1/* $Id: symtab.c,v 1.11 2014/03/26 00:17:09 Tom.Shields Exp $ */
2
3#include "defs.h"
4
5/* TABLE_SIZE is the number of entries in the symbol table. */
6/* TABLE_SIZE must be a power of two.			    */
7
8#define	TABLE_SIZE 1024
9
10static bucket **symbol_table = 0;
11bucket *first_symbol;
12bucket *last_symbol;
13
14static int
15hash(const char *name)
16{
17    const char *s;
18    int c, k;
19
20    assert(name && *name);
21    s = name;
22    k = *s;
23    while ((c = *++s) != 0)
24	k = (31 * k + c) & (TABLE_SIZE - 1);
25
26    return (k);
27}
28
29bucket *
30make_bucket(const char *name)
31{
32    bucket *bp;
33
34    assert(name != 0);
35
36    bp = TMALLOC(bucket, 1);
37    NO_SPACE(bp);
38
39    bp->link = 0;
40    bp->next = 0;
41
42    bp->name = TMALLOC(char, strlen(name) + 1);
43    NO_SPACE(bp->name);
44
45    bp->tag = 0;
46    bp->value = UNDEFINED;
47    bp->index = 0;
48    bp->prec = 0;
49    bp->class = UNKNOWN;
50    bp->assoc = TOKEN;
51#if defined(YYBTYACC)
52    bp->args = -1;
53    bp->argnames = 0;
54    bp->argtags = 0;
55    bp->destructor = 0;
56#endif
57    strcpy(bp->name, name);
58
59    return (bp);
60}
61
62bucket *
63lookup(const char *name)
64{
65    bucket *bp, **bpp;
66
67    bpp = symbol_table + hash(name);
68    bp = *bpp;
69
70    while (bp)
71    {
72	if (strcmp(name, bp->name) == 0)
73	    return (bp);
74	bpp = &bp->link;
75	bp = *bpp;
76    }
77
78    *bpp = bp = make_bucket(name);
79    last_symbol->next = bp;
80    last_symbol = bp;
81
82    return (bp);
83}
84
85void
86create_symbol_table(void)
87{
88    int i;
89    bucket *bp;
90
91    symbol_table = TMALLOC(bucket *, TABLE_SIZE);
92    NO_SPACE(symbol_table);
93
94    for (i = 0; i < TABLE_SIZE; i++)
95	symbol_table[i] = 0;
96
97    bp = make_bucket("error");
98    bp->index = 1;
99    bp->class = TERM;
100
101    first_symbol = bp;
102    last_symbol = bp;
103    symbol_table[hash("error")] = bp;
104}
105
106void
107free_symbol_table(void)
108{
109    FREE(symbol_table);
110    symbol_table = 0;
111}
112
113void
114free_symbols(void)
115{
116    bucket *p, *q;
117
118    for (p = first_symbol; p; p = q)
119    {
120	q = p->next;
121	FREE(p);
122    }
123}
124