CC -- .. include:: ENV_VAR.txt Preferred executable for compiling ``C`` language files. Will only be used by CMake on the first configuration to determine ``C`` compiler, after which the value for ``CC`` is stored in the cache as :variable:`CMAKE_C_COMPILER _COMPILER>`. For any configuration run (including the first), the environment variable will be ignored if the :variable:`CMAKE_C_COMPILER _COMPILER>` variable is defined.