1  /* Test for mktime (4)
       2     Copyright (C) 2021-2023 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  const struct tm tm0 =
      24    {
      25      .tm_year = 70,
      26      .tm_mon = 0,
      27      .tm_mday = 1,
      28      .tm_hour = 0,
      29      .tm_min = 0,
      30      .tm_sec = 0,
      31      .tm_wday = 4,
      32      .tm_yday = 0,
      33    };
      34  
      35  const struct tm tmY2038 =
      36    {
      37      .tm_year = 138,
      38      .tm_mon = 0,
      39      .tm_mday = 19,
      40      .tm_hour = 3,
      41      .tm_min = 14,
      42      .tm_sec = 7,
      43    };
      44  
      45  const struct tm tm32bitmax =
      46    {
      47      .tm_year = 206,
      48      .tm_mon = 1,
      49      .tm_mday = 7,
      50      .tm_hour = 6,
      51      .tm_min = 28,
      52      .tm_sec = 15,
      53    };
      54  
      55  static
      56  int test_mktime_helper (struct tm *tm, long long int exp_val, int line)
      57  {
      58    time_t result, t;
      59  
      60    /* Check if we run on port with 32 bit time_t size.  */
      61    if (__builtin_add_overflow (exp_val, 0, &t))
      62      return 0;
      63  
      64    result = mktime (tm);
      65    if (result == (time_t) -1)
      66      FAIL_RET ("*** mktime failed: %m in line: %d", line);
      67  
      68    if ((long long int) result != exp_val)
      69      FAIL_RET ("*** Result different than expected (%lld != %lld) in %d\n",
      70                (long long int) result, exp_val, line);
      71  
      72    return 0;
      73  }
      74  
      75  static int
      76  do_test (void)
      77  {
      78    struct tm t;
      79    /* Use glibc time zone extension "TZ=:" to to guarantee that UTC
      80       without leap seconds is used for the test.  */
      81    TEST_VERIFY_EXIT (setenv ("TZ", ":", 1) == 0);
      82  
      83    /* Check that mktime (1970-01-01 00:00:00) returns 0.  */
      84    t = tm0;
      85    test_mktime_helper (&t, 0, __LINE__);
      86  
      87    /* Check that mktime (2038-01-19 03:14:07) returns 0x7FFFFFFF.  */
      88    t = tmY2038;
      89    test_mktime_helper (&t, 0x7fffffff, __LINE__);
      90  
      91    /* Check that mktime (2038-01-19 03:14:08) returns 0x80000000
      92       (time_t overflow).  */
      93    t = tmY2038;
      94    t.tm_sec++;
      95    test_mktime_helper (&t, 0x80000000, __LINE__);
      96  
      97    /* Check that mktime (2106-02-07 06:28:15) returns 0xFFFFFFFF.  */
      98    t = tm32bitmax;
      99    test_mktime_helper (&t, 0xFFFFFFFF, __LINE__);
     100  
     101    /* Check that mktime (2106-02-07 06:28:16) returns 0x100000000.  */
     102    t = tm32bitmax;
     103    t.tm_sec++;
     104    test_mktime_helper (&t, 0x100000000, __LINE__);
     105  
     106    return 0;
     107  }
     108  
     109  #include <support/test-driver.c>