Macro arkui_main 

macro_rules! arkui_main {
    ($root:expr) => { ... };
}

Expands to the day_arkui_start C export the HarmonyOS ArkUI shim’s start(...) NAPI wrapper calls (from ArkTS: import native from 'libday_arkui.so'; native.start(nodeContent, w, h, density)). It mounts the app’s root piece into the ArkTS NodeContent and runs the loop.

day::arkui_main!(root);