configure: add options ability

There are more and more global environment variables that land everywhere
in configure, which is making user hard to know which one does what.
Using command-line options would make it easier for users to learn or
remember the config options.

This patch converts the INCLUDE variable to command option first. Check
if the first variable has '-' to compile with the old INCLUDE path
setting method.

Signed-off-by: Hangbin Liu <haliu@redhat.com>
Signed-off-by: David Ahern <dsahern@kernel.org>

diff --git a/configure b/configure
index 179eae08c161b7ea081828d56a4d21379770c57c..c58419c27a716a82e8ff56609d8aa3ccf73b94d0 100755 (executable)
--- a/configure
+++ b/configure
@@ -7,7 +7,7 @@
 #                           off: disable libbpf probing
 #   LIBBPF_DIR              Path to libbpf DESTDIR to use
 
-INCLUDE=${1:-"$PWD/include"}
+INCLUDE="$PWD/include"
 
 # Output file which is input to Makefile
 CONFIG=config.mk
@@ -486,6 +486,35 @@ endif
 EOF
 }
 
+usage()
+{
+       cat <<EOF
+Usage: $0 [OPTIONS]
+       --include_dir           Path to iproute2 include dir
+       -h | --help             Show this usage info
+EOF
+       exit $1
+}
+
+# Compat with the old INCLUDE path setting method.
+if [ $# -eq 1 ] && [ "$(echo $1 | cut -c 1)" != '-' ]; then
+       INCLUDE="$1"
+else
+       while true; do
+               case "$1" in
+                       --include_dir)
+                               INCLUDE=$2
+                               shift 2 ;;
+                       -h | --help)
+                               usage 0 ;;
+                       "")
+                               break ;;
+                       *)
+                               usage 1 ;;
+               esac
+       done
+fi
+
 echo "# Generated config based on" $INCLUDE >$CONFIG
 quiet_config >> $CONFIG