Evaluating the usage of fault localization in automated program repair: an empirical study

Fault localization techniques are originally proposed to assist in manual debugging by generally producing a rank list of suspicious locations.With the increasing popularity of automated program repair,the fault localization techniques have been introduced to effectively reduce the search space of automated program repair.Unlike developers who mainly focus on the rank information,current automated program repair has two strategies to use the fault localization information:suspiciousness-first algorithm(SFA)based on the suspiciousness accuracy and rank-first algorithm(RFA)relying on the rank accuracy.However,despite the fact that the two different usages are widely adopted by current automated program repair and may result in different repair results,little is known about the impacts of the two strategies on automated program repair.In this paper we empirically compare the performance of SFA and RFA in the context of automated program repair.Specifically,we implement the two strategies and six well-studied fault localization techniques into four state-of-the-art automated program repair tools,and then use these tools to perform repair experiments on 60 real-world bugs from Defects4J.Our study presents a number of interesting findings:RFA outperforms SFA in 70.02%of cases when measured by the number of candidate patches generated before a valid patch is found(NCP),while SFA performs better in parallel repair and patch diversity;the performance of SFA can be improved by increasing the suspiciousness accuracy of fault localization techniques;finally,we use SimFix that deploys SFA to successfully repair four extra Defects4J bugs which cannot be repaired by SimFix originally using RFA.These observations provide a new perspective for future research on the usage and improvement of fault localization in automated program repair.     

软件缺陷自动修复技术综述

软件缺陷是软件开发和维护过程中不可避免的.随着现代软件规模的不断变大,软件缺陷的数量以及修复难度随之增加,为企业带来了巨大的经济损失.修复软件缺陷,成为了开发人员维护软件质量的重大负担.软件缺陷自动修复技术有希望将开发者从繁重的调试中解脱出来,近年来成为热门的研究领域之一.搜集了 94篇该领域最新的高水平论文,进行了详...     

An approach to automatic deductive synthesis of functional programs

The work deals with automatic deductive synthesis of functional programs. Formal specification of a program is taken as a mathematical existence theorem and while proving it, we derive a program and simultaneously prove that this program corresponds to given specification. Several problems have to be resolved for automatic synthesis: the choice of synthesis rules that allows us to derive the basic constructions of a functional program, order of rule application and choice of a particular induction rule. The method proposed here is based on the deductive tableau method. The basic method gives rules for functional program construction. To determine the proof strategy we use some external heuristics, including rippling. And for the induction hypothesis formation the combination of rippling and the deductive tableau method became very useful. The proposed techniques are implemented in the system ALISA (Automatic Lisp Synthesizer) and used for automatic synthesis of several functions in the Lisp language. The work has been partially supported by RFBR grant 05-01-00948a.     

Using classes as specifications for automatic construction of programs in the NUT system

It is shown, how the object-oriented programming paradigm has been combined with automatic program construction in the NUT system: type information extracted from a class specification is being used for automatic construction of methods for the class. Special compute-messages are introduced as requests for program synthesis which can be done statically or dynamically. Particular features of the specification language which support the program synthesis are considered and applications of this method are outlined.     

Derivation of efficient parallel programs: An example from genetic sequence analysis

Implementation issues such as synchronization, implementation of abstract data types, and scheduling of processes are usually not addressed in the formal derivation of parallel programs. We seek to redress the situation by considering these issues in the context of developing an efficient implementation of an actual parallel program. The computational problem that we proceed by developingan algorithm in Unity and investigating the issues that arise in producing an efficient C implementation of the resulting algorithm. Along the way, we develop some theorems about program refinements, and illustrate the usefulness of the theorems in the context of refining the original Unity program.Work supported in part by ONR Grants N00014-86-K-0763 and N00014-87-K-0510 while the author was at The University of Texas at Austin.     

面向程序自动修复的缺陷分类方法研究*

程序自动修复是近年软件工程的研究热点,但其发展难以满足工业应用的要求。分析了自动修复技术的局限性,引入了缺陷分类的思想,并与正交缺陷分类方法相结合,提出了面向软件自动修复的缺陷分类方法(APRDC)。基于APRDC提出了自动修复技术集成的思想。实验中将基于APRDC与基于随机的自动修复技术集成工具作了比较。实验结果表明基于APRDC方法的自动修复技术的集成提高了修复效果,同时也表明了APRDC方法的有效性。     

