Professional C++

Chapter 20. Conquering Debugging

Your code will contain bugs. Every professional programmer would like to write bug-free code, but the reality is that few software engineers succeed in this endeavor. As computer users know, bugs are endemic in computer software. The software that you write is probably no exception. Therefore, unless you plan to bribe your coworkers into fixing all your bugs, you cannot be a Professional C++ programmer without knowing how to debug C++ code. One factor that often distinguishes an experienced programmer from a novice is his or her debugging skills.

Despite the obvious importance of debugging, it is rarely given enough attention in courses and books. Debugging seems to be the type of skill that everyone wants you to know, but no one knows how to teach. This chapter attempts to provide you with concrete guidelines and techniques for debugging even the most galling problems. The contents include an introduction to the Fundamental Law of Debugging and bug taxonomies, followed by tips for avoiding bugs. Techniques for planning for bugs include error logging, debug traces, and asserts. The chapter concludes with specific tips for debugging the problems that arise, including techniques for reproducing bugs, debugging reproducible bugs, debugging nonreproducible bugs, debugging memory errors, and debugging multithreaded programs. The chapter concludes with a step-by-step debugging example.

The Fundamental Law of Debugging

The first rule of debugging is to be ...