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      1 /*	$NetBSD: lookup.c,v 1.9 2009/04/13 04:35:36 lukem Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1983, 1993
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. Neither the name of the University nor the names of its contributors
     16  *    may be used to endorse or promote products derived from this software
     17  *    without specific prior written permission.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     29  * SUCH DAMAGE.
     30  */
     31 
     32 #include <sys/cdefs.h>
     33 #ifndef lint
     34 #if 0
     35 static char sccsid[] = "@(#)lookup.c	8.1 (Berkeley) 6/9/93";
     36 #else
     37 __RCSID("$NetBSD: lookup.c,v 1.9 2009/04/13 04:35:36 lukem Exp $");
     38 #endif
     39 #endif /* not lint */
     40 
     41 #include "defs.h"
     42 
     43 	/* symbol types */
     44 #define VAR	1
     45 #define CONST	2
     46 
     47 struct syment {
     48 	int	s_type;
     49 	char	*s_name;
     50 	struct	namelist *s_value;
     51 	struct	syment *s_next;
     52 };
     53 
     54 static struct syment *hashtab[HASHSIZE];
     55 
     56 /*
     57  * Define a variable from a command line argument.
     58  */
     59 void
     60 define(char *name)
     61 {
     62 	char *cp, *s;
     63 	struct namelist *nl;
     64 	struct namelist *value;
     65 
     66 	value = NULL;
     67 
     68 	if (debug)
     69 		printf("define(%s)\n", name);
     70 
     71 	cp = strchr(name, '=');
     72 	if (cp == NULL)
     73 		value = NULL;
     74 	else if (cp[1] == '\0') {
     75 		*cp = '\0';
     76 		value = NULL;
     77 	} else if (cp[1] != '(') {
     78 		*cp++ = '\0';
     79 		value = makenl(cp);
     80 	} else {
     81 		nl = NULL;
     82 		*cp++ = '\0';
     83 		do
     84 			cp++;
     85 		while (*cp == ' ' || *cp == '\t');
     86 		for (s = cp; ; s++) {
     87 			switch (*s) {
     88 			case ')':
     89 				*s = '\0';
     90 			case '\0':
     91 				break;
     92 			case ' ':
     93 			case '\t':
     94 				*s++ = '\0';
     95 				while (*s == ' ' || *s == '\t')
     96 					s++;
     97 				if (*s == ')')
     98 					*s = '\0';
     99 				break;
    100 			default:
    101 				continue;
    102 			}
    103 			if (nl == NULL)
    104 				value = nl = makenl(cp);
    105 			else {
    106 				nl->n_next = makenl(cp);
    107 				nl = nl->n_next;
    108 			}
    109 			if (*s == '\0')
    110 				break;
    111 			cp = s;
    112 		}
    113 	}
    114 	(void) lookup(name, REPLACE, value);
    115 }
    116 
    117 /*
    118  * Lookup name in the table and return a pointer to it.
    119  * LOOKUP - just do lookup, return NULL if not found.
    120  * INSERT - insert name with value, error if already defined.
    121  * REPLACE - insert or replace name with value.
    122  */
    123 
    124 struct namelist *
    125 lookup(char *name, int action, struct namelist *value)
    126 {
    127 	unsigned n;
    128 	char *cp;
    129 	struct syment *s;
    130 	char lbuf[256];
    131 
    132 	if (debug)
    133 		printf("lookup(%s, %d, %lx)\n", name, action, (long)value);
    134 
    135 	n = 0;
    136 	for (cp = name; *cp; )
    137 		n += *cp++;
    138 	n %= HASHSIZE;
    139 
    140 	for (s = hashtab[n]; s != NULL; s = s->s_next) {
    141 		if (strcmp(name, s->s_name))
    142 			continue;
    143 		if (action != LOOKUP) {
    144 			if (action != INSERT || s->s_type != CONST) {
    145 				(void)snprintf(lbuf, sizeof(lbuf),
    146 				    "%s redefined", name);
    147 				yyerror(lbuf);
    148 			}
    149 		}
    150 		return(s->s_value);
    151 	}
    152 
    153 	if (action == LOOKUP) {
    154 		(void)snprintf(lbuf, sizeof(lbuf), "%s undefined", name);
    155 		yyerror(lbuf);
    156 		return(NULL);
    157 	}
    158 
    159 	s = ALLOC(syment);
    160 	if (s == NULL)
    161 		fatal("ran out of memory\n");
    162 	s->s_next = hashtab[n];
    163 	hashtab[n] = s;
    164 	s->s_type = action == INSERT ? VAR : CONST;
    165 	s->s_name = name;
    166 	s->s_value = value;
    167 	return(value);
    168 }
    169