+libfilter_la_CFLAGS = -include filter-symbols.h $(AM_CFLAGS)
+libfilter_la_LIBADD = $(top_builddir)/src/common/string-utils/libstring-utils.la
+
+AM_YFLAGS = -t -d -v
+
+# start with empty files to clean
+CLEANFILES =
+
+if HAVE_BISON
+# we have bison: we can clean the generated parser files
+CLEANFILES += filter-parser.c filter-parser.h filter-parser.output
+else # HAVE_BISON
+# create target used to stop the build if we want to build the parser,
+# but we don't have the necessary tool to do so
+ERR_MSG = "Error: Cannot build target because bison is missing."
+ERR_MSG += "Make sure bison is installed and run the configure script again."
+
+filter-parser.c filter-parser.h: filter-parser.y
+ @echo $(ERR_MSG)
+ @false
+
+all-local: filter-parser.c filter-parser.h
+endif # HAVE_BISON
+
+if HAVE_FLEX
+# we have flex: we can clean the generated lexer files
+CLEANFILES += filter-lexer.c
+else # HAVE_FLEX
+# create target used to stop the build if we want to build the lexer,
+# but we don't have the necessary tool to do so
+ERR_MSG = "Error: Cannot build target because flex is missing."
+ERR_MSG += "Make sure flex is installed and run the configure script again."
+
+filter-lexer.c: filter-lexer.l
+ @echo $(ERR_MSG)
+ @false
+
+all-local: filter-lexer.c
+endif # HAVE_FLEX