vcs.maemo.org Git - lms/blob - lightmediascanner/m4/as-expand.m4

   1 dnl AS_AC_EXPAND(VAR, CONFIGURE_VAR)
   2 dnl
   3 dnl example
   4 dnl AS_AC_EXPAND(SYSCONFDIR, $sysconfdir)
   5 dnl will set SYSCONFDIR to /usr/local/etc if prefix=/usr/local
   6
   7 AC_DEFUN([AS_AC_EXPAND],
   8 [
   9   EXP_VAR=[$1]
  10   FROM_VAR=[$2]
  11
  12   dnl first expand prefix and exec_prefix if necessary
  13   prefix_save=$prefix
  14   exec_prefix_save=$exec_prefix
  15
  16   dnl if no prefix given, then use /usr/local, the default prefix
  17   if test "x$prefix" = "xNONE"; then
  18     prefix=$ac_default_prefix
  19   fi
  20   dnl if no exec_prefix given, then use prefix
  21   if test "x$exec_prefix" = "xNONE"; then
  22     exec_prefix=$prefix
  23   fi
  24
  25   full_var="$FROM_VAR"
  26   dnl loop until it doesn't change anymore
  27   while true; do
  28     new_full_var="`eval echo $full_var`"
  29     dnl if test "x$new_full_var" = "x$full_var"; then
  30     if test "x${new_full_var:0:1}" != "x\$"; then
  31         break;
  32     fi
  33     full_var=$new_full_var
  34   done
  35
  36   dnl clean up
  37   full_var=$new_full_var
  38   AC_SUBST([$1], "$full_var")
  39
  40   dnl restore prefix and exec_prefix
  41   prefix=$prefix_save
  42   exec_prefix=$exec_prefix_save
  43 ])