cmake_minimum_required(VERSION 3.12.1)
macro(previous_target_sources)
  if(NOT previous_target_sources_fn)
    set(previous_target_sources_fn target_sources)
  endif()

  push(previous_target_sources_fn)
  set(previous_target_sources_fn _${previous_target_sources_fn})
  call(${previous_target_sources_fn} ${ARGN})
  pop(previous_target_sources_fn)
endmacro()
