mocgenerated

Mocgenerated refers to the code produced by the Qt Meta-Object Compiler (moc). It is an essential part of Qt's meta-object system, enabling features such as signals and slots, dynamic properties, and run-time type information for QObject-derived classes.

Process and purpose: The moc scans C++ header files for the Q_OBJECT macro and generates a corresponding source file that implements a meta-object for that class. The generated code provides signal-slot dispatch, property metadata, and run-time type information used by Qt's introspection features. This moc-generated code is compiled together with the rest of the project to produce a working application.

File naming and build integration: Generated files are typically named moc_<header>.cpp or moc_<class>.cpp and are created in the build directory by build tools like qmake or CMake. Developers generally do not edit moc-generated files by hand; they rely on changes to the source headers to trigger re-generation.

Maintenance and troubleshooting: If moc does not run or fails to generate expected data, signals and slots or dynamic properties may not function. Ensure headers containing Q_OBJECT are reachable by the build system, and that moc is configured to process those headers. In template or inline scenarios, practitioners may use guards such as Q_MOC_RUN to control what moc processes to avoid errors.

Impact and scope: Moc-generated code is central to Qt’s mechanism for enabling signals and slots and for providing a rich meta-object interface. It operates behind the scenes, allowing QObject-based classes to interact with the framework’s event system and runtime introspection without manual boilerplate.

See also: Qt, Q_OBJECT, signals and slots, meta-object compiler, moc.