# ===========================================================================

# https://www.gnu.org/software/autoconf-archive/ax_prog_flex_version.html

# ===========================================================================

#

# SYNOPSIS

#

# AX_PROG_FLEX_VERSION([VERSION],[ACTION-IF-TRUE],[ACTION-IF-FALSE])

#

# DESCRIPTION

#

# Makes sure that flex version is greater or equal to the version

# indicated. If true the shell commands in ACTION-IF-TRUE are executed. If

# not the shell commands in commands in ACTION-IF-TRUE are executed. If

# not the shell commands in ACTION-IF-FALSE are run. Note if $FLEX is not

# set (for example by running AC_CHECK_PROG or AC_PATH_PROG) the macro

# will fail.

#

# Example:

#

# AC_PATH_PROG([FLEX],[flex])

# AX_PROG_FLEX_VERSION([2.5.39],[ ... ],[ ... ])

#

# This will check to make sure that the flex you have is at least version

# 2.5.39 or greater.

#

# NOTE: This macro uses the $FLEX variable to perform the check.

#

# LICENSE

#

# Copyright (c) 2015 Jonathan Rajotte-Julien <jonathan.rajotte-julien@efficios.com>

#

# Copying and distribution of this file, with or without modification, are

# permitted in any medium without royalty provided the copyright notice

# and this notice are preserved. This file is offered as-is, without any

# warranty.

#serial 2

AC_DEFUN([AX_PROG_FLEX_VERSION],[

AC_REQUIRE([AC_PROG_SED])

AC_REQUIRE([AC_PROG_GREP])

AS_IF([test -n "$FLEX"],[

ax_flex_version="$1"

AC_MSG_CHECKING([for flex version])

changequote(<<,>>)

flex_version=`$FLEX --version 2>&1 \

| $SED -n -e '/flex /s/.* (\{0,1\}\([0-9]*\.[0-9]*\.[0-9]*\))\{0,1\}.*/\1/;p'`

changequote([,])

AC_MSG_RESULT($flex_version)

AC_SUBST([FLEX_VERSION],[$flex_version])

AX_COMPARE_VERSION([$flex_version],[ge],[$ax_flex_version],[

:

$2

],[

:

$3

])

],[

AC_MSG_WARN([could not find flex])

$3

])

])