A Program Simplification Method for Generating Test Input Values Using Symbolic Execution

Symbolic execution can automatically generate test input values that cover the execution paths of programs. It enables us to test functions of even huge COBOL legacy programs, but the execution time substantially increases when the number of instructions in the input program is large. In this research, we propose a method that removes instructions that do not affect execution paths using program slicing. Applying the method to three functions in COBOL programs reduced the execution time by up to 70% by removing instructions that manipulate variables not related to the execution paths. This result suggests that our method enables symbolic execution to generate input values even from huge COBOL programs.