Dead Code

Dead code is a bad smell. It is conjectured to be harmful and it appears to be also a common phenomenon in software systems. Surprisingly, dead code has received little empirical attention from the software engineering research community. This post-doctoral track paper shows the main results of a multi-study investigation into dead code with an overarching goal to study when and why developers introduce dead code, how they perceive and cope with it, and whether dead code is harmful. This investigation is composed of semi-structured interviews with software professionals and four experiments at the University of Basilicata and the College of William & Mary. The results suggest that it is worth studying dead code not only in maintenance and evolution phases, where the results suggest that its presence is detrimental to developers, but also in design and implementation phases, where source code is born dead because developers consider dead code as a sort of reuse means. The results also foster the development of tools for detecting dead code. In this respect, two approaches were proposed and then implemented in two prototypes of supporting tool.