The Use and Implementation of Coding Standards for High-Confidence Embedded Systems

The use of coding standards in safety-critical embedded software development is growing because they reduce the risk of unsafe code escaping into production devices. Three prominent rule sets comprising 345 unique rules are studied. Each rule is classified by its rationale. Techniques for detecting violations of the rules are discussed, and each of the rules is further classified by the technology best suited for its enforcement. Many rules are found to be ambiguous or prone to subjective interpretations. This is a particular problem for automatic enforcement as tools require a precise specification. For some classes of rules, theoretical and technological limitations mean that tools may report violations where no such violations occur. Strategies for managing these false positives are discussed. Broad recommendations for adoption and enforcement of rules are given.