caffe2/observers/CMakeLists.txt

if(USE_OBSERVERS)
  message(STATUS "Include Observer library")
  set(Caffe2_CONTRIB_OBSERVERS_CPU_SRC
    "${CMAKE_CURRENT_SOURCE_DIR}/time_observer.cc"
  )

  set(Caffe2_CPU_SRCS ${Caffe2_CPU_SRCS} ${Caffe2_CONTRIB_OBSERVERS_CPU_SRC})
  set(Caffe2_CPU_SRCS ${Caffe2_CPU_SRCS} PARENT_SCOPE)
endif()