微弱GPS信号的翻转位预测捕获算法

微弱全球定位系统(GPS)卫星信号的捕获需要较长的积分时间,但受导航数据位翻转的影响,一般采用10ms的相干积分。为进一步提高捕获灵敏度,提出了一种数据位翻转预估算法,该算法通过对多组信号积分结果的对比估算出翻转位的位置,舍弃存在位翻转的5ms数据从而消除其影响,并对其余数据进行15ms的分块相干积分。同时,为降低分块相干积分中非相干积分的平方损耗,采用差分相干积分对其进行改进,并在运算过程中采用“先累加后相关”的方式,在进一步提高捕获灵敏度的同时降低运算复杂度。仿真结果表明,该算法能高效地捕获到信噪比低至-50dB的信号,可有效地提高GPS接收机的捕获灵敏度和捕获效率。     

Formal Derivation of Graph AlgorithmicPrograms Using Partition-and-Recur

In this paper,we derive,by presenting some suitable notations,three typical graph algorithms and corresponding programs using a unified approach,partition-and-recur.We putemphasis on the derivation rather than the algorithms themselves.The main ideas and ingenuity of these algorithms are revealed by formula deduction.Success in these examples gives us more evidence that partition-and-recur is a simple and practical approach and developing enough suitable notations is the key in designing and deriving efficient and correct algorithmic programs.     

易挥发弱电解质体系化学及相平衡计算的遗传算法

基于Gibbs自由能最小化原理,提出用遗传算法计算易挥发弱电解质体系化学及相平衡问题。首先建立了易挥发弱电解质体系Gibbs自由能的计算模型,将含化学反应平衡和相平衡计算问题转化为有约束的最优化问题．并应用遗传算法求解;其次在算法实施时提出两点改进,即通过对优化变量采取动态边界的可行域编码方法来处理问题约束和引入反应平衡常数来提高低含量组分的计算精度;最后对两个算例进行了计算。计算表明,本文计算结果与文献值相吻合,并且简单易实施,是这类问题计算的有效方法。     

Path testing of computer programs with loops using a tool for simple loop patterns

The purpose of this paper is to present a method for testing computer programs with iteration loops. Given such programs, we have shown that for classes of program paths, identified as sequences of simple loop paths, there is a characterizing function called a simple loop pattern. The key idea of simple loop patterns is that these special functions form a base set which can represent any path computation in the given program. A software tool called SILOP has been developed to automatically generate these simple loop patterns, and each corresponding sequence of simple loop paths can be considered as a test case. The tester uses each test case, and with knowledge of the application program, can generate corresponding test data. This paper also presents a method for selecting the specific paths and test data to determine the simple loop pattern reliably. The tester can use this selection method to predict the number of tests required. In order to apply this selection method, the given program must be a linear computer program. The SILOP tool and this test selection method have been applied to commercial software; in this paper, this computational experience is reported and several examples are given to demonstrate the approach.     

Realization of highly energy efficient pick-and-place tasks using resonance-based robot motion control

In resonance-based robot motion control, the potential energy stored in mechanical elasticity is effectively utilized to generate robot motion; therefore, high energy efficiency is expected when the desired motions are periodic. However, several practical problems arise when resonance-based robot motion control is applied to pick-and-place tasks. This paper proposes methods to solve these problems. First, experiments are conducted to verify the energy efficiency of resonance-based robot motion control when a SCARA-type robot performs a pick-and-place task. Second, as a previous method can only treat two points and increasing of the number pick-and-place points is critically important to conduct actual pick-and-place tasks in factories, methods are proposed to increase the number of the pick and/or place points. Finally, the performance of the proposed method is experimentally investigated.     

Performance evaluation of subsea BOP control systems using dynamic Bayesian networks with imperfect repair and preventive maintenance

The work presents a dynamic Bayesian networks (DBN) modeling of series, parallel and 2-out-of-3 (2oo3) voting systems, taking account of common-cause failure, imperfect coverage, imperfect repair and preventive maintenance. Seven basic events of one, two or three component failure are proposed to model the common-cause failure of the three-components-systems. The imperfect coverage is modeled in the conditional probability table by defining a coverage factor. A multi-state degraded component is used to model the imperfect repair and preventive maintenance. Using the proposed method, a DBN modeling of a subsea blowout preventer (BOP) control system is built, and the reliability and availability are evaluated. The mutual information is researched in order to assess the important degree of basic events. The effects of degradation probability, failure rate and mean time to repair (MTTR) on the performances are studied. The results show that the repairs and maintenance can improve the system performance significantly, whereas the imperfect repair cannot degrade the system performance significantly in comparison with the perfect repair, and the preventive maintenance can improve the system performance slightly in comparison with the imperfect repair. In order to improve the performance of subsea BOP control system, the single surface components and the components with all-common-cause failure should given more attention. The influence of degradation probability on the performance is in the order of PLC, PC and ES. The influence of failure rate and MTTR on the performance is in the order of PLC, ES, PC, DO, DI and AI.