Java target fails native compiling, maybe because of a class type parameter

[Hitmark7]

Hello everyone.

I have found a piece of code that compiles correctly for all targets, but Java. An error is thrown during the native compilation, and I think is related to the classes hierarchy or the classes type parameters. This is the code:

class
    Controller
{

    public function new():Void {}

    public function action():Void {
        throw "implement me";
    }

}

class
    HomeController
    extends
        Controller
{

    override public function action():Void {
        trace("home sweet home");
    }

}

class
    ControllerBuilder<
        TController:Controller
    >
{

    public function new():Void {}

    public function build():TController {
        throw "implement me";
    }

}

class
    HomeBuilder
    extends
        ControllerBuilder<
            HomeController
        >
{

    override public function build():HomeController {
        return new HomeController();
    }

}

class
    Route1<
        TController:Controller
    >
{

    public function new():Void {}

    public function buildController():TController {
        throw "implement me";
    }

}

class
    Route2
    extends
        Route1<
            Controller
        >
{}

class
    Route3<
        TController:Controller,
        TControllerBuilder:ControllerBuilder<
            TController
        >
    >
    extends
        Route2
{

    override public function buildController():TController {
        var
            controllerBuilder:TControllerBuilder = makeControllerBuilder(),
            controller:TController = controllerBuilder.build()
        ;
        return controller;    // This is the problematic line
    }

        private function makeControllerBuilder():TControllerBuilder {
            throw "implement me";
        }

}

class
    HomeRoute
    extends
        Route3<
            HomeController,
            HomeBuilder
        >
{

    override private function makeControllerBuilder():HomeBuilder {
        return new HomeBuilder();
    }

}

class Main {

    static public function main():Void {
        var
            route:HomeRoute = new HomeRoute(),
            controller:HomeController = route.buildController()
        ;
        controller.action();
    }

}

Three classes: Route, ControllerBuilder and Controller. On Route.buildController a ControllerBuilder is created and its build method gets called, where the Controller gets actually created.

Trying to compile that for the Java target using the Haxe Compiler 3.2.1 on Linux x64 throws this:

haxelib run hxjava hxjava_build.txt --haxe-version 3201 --feature-level 1
javac "-sourcepath" "src" "-d" "obj" "-g:none" "@cmd"
src/haxe/root/Route3.java:52: error: incompatible types
                return controller;
                       ^
  required: Controller
  found:    TController
  where TController is a type-variable:
    TController extends Object declared in class Route3
1 error
Compilation error
Native compilation failed
Error: Build failed

Peeking into the generated Route3.java file I find this:

package haxe.root;

import haxe.root.*;

@SuppressWarnings(value={"rawtypes", "unchecked"})
public class Route3<TController, TControllerBuilder> extends haxe.root.Route2
{

...
   
    @Override public haxe.root.Controller buildController()
    {
        //line 89 ".../Main.hx"
        TControllerBuilder controllerBuilder = this.makeControllerBuilder();
        //line 90 ".../Main.hx"
        TController controller = ((TController) (haxe.lang.Runtime.callField(controllerBuilder, "build", null)) );
        //line 92 ".../Main.hx"
        return controller;
    }

...

I guess that the problem is the returning type of the buildController function, that should be TController instead of haxe.root.Controller .

What do you think? Is the hierarchy chain weird or something? Is it a Java target bug?

Thanks!