dpdkstrip: add a preprocessor tool for stripping dpdk blocks

Normally, in C code, pre-processing macros can be used to enable/disable
specific functionality based on switches passed to configure.  This works
for DPDK using the --with-dpdk flag, which sets the DPDK_NETDEV define to
the appropriate value.

However, not all files are processed with the C pre-processor.  For those
files which are not, this commit adds a new pre-processor tool for .in
files to either include or exclude those stanzas as appropriate.

Signed-off-by: Aaron Conole <aconole@redhat.com>
Signed-off-by: Russell Bryant <russell@ovn.org>

Makefile.am

@@ -82,6 +82,7 @@ EXTRA_DIST = \
 	build-aux/cksum-schema-check \
 	build-aux/calculate-schema-cksum \
 	build-aux/dist-docs \
+	build-aux/dpdkstrip.pl \
 	build-aux/sodepends.pl \
 	build-aux/soexpand.pl \
 	build-aux/xml2nroff \

build-aux/dpdkstrip.pl

@@ -0,0 +1,35 @@
+# Copyright (c) 2017 Red Hat, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at:
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+use strict;
+use warnings;
+use Getopt::Long;
+
+my ($check_dpdk) = 0;
+my ($disabled_print) = 0;
+
+Getopt::Long::Configure ("bundling");
+GetOptions("dpdk!" => \$check_dpdk) or exit(1);
+
+OUTER: while (<STDIN>) {
+    if (/@(begin|end)_dpdk@/) {
+        if (!$check_dpdk) {
+            $disabled_print = ! $disabled_print;
+        }
+        next;
+    }
+
+    print $_ unless $disabled_print;
+}
+exit 0;