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 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 = 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 * 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 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 135 free_symbol_table(void) 136 { 137 free(symbol_table); 138 symbol_table = 0; 139 } 140 141 142 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