/*
 * Mach Operating System
 * Copyright (c) 1991,1990 Carnegie Mellon University
 * All Rights Reserved.
 *
 * Permission to use, copy, modify and distribute this software and its
 * documentation is hereby granted, provided that both the copyright
 * notice and this permission notice appear in all copies of the
 * software, derivative works or modified versions, and any portions
 * thereof, and that both notices appear in supporting documentation.
 *
 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS
 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
 *
 * Carnegie Mellon requests users of this software to return to
 *
 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
 *  School of Computer Science
 *  Carnegie Mellon University
 *  Pittsburgh PA 15213-3890
 *
 * any improvements or extensions that they make and grant Carnegie the
 * rights to redistribute these changes.
 *
 * $FreeBSD: src/sys/ddb/db_variables.c,v 1.18 1999/08/28 00:41:11 peter Exp $
 */

/*
 *      Author: David B. Golub, Carnegie Mellon University
 *      Date:   7/90
 */

#include <sys/param.h>
#include <sys/systm.h>

#include <ddb/ddb.h>
#include <ddb/db_lex.h>
#include <ddb/db_variables.h>

static int      db_find_variable (struct db_variable **varp);
static void     db_write_variable (struct db_variable *, db_expr_t *);

#ifdef notused
static int      db_set_variable (db_expr_t value);
#endif

static struct db_variable db_vars[] = {
        { "radix",      &db_radix, NULL },
        { "maxoff",     &db_maxoff, NULL },
        { "maxwidth",   &db_max_width, NULL },
        { "tabstops",   &db_tab_stop_width, NULL },
};
static struct db_variable *db_evars = db_vars + NELEM(db_vars);

static int
db_find_variable(struct db_variable **varp)
{
        int     t;
        struct db_variable *vp;

        t = db_read_token();
        if (t == tIDENT) {
            for (vp = db_vars; vp < db_evars; vp++) {
                if (!strcmp(db_tok_string, vp->name)) {
                    *varp = vp;
                    return (1);
                }
            }
            for (vp = db_regs; vp < db_eregs; vp++) {
                if (!strcmp(db_tok_string, vp->name)) {
                    *varp = vp;
                    return (1);
                }
            }
        }
        db_error("Unknown variable\n");
        return (0);
}

int
db_get_variable(db_expr_t *valuep)
{
        struct db_variable *vp;

        if (!db_find_variable(&vp))
            return (0);

        db_read_variable(vp, valuep);

        return (1);
}

#ifdef notused
static int
db_set_variable(db_expr_t value)
{
        struct db_variable *vp;

        if (!db_find_variable(&vp))
            return (0);

        db_write_variable(vp, &value);

        return (1);
}
#endif

void
db_read_variable(struct db_variable *vp, db_expr_t *valuep)
{
        db_varfcn_t     *func = vp->fcn;

        if (func == NULL)
            *valuep = *(vp->valuep);
        else
            (*func)(vp, valuep, DB_VAR_GET);
}

static void
db_write_variable(struct db_variable *vp, db_expr_t *valuep)
{
        db_varfcn_t     *func = vp->fcn;

        if (func == NULL)
            *(vp->valuep) = *valuep;
        else
            (*func)(vp, valuep, DB_VAR_SET);
}

void
db_set_cmd(db_expr_t dummy1, boolean_t dummy2, db_expr_t dummy3, char *dummy4)
{
        db_expr_t       value;
        struct db_variable *vp;
        int     t;

        t = db_read_token();
        if (t != tDOLLAR) {
            db_error("Unknown variable\n");
            return;
        }
        if (!db_find_variable(&vp)) {
            db_error("Unknown variable\n");
            return;
        }

        t = db_read_token();
        if (t != tEQ)
            db_unread_token(t);

        if (!db_expression(&value)) {
            db_error("No value\n");
            return;
        }
        if (db_read_token() != tEOL) {
            db_error("?\n");
        }

        db_write_variable(vp, &value);
}