To analyze code, Sonar utilizes some of the most popular and proven tools available in the open source community. These tools pass through source code performing standard checks reviewing errors and possible bugs, each from their own perspective. The nature of the checks range from minor styling ones, for example the detection of unwanted trailing spaces, to more complex ones that easily promote to potential bugs, such as unchecked variables eligible to result in null references. Since version 2.1 Sonar provides its own rules engine too, based on Squid.
Sonar includes the following five analyzers: