1 /* Test for ctime
2    Copyright (C) 2021-2022 Free Software Foundation, Inc.
3    This file is part of the GNU C Library.
4 
5    The GNU C Library is free software; you can redistribute it and/or
6    modify it under the terms of the GNU Lesser General Public
7    License as published by the Free Software Foundation; either
8    version 2.1 of the License, or (at your option) any later version.
9 
10    The GNU C Library is distributed in the hope that it will be useful,
11    but WITHOUT ANY WARRANTY; without even the implied warranty of
12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13    Lesser General Public License for more details.
14 
15    You should have received a copy of the GNU Lesser General Public
16    License along with the GNU C Library; if not, see
17    <https://www.gnu.org/licenses/>.  */
18 
19 #include <time.h>
20 #include <stdlib.h>
21 #include <support/check.h>
22 
23 static int
do_test(void)24 do_test (void)
25 {
26   char *str;
27   char strb[32];
28   time_t t;
29 
30   /* Use glibc time zone extension "TZ=:" to to guarantee that UTC
31      without leap seconds is used for the test.  */
32   TEST_VERIFY_EXIT (setenv ("TZ", ":", 1) == 0);
33   tzset ();
34 
35   /* Check if the epoch time can be converted.  */
36   t = 0;
37   str = ctime (&t);
38   TEST_COMPARE_STRING (str, "Thu Jan  1 00:00:00 1970\n");
39 
40   /* Same as before but with ctime_r.  */
41   str = ctime_r (&t, strb);
42   TEST_VERIFY (str == strb);
43   TEST_COMPARE_STRING (str, "Thu Jan  1 00:00:00 1970\n");
44 
45   /* Check if the max time value for 32 bit time_t can be converted.  */
46   t = 0x7fffffff;
47   str = ctime (&t);
48   TEST_COMPARE_STRING (str, "Tue Jan 19 03:14:07 2038\n");
49 
50   /* Same as before but with ctime_r.  */
51   str = ctime_r (&t, strb);
52   TEST_VERIFY (str == strb);
53   TEST_COMPARE_STRING (str, "Tue Jan 19 03:14:07 2038\n");
54 
55   /* Check if we run on port with 32 bit time_t size */
56   time_t tov;
57   if (__builtin_add_overflow (t, 1, &tov))
58     return 0;
59 
60   /* Check if the time is converted after 32 bit time_t overflow.  */
61   str = ctime (&tov);
62   TEST_COMPARE_STRING (str, "Tue Jan 19 03:14:08 2038\n");
63 
64   /* Same as before but with ctime_r.  */
65   str = ctime_r (&tov, strb);
66   TEST_VERIFY (str == strb);
67   TEST_COMPARE_STRING (str, "Tue Jan 19 03:14:08 2038\n");
68 
69   return 0;
70 }
71 
72 #include <support/test-driver.c>
73