Why won't CMake compile this protobuff class?

Question

So I am trying to follow an example about how to add a topic using Gazebo's subscription service. Alas, one of the steps is to create a protobuf object and unfortunately, my protobuff class just will not compile when I run CMake. Here is what I have so far:

import "vector3d.proto";

message ModelVelResponse
{
  required AVelV angularVel = 1;
  required LVelV linearVel = 2;
}

message AVelV{
  repeated gazebo.msgs.Vector3d  angularVel = 1;
}

message LVelV{
  repeated gazebo.msgs.Vector3d  linearVel = 1;
}

and here is my cmake file

cmake_minimum_required(VERSION 2.8 FATAL_ERROR)

find_package(Protobuf REQUIRED)

set(PROTOBUF_IMPORT_DIRS)
foreach(ITR ${GAZEBO_INCLUDE_DIRS})
  if(ITR MATCHES ".*gazebo-[0-9.]+$")
    set(PROTOBUF_IMPORT_DIRS "${ITR}/gazebo/msgs/proto")
  endif()
endforeach()

set (msgs
  velocity_message.proto
  ${PROTOBUF_IMPORT_DIRS}/vector3d.proto
  ${PROTOBUF_IMPORT_DIRS}/header.proto
  ${PROTOBUF_IMPORT_DIRS}/time.proto
)
PROTOBUF_GENERATE_CPP(PROTO_SRCS PROTO_HDRS ${msgs})
add_library(velocity_msgs SHARED ${PROTO_SRCS})
target_link_libraries(velocity_msgs ${PROTOBUF_LIBRARY})

find_package(Boost REQUIRED COMPONENTS system)
include_directories(${Boost_INCLUDE_DIRS})
link_directories(${Boost_LIBRARY_DIRS})

include (FindPkgConfig)
if (PKG_CONFIG_FOUND)
  pkg_check_modules(GAZEBO gazebo)
endif()
include_directories(${GAZEBO_INCLUDE_DIRS})
link_directories(${GAZEBO_LIBRARY_DIRS})

add_library(model_vel SHARED model_vel.cc)
target_link_libraries(model_vel ${GAZEBO_LIBRARIES} ${Boost_LIBRARIES})

Any idea what I am doing wrong? My protobuf file in a "msgs" subdirectory but when I move the code that is suppose to generate the protobuf libs into the subdirectory it still fails to compile. It does not through out any errors either.

Update: I am basing my code off this tutorial.

Answer 1

I solved this issue by changing the make file to so:

find_package(Protobuf REQUIRED)


set(PROTOBUF_IMPORT_DIRS)
foreach(ITR ${GAZEBO_INCLUDE_DIRS})
  if(ITR MATCHES ".*gazebo-[0-9.]+$")
    set(PROTOBUF_IMPORT_DIRS "${ITR}/gazebo/msgs/proto")
  endif()
endforeach()

    set (msgs
      velocity_message.proto
      ${PROTOBUF_IMPORT_DIRS}/vector3d.proto
      ${PROTOBUF_IMPORT_DIRS}/header.proto
      ${PROTOBUF_IMPORT_DIRS}/time.proto
    )
    PROTOBUF_GENERATE_CPP(PROTO_SRCS PROTO_HDRS ${msgs})
    add_library(velocity_msgs SHARED ${PROTO_SRCS})
    target_link_libraries(velocity_msgs ${PROTOBUF_LIBRARY})

I just had to add it as a shared library.