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Why you should run static code analysis…

Evgenii Ryzhkov
Articles: 125

Why you should run static code analysis regularly and not from time to time (for instance, at "each release")

While developing and helping people to use static code analyzers, we constantly encounter an inefficient approach to using these tools. Developers would launch the tool, find and fix interesting software errors and then launch the tool only from time to time, for instance, when a new version is released. This approach is destined to fail. I will tell you why.

In general, the most complicated and "heavy-going" stage in the process of using tools of static code analysis is their integration. The point is that any static analyzer always generates rather many messages (including false alarms) and you will anyway get plenty of these messages at first launches. You must somehow "force your way through" them - either fix errors in code or mark them as false alarms. This way or another, you must make the analyzer not generate these messages anymore. After that users often put the tool aside till "the next time", say, till preparing a new version of their products.

It is not right because again too many analyzer-generated messages will accumulate and you will feel reluctant to fix them. A correct way of using a static code analyzer is to run it regularly and fix detected issues at once. For instance, you may run static analysis nightly together with night builds.

There is another more crucial reason why irregular launch of a static analyzer is too inefficient. Most errors that could be detected by static code analysis at once are detected with the help of other testing methods instead. The cost and time of error fixing rise several times.

PVS-Studio has a mechanism that allows you to run code analysis from the command line. This method of launching the tool is very convenient to integrate into the procedure of night builds. In this case, all the project's files will be checked and at morning you may study the report with new errors found.

If analysis of all the files takes too much time (it is typical of large projects), you may set PVS-Studio to check only some files. Here you may read how to do that. In brief, you may either check files modified during the last day (or several days) or check only files specified in the list (the list itself is a file defined in the command line). In this case, first, you will get a list of new issues found in code every morning and, second, it will take you quite little time. The "Check only Files Modified In" setting might be useful when launching PVS-Studio manually while writing the code. For instance, having finished modification of a large program's fragment and made the code compile well, you may run PVS-Studio. The analyzer will quickly check only those files which have been modified today.