bun-src/scripts/rust-miri.ts

#!/usr/bin/env bun
/**
 * `cargo miri test` for the crates Miri can interpret end to end.
 *
 * Miri interprets MIR and catches UB (use-after-free, out-of-bounds,
 * uninit reads, data races, aliasing violations) at runtime. It cannot call
 * foreign functions beyond the libc subset it ships shims for, so this only
 * covers the (nearly) pure-Rust corner of the workspace — which is also where
 * `unsafe` density is highest.
 *
 * Aliasing model: `-Zmiri-tree-borrows`, not the default Stacked Borrows.
 * Stacked Borrows invalidates every raw pointer derived from `&mut self` the
 * moment a later `&mut self` is formed — which is the entire premise of
 * `HiveArray`, `MultiArrayList`, the slot pools, etc. (claim a stable
 * `*mut T`, mutate the container, deref the pointer afterward). Tree Borrows
 * is the candidate replacement spec, allows that pattern, and still catches
 * the bugs we care about.
 *
 * Usage:
 *   bun run rust:miri              # default crate set, crates run concurrently
 *   bun run rust:miri -p bun_foo   # extra args go straight to one `cargo miri test`
 */

import { spawn, spawnSync } from "node:child_process";
import { existsSync } from "node:fs";
import { availableParallelism } from "node:os";
import { resolve } from "node:path";

const repo = resolve(import.meta.dirname, "..");

// Crates that pass `cargo miri test` under Tree Borrows. To add one it must
// (a) have at least one `#[test]`, (b) compile under `--cfg test`, (c) at test
// runtime only call `extern "C"` functions Miri has shims for (libc's futex and
// thread APIs are; vendored C is not) — otherwise Miri reports
// `unsupported operation: can't call foreign function`.
//
// Ordered longest-running-under-Miri first so the concurrent run below starts
// the long poles immediately; everything after bun_hash takes seconds.
const MIRI_CRATES = [
  "bun_collections",
  "bun_ast",
  "bun_paths",
  "bun_hash",
  "bun_base64",
  "bun_clap",
  "bun_dispatch",
  "bun_errno",
  "bun_http_types",
  "bun_md",
  "bun_ptr",
  "bun_resolve_builtins",
  "bun_shell_parser",
  "bun_threading",
  "bun_wyhash",
];

function run(cmd: string, args: string[], opts: Parameters<typeof spawnSync>[2] = {}) {
  return spawnSync(cmd, args, { stdio: "inherit", cwd: repo, ...opts });
}

// `bun_core/build.rs` needs `build_options.rs`; cargo can't resolve the
// workspace until `vendor/lolhtml/` (a path dep) exists. Both come from the
// configure step, which is a no-op when already done.
const buildOptionsRs = resolve(repo, "build/debug/codegen/build_options.rs");
const lolhtmlCargo = resolve(repo, "vendor/lolhtml/Cargo.toml");
if (!existsSync(buildOptionsRs) || !existsSync(lolhtmlCargo)) {
  console.log("\x1b[36m[setup]\x1b[0m bun run build --configure-only");
  if (run("bun", ["run", "build", "--configure-only"]).status !== 0) process.exit(1);
  if (!existsSync(lolhtmlCargo) && run("ninja", ["-C", "build/debug", "clone-lolhtml"]).status !== 0) {
    process.exit(1);
  }
  // Re-check: configure can succeed without producing these (e.g. partial
  // checkout, ninja target rename) — fail fast instead of letting cargo
  // produce a confusing workspace-resolution error.
  for (const [path, hint] of [
    [buildOptionsRs, "bun run build --configure-only"],
    [lolhtmlCargo, "ninja -C build/debug clone-lolhtml"],
  ] as const) {
    if (!existsSync(path)) {
      console.error(`\x1b[31m[error]\x1b[0m ${path} still missing after setup — try: ${hint}`);
      process.exit(1);
    }
  }
}

const env = {
  ...process.env,
  MIRIFLAGS: ["-Zmiri-tree-borrows", process.env.MIRIFLAGS ?? ""].join(" ").trim(),
};

// Explicit args: one plain `cargo miri test`, output straight through.
const extraArgs = process.argv.slice(2);
if (extraArgs.length > 0) {
  console.log(`\x1b[36m[miri]\x1b[0m cargo miri test ${extraArgs.join(" ")}`);
  process.exit(run("cargo", ["miri", "test", ...extraArgs], { env }).status ?? 1);
}

// Default set: Miri interprets one test at a time per process, so a single
// `cargo miri test -p a -p b ...` is serial end to end. Build everything once,
// then run one `cargo miri test -p <crate>` per crate concurrently.
const allCrates = MIRI_CRATES.flatMap(c => ["-p", c]);
console.log(`\x1b[36m[miri]\x1b[0m cargo miri test --no-run ${allCrates.join(" ")}`);
if (run("cargo", ["miri", "test", "--no-run", ...allCrates], { env }).status !== 0) process.exit(1);

type Result = { crate: string; ok: boolean; seconds: number; output: string };

function testCrate(crate: string): Promise<Result> {
  return new Promise(done => {
    const started = Date.now();
    const chunks: Buffer[] = [];
    const child = spawn("cargo", ["miri", "test", "-p", crate, "--color", "always"], { cwd: repo, env });
    child.stdout.on("data", chunk => chunks.push(chunk));
    child.stderr.on("data", chunk => chunks.push(chunk));
    child.on("close", code =>
      done({ crate, ok: code === 0, seconds: (Date.now() - started) / 1000, output: Buffer.concat(chunks).toString() }),
    );
  });
}

const width = Math.max(1, Math.min(availableParallelism(), MIRI_CRATES.length));
console.log(`\x1b[36m[miri]\x1b[0m ${MIRI_CRATES.length} crates, ${width} at a time`);
const queue = [...MIRI_CRATES];
const results: Result[] = [];
const inActions = !!process.env.GITHUB_ACTIONS;

async function worker() {
  for (let crate = queue.shift(); crate; crate = queue.shift()) {
    const result = await testCrate(crate);
    results.push(result);
    const status = result.ok ? "\x1b[32mok\x1b[0m" : "\x1b[31mFAILED\x1b[0m";
    console.log(`\x1b[36m[miri]\x1b[0m ${result.crate} ${status} ${result.seconds.toFixed(0)}s`);
    if (!result.ok || !inActions) {
      console.log(result.output);
    } else {
      console.log(`::group::${result.crate} output\n${result.output}\n::endgroup::`);
    }
  }
}

await Promise.all(Array.from({ length: width }, worker));

const failed = results.filter(r => !r.ok).map(r => r.crate);
if (failed.length) {
  console.error(`\x1b[31m[miri]\x1b[0m failed: ${failed.join(", ")}`);
  process.exit(1);
}
console.log(`\x1b[36m[miri]\x1b[0m all ${results.length} crates passed`);