DIRNT Artifact: corresponding to our SPIN 2026 paper "Recurrence-seeking Tests for Non-termination"

ABSTRACT
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DIRNT is a non-termination (NT) checking technique based on recurrence-seeking tests. DIRNT generates tests designed to steer program execution toward state-recurrent behavior and reports NT when recurrence is observed during execution. Unlike symbolic approaches, which derive NT evidence primarily through symbolic reasoning, DIRNT uses symbolic reasoning only to construct tests that guide execution toward repeating runtime behavior. Unlike execution-based approaches, DIRNT systematically generates such tests with recurrence as the explicit objective rather than relying on unguided runs.

We implemented DIRNT for C programs and evaluated it on SV-COMP NT benchmarks and on instances derived from real-world open-source software. DIRNT solves 98% of SV-COMP tasks and 90% of OSS-derived tasks, compared to 75–88% on SV-COMP and 65% on OSS for the best-performing state-of-the-art techniques under the same resource limits.

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ARCHIVE CONTENTS
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This archive contains the DIRNT tool, benchmark sets, configuration files, and scripts required to reproduce the experimental results reported in the paper, as detailed below.