Embedded Open Source Summit 2023

While adhering to certain coding styles is a good practice in software projects, adhering to coding guidelines for safety critical applications is still something rather exotic in open source projects. As open source projects now more and more start to address the needs of functional safety applications, considering coding guidelines preferred by existing functional safety projects seems to become necessary. The most used rules for coding guidelines in the safety critical context are MISRA rules. While applying these can be quite beneficial for most applications, there is a significant number of exceptions where blindly following these rules causes more problems than it solves. With this talk the authors discuss the most common coding guidelines, best practices and arguments when following the MISRA rules conflicts with the expectations of the project. Acceptance criteria for non-compliance cases along with examples of acceptable deviations will be presented. This talk is not contra coding guidelines, but illustrates how coding guidelines are beneficial for a project, what to consider when designing a project’s coding guidelines and how the lessons learned by the application of MISRA rule sets can be applied to languages that are not (yet?) covered by widely accepted rule sets.