Question

EDIT: There must be some way I can approach this without writing a whole new debugger. I’m currently looking into ways to build on top of the existing java debugger. If anyone has any ideas on how to grab information the Java debugger already has (about stack frames, variables, raw data etc.), that would be really helpful.

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What I’m trying to do is I have this framework/API built on Java, and I would like to write an eclipse plugin debugger that is customized to my framework. Here is a simple example:

I have two classes, one called scope and one called variable. The scope holds a map of variables. The code is all in java, but I’m using this scope-variable relationship almost like a new language, and would like a variable debug tab that gives me a list of currently active scopes with the variables that are currently stored inside. Here is some code:

import java.util.Hashtable;

public class Scope {
    private Hashtable<String, Variable> variableList = new Hashtable<String, Variable>();

   // constructor 
    public Scope(){

    }

    public void put(String key, Variable v){
        variableList.put(key, v);
    }

    public Variable get(String key){
        return variableList.get(key);
    }


}

public class Variable {

    private String value;
    private String name;

    public Variable(String aName, String aValue){
        name = aName;
        value = aValue;
    }

    public String getValue(){
        return value;
    }

    public String getName(){
        return name;
    }

    public void setValue(String aValue){
        value = aValue;
    }
}

This is obviously an extremely simple example, but I would like to accomplish something similar to this where I can get a variables window, set a breakpoint, and have a “debugger” list out my active scope objects and the variable objects inside.

I’ve been trying to read and understand: http://www.eclipse.org/articles/Article-Debugger/how-to.html

and its pretty dense (as well as extremely outdated), but I will try to take some time to understand it. I just wanted to see if anyone had any high level recommendations on how to approach this type of problem, as I have little experience developing plugins in eclipse or making debuggers.

Thanks!

Answer 1

having worked on the eclipse edc debugger, it sounds like writing a whole debugger is not so much what you want.

it sounds like while running the debugger, you will have access to the objects that have the variables and scopes you are interested in.

you can use toString() in the classes themselves or use detail formatters to display a variation on the information you want. the toString() call can get quite detailed and nest into calls, show whole arrays, etc. detail formatters can also be quite complex.

see http://www.robertwloch.net/2012/01/eclipse-tips-tricks-detail-formatter/ . it’s the best of several URLs (i have no association with the author).

once you are happy with the output of the Variable and Scope objects, you should be able to add watch expressions that will always show them in your expressions window (thus you don’t have to rely on local variables in the stack frame you may be in).

this should then give you the list of Variables and Scopes from your framework that you are tracking … hopefully without having to write an entire eclipse debugger plugin to do so.