Reengineering Idiomatic Exception Handling in Legacy C Code

Some legacy programming languages, e.g., C, do not provide adequate support for exception handling. As a result, users of these legacy programming languages often implement exception handling by applying an idiom. An idiomatic style of implementation has a number of drawbacks: applying idioms can be fault prone and requires significant effort. Modern programming languages provide support for structured exception handling (SEH) that makes idioms largely obsolete. Additionally, aspect-oriented programming (AOP) is believed to further reduce the effort of implementing exception handling. This paper investigates the gains that can be achieved by reengineering the idiomatic exception handling of a legacy C component to these modern techniques. First, we will reengineer a C component such that its exception handling idioms are almost completely replaced by SEH constructs. Second, we will show that the use of AOP for exception handling can be beneficial, even though the benefits are limited by inconsistencies in the legacy implementation.