/*
 * Copyright (C) 2010 Joel Rosdahl
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 3 of the License, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc., 51
 * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include "ccache.h"
#include <stdlib.h>
#include <string.h>
#include <errno.h>

struct exit_function {
	void (*function)(void *);
	void *context;
	struct exit_function *next;
};

struct nullary_exit_function {
	void (*function)(void);
};

static struct exit_function *exit_functions;

static void
call_nullary_exit_function(void *context)
{
	struct nullary_exit_function *p = (struct nullary_exit_function*)context;
	p->function();
	free(p);
}

/*
 * Initialize exit functions. Must be called once before exitfn_add* are used.
 */
void
exitfn_init(void)
{
	if (atexit(exitfn_call) != 0) {
		fatal("atexit failed: %s", strerror(errno));
	}
}

/*
 * Add a nullary function to be called context when ccache exits. Functions are
 * called in reverse order.
 */
void
exitfn_add_nullary(void (*function)(void))
{
	struct nullary_exit_function *p = x_malloc(sizeof(*p));
	p->function = function;
	exitfn_add(call_nullary_exit_function, p);
}

/*
 * Add a function to be called with a context parameter when ccache exits.
 * Functions are called in reverse order.
 */
void
exitfn_add(void (*function)(void *), void *context)
{
	struct exit_function *p;

	p = x_malloc(sizeof(*p));
	p->function = function;
	p->context = context;
	p->next = exit_functions;
	exit_functions = p;
}

/*
 * Call added functions.
 */
void
exitfn_call(void)
{
	struct exit_function *p = exit_functions, *q;
	while (p) {
		p->function(p->context);
		q = p;
		p = p->next;
		free(q);
	}
	exit_functions = NULL;
}