Apr 2026· Proceedings of the 2026 IEEE/ACM 48th International Conference on Software Engineering· pp. 742-753· 0 citations· 56 references
Computer Science
TL;DR
This paper presents HarnessLLM, an automated workflow that leverages LLMs to generate verification harnesses for Rust code directly from existing test suites and is the first work to use LLMs for generating harnesses aimed at memory safety verification in real-world Rust projects.
Abstract
Rust’s ownership and type system offer strong memory safety guarantees, but unsafe code and runtime panics still present significant risks. Formal verification is essential to ensure memory safety, but developing verification harnesses remains a challenging and manual task. Although large language models (LLMs) have shown strong performance in various code analysis tasks, directly applying them to harness generation often results in inaccurate API invocations, inefficient nondeterministic data generation, and fabricated fixes. In this paper, we present HarnessLLM, an automated workflow that leverages LLMs to generate verification harnesses for Rust code directly from existing test suites. HarnessLLM automatically extracts calling scenarios from test cases, generates nondeterministic arguments based on dependency analysis, and incrementally synthesizes harnesses. It then iteratively refines the harnesses, preserving critical code regions and reporting fabricated types or functions to LLMs for correction. In our evaluation on 9 real-world Rust codebases, HarnessLLM extracted 294 calling scenarios from 494 test cases with 94.66% precision and generated harnesses for all scenarios in an average of 145 seconds each. It outperformed the existing approach, Autoharness, which succeeded on only 41% of those scenarios. Finally, 6 real-world memory safety bugs were detected using the generated harnesses, demonstrating the practical utility of our approach in verification. To our knowledge, this is the first work to use LLMs for generating harnesses aimed at memory safety verification in real-world Rust projects.
A reproducible benchmarking platform that evaluates open-source LLMs on Verilog RTL generation across 50 curated tasks consisting of combinational, sequential, finite state machine (FSM), and mixed designs, enabling reproducible evaluation of generative AI for hardware design workflows.
RTL-Obliger is presented, a neuro-symbolic framework that infers implicit security obligations of register-transfer-level RTL in a functionality-preserving two-stage generation and raises mean all-pass rates.
Guang Yang, Xing Hu, Xiang Chen et al.· 0 citations
The results show that executable feedback can repair secure-code generation, but its benefits depend on the model, task, feedback entry point, and especially test coverage.
Yun-Hao Liang, Cheng-Guang Gan, Rui-Xuan Ying et al.· 1 citation
Large language models (LLMs) are increasingly being explored for automating SystemVerilog Assertion (SVA) generation, yet most evaluations report correctness on a single syntactic representation of an input. Such point accuracy does not reveal whether a model's correct output is stable when the same RTL behavior is written differently. This paper presents a controlled metamorphic evaluation of LLM-based SVA generation under semantics-preserving RTL transformations. Starting from the VERT dataset, we construct a quality-filtered conditional-control pool and a stratified 40-program evaluation set containing 295 assignment behaviors. We evaluate two open code models, Qwen2.5-Coder-7B and DeepSeek-Coder-V2-Lite, with an identical evaluation prompt and greedy decoding. Three transformations are studied: operand reordering, deterministic identifier renaming, and redundant parenthesization. Beyond baseline and transformed accuracy, we measure conditional robustness, invariance failure, and any-flip rate, with 10,000-sample clustered bootstrap intervals at the RTL-program level. Across all six model-transformation conditions, 9.7%-27.0% of behaviors that were correct on the original RTL become incorrect after a semantics-preserving transformation. Aggregate accuracy can therefore hide substantial instability: under identifier renaming, DeepSeek-Coder-V2-Lite improves from 53.9% to 63.7% accuracy while 19.5% of its originally correct behaviors fail. Manual review of 30 sampled correct-to-wrong transitions identifies dropped path predicates, branch-polarity errors, Boolean-structure corruption, and output-contract violations. The results show that point accuracy alone is insufficient for characterizing LLM reliability in assertion generation and motivate robustness-aware evaluation for AI-assisted hardware verification.
Rust's ownership and type system provide strong memory safety guarantees, but unsafe code still presents memory safety risks. Formal verification is crucial for ensuring memory safety, but writing precise specifications for unsafe Rust is challenging and largely manual. Large language models (LLMs) have shown promise in generating formal specifications but are often code-centric, prone to inheriting implementation flaws, and lack systematic quality assessment. In this paper, we present KaPilot, a multi-agent framework for automatically generating specifications to verify unsafe Rust memory safety using Kani. The process begins with lightweight program analysis and proof harness generation. The SafetyReq agent extracts a concise, refined list of safety requirements from the target Rust function's documentation, which guides the SpecGenerate agent in producing initial specifications that specify memory safety concerns. Then, the specifications are iteratively refined through a generate-precheck-verify loop involving SpecGenerate, SpecPrecheck, and SpecVerify agents, which assess quality and feed errors back. By executing this loop multiple times, KaPilot generates a set of candidate specifications. Finally, the shuffle-and-implication strategy is applied to systematically determine the best specification from these candidates. We evaluated KaPilot on 54 unsafe Rust functions with ground truth and 70 without. KaPilot achieved 88.9% and 71.4% specification generation success, respectively, with 57.4% of generated specifications equivalent to or stronger than the ground truth. Compared with AutoSpec, KaPilot produces 14.8% more verifiable specifications and 25.9% more equivalent-or-better specifications.
