CMakeLists.txt

cmake_minimum_required(VERSION 3.14)
project("ROS2 Master")

# usually I put this in a separate file include("/opt/ros/_common/Colcon.cmake")
function(colcon_add_subdirectories)
  cmake_parse_arguments(PARSE_ARGV 0 "ARG" "" "BUILD_BASE;BASE_PATHS" "")

  message("search criteria: ${ARGV}")

  execute_process(COMMAND colcon list
		--paths-only
		--base-paths ${ARG_BASE_PATHS}
		--topological-order
		${ARG_UNPARSED_ARGUMENTS}
		OUTPUT_VARIABLE paths)
  string(STRIP "${paths}" paths)
  string(REPLACE "\n" ";" paths "${paths}")

  MESSAGE("colcon shows paths ${paths}")

  foreach(path IN LISTS paths)
    message("...examining ${path}")
    # if(EXISTS "${path}/CMakeLists.txt")
    execute_process(COMMAND colcon info --paths "${path}" OUTPUT_VARIABLE package_info)
    if(NOT "${package_info}" MATCHES "type:[ \t]+(cmake|ros.ament_cmake|ros.cmake)")
      message("skipping non-cmake project")
    elseif(NOT "${package_info}" MATCHES "name:[ \t]+([^ \r\n\t]*)")
      message(WARNING "could not identify package at ${path}")
    else()
      set(name "${CMAKE_MATCH_1}")
      message("...adding package ${name} from path ${path}")
      MESSAGE("package info: ${package_info}")

      get_filename_component(BUILD_PATH "${name}" ABSOLUTE BASE_DIR "${ARG_BUILD_BASE}")

      add_subdirectory("${path}" "${BUILD_PATH}")
    endif()
  endforeach()
endfunction()

colcon_add_subdirectories(
	BUILD_BASE "${PROJECT_SOURCE_DIR}/build"
	BASE_PATHS "${PROJECT_SOURCE_DIR}/src/"
	--packages-select rmw_cyclonedds_cpp performance_test
)