time/tst-ctime.c

   1 /* Test for ctime
   2    Copyright (C) 2021 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   time_t t;
  28
  29   /* Use glibc time zone extension "TZ=:" to to guarantee that UTC
  30      without leap seconds is used for the test.  */
  31   TEST_VERIFY_EXIT (setenv ("TZ", ":", 1) == 0);
  32   tzset ();
  33
  34   /* Check if the epoch time can be converted.  */
  35   t = 0;
  36   str = ctime (&t);
  37   TEST_COMPARE_STRING (str, "Thu Jan  1 00:00:00 1970\n");
  38
  39   /* Check if the max time value for 32 bit time_t can be converted.  */
  40   t = 0x7fffffff;
  41   str = ctime (&t);
  42   TEST_COMPARE_STRING (str, "Tue Jan 19 03:14:07 2038\n");
  43
  44   /* Check if we run on port with 32 bit time_t size */
  45   time_t tov;
  46   if (__builtin_add_overflow (t, 1, &tov))
  47     return 0;
  48
  49   /* Check if the time is converted after 32 bit time_t overflow.  */
  50   str = ctime (&tov);
  51   TEST_COMPARE_STRING (str, "Tue Jan 19 03:14:08 2038\n");
  52
  53   return 0;
  54 }
  55
  56 #include <support/test-driver.c>