xref: /openbsd-src/usr.bin/yacc/symtab.c (revision a28daedfc357b214be5c701aa8ba8adb29a7f1c2)
1 /*	$OpenBSD: symtab.c,v 1.12 2005/06/10 16:40:45 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. 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 #ifndef lint
37 #if 0
38 static char sccsid[] = "@(#)symtab.c	5.3 (Berkeley) 6/1/90";
39 #else
40 static char rcsid[] = "$OpenBSD: symtab.c,v 1.12 2005/06/10 16:40:45 pvalchev Exp $";
41 #endif
42 #endif /* not lint */
43 
44 #include "defs.h"
45 
46 /* TABLE_SIZE is the number of entries in the symbol table. */
47 /* TABLE_SIZE must be a power of two.			    */
48 
49 #define	TABLE_SIZE 1024
50 
51 
52 bucket **symbol_table;
53 bucket *first_symbol;
54 bucket *last_symbol;
55 
56 int hash(char *);
57 
58 
59 int
60 hash(char *name)
61 {
62     char *s;
63     int c, k;
64 
65     assert(name && *name);
66     s = name;
67     k = *s;
68     while ((c = *++s))
69 	k = (31*k + c) & (TABLE_SIZE - 1);
70 
71     return (k);
72 }
73 
74 
75 bucket *
76 make_bucket(char *name)
77 {
78     bucket *bp;
79 
80     assert(name);
81     bp = (bucket *) MALLOC(sizeof(bucket));
82     if (bp == 0) no_space();
83     bp->link = 0;
84     bp->next = 0;
85     bp->name = strdup(name);
86     if (bp->name == 0) no_space();
87     bp->tag = 0;
88     bp->value = UNDEFINED;
89     bp->index = 0;
90     bp->prec = 0;
91     bp-> class = UNKNOWN;
92     bp->assoc = TOKEN;
93 
94     return (bp);
95 }
96 
97 
98 bucket *
99 lookup(char *name)
100 {
101     bucket *bp, **bpp;
102 
103     bpp = symbol_table + hash(name);
104     bp = *bpp;
105 
106     while (bp)
107     {
108 	if (strcmp(name, bp->name) == 0) return (bp);
109 	bpp = &bp->link;
110 	bp = *bpp;
111     }
112 
113     *bpp = bp = make_bucket(name);
114     last_symbol->next = bp;
115     last_symbol = bp;
116 
117     return (bp);
118 }
119 
120 
121 void
122 create_symbol_table(void)
123 {
124     int i;
125     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 void
143 free_symbol_table(void)
144 {
145     FREE(symbol_table);
146     symbol_table = 0;
147 }
148 
149 
150 void
151 free_symbols(void)
152 {
153     bucket *p, *q;
154 
155     for (p = first_symbol; p; p = q)
156     {
157 	q = p->next;
158 	FREE(p);
159     }
160 }
161