7b6731fd3b
This commit moves our `links` annotation in the `wasm-bindgen` crate to the `wasm-bindgen-shared` crate. The `links` annotation is used to ensure that there's only one version of `wasm-bindgen` in a crate graph because if there are multiple versions then a CLI surely cannot actually process the wasm binary (as the multiple versions likely have different formats in their custom sections). Discovered in #1373 it looks like the usage in `wasm-bindgen` isn't quite sufficient to cause this deduplication. It turns out that `wasm-bindgen-shared`, a very core dependency, is actually the most critical to be deduplicated since its the one that defines the format of the custom section. In #1373 a case came up where `wasm-bindgen` was deduplciated but there were two versions of `wasm-bindgen-shared` in the crate graph, meaning that a `[patch]` for only `wasm-bindgen` wasn't sufficient, but rather `web-sys` and/or `js-sys` also needed a `[patch]` annotation to ensure everyone used the right dependencies. This commit won't actually fix #1373 to the point where it "just works", but what it does do is present a better error message than an internal panic of `wasm-bindgen`. The hope is that by moving the `links` annotation we can catch more errors of this crate graph duplication, leading to more `[patch]` annotations locally. Closes #1373
wasm-bindgen
Facilitating high-level interactions between wasm modules and JavaScript.
Import JavaScript things into Rust and export Rust things to JavaScript.
extern crate wasm_bindgen;
use wasm_bindgen::prelude::*;
// Import the `window.alert` function from the Web.
#[wasm_bindgen]
extern "C" {
fn alert(s: &str);
}
// Export a `greet` function from Rust to JavaScript, that alerts a
// hello message.
#[wasm_bindgen]
pub fn greet(name: &str) {
alert(&format!("Hello, {}!", name));
}
Use exported Rust things from JavaScript with ECMAScript modules!
import { greet } from "./hello_world";
greet("World!");
Features
-
Lightweight. Only pay for what you use.
wasm-bindgenonly generates bindings and glue for the JavaScript imports you actually use and Rust functionality that you export. For example, importing and using thedocument.querySelectormethod doesn't causeNode.prototype.appendChildorwindow.alertto be included in the bindings as well. -
ECMAScript modules. Just import WebAssembly modules the same way you would import JavaScript modules. Future compatible with WebAssembly modules and ECMAScript modules integration.
-
Designed with the "host bindings" proposal in mind. Eventually, there won't be any JavaScript shims between Rust-generated wasm functions and native DOM methods. Because the wasm functions are statically type checked, some of those native methods' dynamic type checks should become unnecessary, promising to unlock even-faster-than-JavaScript DOM access.
Guide
📚 Read the wasm-bindgen guide here! 📚
You can find general documentation about Rust and WebAssembly here.
API Docs
License
This project is licensed under either of
- Apache License, Version 2.0, (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
- MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)
at your option.
Contribution
See the "Contributing" section of the guide for information on
hacking on wasm-bindgen!
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in this project by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.