build script support to build tools like xdpdump

Summary:
This allows building of xdpdump via the central build-script. (follow up from
#110)

Reviewed By: avasylev

Differential Revision: D25877843

fbshipit-source-id: 7977e88a2251b4d0b98a23e90f521992c8c9bc08

CMakeLists.txt

@@ -50,6 +50,10 @@ if(DEFINED ENV{CMAKE_BUILD_EXAMPLE_GRPC})
     add_subdirectory(example_grpc)
 endif()
 
+if(DEFINED ENV{CMAKE_BUILD_TOOLS})
+    add_subdirectory(tools)
+endif()
+
 install(
   EXPORT katran-exports
   FILE katran-targets.cmake

build_katran.sh

@@ -85,6 +85,11 @@ if [ -z "$BUILD_EXAMPLE_GRPC" ]; then
     export CMAKE_BUILD_EXAMPLE_GRPC="$BUILD_EXAMPLE_GRPC"
 fi
 
+if [ -n "$BUILD_TOOLS" ]; then
+    BUILD_TOOLS=1
+    export CMAKE_BUILD_TOOLS="$BUILD_TOOLS"
+fi
+
 get_dev_tools() {
     if [ -f /etc/redhat-release ]; then
         sudo yum install -y epel-release

tools/xdpdump/CMakeLists.txt

@@ -45,7 +45,6 @@ target_link_libraries(xdpdump
   "${PTHREAD}"
   "${LIBDC}"
   "${DL}"
-  "libevent:libevent"
   "${EVENT_CORE}"
   "${LIBIBERTY}"
   iphelpers