message: CMakeLists.txt: Cleanup MODULE_LIST usage
  Removed redundant usage of MODULE_LIST and SUBDIRS variables.
  Treat utilities and interfaces directories the same (add both if not
  added when using MODULE_LIST).
diff: @@ -796,25 +796,31 @@ set(UPM_TARGETS_NODEJS "" CACHE INTERNAL "List of NodeJs target names")
  set(UPM_TARGETS_PYTHON2 "" CACHE INTERNAL "List of Python2 target names")
  set(UPM_TARGETS_PYTHON3 "" CACHE INTERNAL "List of Python3 target names")
  -# Add subdirectories from MODULE_LIST if defined
  -# Example -DMODULE_LIST="dfrph;rotaryencoder"
  -if (MODULE_LIST)
  - set(SUBDIRS ${MODULE_LIST})
  - # Add interfaces directory
  - set(SUBDIRS ${SUBDIRS} interfaces)
  -else()
  - # Otherwise, add all subdirectories
  - subdirlist(SUBDIRS ${CMAKE_CURRENT_SOURCE_DIR})
  +# MODULE_LIST can be specified on the CMake command line to specify
  +# a list of directories under src to include in the build.
  +# MODULE_LIST is optional.
  +# If MODULE_LIST is provided, only add the directories specified
  +# If MODULE_LIST is NOT provided, add all subdirectories under src
  +# Example (-DMODULE_LIST="dfrph;rotaryencoder")
  +if (NOT MODULE_LIST)
  + # If no module list, add all subdirectories
  + subdirlist(MODULE_LIST ${CMAKE_CURRENT_SOURCE_DIR})
  endif()
  -# If the SUBDIRS list does NOT include the utilities directory, add it since
  +# If the module list does NOT include the utilities directory, prepend it since
  # most sensor library targets depend on utilities
  -if (NOT "${SUBDIRS}" MATCHES utilities)
  - add_subdirectory(${CMAKE_SOURCE_DIR}/src/utilities)
  +if (NOT "${MODULE_LIST}" MATCHES ";utilities;")
  + set(MODULE_LIST "utilities;${MODULE_LIST}")
  +endif()
  +
  +# If the module list does NOT include the interfaces directory, prepend it since
  +# some sensor library targets depend on interfaces
  +if (NOT "${MODULE_LIST}" MATCHES ";interfaces;")
  + set(MODULE_LIST "interfaces;${MODULE_LIST}")
  endif()
  -# Iterate over each directory in SUBDIRS
  -foreach(subdir ${SUBDIRS})
  +# Iterate over each directory in MODULE_LIST
  +foreach(subdir ${MODULE_LIST})
  if(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/${subdir}/CMakeLists.txt)
  add_subdirectory(${subdir})
  endif()
  