Extensive experimental studies have shown that in lower mammals, neuronal orientation preference in the primary visual cortex is organized in disordered "salt-and-pepper" organizations. In contrast, higher-order mammals display a continuous variation in orientation preference, forming pinwheel-like structures. Despite these observations, the spiking mechanisms underlying the emergence of these distinct topological structures and their functional roles in visual processing remain poorly understood. To address this, we developed a self-evolving spiking neural network model with Hebbian plasticity, trained using physiological parameters characteristic of rodents, cats, and primates, including retinotopy, neuronal morphology, and connectivity patterns. Our results identify critical factors, such as the degree of input visual field overlap, neuronal connection range, and the balance between localized connectivity and long-range competition, that determine the emergence of either salt-and-pepper or pinwheel-like topologies. Furthermore, we demonstrate that pinwheel structures exhibit lower wiring costs and enhanced sparse coding capabilities compared to salt-and-pepper organizations. They also maintain greater coding robustness against noise in naturalistic visual stimuli. These findings suggest that such topological structures confer significant computational advantages in visual processing and highlight their potential application in the design of brain-inspired deep learning networks and algorithms.

This research focuses on the false data injection attacks (FDI) and communication resource competition in single-master–multiple-slaves (SMMSs) teleoperation systems and proposes a security control strategy based on dynamic try-once-discard (DTOD) scheduling protocol. An attack detector is designed to detect FDI attacks on signals transmitted through the communication channel. With the attack detection result, a DTOD scheduling protocol is designed to dynamically adjust the transmission priority of the slaves. Using the attack detection result and scheduled position and velocity, a switching controller is developed to ensure the position tracking between the master and slaves. The stability of the overall system is proven via Lyapunov functions, and comparative results validate the effectiveness of the proposed strategy. The proposed strategy not only optimizes resource allocation but also effectively defends against cyberattacks, enhancing the stability and tracking accuracy of SMMS teleoperation systems.

Crash reports play a crucial role in software maintenance as they inform developers about the issues encountered in mobile applications. Developers must reproduce the reported crash before fixing it, which is extremely time-consuming and tedious. Existing studies have focused on automatic crash reproduction with step-by-step instructions. However, a non-neglectable portion of crash reports only provides a one-sentence overview, which merely describes the final crash-triggering action. These reports require developers to invest more effort in understanding and fixing the issues while existing techniques cannot handle them due to the lack of step-by-step guidance, thus calling for a greater need for automatic support. Leveraging the capability of Large Language Models (LLMs) in combining acting and reasoning, we propose ReActDroid, an automated approach to reproduce mobile application crashes directly from the crash overview. ReActDroid utilizes ReAct prompting to augment the app-specific knowledge and exploration history, enabling the LLM to derive the necessary steps for triggering the crash from a comprehensive and historical perspective. We evaluate ReActDroid on 102 crash reports from 69 popular Android apps and successfully reproduce 57.8% of the crashes, surpassing the performance of state-of-the-art baselines by 69% to 321%. Besides, the average reproducing time is 51.8 seconds, outperforming the baselines by 73% to 949%. We also evaluate the usefulness of ReActDroid with promising results.

Crash reports are vital for software maintenance since they allow the developers to be informed of the problems encountered in the mobile application. Before fixing, developers need to reproduce the crash, which is an extremely time-consuming and tedious task. Existing studies conducted the automatic crash reproduction with the natural language described reproducing steps. Yet we find a non-neglectable portion of crash reports only contain the stack trace when the crash occurs. Such stack-trace-only crashes merely reveal the last GUI page when the crash occurs, and lack step-by-step guidance. Developers tend to spend more effort in understanding the problem and reproducing the crash, and existing techniques cannot work on this, thus calling for a greater need for automatic support. This paper proposes an approach named CrashTranslator to automatically reproduce mobile application crashes directly from the stack trace. It accomplishes this by leveraging a pre-trained Large Language Model to predict the exploration steps for triggering the crash, and designing a reinforcement learning based technique to mitigate the inaccurate prediction and guide the search holistically. We evaluate CrashTranslator on 75 crash reports involving 58 popular Android apps, and it successfully reproduces 61.3% of the crashes, outperforming the state-of-the-art baselines by 109% to 206%. Besides, the average reproducing time is 68.7 seconds, outperforming the baselines by 302% to 1611%. We also evaluate the usefulness of CrashTranslator with promising results.

Pre-trained large language models (LLMs) have recently emerged as a breakthrough technology in natural language processing and artificial intelligence, with the ability to handle large-scale datasets and exhibit remarkable performance across a wide range of tasks. Meanwhile, software testing is a crucial undertaking that serves as a cornerstone for ensuring the quality and reliability of software products. As the scope and complexity of software systems continue to grow, the need for more effective software testing techniques becomes increasingly urgent, making it an area ripe for innovative approaches such as the use of LLMs. This paper provides a comprehensive review of the utilization of LLMs in software testing. It analyzes 102 relevant studies that have used LLMs for software testing, from both the software testing and LLMs perspectives. The paper presents a detailed discussion of the software testing tasks for which LLMs are commonly used, among which test case preparation and program repair are the most representative. It also analyzes the commonly used LLMs, the types of prompt engineering that are employed, as well as the accompanied techniques with these LLMs. It also summarizes the key challenges and potential opportunities in this direction. This work can serve as a roadmap for future research in this area, highlighting potential avenues for exploration, and identifying gaps in our current understanding of the use of LLMs in software testing.

