Advances in Usability of Formal Methods for Code Verification with Frama-C

Abstract

Industrial usage of code analysis tools based on semantic analysis, such as the Frama-C platform, poses several challenges, from the setup of analyses to the exploitation of their results. In this paper, we discuss two of these challenges. First, such analyses require detailed information about the code structure and the build process, which are often not documented, being part of the implicit build chain used by the developers. Unlike heuristics-based tools, which can deal with incomplete information, semantics-based tools require stubs or specifications for external library functions, compiler builtins, non-standard extensions, etc. Setting up a new analysis has a high cost, which precludes industrial users from trying such tools, since the return on investment is not clear in advance: the analysis may reveal itself of little use w.r.t. the invested time. Improving the usability of this first step is essential for the widespread adoption of formal methods in software development. A second aspect that is essential for successful analyses is understanding the data and navigating it. Visualizing data and rendering it in an interactive manner allows users to considerably speed up the process of refining the analysis results. We present some approaches to both of these issues, derived from experience with code bases given by industrial partners.