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 * 4. Neither the name of the University nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33 #if 0
34 #ifndef lint
35 static char sccsid[] = "@(#)symtab.c 5.3 (Berkeley) 6/1/90";
36 #endif
37 #endif
38
39 #include <sys/cdefs.h>
40 __FBSDID("$FreeBSD: stable/9/usr.bin/yacc/symtab.c 216370 2010-12-11 08:32:16Z joel $");
41
42 #include <stdlib.h>
43 #include <string.h>
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 static int hash(const char *);
52
53 bucket **symbol_table;
54 bucket *first_symbol;
55 bucket *last_symbol;
56
57
58 static int
hash(const char * name)59 hash(const char *name)
60 {
61 const char *s;
62 int c, k;
63
64 assert(name && *name);
65 s = name;
66 k = *s;
67 while ((c = *++s))
68 k = (31*k + c) & (TABLE_SIZE - 1);
69
70 return (k);
71 }
72
73
74 bucket *
make_bucket(const char * name)75 make_bucket(const char *name)
76 {
77 bucket *bp;
78
79 assert(name);
80 bp = malloc(sizeof(bucket));
81 if (bp == 0) no_space();
82 bp->link = 0;
83 bp->next = 0;
84 bp->name = malloc(strlen(name) + 1);
85 if (bp->name == 0) no_space();
86 bp->tag = 0;
87 bp->value = UNDEFINED;
88 bp->index = 0;
89 bp->prec = 0;
90 bp-> class = UNKNOWN;
91 bp->assoc = TOKEN;
92
93 if (bp->name == 0) no_space();
94 strcpy(bp->name, name);
95
96 return (bp);
97 }
98
99
100 bucket *
lookup(char * name)101 lookup(char *name)
102 {
103 bucket *bp, **bpp;
104
105 bpp = symbol_table + hash(name);
106 bp = *bpp;
107
108 while (bp)
109 {
110 if (strcmp(name, bp->name) == 0) return (bp);
111 bpp = &bp->link;
112 bp = *bpp;
113 }
114
115 *bpp = bp = make_bucket(name);
116 last_symbol->next = bp;
117 last_symbol = bp;
118
119 return (bp);
120 }
121
122
123 void
create_symbol_table(void)124 create_symbol_table(void)
125 {
126 int i;
127 bucket *bp;
128
129 symbol_table = malloc(TABLE_SIZE*sizeof(bucket *));
130 if (symbol_table == 0) no_space();
131 for (i = 0; i < TABLE_SIZE; i++)
132 symbol_table[i] = 0;
133
134 bp = make_bucket("error");
135 bp->index = 1;
136 bp->class = TERM;
137
138 first_symbol = bp;
139 last_symbol = bp;
140 symbol_table[hash("error")] = bp;
141 }
142
143
144 void
free_symbol_table(void)145 free_symbol_table(void)
146 {
147 free(symbol_table);
148 symbol_table = 0;
149 }
150
151
152 void
free_symbols(void)153 free_symbols(void)
154 {
155 bucket *p, *q;
156
157 for (p = first_symbol; p; p = q)
158 {
159 q = p->next;
160 free(p);
161 }
162 }
163