m4/ax_prog_flex.m4

   1 # ===========================================================================
   2 #       http://www.gnu.org/software/autoconf-archive/ax_prog_flex.html
   3 # ===========================================================================
   4 #
   5 # SYNOPSIS
   6 #
   7 #   AX_PROG_FLEX(ACTION-IF-TRUE,ACTION-IF-FALSE)
   8 #
   9 # DESCRIPTION
  10 #
  11 #   Check whether flex is the scanner generator. Run ACTION-IF-TRUE if
  12 #   successful, ACTION-IF-FALSE otherwise
  13 #
  14 # LICENSE
  15 #
  16 #   Copyright (c) 2009 Francesco Salvestrini <salvestrini@users.sourceforge.net>
  17 #   Copyright (c) 2010 Diego Elio Petteno` <flameeyes@gmail.com>
  18 #
  19 #   This program is free software; you can redistribute it and/or modify it
  20 #   under the terms of the GNU General Public License as published by the
  21 #   Free Software Foundation; either version 2 of the License, or (at your
  22 #   option) any later version.
  23 #
  24 #   This program is distributed in the hope that it will be useful, but
  25 #   WITHOUT ANY WARRANTY; without even the implied warranty of
  26 #   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
  27 #   Public License for more details.
  28 #
  29 #   You should have received a copy of the GNU General Public License along
  30 #   with this program. If not, see <http://www.gnu.org/licenses/>.
  31 #
  32 #   As a special exception, the respective Autoconf Macro's copyright owner
  33 #   gives unlimited permission to copy, distribute and modify the configure
  34 #   scripts that are the output of Autoconf when processing the Macro. You
  35 #   need not follow the terms of the GNU General Public License when using
  36 #   or distributing such scripts, even though portions of the text of the
  37 #   Macro appear in them. The GNU General Public License (GPL) does govern
  38 #   all other use of the material that constitutes the Autoconf Macro.
  39 #
  40 #   This special exception to the GPL applies to versions of the Autoconf
  41 #   Macro released by the Autoconf Archive. When you make and distribute a
  42 #   modified version of the Autoconf Macro, you may extend this special
  43 #   exception to the GPL to apply to your modified version as well.
  44
  45 #serial 12
  46
  47 # mattst88:
  48 #     Replaced m4_ifnblank(...) with m4_ifval(m4_normalize(...), ...)
  49 #     since m4_ifnblank requires autoconf-2.64.
  50
  51 AC_DEFUN([AX_PROG_FLEX], [
  52   AC_REQUIRE([AM_PROG_LEX])
  53   AC_REQUIRE([AC_PROG_EGREP])
  54
  55   AC_CACHE_CHECK([if flex is the lexer generator],[ax_cv_prog_flex],[
  56     AS_IF([$LEX --version 2>/dev/null | $EGREP -qw '^g?flex'],
  57       [ax_cv_prog_flex=yes], [ax_cv_prog_flex=no])
  58   ])
  59   AS_IF([test "$ax_cv_prog_flex" = "yes"],
  60     m4_ifval(m4_normalize([$1]), [[$1]]),
  61     m4_ifval(m4_normalize([$2]), [[$2]])
  62   )
  63 ])