Coccinelle is a tool to match and transform

Program transformation

A program transformation is any operation that takes a computer program and generates another program. In many cases the transformed program is required to be semantically equivalent to the original, relative to a particular formal semantics and in fewer cases the transformations result in programs...

 the source code

Source code

In computer science, source code is text written using the format and syntax of the programming language that it is being written in. Such a language is specially designed to facilitate the work of computer programmers, who specify the actions to be performed by a computer mostly by writing source...

 of programs written in the programming language

Programming language

A programming language is an artificial language designed to communicate instructions to a machine, particularly a computer. Programming languages can be used to create programs that control the behavior of a machine and/or to express algorithms precisely....

 C

C (programming language)

C is a general-purpose computer programming language developed between 1969 and 1973 by Dennis Ritchie at the Bell Telephone Laboratories for use with the Unix operating system....

. Coccinelle was initially used to aid the evolution of Linux

Linux

Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...

; with support for changes to library application programming interface

Application programming interface

An application programming interface is a source code based specification intended to be used as an interface by software components to communicate with each other...

s (APIs) such as renaming a function

Subroutine

In computer science, a subroutine is a portion of code within a larger program that performs a specific task and is relatively independent of the remaining code....

, adding a function argument which value is somehow context-dependent, and reorganizing a data structure

Data structure

In computer science, a data structure is a particular way of storing and organizing data in a computer so that it can be used efficiently.Different kinds of data structures are suited to different kinds of applications, and some are highly specialized to specific tasks...

. The tool is freely available under an open source

Open source

The term open source describes practices in production and development that promote access to the end product's source materials. Some consider open source a philosophy, others consider it a pragmatic methodology...

 license.

The source code to be matched and/or replaced is specified using a pattern that is very similar to C (the Semantic Patch Language).

Example

@@
expression lock, flags;
expression urb;
@@

spin_lock_irqsave(lock, flags);
<...
- usb_submit_urb(urb)
+ usb_submit_urb(urb, GFP_ATOMIC)
...>
spin_unlock_irqrestore(lock, flags);

@@
expression urb;
@@

- usb_submit_urb(urb)
+ usb_submit_urb(urb, GFP_KERNEL)

Development

Support is provided by IRILL

IRILL

The Innovation and research initiative for free software is a French research center.This centre was created in September 2010 by INRIA with Pierre and Marie Curie University and Paris Diderot University and is located at the INRIA in Paris. Roberto Di Cosmo is the director of IRILL.IRILL aims to...

 and funding for the development of Coccinelle has been provided by the Agence Nationale de la Recherche (France), the Danish Research Council for Technology and Production Sciences and INRIA.

External links

• Official release tracking repository at GitHub
  Github
  GitHub is a web-based hosting service for software development projects that use the Git revision control system. GitHub offers both commercial plans and free accounts for open source projects...
  
  
• Articles describing the use of Coccinelle
• Coccinelle wiki