Static program analysis tools are critical to the eld of software engineering, allowing us to compile, refactor, verify, and understand our code. Because modern software is built on top of reusable libraries and frameworks, whole program analysis is prohibitively expensive, hence tools must instead perform partial program analysis-analysis of a proper subset of a program's implementation. Missing data ow semantics of these components introduce problematic gaps for many use cases, including security-critical analyses. Prior attempts to overcome this, including handwritten models, heuristics, and dynamically-inferred specications, are too coarse for many analysis use cases, introducing inaccuracies.