) no_space();
89     bp->link = 0;
90     bp->next = 0;
91     bp->name = MALLOC(strlen(name) + 1);
92     if (bp->name == 0) no_space();
93     bp->tag = 0;
94     bp->value = UNDEFINED;
95     bp->index = 0;
96     bp->prec = 0;
97     bp-> class = UNKNOWN;
98     bp->assoc = TOKEN;
99 
100     if (bp->name == 0) no_space();
101     strcpy(bp->name, name);
102 
103     return (bp);
104 }
105 
106 
107 bucket *
108 lookup(name)
109 char *name;
110 {
111     register bucket *bp, **bpp;
112 
113     bpp = symbol_table + hash(name);
114     bp = *bpp;
115 
116     while (bp)
117     {
118 	if (strcmp(name, bp->name) == 0) return (bp);
119 	bpp = &bp->link;
120 	bp = *bpp;
121     }
122 
123     *bpp = bp = make_bucket(name);
124     last_symbol->next = bp;
125     last_symbol = bp;
126 
127     return (bp);
128 }
129 
130 
131 void
132 create_symbol_table()
133 {
134     register int i;
135     register bucket *bp;
136 
137     symbol_table = (bucket **) MALLOC(TABLE_SIZE*sizeof(bucket *));
138     if (symbol_table == 0) no_space();
139     for (i = 0; i < TABLE_SIZE; i++)
140 	symbol_table[i] = 0;
141 
142     bp = make_bucket("error");
143     bp->index = 1;
144     bp->class = TERM;
145 
146     first_symbol = bp;
147     last_symbol = bp;
148     symbol_table[hash("error")] = bp;
149 }
150 
151 
152 void
153 free_symbol_table()
154 {
155     FREE(symbol_table);
156     symbol_table = 0;
157 }
158 
159 
160 void
161 free_symbols()
162 {
163     register bucket *p, *q;
164 
165     for (p = first_symbol; p; p = q)
166     {
167 	q = p->next;
168 	FREE(p);
169     }
170 }
171