logic involved

You might stumble over complex Ant based projects now and then, and you won’t have nothing but complex macros and run tasks to start the application. In other words: you require detecting skills to create a debugable Eclipse project.
But there’s a cool and simple way to collect vm arguments, options and paths: use VisualVM to connect to the running application and copy the runtime settings:

1. invoke the Ant run task or macro to start the application
2. start VisualVM and connect to the app
3. copy the runtime settings
4. stop the app
5. create a new Eclipse project, if you don’t already have one
6. create a new debug launch config and apply the recovered settings from step 2.
7. run the launch config, and refine as required

That’s it