dnl -*- mode: Autoconf; -*-

dnl -----------------------------------------------------------------------------------------
dnl check for flex
dnl -----------------------------------------------------------------------------------------

AC_MSG_NOTICE([................................................................................])
AC_MSG_NOTICE([CHECKING FLEX])
AC_MSG_NOTICE([................................................................................])

AC_PROG_LEX

tr_flex_usable=no

if test "x$LEX" != x -a "x$LEX" != "x:";  then
  AC_MSG_CHECKING([if flex supports required features])

  [tr_flex_version=`$LEX --version | sed -e 's:^[^0-9]*::' | awk -F. '{print $1 * 10000 + $2 * 100 + $3}'`]

  if test "$tr_flex_version" -ge 20535;  then
    tr_flex_usable=yes
  fi

  AC_MSG_RESULT($tr_flex_usable)
fi

if test "x$tr_flex_usable" != "xyes"; then
  AC_MSG_ERROR([Please install flex version 2.5.35 or higher from http://ftp.gnu.org/gnu/flex/])
fi

AC_MSG_CHECKING([FLEX version])
TRI_FLEX_VERSION=`$LEX --version`
AC_MSG_RESULT([$TRI_FLEX_VERSION])

AM_CONDITIONAL(ENABLE_FLEX, test "x$tr_flex_usable" = xyes)

dnl -----------------------------------------------------------------------------------------
dnl informational output
dnl -----------------------------------------------------------------------------------------

LIB_INFO="$LIB_INFO|FLEX VERSION: ${TRI_FLEX_VERSION}"