GSoC/GCI Archive
Google Code-in 2010 Mono Project

Gendarme rule to ensure engines are not used without [EngineDependency]

completed by: Yuri Stuken

mentors: spouliot


Gendarme is a static analysis tool to find problems in .NET software. Gendarme inspects executables and libraries that contain code in ECMA CIL format (Mono and .NET) and looks for common problems with the code, problems that compiler do not typically check or have not historically checked.



The task is to write a Gendarme rule that ensure rules using some Engine-derived features are subscribing to the engine using the [EngineDependency] attribute. There are presently two cases when this can occurs:

(1) a rule using OpCodeEngine.* or OpCodeBitmask.* but is not (or does not inherit from) a rule decorated with [EngineDependency (OpCodeEngine)]

(2) a rule using NamespaceEngine.* but is not (or does not inherit from) a rule decorated with [EngineDependency (NamespaceEngine)]

In both case the rules won't work correctly - unless another rule has already subscribed to the same engine (i.e. using the rule alone won't work). The rule could be named "MissingEngineDependencyRule" inside Gendarme.Rules.Gendarme.dll



To complete the task the student must provide:

*  the rules, written in C#. The source code must follow the Mono source code guidelines (available at Also a 'self-check' must be done one the code (i.e. you need to run gendarme on your own code) and the defects, if any, must be fixed (in doubt please ask for guidance on IRC).

* its documentation (in-source xmldoc) that includes 'good' and 'bad' examples; and

* the unit tests (also in C# using the gendarme helpers around NUnit) proving the rule is working as intended

* a patch to fix all such issues (if any) in Gendarme rules

Once ready the files (or the patch) can be submitted to the mentor for review.



* In order to avoid misunderstandings you should start by writing your unit tests and ask for a review of them. That will quickly tell you if you're on the right path to solve the problem.

* Gendarme provides hundreds of rules that can be used as example, here's one





* Gendarme web site:

* Mailing-list / discussions:

* IRC: #gendarme on GimpNET