m4/pdns_check_flex.m4

   1 AC_DEFUN([PDNS_CHECK_FLEX], [
   2   AC_REQUIRE([AC_PROG_LEX])
   3   AC_REQUIRE([AC_PROG_EGREP])
   4
   5   AC_CACHE_CHECK([if the lexer is flex],[pdns_cv_prog_flex],[
   6     AS_IF([$LEX --version 2>/dev/null | $EGREP -q '^flex '],
   7       [pdns_cv_prog_flex=yes], [pdns_cv_prog_flex=no])
   8   ])
   9
  10   AS_IF([test "x$pdns_cv_prog_flex" = "xno"], [
  11     AS_IF([test ! -f "${srcdir}/pdns/bindlexer.c"],
  12       [AC_MSG_ERROR([flex is missing and you don't have ${srcdir}/pdns/bindlexer.c. Please install flex])]
  13     )]
  14   )
  15 ])