@ARTICLE{pldi23-medea,
  title     = "{Conflict-Driven} Synthesis for Layout Engines",
  author    = "Liu, Junrui and Chen, Yanju and Atkinson, Eric and Feng, Yu and
               Bodik, Rastislav",
  abstract  = "Modern web browsers rely on layout engines to convert HTML
               documents to layout trees that specify color, size, and
               position. However, existing layout engines are notoriously
               difficult to maintain because of the complexity of web
               standards. This is especially true for incremental layout
               engines, which are designed to improve performance by updating
               only the parts of the layout tree that need to be changed. In
               this paper, we propose Medea, a new framework for automatically
               generating incremental layout engines. Medea separates the
               specification of the layout engine from its incremental
               implementation, and guarantees correctness through layout engine
               synthesis. The synthesis is driven by a new iterative algorithm
               based on detecting conflicts that prevent optimality of the
               incremental algorithm. We evaluated Medea on a fragment of HTML
               layout that includes challenging features such as margin
               collapse, floating layout, and absolute positioning. Medea
               successfully synthesized an incremental layout engine for this
               fragment. The synthesized layout engine is both correct and
               efficient. In particular, we demonstrated that it avoids
               real-world bugs that have been reported in the layout engines of
               Chrome, Firefox, and Safari. The incremental layout engine
               synthesized by Medea is up to 1.82$\times$ faster than a naive
               incremental baseline. We also demonstrated that our
               conflict-driven algorithm produces engines that are 2.74$\times$
               faster than a baseline without conflict analysis.",
  journal   = "Proc. ACM Program. Lang.",
  publisher = "Association for Computing Machinery",
  volume    =  7,
  number    = "PLDI",
  month     =  jun,
  year      =  2023,
  address   = "New York, NY, USA",
  keywords  = "program synthesis"
}