Program Slicing and its Applications

A lecture based on

Part OneThe Concept of Program Slicing

Introduction

Definition

Subset of program behavior

Example program P

Example slice S1

Example slice S2

Example slice S3

Value trace

Example

Example program

A value trace

Another possible value trace

Remark

Slicing criterion

Example slicing criteria

Projection

Example projection

Another example projection

Yet another example projection

Formal definition of a slice

Example (continued)

Comment

Finding slices

Statement minimal slices

The impossibility

How to find slices?

Assumptions

Directed graph

Notations

Flow graph

Hammock graph

An assumption

DEF and REF sets

Relevant variables

PPT Slide

Statement to be included

Property of S0(C)

Indirect influence

Properties of INFL(b)

To include all indirect influences, the statements with direct influence on B0(C) must now be considered, and then the branch statements influencing those new statements, and so on.

More on influence

Remarks

Counter example

Counter example (continued)

Email: jhuang@cs.uh.edu

Home Page: www.cs.uh.edu/~jhuang