Disclaimer – I am not in any ways affiliated with Sonar Source, I just happen to be using their product(s), and the stuff I’ve seen so far, is simply amazing as far as I am concerned!
As software developers, we are non-stop fighting the never ending recurring battle against "code rot". Code rot often implies that our Program Manager asks us for a feature, and we sneak in an additional "if" statement in one method, and a couple of "while" statements in another method, and our program manager is pleased with the effect. Slowly over time of course, the effect this approach has on our code, is less cohesion, clarity, and readability, in our classes, methods, and modules – And our code slowly mutates over time to become "a big ball of mud", until it reaches that point where it’s no longer possible to maintain.