/*      $NetBSD: lookup.c,v 1.9 2009/04/13 04:35:36 lukem Exp $ */

/*
* Copyright (c) 1983, 1993
*      The Regents of the University of California.  All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
*    may be used to endorse or promote products derived from this software
*    without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/

#include <sys/cdefs.h>
#ifndef lint
#if 0
static char sccsid[] = "@(#)lookup.c    8.1 (Berkeley) 6/9/93";
#else
__RCSID("$NetBSD: lookup.c,v 1.9 2009/04/13 04:35:36 lukem Exp $");
#endif
#endif /* not lint */

#include "defs.h"

       /* symbol types */
#define VAR     1
#define CONST   2

struct syment {
       int     s_type;
       char    *s_name;
       struct  namelist *s_value;
       struct  syment *s_next;
};

static struct syment *hashtab[HASHSIZE];

/*
* Define a variable from a command line argument.
*/
void
define(char *name)
{
       char *cp, *s;
       struct namelist *nl;
       struct namelist *value;

       value = NULL;

       if (debug)
               printf("define(%s)\n", name);

       cp = strchr(name, '=');
       if (cp == NULL)
               value = NULL;
       else if (cp[1] == '\0') {
               *cp = '\0';
               value = NULL;
       } else if (cp[1] != '(') {
               *cp++ = '\0';
               value = makenl(cp);
       } else {
               nl = NULL;
               *cp++ = '\0';
               do
                       cp++;
               while (*cp == ' ' || *cp == '\t');
               for (s = cp; ; s++) {
                       switch (*s) {
                       case ')':
                               *s = '\0';
                       case '\0':
                               break;
                       case ' ':
                       case '\t':
                               *s++ = '\0';
                               while (*s == ' ' || *s == '\t')
                                       s++;
                               if (*s == ')')
                                       *s = '\0';
                               break;
                       default:
                               continue;
                       }
                       if (nl == NULL)
                               value = nl = makenl(cp);
                       else {
                               nl->n_next = makenl(cp);
                               nl = nl->n_next;
                       }
                       if (*s == '\0')
                               break;
                       cp = s;
               }
       }
       (void) lookup(name, REPLACE, value);
}

/*
* Lookup name in the table and return a pointer to it.
* LOOKUP - just do lookup, return NULL if not found.
* INSERT - insert name with value, error if already defined.
* REPLACE - insert or replace name with value.
*/

struct namelist *
lookup(char *name, int action, struct namelist *value)
{
       unsigned n;
       char *cp;
       struct syment *s;
       char lbuf[256];

       if (debug)
               printf("lookup(%s, %d, %lx)\n", name, action, (long)value);

       n = 0;
       for (cp = name; *cp; )
               n += *cp++;
       n %= HASHSIZE;

       for (s = hashtab[n]; s != NULL; s = s->s_next) {
               if (strcmp(name, s->s_name))
                       continue;
               if (action != LOOKUP) {
                       if (action != INSERT || s->s_type != CONST) {
                               (void)snprintf(lbuf, sizeof(lbuf),
                                   "%s redefined", name);
                               yyerror(lbuf);
                       }
               }
               return(s->s_value);
       }

       if (action == LOOKUP) {
               (void)snprintf(lbuf, sizeof(lbuf), "%s undefined", name);
               yyerror(lbuf);
               return(NULL);
       }

       s = ALLOC(syment);
       if (s == NULL)
               fatal("ran out of memory\n");
       s->s_next = hashtab[n];
       hashtab[n] = s;
       s->s_type = action == INSERT ? VAR : CONST;
       s->s_name = name;
       s->s_value = value;
       return(value);
}