I am exploring Android's new declarative UI framework, Jetpack Compose. After learning the basics, I am interested in how it's implemented, in which I am mostly interested in how a @Composable function is compiled. From some speech videos I learned that it requires a certain Kotlin language plugin/feature since 1.4 but they don't say what. I have also tried to use the "Show Kotlin Bytecode" feature in IntelliJ IDEA but there seem to be compilation errors.
So under the hood, what does this new Kotlin 1.4 language plugin/feature do and what definitions are generated from compiling one @Composable function?