1  /* Test of <sys/select.h> substitute.
       2     Copyright (C) 2007-2023 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 Bruno Haible <bruno@clisp.org>, 2007.  */
      18  
      19  #include <config.h>
      20  
      21  #include <sys/select.h>
      22  
      23  /* Check that the 'struct timeval' type is defined.  */
      24  struct timeval a;
      25  
      26  /* Check that a.tv_sec is wide enough to hold a time_t, ignoring
      27     signedness issues.  */
      28  typedef int verify_tv_sec_type[sizeof (time_t) <= sizeof (a.tv_sec) ? 1 : -1];
      29  
      30  /* Check that sigset_t is defined.  */
      31  sigset_t t2;
      32  
      33  #include "signature.h"
      34  
      35  /* The following may be macros without underlying functions, so only
      36     check signature if they are not macros.  */
      37  #ifndef FD_CLR
      38  SIGNATURE_CHECK (FD_CLR, void, (int, fd_set *));
      39  #endif
      40  #ifndef FD_ISSET
      41  SIGNATURE_CHECK (FD_ISSET, void, (int, fd_set *));
      42  #endif
      43  #ifndef FD_SET
      44  SIGNATURE_CHECK (FD_SET, int, (int, fd_set *));
      45  #endif
      46  #ifndef FD_ZERO
      47  SIGNATURE_CHECK (FD_ZERO, void, (fd_set *));
      48  #endif
      49  
      50  int
      51  main (void)
      52  {
      53    /* Check that FD_ZERO can be used.  This should not yield a warning
      54       such as "warning: implicit declaration of function 'memset'".  */
      55    fd_set fds;
      56    FD_ZERO (&fds);
      57  
      58    return 0;
      59  }