Help interpreting load time error

[slavik262]

I have a few things:

• This is only slightly related to your problem, but if you're going to implement an Autonomous() or OperatorControl() in MyRobot, you'll need to make these functions virtual in TrcRobot. The deconstructor for MyRobot (MyRobot::~MyRobot) also won't be called unless you make a virtual deconstructor in TrcRobot. Make sure to check inheritence for stuff like this.
  
• An "undefined symbol" basically means that the program can't find a function or piece of code where it thinks there should be one. This could be caused by different things:
  • A header file contains the definition of a function, and the source files either don't have the function at all or the function has a different definition in the source files. (This is usually caught during compile-time though).
  • Your versions are off. The code's looking for something in the WPI library where it shouldn't be. Make sure both your robot and your WindRiver workbench have the newest updates.

Taking a second look at it, though, I thought of this:

Since the undefined symbol is "_ZTV8TrcRobot.", I'd guess this is caused by neither of the above possibilities, but something involving inheritance. Put constructors in both TrcRobot and MyRobot (you only have one in MyRobot right now). The START_ROBOT_CLASS macro instantiates the class you give it, which will call not just call the base constructor SimpleRobot::SimpleRobot() but also TrcRobot::TrcRobot() and MyRobot::MyRobot(). I'm guessing that after calling the SimpleRobot constructor it looks for the TrcRobot constructor and freaks out when there isn't one.

Let me know if this fixes the problem.

[mikets]

Yes, I have constructors on both MyRobot and TrcRobot (sorry that I simplified too much and did not show them in my code example). I suspect about inheritance too. So if the undefined symbol means it could not find the constructor of TrcRobot, I am puzzled because it's there. I am going to cut everything non-essential out to isolate the problem tonight and see what it is really complaining.

[slavik262]

Cool. If I can help any more, feel free to post here or PM me.