Why Programs Fail, 2nd Edition

CHAPTER 14 Isolating Cause–Effect Chains

This chapter presents a way of narrowing down failure causes even further. By extracting and comparing program states, delta debugging automatically isolates the variables and values that cause the failure, resulting in a cause–effect chain of the failure:” variable x was 42; therefore p became null; and thus the program failed.”

14.1 USELESS CAUSES

In Chapter 13, we saw how to isolate inputs, code changes, or schedules that cause a given failure. In many cases, such causes directly lead to the defect in question. There are cases, though, where a difference in the input, for instance, gives few clues, if any, to the nature of the error. This is particularly true if program processes input at several ...