  Dataflow analysis is a powerful code analysis technique that reasons
dependencies between program values, offering support for code optimization,
program comprehension, and bug detection. Existing approaches require the
successful compilation of the subject program and customizations for downstream
applications. This paper introduces LLMDFA, an LLM-powered dataflow analysis
framework that analyzes arbitrary code snippets without requiring a compilation
infrastructure and automatically synthesizes downstream applications. Inspired
by summary-based dataflow analysis, LLMDFA decomposes the problem into three
sub-problems, which are effectively resolved by several essential strategies,
including few-shot chain-of-thought prompting and tool synthesis. Our
evaluation has shown that the design can mitigate the hallucination and improve
the reasoning ability, obtaining high precision and recall in detecting
dataflow-related bugs upon benchmark programs, outperforming state-of-the-art
(classic) tools, including a very recent industrial analyzer.
