mirror of
https://github.com/danbulant/oxc
synced 2026-05-19 20:28:58 +00:00
2064ae9e0a
part of #3213 We should only have one diagnostic struct instead 353 copies of them, so we don't end up choking LLVM with 50k lines of the same code due to monomorphization. If the proposed approach is good, then I'll start writing a codemod to turn all the existing structs to plain functions. --- Background: Using `--timings`, we see `oxc_linter` is slow on codegen (the purple part).  The crate currently contains 353 miette errors. [cargo-llvm-lines](https://github.com/dtolnay/cargo-llvm-lines) displays ``` cargo llvm-lines -p oxc_linter --lib --release Lines Copies Function name ----- ------ ------------- 830350 33438 (TOTAL) 29252 (3.5%, 3.5%) 808 (2.4%, 2.4%) <alloc::boxed::Box<T,A> as core::ops::drop::Drop>::drop 23298 (2.8%, 6.3%) 353 (1.1%, 3.5%) miette::eyreish::error::object_downcast 19062 (2.3%, 8.6%) 706 (2.1%, 5.6%) core::error::Error::type_id 12610 (1.5%, 10.1%) 65 (0.2%, 5.8%) alloc::raw_vec::RawVec<T,A>::grow_amortized 12002 (1.4%, 11.6%) 706 (2.1%, 7.9%) miette::eyreish::ptr::Own<T>::boxed 9215 (1.1%, 12.7%) 115 (0.3%, 8.2%) core::iter::traits::iterator::Iterator::try_fold 9150 (1.1%, 13.8%) 1 (0.0%, 8.2%) oxc_linter::rules::RuleEnum::read_json 8825 (1.1%, 14.9%) 353 (1.1%, 9.3%) <miette::eyreish::error::ErrorImpl<E> as core::error::Error>::source 8822 (1.1%, 15.9%) 353 (1.1%, 10.3%) miette::eyreish::error::<impl miette::eyreish::Report>::construct 8119 (1.0%, 16.9%) 353 (1.1%, 11.4%) miette::eyreish::error::object_ref 8119 (1.0%, 17.9%) 353 (1.1%, 12.5%) miette::eyreish::error::object_ref_stderr 7413 (0.9%, 18.8%) 353 (1.1%, 13.5%) <miette::eyreish::error::ErrorImpl<E> as core::fmt::Display>::fmt 7413 (0.9%, 19.7%) 353 (1.1%, 14.6%) miette::eyreish::ptr::Own<T>::new 6669 (0.8%, 20.5%) 39 (0.1%, 14.7%) alloc::raw_vec::RawVec<T,A>::try_allocate_in 6173 (0.7%, 21.2%) 353 (1.1%, 15.7%) miette::eyreish::error::<impl miette::eyreish::Report>::from_std 6027 (0.7%, 21.9%) 70 (0.2%, 16.0%) <alloc::vec::Vec<T> as alloc::vec::spec_from_iter_nested::SpecFromIterNested<T,I>>::from_iter 6001 (0.7%, 22.7%) 353 (1.1%, 17.0%) miette::eyreish::error::object_drop 6001 (0.7%, 23.4%) 353 (1.1%, 18.1%) miette::eyreish::error::object_drop_front 5648 (0.7%, 24.1%) 353 (1.1%, 19.1%) <miette::eyreish::error::ErrorImpl<E> as core::fmt::Debug>::fmt ``` It's totalling more than 50k llvm lines, and is putting pressure on rustc codegen (the purple part on `oxc_linter` in the image above. --- It's pretty obvious by looking at https://github.com/zkat/miette/blob/main/src/eyreish/error.rs, the generics can expand out to lots of code. |
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| src | ||
| .gitignore | ||
| Cargo.toml | ||
| package.json | ||
| pnpm-lock.yaml | ||
| README.md | ||
| test-node.mjs | ||
About
Experimental wasm package for the oxc parser, with full TypeScript typings support.
This package is built with different wasm-pack's target builds:
wasm-pack build --target webfor bundler (webpack / vite) consumption.wasm-pack build --target nodejsfor node.js
And exports the files as
"main": "./node/oxc_parser_wasm.js",
"browser": "./web/oxc_parser_wasm.js",
"types": "./node/oxc_parser_wasm.d.ts",
Checkout oxc-parser for usage in node.js via napi bindings.
Source code: https://github.com/oxc-project/oxc/tree/main/wasm/parser
Usage
import initWasm, { parseSync } from "@oxc-parser/wasm";
async function main() {
await initWasm();
const code = "let foo";
const result = parseSync(code, { sourceFilename: "test.ts" });
console.log(result);
}
main();
Notes
UTF8 vs UTF16 byte offsets
The span value returned from the ASTs and diagnostics is in UTF8 byte offsets. Converting to UTF16 byte offsets:
let sourceTextUtf8 = new TextEncoder().encode(sourceText);
const convertToUtf8 = (sourceTextUtf8, d) => {
return new TextDecoder().decode(sourceTextUtf8.slice(0, d)).length;
}
const diagnostics = result.errors.map((d) => ({
from: convertToUtf8(sourceTextUtf8, d.start),
to: convertToUtf8(sourceTextUtf8, d.end),
severity: d.severity.toLowerCase(),
message: d.message,
}));
Vite
wasm-pack build --target web is used for the wasm build.
You may need something like https://github.com/nshen/vite-plugin-wasm-pack to get it working with vite,
otherwise vite will load the wasm file as a HTML file causing a CompileError: WebAssembly.instantiate(): expected magic word error.