Assessing the effect of clones on changeability

Abstract

To prioritize software maintenance activities, it is important to identify which programming flaws impact most on an application's evolution. Recent empirical studies on such a flaw, code clones, have focused on one of the arguments to consider clones harmful, namely, that related clones are not updated consistently. We believe that a wider notion is needed to assess the effect of cloning on evolution. This paper compares measures of the maintenance effort on methods with clones against those without. Statistical and graphical analysis suggests that having a clone may increase the maintenance effort of changing a method. The effort seems to increase depending on the percentage of the system affected whenever the methods that share the clone are modified. We also found that some methods seem to increase significantly their maintenance effort when a clone was present. However, the characteristics analyzed in these methods did not reveal any systematic relation between cloning and such maintenance effort increase.

A Survey on Mining Software Repositories

“…After that, they observed that clones influenced the maintenance effort by analyzing the effect of clones to changeability. However, they could not find systematic relation between them [159]. Rahman et al empirically validated the general negative characteristics of clones [112].…”

“…Decision tree has been used to predict developers' contribution in [145]. In [65], SVM has been applied for the bug triage and in [147], association rule mining has refactoring [72], [73] API-change [74], [75], [77], [80], [81] change patterns [83]- [88], [90], [160] team-activity developer's contribution [55], [91], [93], [94], [154] experties of developers [96], [97], [149] tool support [98], [99], [128], [151] helpful information [100] comprehension visualization [101], [102], [156] identifiers [104], [105], [153] recording operations [106] validation metrics [45], [107], [157] tool [108] clones [109]- [112], [150], [159] bug [113], [114] development& evolution development [118]- [120] evolution …”

Do Code Smells Impact the Effort of Different Maintenance Programming Activities?

“…Deligiannis et al [14] conducted an observational study where four participants evaluated two systems, one compliant and one non-compliant to the principle of avoiding God classes, and concluded that familiarity with the application domain plays an important role when judging negative effects on completeness, correctness and consistency during comprehension tasks. Lozano and Wermelinger [15] compared the maintenance effort of methods during periods when they did not contained a clone and when they did contained a clone. They found that there was no increase in the maintenance effort in 50% of the cases.…”

Tracking clones' imprint

“…Find the origin of methods All methods that seem new at each commit transaction are compared against all methods that seem deleted in the same commit transaction in order to detect renamings, or movement of methods to other classes or packages (see [13] …”

“…In previous work we measured changes and co-changes of methods while cloned vs. while not cloned [15], we compared the ease to change cloned methods vs. not-cloned-methods [13], and the relation between method characteristics and their ease to change [14]. Our previous work tried to find trends on the effect of clones in methods using measurements that depended on the periods cloned and not cloned of each method analyzed.…”