configure: Add check for lex, yacc

Signed-off-by: Geoff Levand <geoff@infradead.org>
Signed-off-by: Samuel Mendoza-Jonas <sam@mendozajonas.com>

diff --git a/configure.ac b/configure.ac
index 3ed41eee7bdd984b73794f92158b1acfaab008cd..f394de6369cf2c3f54c67bf91d92b0ef52546e00 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -26,7 +26,13 @@ AS_IF([test "x$CFLAGS" = "x"], [AC_SUBST([CFLAGS], [""])])
 
 AC_PROG_CC
 AC_PROG_LEX
+if test -z "$($LEX --version)"; then
+       AC_MSG_ERROR([[Please install flex/lex]])
+fi
 AC_PROG_YACC
+if test -z "$($YACC --version)"; then
+       AC_MSG_ERROR([[Please install bison/yacc]])
+fi
 AC_PROG_INSTALL
 
 AM_INIT_AUTOMAKE