1  /* Unit test for _Unwind_Backtrace in a shared object constructor.
       2     Copyright (C) 2018-2023 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 <unwind.h>
      20  #include <unistd.h>
      21  
      22  static _Unwind_Reason_Code
      23  callback (struct _Unwind_Context *ctx, void *arg)
      24  {
      25    return _URC_NO_REASON;
      26  }
      27  
      28  static void
      29  __attribute__ ((constructor))
      30  do_unwind (void)
      31  {
      32    /* Arrange for this test to be killed if _Unwind_Backtrace runs into an
      33       endless loop.  We cannot use the test driver since the test needs to
      34       run in a constructor.  */
      35    alarm (20);
      36    _Unwind_Backtrace (callback, 0);
      37  }
      38  
      39  void
      40  dummy (void)
      41  {
      42  }