Object-oriented code smells are well-known concepts in software engineering that refer to bad design and development practices commonly observed in software systems. With the emergence of mobile apps, new classes of code smells have been identified by the research community as mobile-specific code smells. These code smells are presented as symptoms of important performance issues or bottlenecks. Despite the multiple empirical studies about these new code smells, their diffuseness and evolution along change histories remains unclear.

We present in this article a large-scale empirical study that inspects the introduction, evolution, and removal of Android code smells. This study relies on data extracted from 324 apps, a manual analysis of 561 smell-removing commits, and discussions with 25 Android developers. Our findings reveal that the high diffuseness of mobile-specific code smells is not a result of releasing pressure. We also found that the removal of these code smells is generally a side effect of maintenance activities as developers do not refactor smell instances even when they are aware of them.

面向对象的代码气味是软件工程中众所周知的概念，涉及到软件系统中常见的不良设计和开发实践。随着移动应用程序的出现，研究团体已经将新的代码气味类别识别为特定于移动设备的代码气味。这些代码气味表示为重要的性能问题或瓶颈的症状。尽管对这些新代码的气味进行了多次实证研究，但它们沿变化历史的扩散和演变仍不清楚。

在本文中，我们将进行大规模的实证研究，以检查Android代码异味的引入，演变和消除。这项研究依赖于从324个应用程序中提取的数据，对561个消除气味的提交进行的手动分析以及与25个Android开发人员的讨论。我们的发现表明，特定于移动设备的代码气味的高度扩散不是释放压力的结果。我们还发现，消除这些代码气味通常是维护活动的副作用，因为即使开发人员意识到气味实例也不会重构气味实例。