message: cmake: avoid excessive output from cmake --trace/--trace-expand
  `cmake . --trace-expand -DCMAKE_TRACE_MODE=1`
diff: @@ -8,7 +8,20 @@ include(CMakeParseArguments)
  function(ocv_cmake_dump_vars)
  set(OPENCV_SUPPRESS_DEPRECATIONS 1) # suppress deprecation warnings from variable_watch() guards
  get_cmake_property(__variableNames VARIABLES)
  - cmake_parse_arguments(DUMP "" "TOFILE" "" ${ARGN})
  + cmake_parse_arguments(DUMP "FORCE" "TOFILE" "" ${ARGN})
  +
  + # avoid generation of excessive logs with "--trace" or "--trace-expand" parameters
  + # Note: `-DCMAKE_TRACE_MODE=1` should be passed to CMake through command line. It is not a CMake buildin variable for now (2020-12)
  + # Use `cmake . -UCMAKE_TRACE_MODE` to remove this variable from cache
  + if(CMAKE_TRACE_MODE AND NOT DUMP_FORCE)
  + if(DUMP_TOFILE)
  + file(WRITE ${CMAKE_BINARY_DIR}/${DUMP_TOFILE} "Skipped due to enabled CMAKE_TRACE_MODE")
  + else()
  + message(AUTHOR_WARNING "ocv_cmake_dump_vars() is skipped due to enabled CMAKE_TRACE_MODE")
  + endif()
  + return()
  + endif()
  +
  set(regex "${DUMP_UNPARSED_ARGUMENTS}")
  string(TOLOWER "${regex}" regex_lower)
  set(__VARS "")
  