build-sys: add parse-date.y

* add lib/parse-date.y to build system
* add necessary autotools stuff to generate .c on the fly
  (autotools are smart enough to add generated file to tarball)
* check for bison version by ./autogen.sh
* add non-wanted junk to .gitignore

With some modification by J William Piggott with regard to
moving the parse-date API into timeutils.h

Signed-off-by: J William Piggott <elseifthen@gmx.com>

.gitignore

@@ -55,6 +55,7 @@ test-suite.log
 tests/run.sh.log
 tests/run.sh.trs
 update.log
+ylwrap
 
 #
 # binaries

autogen.sh

@@ -67,6 +67,25 @@ test -f sys-utils/mount.c || {
 	DIE=1
 }
 
+if ! (bison --version) < /dev/null > /dev/null 2>&1; then
+	echo
+	echo "You must have bison installed to build the util-linux."
+	echo
+	DIE=1
+else
+	lexver=$(bison --version | awk '/bison \(GNU Bison\)/ { print $4 }')
+	case "$lexver" in
+		[2-9].*)
+			;;
+		*)
+			echo
+			echo "You must have bison version >= 2.x, but you have $lexver."
+			echo
+			DIE=1
+			;;
+	esac
+fi
+
 LIBTOOLIZE=libtoolize
 case `uname` in Darwin*) LIBTOOLIZE=glibtoolize ;; esac
 if ! ($LIBTOOLIZE --version) < /dev/null > /dev/null 2>&1; then
@@ -104,6 +123,7 @@ echo "   autoconf:   $(autoconf --version | head -1)"
 echo "   autoheader: $(autoheader --version | head -1)"
 echo "   automake:   $(automake --version | head -1)"
 echo "   libtoolize: $($LIBTOOLIZE --version | head -1)"
+echo "   bison:      $(bison --version | head -1)"
 
 rm -rf autom4te.cache
 

configure.ac

@@ -99,6 +99,7 @@ AC_SUBST([usrlib_execdir])
 AM_PROG_CC_C_O
 AC_PROG_MKDIR_P
 AC_PROG_CC_STDC
+AC_PROG_YACC
 AC_CANONICAL_HOST
 AC_C_CONST
 AC_C_VOLATILE
@@ -153,7 +154,6 @@ PKG_PROG_PKG_CONFIG
 GTK_DOC_CHECK([1.10])
 AC_PATH_PROG([XSLTPROC], [xsltproc])
 
-
 linux_os=no
 bsd_os=no
 AS_CASE([${host_os}],

lib/.gitignore

@@ -0,0 +1 @@
+parse-date.c

lib/Makemodule.am

@@ -16,6 +16,7 @@ libcommon_la_SOURCES = \
 	lib/mbsedit.c\
 	lib/md5.c \
 	lib/pager.c \
+	lib/parse-date.y \
 	lib/path.c \
 	lib/randutils.c \
 	lib/setproctitle.c \