CMake/Help/prop_tgt/AUTOMOC.rst

51 lines
2.3 KiB
ReStructuredText

AUTOMOC
-------
Should the target be processed with automoc (for Qt projects).
AUTOMOC is a boolean specifying whether CMake will handle the Qt ``moc``
preprocessor automatically, i.e. without having to use the
:module:`QT4_WRAP_CPP() <FindQt4>` or QT5_WRAP_CPP() macro. Currently Qt4 and Qt5 are
supported.
When this property is set ``ON``, CMake will scan the
source files at build time and invoke moc accordingly.
* If an ``#include`` statement like ``#include "moc_foo.cpp"`` is found,
the ``Q_OBJECT`` class declaration is expected in the header, and
``moc`` is run on the header file. A ``moc_foo.cpp`` file will be
generated from the source's header into the
:variable:`CMAKE_CURRENT_BINARY_DIR` directory. This allows the
compiler to find the included ``moc_foo.cpp`` file regardless of the
location the original source. However, if multiple source files
in different directories do this then their generated moc files would
collide. In this case a diagnostic will be issued.
* If an ``#include`` statement like ``#include "foo.moc"`` is found,
then a ``Q_OBJECT`` is expected in the current source file and ``moc``
is run on the file itself. Additionally, header files with the same
base name (like ``foo.h``) or ``_p`` appended to the base name (like
``foo_p.h``) are parsed for ``Q_OBJECT`` macros, and if found, ``moc``
is also executed on those files. ``AUTOMOC`` checks multiple header
alternative extensions, such as ``hpp``, ``hxx`` etc when searching
for headers. The resulting moc files, which are not included as shown
above in any of the source files are included in a generated
``<targetname>_automoc.cpp`` file, which is compiled as part of the
target.
This property is initialized by the value of the :variable:`CMAKE_AUTOMOC`
variable if it is set when a target is created.
Additional command line options for moc can be set via the
:prop_tgt:`AUTOMOC_MOC_OPTIONS` property.
By enabling the :variable:`CMAKE_AUTOMOC_RELAXED_MODE` variable the
rules for searching the files which will be processed by moc can be relaxed.
See the documentation for this variable for more details.
The global property :prop_gbl:`AUTOGEN_TARGETS_FOLDER` can be used to group the
automoc targets together in an IDE, e.g. in MSVS.
See the :manual:`cmake-qt(7)` manual for more information on using CMake
with Qt.