Combining two CMakeLists.txt file (ROS and Libtorch) - cmake

Question

I am trying to combine two CMakeLists.txt files to compile a C++ program that has both ROS and Libtorch dependencies. The individual files are provided below:
Libtorch CMakeLists.txt file:
cmake_minimum_required(VERSION 3.0 FATAL_ERROR)
project(example-app)
find_package(Torch REQUIRED)
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${TORCH_CXX_FLAGS}")
add_executable(example-app example-app.cpp)
target_link_libraries(example-app "${TORCH_LIBRARIES}")
set_property(TARGET example-app PROPERTY CXX_STANDARD 14)
# The following code block is suggested to be used on Windows.
# According to https://github.com/pytorch/pytorch/issues/25457,
# the DLLs need to be copied to avoid memory errors.
if (MSVC)
file(GLOB TORCH_DLLS "${TORCH_INSTALL_PREFIX}/lib/*.dll")
add_custom_command(TARGET example-app
POST_BUILD
COMMAND ${CMAKE_COMMAND} -E copy_if_different
${TORCH_DLLS}
$<TARGET_FILE_DIR:example-app>)
endif (MSVC)
I found this here: https://pytorch.org/cppdocs/installing.html
ROS CMakeListis.txt file:
cmake_minimum_required(VERSION 2.8.3)
project(fly_bot_cpp)
find_package(catkin REQUIRED COMPONENTS
roscpp
rospy
std_msgs
geometry_msgs
tf
gazebo_msgs
)
include_directories(
include
${catkin_INCLUDE_DIRS}
${Boost_INCLUDE_DIRS}
)
add_executable(example src/example.cpp)
target_link_libraries(example ${catkin_LIBRARIES})
The program example-app.cpp has both libraries of ROS and LibTorch.
So here is what i tried to do:
cmake_minimum_required(VERSION 2.8.3)
project(fly_bot_cpp)
set(CMAKE_PREFIX_PATH="home/jarvis/libtorch;/opt/ros/melodic")
find_package(catkin REQUIRED COMPONENTS
roscpp
std_msgs
geometry_msgs
tf
rospy
message_generation
)
find_package(Torch REQUIRED)
include_directories(
include
${catkin_INCLUDE_DIRS}
${Boost_INCLUDE_DIRS}
)
add_executable(test_quad src/test_quad.cpp)
target_link_libraries(test_quad ${catkin_LIBRARIES} "${TORCH_LIBRARIES}")
set_property(TARGET test_quad PROPERTY CXX_STANDARD 14)
The code test_quad.cpp (previously referred to as example-app.cpp) contains ros header files and torch header files:
#include "ros/ros.h"
#include <torch/torch.h>
.
.
.
However, I get the following error.
fatal error: torch/torch.h: No such file or directory
#include <torch/torch.h>
^~~~~~~~~~~~~~~
compilation terminated.
Can someone please help me out??
Thank you so much.

Answer 1

Remove the quotes around ${TORCH_LIBRARIES} in your target_link_libraries.
The line should look like this
target_link_libraries(test_quad ${catkin_LIBRARIES} ${TORCH_LIBRARIES})
This should resolve the torch header.
Please also take a look at this post to find some more answers to where you might get stuck in the future-https://answers.ros.org/question/347885/combining-cmakeliststxt-of-libtorch-and-cmakeliststxt-of-ros-package/#
I hope this answer is helpful to someone new coming onboard to ros and libtorch :)