Static Code Analysis - Which ones to turn on first?

Question

Hi,
We're using VS2008 with the built in static code analysis rule set.
We've got a relatively large C# solution (150+ projects) and while some of the projects (< 20) are using static code analysis religiously, most are not. We want to start enforcing static code analysis on all projects, but enabling all rules would create a massive distraction to our current projects. Which of the many static code analysis rules that are available should we turn on first? Which rules have the biggest bang for the buck? If you could give me your prioritized top 20, I'd greatly appreciate it.
Thanks in advance,
--Ed.S.

Answer 1

If you going to localize your project/ it is going to be used in different countries, then definitely enable localization rules. It will find all call to all sort of Format/Parse functions that do not specify CultureInfo. Bugs involving not specified CultureInfo are hard to find in testing, but they will really bite you in the ass, when your French client will ask: why your program does not work/crash on numbers with "," as decimal separator.

Answer 2

In my experience code analysis warnings of all types show 'hidden' bugs or flaws in your code. Fixing these can solve some real problems. I have not found a list of warnings that I would like to disable.

Instead, I would turn them on one project at a time and fix all the warnings in that project before moving to the next.

If you want to turn things off I would consider not checking the Naming rules (unless you are shipping a library, APIs or other externally exposed methods) and Globalization rules. (unless your applications make active use of Globalization). It depends a bit on your situation which make sense.

Answer 3

Given that the Studio ones are similar to FxCop's rules, I can tell you which ones I'd turn on last.

If internationalization is not on the horizon, turn off Globalization Rules.

Turn off Performance Rules initially. Optimize when you need to.

Fit the others to your team and your projects. Turn off individual rules that aren't applicable. In particular, Naming Rules may need to be adjusted.

EDIT: The most important thing is to reduce noise. If every project has 200 warnings and stays that way for months, everyone will ignore them. Turn on the rules that matter to your team, clean up the code to get 100% passing (or suppress the exceptions - and there will be exceptions; these are guidelines), then enforce keeping the code clean.

Answer 4

I somewhat agree with Jeroen Huinink's answer.

I would turn on all the rules that you think a project should follow and fix them as soon as possible. You don't have to fix them all now, but as you go through and fix a defect or refactor a method in a module, you can always clean up the issues found by static analysis in that method or module. New code should adhere to your rules and existing code should be transformed into adherence as quickly as possible, but you don't need to drop everything to make that happen.

Your development team can also look at the issues for a project and prioritize them, perhaps filing defects in your issue tracking system for the most critical problems so that they are addressed quickly and by the appropriate developer.

Answer 5

The very first rules you should activate for a project are those for which you don't yet have any violations in that project. This will allow you to avoid introducing new problems without costing you any additional clean-up effort.

As for the rest, given that you're already using code analysis on other projects, your best input for which rules are most likely to be broken with serious consequences is probably the developers who work on those projects. If you don't have enough overlap between projects to get meaningful feedback from developers, you might want to consider starting with the rules that are included in the Microsoft Minimum Recommended Rules rule set in Visual Studio 2010.

If you are planning on actually cleaning up existing violations in any given project, you may want to consider using FxCop instead of VS Code Analysis until the clean-up is complete. This would allow you to activate rules immediately while keeping "for clean-up" exclusions of existing violations outside your source code.