CMAKE_<LANG>_COMPILER_LAUNCHER
------------------------------

Default value for :prop_tgt:`<LANG>_COMPILER_LAUNCHER` target property.
This variable is used to initialize the property on each target as it is
created.  This is done only when ``<LANG>`` is ``C``, ``CXX``, ``Fortran``,
or ``CUDA``.

This variable is initialized to the :envvar:`CMAKE_<LANG>_COMPILER_LAUNCHER`
environment variable if it is set.
