Help/prop_tgt/AUTOGEN_ORIGIN_DEPENDS.rst

AUTOGEN_ORIGIN_DEPENDS
----------------------

Switch for forwarding origin target dependencies to the corresponding
``_autogen`` target.

Targets which have their :prop_tgt:`AUTOMOC` or :prop_tgt:`AUTOUIC` property
``ON`` have a corresponding ``_autogen`` target which generates
``moc`` and ``uic`` files.  As this ``_autogen`` target is created at
generate-time, it is not possible to define dependencies of it using
e.g.  :command:`add_dependencies`.  Instead the
:prop_tgt:`AUTOGEN_ORIGIN_DEPENDS` target property decides whether the origin
target dependencies should be forwarded to the ``_autogen`` target or not.

By default :prop_tgt:`AUTOGEN_ORIGIN_DEPENDS` is initialized from
:variable:`CMAKE_AUTOGEN_ORIGIN_DEPENDS` which is ``ON`` by default.

In total the dependencies of the ``_autogen`` target are composed from

- forwarded origin target dependencies
  (enabled by default via :prop_tgt:`AUTOGEN_ORIGIN_DEPENDS`)
- additional user defined dependencies from :prop_tgt:`AUTOGEN_TARGET_DEPENDS`

See the :manual:`cmake-qt(7)` manual for more information on using CMake
with Qt.

Note
^^^^

Disabling :prop_tgt:`AUTOGEN_ORIGIN_DEPENDS` is useful to avoid building of
origin target dependencies when building the ``_autogen`` target only.
This is especially interesting when a
:variable:`global autogen target <CMAKE_GLOBAL_AUTOGEN_TARGET>` is enabled.

When the ``_autogen`` target doesn't require all the origin target's
dependencies, and :prop_tgt:`AUTOGEN_ORIGIN_DEPENDS` is disabled, it might be
necessary to extend :prop_tgt:`AUTOGEN_TARGET_DEPENDS` to add missing
dependencies.