time/tst-mktime4.c

   1 /* Test for mktime (4)
   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 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>