Chapter 9: Tracking and Squashing Bugs

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[God] must have an inordinate fondness for beetles.

—J.B.S. Haldane

Overview

By the same token, we software developers must dearly love bugs—we create so many of them. Okay, so perhaps we don’t lavish the same gentle affection on our bugs that those shiny new beetles presumably get, but that doesn’t cut down on their number. Author Steve McConnell (in his book Code Complete [Microsoft Press, 1993]) cites an industry average of 15 to 50 errors per thousand lines of code, and suggests that some projects have 10 times that many. Imagine trying to deal with 500 errors in a thousand lines of code!

In this chapter, I’m going to introduce you to some strategies designed to lower those numbers. I won’t try to teach you how to use the debugger or analyze running code. Rather, this chapter is about a whole constellation of factors that surround the hunt for bugs: managing risk, testing code, working with hardware, and tracking the bug activity.

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