Lightweight Semi-Dynamic Methods for EÆcient and Eective Program Slicing

When we try to debug a large program eectively, it is very important to separate a suspicious program portion from the overall source program. Pro-gram slicing is a promising technique to extract a program portion; however, it remains diÆcult issues. Static slicing sometimes produces a large portion of the source program, especially for a program with arrays and pointers. Dynamic slicing requires unacceptably huge run-time overhead. In this pa-per, we discuss intermediate semi-dynamic methods between static and dy-namic slicing. We propose two slicing methods named call-mark slicing and dependence-cache slicing. These algorithms have been implemented in our experimental slicing system, and execution data for several sample programs have been collected. The result shows that call-mark slicing reduces the slice size by about 10{20 % from the static slice size, with very little overhead increase. Also, dependence-cache slice reduces by about 30{90%, even for programs using arrays, with aordable run-time overhead increase. These slicing methods will be important features for eective debugging environ-ments