Automatic test data generation of character string.ppt

Automatic Test Data Generation of Character String
Zhao Ruilian
Outline
Introduction
Automatic test data generation
Character string predicate
Automatic test data generation of character string
A example
Conclusion and Future work
Introduction
Software testing is usually difficult, expensive and time consuming.
Accounts for up to 50% of the cost
of whole software development .
If test data could be automatically generated,
the cost of software testing would be significantly reduced.
Introduction
There are many automatic test data generation approaches.
The most used are:
Random test data generation
Symbolic execution-based test data generation
Dynamic test data generation
Introduction
Each approach has its own advantages.
Little attention has been paid to the problem of test data
generation for programs whose inputs are character string.
Introduction
Character string is an important element in programming.
How to automatically generate test data of character string
Automatic test data generation
Random test data generation develops test data
at random until a useful input is found
Random test data generation is easy to implement.
Random test data generation
In fact, random test data generation is generally
ineffective on realistic programs.
Automatic test data generation
Symbolic execution-based test data generation
But, symbolic execution is putational intensive
and a number of technical problems are met in practice.
indefinite loops, subprogram call, array reference and so on
The basic idea in a symbolic execution system is to allow numeric
variables to take on symbolic values instead of numeric values.
Automatic test data generation
Symbolic execution-based test data generation
If input variable is character string variable
strncpy(tempstr,instr,5);
strupr(tempstr);
if (strcmp(tempstr,”LEFT”)<0);
instr is a input variable of
character string
It is difficult to express the value of variable tempstr in terms of
the sym