unix/m4/intdiv0.m4

# intdiv0.m4 serial 1 (gettext-0.11.3)
dnl Copyright (C) 2002 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
dnl with or without modifications, as long as this notice is preserved.

dnl From Bruno Haible.

AC_DEFUN([gt_INTDIV0],
[
  AC_REQUIRE([AC_PROG_CC])dnl
  AC_REQUIRE([AC_CANONICAL_HOST])dnl

  AC_CACHE_CHECK([whether integer division by zero raises SIGFPE],
    gt_cv_int_divbyzero_sigfpe,
    [
      AC_TRY_RUN([
#include <stdlib.h>
#include <signal.h>

static void
#ifdef __cplusplus
sigfpe_handler (int sig)
#else
sigfpe_handler (sig) int sig;
#endif
{
  /* Exit with code 0 if SIGFPE, with code 1 if any other signal.  */
  exit (sig != SIGFPE);
}

int x = 1;
int y = 0;
int z;
int nan;

int main ()
{
  signal (SIGFPE, sigfpe_handler);
/* IRIX and AIX (when "xlc -qcheck" is used) yield signal SIGTRAP.  */
#if (defined (__sgi) || defined (_AIX)) && defined (SIGTRAP)
  signal (SIGTRAP, sigfpe_handler);
#endif
/* Linux/SPARC yields signal SIGILL.  */
#if defined (__sparc__) && defined (__linux__)
  signal (SIGILL, sigfpe_handler);
#endif

  z = x / y;
  nan = y / y;
  exit (1);
}
], gt_cv_int_divbyzero_sigfpe=yes, gt_cv_int_divbyzero_sigfpe=no,
        [
          # Guess based on the CPU.
          case "$host_cpu" in
            alpha* | i[34567]86 | m68k | s390*)
              gt_cv_int_divbyzero_sigfpe="guessing yes";;
            *)
              gt_cv_int_divbyzero_sigfpe="guessing no";;
          esac
        ])
    ])
  case "$gt_cv_int_divbyzero_sigfpe" in
    *yes) value=1;;
    *) value=0;;
  esac
  AC_DEFINE_UNQUOTED(INTDIV0_RAISES_SIGFPE, $value,
    [Define if integer division by zero raises signal SIGFPE.])
])