1 /* 2 * Copyright (c) 1983 Regents of the University of California. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #ifndef lint 35 static char sccsid[] = "@(#)lookup.c 5.5 (Berkeley) 6/1/90"; 36 #endif /* not lint */ 37 38 #include "defs.h" 39 40 /* symbol types */ 41 #define VAR 1 42 #define CONST 2 43 44 struct syment { 45 int s_type; 46 char *s_name; 47 struct namelist *s_value; 48 struct syment *s_next; 49 }; 50 51 static struct syment *hashtab[HASHSIZE]; 52 53 /* 54 * Define a variable from a command line argument. 55 */ 56 define(name) 57 char *name; 58 { 59 register char *cp, *s; 60 register struct namelist *nl; 61 struct namelist *value; 62 63 if (debug) 64 printf("define(%s)\n", name); 65 66 cp = index(name, '='); 67 if (cp == NULL) 68 value = NULL; 69 else if (cp[1] == '\0') { 70 *cp = '\0'; 71 value = NULL; 72 } else if (cp[1] != '(') { 73 *cp++ = '\0'; 74 value = makenl(cp); 75 } else { 76 nl = NULL; 77 *cp++ = '\0'; 78 do 79 cp++; 80 while (*cp == ' ' || *cp == '\t'); 81 for (s = cp; ; s++) { 82 switch (*s) { 83 case ')': 84 *s = '\0'; 85 case '\0': 86 break; 87 case ' ': 88 case '\t': 89 *s++ = '\0'; 90 while (*s == ' ' || *s == '\t') 91 s++; 92 if (*s == ')') 93 *s = '\0'; 94 break; 95 default: 96 continue; 97 } 98 if (nl == NULL) 99 value = nl = makenl(cp); 100 else { 101 nl->n_next = makenl(cp); 102 nl = nl->n_next; 103 } 104 if (*s == '\0') 105 break; 106 cp = s; 107 } 108 } 109 (void) lookup(name, REPLACE, value); 110 } 111 112 /* 113 * Lookup name in the table and return a pointer to it. 114 * LOOKUP - just do lookup, return NULL if not found. 115 * INSERT - insert name with value, error if already defined. 116 * REPLACE - insert or replace name with value. 117 */ 118 119 struct namelist * 120 lookup(name, action, value) 121 char *name; 122 int action; 123 struct namelist *value; 124 { 125 register unsigned n; 126 register char *cp; 127 register struct syment *s; 128 char buf[256]; 129 130 if (debug) 131 printf("lookup(%s, %d, %x)\n", name, action, value); 132 133 n = 0; 134 for (cp = name; *cp; ) 135 n += *cp++; 136 n %= HASHSIZE; 137 138 for (s = hashtab[n]; s != NULL; s = s->s_next) { 139 if (strcmp(name, s->s_name)) 140 continue; 141 if (action != LOOKUP) { 142 if (action != INSERT || s->s_type != CONST) { 143 (void)sprintf(buf, "%s redefined", name); 144 yyerror(buf); 145 } 146 } 147 return(s->s_value); 148 } 149 150 if (action == LOOKUP) { 151 (void)sprintf(buf, "%s undefined", name); 152 yyerror(buf); 153 return(NULL); 154 } 155 156 s = ALLOC(syment); 157 if (s == NULL) 158 fatal("ran out of memory\n"); 159 s->s_next = hashtab[n]; 160 hashtab[n] = s; 161 s->s_type = action == INSERT ? VAR : CONST; 162 s->s_name = name; 163 s->s_value = value; 164 return(value); 165 } 166