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
hash(char * name)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 *
make_bucket(char * name)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 *
lookup(char * name)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
create_symbol_table(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
free_symbol_table(void)135 free_symbol_table(void)
136 {
137 free(symbol_table);
138 symbol_table = 0;
139 }
140
141
142 void
free_symbols(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 }
152