Crates in Firefox Over FFI
Lightningat RustConf 2026 · on Wednesday, 2026-09-09· at 17:30· Room 511 | Palais des Congrès de Montréal, Palais des Congrès de Montréal·
summary
Implements URLPattern in Firefox by vendoring Dolan crate into libul, generating JS-callable C++ bindings with webl and using cbindgen-style glue so Rust code is called from the DOM. Addresses ownership gaps with opaque pointers and unsafe marshalling across FFI, stores parsed pattern objects in DOM to avoid repeated parsing, and updates the crate to use SpiderMonkey’s ECMAScript regex. Adds JS context creation, rooting to prevent GC and UTF‑8/16 conversions; outcome: working API with decent performance after these cross-language fixes.
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