1  /* __gmp_invalid_operation -- invalid floating point operation.
       2  
       3     THE FUNCTIONS IN THIS FILE ARE FOR INTERNAL USE ONLY.  THEY'RE ALMOST
       4     CERTAIN TO BE SUBJECT TO INCOMPATIBLE CHANGES OR DISAPPEAR COMPLETELY IN
       5     FUTURE GNU MP RELEASES.
       6  
       7  Copyright 2003 Free Software Foundation, Inc.
       8  
       9  This file is part of the GNU MP Library.
      10  
      11  The GNU MP Library is free software; you can redistribute it and/or modify
      12  it under the terms of either:
      13  
      14    * the GNU Lesser General Public License as published by the Free
      15      Software Foundation; either version 3 of the License, or (at your
      16      option) any later version.
      17  
      18  or
      19  
      20    * the GNU General Public License as published by the Free Software
      21      Foundation; either version 2 of the License, or (at your option) any
      22      later version.
      23  
      24  or both in parallel, as here.
      25  
      26  The GNU MP Library is distributed in the hope that it will be useful, but
      27  WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
      28  or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
      29  for more details.
      30  
      31  You should have received copies of the GNU General Public License and the
      32  GNU Lesser General Public License along with the GNU MP Library.  If not,
      33  see https://www.gnu.org/licenses/.  */
      34  
      35  #include "config.h"
      36  
      37  #include <signal.h>
      38  #include <stdlib.h>
      39  
      40  #if HAVE_UNISTD_H
      41  #include <unistd.h>  /* for getpid */
      42  #endif
      43  
      44  #include "gmp-impl.h"
      45  
      46  
      47  /* Incidentally, kill is not available on mingw, but that's ok, it has raise
      48     and we'll be using that.  */
      49  #if ! HAVE_RAISE
      50  #define raise(sig)   kill (getpid(), sig)
      51  #endif
      52  
      53  
      54  /* __gmp_invalid_operation is for an invalid floating point operation, like
      55     mpz_set_d on a NaN or Inf.  It's done as a subroutine to minimize code in
      56     places raising an exception.
      57  
      58     feraiseexcept(FE_INVALID) is not used here, since unfortunately on most
      59     systems it would require libm.
      60  
      61     Alternatives:
      62  
      63     It might be possible to check whether a hardware "invalid operation" trap
      64     is enabled or not before raising a signal.  This would require all
      65     callers to be prepared to continue with some bogus result.  Bogus returns
      66     are bad, but presumably an application disabling the trap is prepared for
      67     that.
      68  
      69     On some systems (eg. BSD) the signal handler can find out the reason for
      70     a SIGFPE (overflow, invalid, div-by-zero, etc).  Perhaps we could get
      71     that into our raise too.
      72  
      73     i386 GLIBC implements feraiseexcept(FE_INVALID) with an asm fdiv 0/0.
      74     That would both respect the exceptions mask and give a reason code in a
      75     BSD signal.  */
      76  
      77  void
      78  __gmp_invalid_operation (void)
      79  {
      80    raise (SIGFPE);
      81    abort ();
      82  }