Software engineering 22 error detection and debugging
- 1. Software Engineering: 22 Errors and Debugging Prof Neeraj Bhargava Vaibhav Khanna Department of Computer Science School of Engineering and Systems Sciences Maharshi Dayanand Saraswati University Ajmer
- 2. 2 Debugging: A Diagnostic Process
- 4. 4 Debugging Effort time required to diagnose the symptom and determine the cause time required to correct the error and conduct regression tests
- 5. 5 Symptoms & Causes symptom cause symptom and cause may be geographically separated symptom may disappear when another problem is fixed cause may be due to a combination of non-errors cause may be due to a system or compiler error cause may be due to assumptions that everyone believes symptom may be intermittent
- 6. 6 Consequences of Bugs damage mild annoying disturbing serious extreme catastrophic infectious Bug Type Bug Categories: function-related bugs,system-related bugs, data bugs, coding bugs, design bugs, documentation bugs, standardsviolations, etc.
- 7. 7 Debugging Techniques brute force / testing backtracking induction deduction
- 8. 8 Correcting the Error Is the cause of the bug reproduced in another part of the program? In many situations, a program defect is caused by an erroneous pattern of logic that may be reproduced elsewhere. What "next bug" might be introduced by the fix I'm about to make? Before the correction is made, the source code (or, better, the design) should be evaluated to assess coupling of logic and data structures. What could we have done to prevent this bug in the first place? This question is the first step toward establishing a statistical software quality assurance approach. If you correct the process as well as the product, the bug will be removed from the current program and may be eliminated from all future programs.
- 9. 9 Final Thoughts • Think -- before you act to correct • Use tools to gain additional insight • If you’re at an impasse, get help from someone else • Once you correct the bug, use regression testing to uncover any side effects
- 10. Assignment • What do you understand by debugging? • What is the difference between Testing and Debugging • Thank You