Abstract
The Linux operating system kernel provides all the interfaces between hardware and application software. It is a very large (13 million lines of code) and complex piece of software, written by several thousand contributors. It is developed on a modular basis, with core modules and peripheraldrivers interacting via APIs (Application Programming Interfaces) that specify how they are to talk to each other. This kernel is constantly evolving, with around 15 000 modifications per quarter, the APIs often being modified to correct errors or introduce new functionalities. Each of these API changes leads to numerous modifications in many parts of the code, which are very painful to do by hand and to validate. The Coccinelle software developed by Julia Lawall and Gilles Muller is based on fine-grained automatic analysis of the semantics of the codes concerned, and makes it possible to automate system updates almost completely. It is now used on a large scale for Linux development.
