|Do you know where your variables are?|
Re (tilly) 2: Are debuggers good?by tilly (Archbishop)
|on Dec 28, 2000 at 17:40 UTC||Need Help??|
I just can't believe all of the people who use debuggers who think that people like Randal and I are just taking a position out of ignorance of how to use a debugger!
Follow through the thread of discussion in the conversation that I pointed to. The exact issue of Kernel Threads under discussion which I pointed to is here, check out sections 1 and 4. In particular the following posts stand out as being particularly relevant. First the one where Linus says, "I am a bastard, and that's OK", and IBM's experience.
Both of those articles are written by competent programmers with years of experience developing in a very complex environment who both know debuggers. Both claim that while debuggers look easy, neither think that they really help. If you read those threads you will find many competent people who absolutely disagree with that position. There are people on either side.
Note that I didn't say that debuggers are useless for debugging. I said I am constantly amazed at how many good programmers don't like them for that purpose but have plenty of other uses. It should be obvious that good programmers who have found other uses for a debugger actually understand what they are and how to use them. Ignorance is not the reason for not choosing to use them.
No, the reason is more subtle. The limit to our ability to develop interesting things lies in our ability to comprehend. Debuggers focus intention at the wrong point. They let us blindly trace through code to find the symptoms of problems. That doesn't help us one bit to notice more subtle symptoms of structural problems in the code. It doesn't help one bit in giving us encouragement to be more careful. It doesn't encourage reflection on the process. It doesn't give us reason to think about the poor schmuck that has to handle our code afterwards.
In short it encourages missing the forest for the trees. But in the end projects are felled by overgrown thickets, not by single trees.
Now I know you will likely disagree. This is an opinion which many people are divided on. But my opinion just happens to be shared by a lot of very competent people. It isn't based on ignorance. Instead it is based on experience and thought about the process. I have repeated this point to plenty of friends. Some make you go, "hmmm". Like the guy who said, "That is true. I have written debuggers. I used to use them all of the time. But then I thought about my own thinking process, and tried not using it for a bit. After that I never looked back."
However one thing we will both agree on. If you don't think about your own development process on an ongoing basics, then there is no question that a debugger would be helpful. They are effective tools, no question about that.