time/tst-ctime.c

   1 /* Test for ctime
   2    Copyright (C) 2021-2024 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
  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>