AC_DEFUN([AC_DEFINE_DIR], [
test "x$prefix" = xNONE && prefix="$ac_default_prefix"
test "x$exec_prefix" = xNONE && exec_prefix='${prefix}'
- ac_define_dir=`eval echo [$]$2`
- ac_define_dir=`eval echo [$]ac_define_dir`
+ last_ac_define_dir=`eval echo [$]$2`
+ ac_define_dir=`eval echo [$]last_ac_define_dir`
+ ac_define_dir_counter=0
+ while test "x[$]last_ac_define_dir" != "x[$]ac_define_dir"; do
+ last_ac_define_dir="[$]ac_define_dir"
+ ac_define_dir=`eval echo [$]last_ac_define_dir`
+ AS_VAR_ARITH([ac_define_dir_counter], [$ac_define_dir_counter + 1])
+ AS_VAR_IF([ac_define_dir_counter], [128],
+ [AC_MSG_ERROR([detected recusive directory expansion when expanding $1=[$]$2: [$]ac_define_dir])
+ break])
+ done
$1="$ac_define_dir"
AC_SUBST($1)
ifelse($3, ,