We Hit a Mark of 1000 Error Samples Collected from Open Source Apps!

16 Sep 2013

Author: Andrey Karpov

Our bug database where we collect samples of software errors detected in open source projects by our PVS-Studio static analyzer has recently reached the mark of 1000 samples!

It was some time ago that we decided to gather all the bugs found by PVS-Studio in open source applications in one place and made a single database. Although we go on with our usual task of writing and publishing articles to report checks (for example, Boost) and re-checks (for example, Chromium) of open source projects, we add every new defect we manage to find into this database. Sometimes the number of detected errors is not enough to write a good article, but they also get added into the database if we find them interesting.

What for do we maintain this bug database? First of all, it is a means of advertising our PVS-Studio code analyzer, of course. People won't read advertising posts which only abstractly praise the tool. One is always interested to know what particular errors it has found and in what particular real-life projects.

On the other hand, we believe that our bug database may serve as an excellent tutorial resource. Imagine you write a book or just an article explaining why it is bad to throw exceptions in C++ destructors. You naturally want to give real-life examples of errors related to this practice. And this is where our database comes in handy: you just open it and find there the diagnostic "V509. The 'throw' operator inside the destructor should be placed within the try..catch block. Raising exception inside the destructor is illegal." You can view the examples of bugs detected by the V509 diagnostic in projects like OGRE, TortoiseSVN and Chromium and cite them in your article, instead of abstract, artificial code samples. Or here's another situation. Imagine you are writing an article about sizeof(). No doubt, all the programmers ought to know the following rule: "The sizeof() operator returns size of the pointer, and not of the array, in given expression." But here we have error samples found by the V511 diagnostic in such projects as Wolfenstein 3D, Chromium, MySQL and Samba. These examples would well suit the demonstration purpose in your article.

Thus, our bug database is an excellent resource to aid preparing of articles and tutorials on C++. Authors are welcome to use it, which is absolutely free.