view rogue4/daemon.c @ 280:70aa5808c782

Fix potential segfaults at restore related to ctime(). In some games, restore() passes the result of ctime() to mvprintw() or some other variadic message-formatting function. If ctime() has not been declared properly, its return type is inferred to be int instead of char *. This does not cause a warning because the compiler does not know the correct type of variadic arguments. On platforms where ints and pointers are not the same size, this can, probably depending on alignment, result in a segfault that is not easy to trace. Including time.h fixes the problem. Some games manually declared ctime() and avoided the bug. These declarations have also been replaced with the include.
author John "Elwin" Edwards
date Fri, 15 Sep 2017 20:51:10 -0400
parents b67b99f6c92b
children
line wrap: on
line source

/*
 * Contains functions for dealing with things that happen in the
 * future.
 *
 * @(#)daemon.c	4.4 (Berkeley) 1/12/82
 *
 * Rogue: Exploring the Dungeons of Doom
 * Copyright (C) 1980, 1981, 1982 Michael Toy, Ken Arnold and Glenn Wichman
 * All rights reserved.
 *
 * See the file LICENSE.TXT for full copyright and licensing information.
 */

#include <curses.h>
#include "rogue.h"

#define EMPTY 0
#define DAEMON -1

#define _X_ { EMPTY }

struct delayed_action d_list[MAXDAEMONS] = {
    _X_, _X_, _X_, _X_, _X_, _X_, _X_, _X_, _X_, _X_,
    _X_, _X_, _X_, _X_, _X_, _X_, _X_, _X_, _X_, _X_, 
};

/*
 * d_slot:
 *	Find an empty slot in the daemon/fuse list
 */
struct delayed_action *
d_slot(void)
{
    register int i;
    register struct delayed_action *dev;

    for (i = 0, dev = d_list; i < MAXDAEMONS; i++, dev++)
	if (dev->d_type == EMPTY)
	    return dev;
#ifdef WIZARD
    debug("Ran out of fuse slots");
#endif
    return NULL;
}

/*
 * find_slot:
 *	Find a particular slot in the table
 */
struct delayed_action *
find_slot(void (*func)())
{
    register int i;
    register struct delayed_action *dev;

    for (i = 0, dev = d_list; i < MAXDAEMONS; i++, dev++)
	if (dev->d_type != EMPTY && func == dev->d_func)
	    return dev;
    return NULL;
}

/*
 * start_daemon:
 *	Start a daemon, takes a function.
 */
void
start_daemon(void (*func)(), int arg, int type)
{
    register struct delayed_action *dev;

    dev = d_slot();
    dev->d_type = type;
    dev->d_func = func;
    dev->d_arg = arg;
    dev->d_time = DAEMON;
}

/*
 * kill_daemon:
 *	Remove a daemon from the list
 */
void
kill_daemon(void (*func)())
{
    register struct delayed_action *dev;

    if ((dev = find_slot(func)) == NULL)
	return;
    /*
     * Take it out of the list
     */
    dev->d_type = EMPTY;
}

/*
 * do_daemons:
 *	Run all the daemons that are active with the current flag,
 *	passing the argument to the function.
 */
void
do_daemons(int flag)
{
    register struct delayed_action *dev;

    /*
     * Loop through the devil list
     */
    for (dev = d_list; dev <= &d_list[MAXDAEMONS-1]; dev++)
	/*
	 * Executing each one, giving it the proper arguments
	 */
	if (dev->d_type == flag && dev->d_time == DAEMON)
	    (*dev->d_func)(dev->d_arg);
}

/*
 * fuse:
 *	Start a fuse to go off in a certain number of turns
 */
void
fuse(void (*func)(), int arg, int time, int type)
{
    register struct delayed_action *wire;

    wire = d_slot();
    wire->d_type = type;
    wire->d_func = func;
    wire->d_arg = arg;
    wire->d_time = time;
}

/*
 * lengthen:
 *	Increase the time until a fuse goes off
 */
void
lengthen(void (*func)(), int xtime)
{
    register struct delayed_action *wire;

    if ((wire = find_slot(func)) == NULL)
	return;
    wire->d_time += xtime;
}

/*
 * extinguish:
 *	Put out a fuse
 */
void
extinguish(void (*func)())
{
    register struct delayed_action *wire;

    if ((wire = find_slot(func)) == NULL)
	return;
    wire->d_type = EMPTY;
}

/*
 * do_fuses:
 *	Decrement counters and start needed fuses
 */
void
do_fuses(int flag)
{
    register struct delayed_action *wire;

    /*
     * Step though the list
     */
    for (wire = d_list; wire <= &d_list[MAXDAEMONS-1]; wire++)
    {
	/*
	 * Decrementing counters and starting things we want.  We also need
	 * to remove the fuse from the list once it has gone off.
	 */
	if (flag == wire->d_type && wire->d_time > 0 && --wire->d_time == 0)
	{
	    wire->d_type = EMPTY;
	    (*wire->d_func)(wire->d_arg);
	}
     }
}