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1 | /* Symbol table manager for Bison, | |
2 | Copyright (C) 1984, 1989 Free Software Foundation, Inc. | |
3 | ||
4 | This file is part of Bison, the GNU Compiler Compiler. | |
5 | ||
6 | Bison is free software; you can redistribute it and/or modify | |
7 | it under the terms of the GNU General Public License as published by | |
8 | the Free Software Foundation; either version 2, or (at your option) | |
9 | any later version. | |
10 | ||
11 | Bison is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
17 | along with Bison; see the file COPYING. If not, write to | |
18 | the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ | |
19 | ||
20 | ||
21 | #include <stdio.h> | |
22 | #include "system.h" | |
23 | #include "new.h" | |
24 | #include "symtab.h" | |
25 | #include "gram.h" | |
26 | ||
27 | ||
28 | bucket **symtab; | |
29 | bucket *firstsymbol; | |
30 | bucket *lastsymbol; | |
31 | ||
32 | ||
33 | ||
34 | int | |
35 | hash(key) | |
36 | char *key; | |
37 | { | |
38 | register char *cp; | |
39 | register int k; | |
40 | ||
41 | cp = key; | |
42 | k = 0; | |
43 | while (*cp) | |
44 | k = ((k << 1) ^ (*cp++)) & 0x3fff; | |
45 | ||
46 | return (k % TABSIZE); | |
47 | } | |
48 | ||
49 | ||
50 | ||
51 | char * | |
52 | copys(s) | |
53 | char *s; | |
54 | { | |
55 | register int i; | |
56 | register char *cp; | |
57 | register char *result; | |
58 | ||
59 | i = 1; | |
60 | for (cp = s; *cp; cp++) | |
61 | i++; | |
62 | ||
63 | result = xmalloc((unsigned int)i); | |
64 | strcpy(result, s); | |
65 | return (result); | |
66 | } | |
67 | ||
68 | ||
69 | void | |
70 | tabinit() | |
71 | { | |
72 | /* register int i; JF unused */ | |
73 | ||
74 | symtab = NEW2(TABSIZE, bucket *); | |
75 | ||
76 | firstsymbol = NULL; | |
77 | lastsymbol = NULL; | |
78 | } | |
79 | ||
80 | ||
81 | bucket * | |
82 | getsym(key) | |
83 | char *key; | |
84 | { | |
85 | register int hashval; | |
86 | register bucket *bp; | |
87 | register int found; | |
88 | ||
89 | hashval = hash(key); | |
90 | bp = symtab[hashval]; | |
91 | ||
92 | found = 0; | |
93 | while (bp != NULL && found == 0) | |
94 | { | |
95 | if (strcmp(key, bp->tag) == 0) | |
96 | found = 1; | |
97 | else | |
98 | bp = bp->link; | |
99 | } | |
100 | ||
101 | if (found == 0) | |
102 | { | |
103 | nsyms++; | |
104 | ||
105 | bp = NEW(bucket); | |
106 | bp->link = symtab[hashval]; | |
107 | bp->next = NULL; | |
108 | bp->tag = copys(key); | |
109 | bp->class = SUNKNOWN; | |
110 | ||
111 | if (firstsymbol == NULL) | |
112 | { | |
113 | firstsymbol = bp; | |
114 | lastsymbol = bp; | |
115 | } | |
116 | else | |
117 | { | |
118 | lastsymbol->next = bp; | |
119 | lastsymbol = bp; | |
120 | } | |
121 | ||
122 | symtab[hashval] = bp; | |
123 | } | |
124 | ||
125 | return (bp); | |
126 | } | |
127 | ||
128 | ||
129 | void | |
130 | free_symtab() | |
131 | { | |
132 | register int i; | |
133 | register bucket *bp,*bptmp;/* JF don't use ptr after free */ | |
134 | ||
135 | for (i = 0; i < TABSIZE; i++) | |
136 | { | |
137 | bp = symtab[i]; | |
138 | while (bp) | |
139 | { | |
140 | bptmp = bp->link; | |
141 | #if 0 /* This causes crashes because one string can appear more than once. */ | |
142 | if (bp->type_name) | |
143 | FREE(bp->type_name); | |
144 | #endif | |
145 | FREE(bp); | |
146 | bp = bptmp; | |
147 | } | |
148 | } | |
149 | FREE(symtab); | |
150 | } |