A MILP-based Approach to Path Sensitization of Embedded Software

We propose a new methodology based on Mixed Integer Linear Programming (MILP) for determining the input values that will exercise a specified execution path in a program. In order to seamlessly handle variable values, pointers and arrays, and variable aliasing, our method uses memory addresses for data references. This implies a dynamic methodology where all decisions are taken as the program executes. During execution, we gather constraints for the MILP problem, whose solution will directly yield the input values for the desired path. We present results that demonstrate the effectiveness of this approach. This methodology was implemented into a fully functional tool that is capable of handling medium sized real programs specified in the C language. Our work is motivated by the complexity of validating embedded systems and uses a similar approach to an existing HDL functional vector generation. The joint solution of the M I LP problems will provide a hardware/software co-validation tool.