if(NOT "$ENV{CC}" STREQUAL "")
  message(STATUS "Test environment already sets CC, test being SKIPPED")
  return()
elseif(CMAKE_GENERATOR MATCHES "Xcode|Visual Studio")
  message(STATUS "This generator never sets CC, test being SKIPPED")
  return()
endif()

enable_language(C)

if("$ENV{CC}" STREQUAL "")
  message(STATUS "CC was left unset")
else()
  message(STATUS "CC was set to $ENV{CC}")
endif()