Bug reports are vital for software maintenance that allow the developers being informed of the problems encountered in the software. Before bug fixing, developers need to reproduce the bugs which is an extremely time-consuming and tedious task, and it is highly expected to automate this process. However, it is challenging to do so considering the imprecise or incomplete natural language described in reproducing steps, and the missing or ambiguous single source of information in GUI components. In this paper, we propose a context-aware bug reproduction approach ScopeDroid which automatically reproduces crashes from textual bug reports for mobile apps. It first constructs a state transition graph (STG) and extracts the contextual information of components. We then design a multi-modal neural matching network to derive the fuzzy matching matrix between all candidate GUI events and reproducing steps. With the STG and matching information, it plans the exploration path for reproducing the bug, and enriches the initial STG iteratively. We evaluate the approach on 102 bug reports from 69 popular Android apps, and it successfully reproduces 63.7% of the crashes, outper-forming the state-of-the-art baselines by 32.6% and 38.3%. We also evaluate the usefulness and robustness of ScopeDroid with promising results. Furthermore, to train the neural matching network, we develop a heuristic-based automated training data generation method, which can potentially motivate and facilitate other activities as user interface operations.

Deep learning (DL)-based code processing models have demonstrated good performance for tasks such as method name prediction, program summarization, and comment generation. However, despite the tremendous advancements, DL models are frequently susceptible to adversarial attacks, which pose a significant threat to the robustness and generalizability of these models by causing them to misclassify unexpected inputs. To address the issue above, numerous DL testing approaches have been proposed; however, these approaches primarily target testing DL applications in the domains of image, audio, and text analysis, etc., and cannot be “directly applied” to “neural models for code” due to the unique properties of programs. In this article, we propose a coverage-based fuzzing framework,CoCoFuzzing, for testing DL-based code processing models. In particular, we first propose 10 mutation operators to automatically generate validly and semantically preserving source code examples as tests, followed by a neuron coverage (NC)-based approach for guiding the generation of tests. The performance ofCoCoFuzzingis evaluated using three state-of-the-art neural code models, i.e., NeuralCodeSum, CODE2SEQ, and CODE2VEC. Our experiment results indicate thatCoCoFuzzingcan generate validly and semantically preserving source code examples for testing the robustness and generalizability of these models and enhancing NC. Furthermore, these tests can be used for adversarial retraining to improve the performance of neural code models.

Automatic API recommendation has been studied for years. There are two orthogonal lines of approaches for this task, i.e., information-retrieval-based (IR-based) and neural-based methods. Although these approaches were reported having remarkable performance, our observation shows that existing approaches can fail due to the following two reasons: 1) most IR-based approaches treat task queries as bag-of-words and use word embedding to represent queries, which cannot capture the sequential semantic information. 2) both the IR-based and the neural-based approaches are weak at distinguishing the semantic difference among lexically similar queries.

Static bug finders (also known as static code analyzers, e.g., Find-Bugs, SonarQube) have been widely-adopted by developers to find bugs in real-world software projects. They leverage predefined heuristic static analysis rules to scan source code or binary code of a software project, and report violations to these rules as warnings to be verified. However, the advantages of static bug finders are overshadowed by such issues as uncovered obvious bugs, false positives, etc. To improve these tools, many techniques have been proposed to filter out false positives reported or design new static analysis rules. Nevertheless, the under-performance of bug finders can also be caused by the incorrectness of current rules contained in the static bug finders, which is not explored yet. In this work, we propose a differential testing approach to detect bugs in the rules of four widely-used static bug finders, i.e., SonarQube, PMD, SpotBugs, and ErrorProne, and conduct a qualitative study about the bugs found. The experiment on 2,728 open source projects reveals 46 bugs in the static bug finders, among which 30 are fixed or confirmed and the left are awaiting confirmation. We also summarize 13 bug patterns in the static analysis rules based on their context and root causes, which can serve as the checklist for designing and implementing other rules and/or in other tools. This study indicates that the commonly-used static bug finders are not as reliable as they might have been envisaged. It not only demonstrates the effectiveness of our approach, but also highlights the need to continue improving the reliability of the static bug finders.

Application Programming Interfaces (APIs) are designed to help developers build software more effectively. Recommending the right APIs for specific tasks is gaining increasing attention among researchers and developers. However, most of the existing approaches are mainly evaluated for general programming tasks using statically typed programming languages such as Java. Little is known about their practical effectiveness and usefulness for machine learning (ML) programming tasks with dynamically typed programming languages such as Python, whose paradigms are fundamentally different from general programming tasks. This is of great value considering the increasing popularity of ML and the large number of new questions appearing on question answering websites. In this work, we set out to investigate the effectiveness of existing API recommendation approaches for Python-based ML programming tasks from Stack Overflow (SO). Specifically, we conducted an empirical study of six widely-used Python-based ML libraries using two state-of-the-art API recommendation approaches, i.e., BIKER and DeepAPI. We found that the existing approaches perform poorly for two main reasons: (1) Python-based ML tasks often require significant long API sequences; and (2) there are common API usage patterns in Python-based ML programming tasks that existing approaches cannot handle. Inspired by our findings, we proposed a simple but effective frequent itemset mining-based approach, i.e., FIMAX, to boost API recommendation approaches, i.e., enhance existing API recommendation approaches for Python-based ML programming tasks by leveraging the common API usage information from SO questions. Our evaluation shows that FIMAX improves existing state-of-the-art API recommendation approaches by up to 54.3% and 57.4% in MRR and MAP, respectively. Our user study with 14 developers further demonstrates the practicality of FIMAX for API recommendation.