1 /* $OpenBSD: symtab.c,v 1.15 2012/04/10 09:08:50 chl 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 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 * 68 make_bucket(char *name) 69 { 70 bucket *bp; 71 72 assert(name); 73 bp = (bucket *) MALLOC(sizeof(bucket)); 74 if (bp == 0) no_space(); 75 bp->link = 0; 76 bp->next = 0; 77 bp->name = strdup(name); 78 if (bp->name == 0) no_space(); 79 bp->tag = 0; 80 bp->value = UNDEFINED; 81 bp->index = 0; 82 bp->prec = 0; 83 bp-> class = UNKNOWN; 84 bp->assoc = TOKEN; 85 86 return (bp); 87 } 88 89 90 bucket * 91 lookup(char *name) 92 { 93 bucket *bp, **bpp; 94 95 bpp = symbol_table + hash(name); 96 bp = *bpp; 97 98 while (bp) 99 { 100 if (strcmp(name, bp->name) == 0) return (bp); 101 bpp = &bp->link; 102 bp = *bpp; 103 } 104 105 *bpp = bp = make_bucket(name); 106 last_symbol->next = bp; 107 last_symbol = bp; 108 109 return (bp); 110 } 111 112 113 void 114 create_symbol_table(void) 115 { 116 bucket *bp; 117 118 symbol_table = CALLOC(TABLE_SIZE, sizeof(bucket *)); 119 if (symbol_table == NULL) no_space(); 120 121 bp = make_bucket("error"); 122 bp->index = 1; 123 bp->class = TERM; 124 125 first_symbol = bp; 126 last_symbol = bp; 127 symbol_table[hash("error")] = bp; 128 } 129 130 131 void 132 free_symbol_table(void) 133 { 134 FREE(symbol_table); 135 symbol_table = 0; 136 } 137 138 139 void 140 free_symbols(void) 141 { 142 bucket *p, *q; 143 144 for (p = first_symbol; p; p = q) 145 { 146 q = p->next; 147 FREE(p); 148 } 149 } 150