1  /*
       2   * Copyright (C) 2005, 2007, 2009-2023 Free Software Foundation, Inc.
       3   *
       4   * This program is free software: you can redistribute it and/or modify
       5   * it under the terms of the GNU General Public License as published by
       6   * the Free Software Foundation, either version 3 of the License, or
       7   * (at your option) any later version.
       8   *
       9   * This program is distributed in the hope that it will be useful,
      10   * but WITHOUT ANY WARRANTY; without even the implied warranty of
      11   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      12   * GNU General Public License for more details.
      13   *
      14   * You should have received a copy of the GNU General Public License
      15   * along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
      16  
      17  /* Written by Jim Meyering and Bruno Haible.  */
      18  
      19  #include <config.h>
      20  
      21  #include <sys/time.h>
      22  
      23  #include "signature.h"
      24  SIGNATURE_CHECK (gettimeofday, int,
      25                   (struct timeval *, GETTIMEOFDAY_TIMEZONE *));
      26  
      27  #include <time.h>
      28  
      29  #include <stdio.h>
      30  #include <stdlib.h>
      31  #include <string.h>
      32  
      33  #include "macros.h"
      34  
      35  static void
      36  test_clobber ()
      37  {
      38    time_t t = 0;
      39    struct tm *lt;
      40    struct tm saved_lt;
      41    struct timeval tv;
      42    lt = localtime (&t);
      43    saved_lt = *lt;
      44    gettimeofday (&tv, NULL);
      45    if (memcmp (lt, &saved_lt, sizeof (struct tm)) != 0)
      46      {
      47        fprintf (stderr, "gettimeofday still clobbers the localtime buffer!\n");
      48        exit (1);
      49      }
      50  }
      51  
      52  static void
      53  test_consistency ()
      54  {
      55    struct timeval tv1;
      56    time_t tt2;
      57    struct timeval tv3;
      58    time_t tt4;
      59  
      60    ASSERT (gettimeofday (&tv1, NULL) == 0);
      61    tt2 = time (NULL);
      62    ASSERT (gettimeofday (&tv3, NULL) == 0);
      63    tt4 = time (NULL);
      64  
      65    /* Verify monotonicity of gettimeofday().  */
      66    ASSERT (tv1.tv_sec < tv3.tv_sec
      67            || (tv1.tv_sec == tv3.tv_sec && tv1.tv_usec <= tv3.tv_usec));
      68  
      69    /* Verify monotonicity of time().  */
      70    ASSERT (tt2 <= tt4);
      71  
      72    /* Verify that the tv_sec field of the result is the same as time(NULL).  */
      73    /* Note: It's here that the dependency to the 'time' module is needed.
      74       Without it, this assertion would sometimes fail on glibc systems, see
      75       https://sourceware.org/bugzilla/show_bug.cgi?id=30200  */
      76    ASSERT (tv1.tv_sec <= tt2);
      77    ASSERT (tt2 <= tv3.tv_sec);
      78    ASSERT (tv3.tv_sec <= tt4);
      79  }
      80  
      81  int
      82  main (void)
      83  {
      84    test_clobber ();
      85    test_consistency ();
      86  
      87    return 0;
      88  }