m4/c-bs-a.m4

   1 #serial 4
   2
   3 dnl From Paul Eggert.
   4
   5 AC_DEFUN([AC_C_BACKSLASH_A],
   6 [
   7   AC_CACHE_CHECK([whether backslash-a works in strings], ac_cv_c_backslash_a,
   8    [AC_TRY_COMPILE([],
   9      [
  10 #if '\a' == 'a'
  11       syntax error;
  12 #endif
  13       char buf['\a' == 'a' ? -1 : 1];
  14       buf[0] = '\a';
  15       return buf[0] != "\a"[0];
  16      ],
  17      ac_cv_c_backslash_a=yes,
  18      ac_cv_c_backslash_a=no)])
  19   if test $ac_cv_c_backslash_a = yes; then
  20     AC_DEFINE(HAVE_C_BACKSLASH_A, 1,
  21       [Define if backslash-a works in C strings.])
  22   fi
  23 ])