# 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 `QT4_WRAP_CPP()` 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 `<CMAKE_CURRENT_BINARY_DIR>/<TARGETNAME>_autogen/include` directory which is automatically added to the target’s `INCLUDE_DIRECTORIES`. 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 `moc_compilation.cpp` file, which is compiled as part of the target.

This property is initialized by the value of the `CMAKE_AUTOMOC` variable if it is set when a target is created.

Additional command line options for moc can be set via the `AUTOMOC_MOC_OPTIONS` property.

By enabling the `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 `AUTOGEN_TARGETS_FOLDER` can be used to group the automoc targets together in an IDE, e.g. in MSVS.

Source C++ files can be excluded from `AUTOMOC` processing by enabling `SKIP_AUTOMOC` or the broader `SKIP_AUTOGEN`.

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