A STUDY OF DEAD DATA MEMBERS IN C++ APPLICATIONS

Object-oriented applications may contain data members that can be remo ved from the application without affecting program behavior. Such ''de ad'' data members may occur due to unused functionality in class libra ries, or due to the programmer losing track of member usage as the app lication changes over time. We present a simple and efficient algorith m for detecting dead data members in CSS applications. This algorithm has been implemented using a prototype version of the IBM VisualAge CS S compiler, and applied to a number of realistic benchmark programs ra nging from 600 to 58,000 lines of code. For the non-trivial benchmarks , we found that up to 27.3% of the data members in the benchmarks are dead (average 12.5%), and that up to 11.6% of the object space of thes e applications may be occupied by dead data members st run-time (avera ge 4.4%).