On Strings in Software Model Checking

Strings represent one of the most common and most intricate data-types found in software programs, with correct string processing often being a decisive factor for correctness and security properties. This has led to a wide range of recent research results on how to analyse programs operating on strings, using methods like testing, fuzzing, symbolic execution, abstract interpretation, or model checking, and, increasingly, support for strings is also added to constraint solvers and SMT solvers. In this paper, we focus on the verification of software programs with strings using model checking. We give a survey of the existing approaches to handle strings in this context, and propose methods based on algebraic data-types, Craig interpolation, and automata learning.