A Fortran 77 interpreter for mutation analysis

Mutation analysis is a powerful technique for testing software systems. In the Mothra project, conducted at Georgia Tech's Software Engineering Research Center, mutation analysis is used as a basis for building an integrated software testing environment. Mutation analysis requires the execution of many slightly differing versions of the same program to evaluate the quality of the data used to test the program. In the current version of the Mothra system, a program to be tested is translated to intermediate code, where it and its mutated versions are executed by an interpreter.In this paper, we discuss some of the unique requirements of an interpreter used in a mutation-based testing environment. We then describe how these requirements affected the design and implementation of the Fortran 77 version of the Mothra interpreter. Other topics covered include the architecture of the interpreter and many of the design elements that it incorporates. We also describe the intermediate language used by Mothra and the features of the interpreter that are needed for software testing.