Understanding and detecting evolution-induced compatibility issues in Android apps

Abstract

The frequent release of Android OS and its various versions bring many compatibility issues to Android Apps. This paper studies and addresses such evolution-induced compatibility problems. We conduct an extensive empirical study over 11 different Android versions and 4,936 Android Apps. Our study shows that there are drastic API changes between adjacent Android versions, with averagely 140.8 new types, 1,505.6 new methods, and 979.2 new fields being introduced in each release. However, the Android Support Library (provided by the Android OS) only supports less than 23% of the newly added methods, with much less support for new types and fields. As a result, 91.84% of Android Apps write additional code to support different OS versions. Furthermore, 88.65% of the supporting codes share a common pattern, which directly compares variable android.os.Build.VERSION.SDK_INT with a constant version number, to use an API of particular versions.