SYSTEM
------

.. versionadded:: 3.25

Specifies that a target is a ``SYSTEM`` library.  This has the following
effects:

* Entries of :prop_tgt:`INTERFACE_INCLUDE_DIRECTORIES` are treated as
  ``SYSTEM`` include directories when compiling consumers.
  Entries of :prop_tgt:`INTERFACE_SYSTEM_INCLUDE_DIRECTORIES` are not
  affected, and will always be treated as ``SYSTEM`` include directories.

For imported targets, this property defaults to true, which means
that their :prop_tgt:`INTERFACE_INCLUDE_DIRECTORIES` are treated
as ``SYSTEM`` by default. If their ``SYSTEM`` property is false,
then their :prop_tgt:`INTERFACE_INCLUDE_DIRECTORIES` will not be
treated as ``SYSTEM``, regardless of the value of the
:prop_tgt:`IMPORTED_NO_SYSTEM` property.

For non-imported targets, this target property is initialized from
the :prop_dir:`SYSTEM` directory property when the target is created.
