/*
 * Copyright (c) 1983 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by the University of California, Berkeley.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 *
 * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#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(name)
        char *name;
{
        register char *cp, *s;
        register struct namelist *nl;
        struct namelist *value;

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

        cp = index(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(name, action, value)
        char *name;
        int action;
        struct namelist *value;
{
        register unsigned n;
        register char *cp;
        register struct syment *s;
        char buf[256];

        if (debug)
                printf("lookup(%s, %d, %x)\n", name, action, 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)sprintf(buf, "%.*s redefined",
                                      sizeof(buf) - sizeof(" redefined"), name);
                                yyerror(buf);
                        }
                }
                return(s->s_value);
        }

        if (action == LOOKUP) {
                (void)sprintf(buf, "%.*s undefined",
                        sizeof(buf) - sizeof(" undefined"), name);
                yyerror(buf);
                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);
}