xref: /freebsd/contrib/elftoolchain/libelftc/elftc_timestamp.c (revision cdebaff820b2a4915a16cedfd511823d78aab171)
1 /*-
2  * Copyright (c) 2016 The FreeBSD Foundation
3  * All rights reserved.
4  *
5  * This software was developed by Ed Maste under sponsorship
6  * of the FreeBSD Foundation.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #include <errno.h>
31 #include <stdlib.h>
32 #include <time.h>
33 #include <libelftc.h>
34 
35 int
36 elftc_timestamp(time_t *timestamp)
37 {
38 	long long source_date_epoch;
39 	char *env, *eptr;
40 
41 	if ((env = getenv("SOURCE_DATE_EPOCH")) != NULL) {
42 		errno = 0;
43 		source_date_epoch = strtoll(env, &eptr, 10);
44 		if (*eptr != '\0')
45 			errno = EINVAL;
46 		if (source_date_epoch < 0)
47 			errno = ERANGE;
48 		if (errno != 0)
49 			return (-1);
50 		*timestamp = source_date_epoch;
51 		return (0);
52 	}
53 	*timestamp = time(NULL);
54 	return (0);
55 }
56