dnl Check whether the st_ino and st_dev stat fields taken together uniquely
dnl identify the file within the system. This is should be true for POSIX
dnl systems; it is known to be false on mingw32.
AC_DEFUN([LIBGFOR_CHECK_WORKING_STAT], [
  AC_CACHE_CHECK([whether the target stat is reliable],
                  libgfor_cv_have_working_stat, [
  AC_RUN_IFELSE([AC_LANG_SOURCE([[
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>

int main ()
{
  FILE *f, *g;
  struct stat st1, st2;

  f = fopen ("foo", "w");
  g = fopen ("bar", "w");
  if (stat ("foo", &st1) != 0 || stat ("bar", &st2))
    return 1;
  if (st1.st_dev == st2.st_dev && st1.st_ino == st2.st_ino)
    return 1;
  fclose(f);
  fclose(g);
  return 0;
}]])], libgfor_cv_have_working_stat=yes, libgfor_cv_have_working_stat=no, [