Interface files are generated in configuration time, not compilation time

link : https://doc.qt.io/QtInterfaceFramework/qtinterfaceframework-interfaceframework-qface-tutorial-example.html#auto-generation

The documentation above says that "this auto-generation process is integrated into the build system and is done at compile time."

But at my environment(Ubuntu + cmake), it seems that the generation of interface files out of qface file is done during cmake configuration time, not during compilation.