Chris Tate fa7bc7c7a0 Warn about likely-hot functions that use untyped values
A build now names the functions of the program's own files that compile
to the dynamic tier and likely run often, so a slow program with a little
untyped code says where the time goes:

  warning SC6101: 3 functions that likely run often use untyped values, which runs slower than typed code:
    advance (nbody.js:22): untyped JavaScript file, in a loop
    ...

- The functions come from the tier assignment lowering already makes
  (Lowerer.dynamicFunctions). Without a profile, a function counts as
  likely hot when a dynamic operation runs inside one of its loops, when
  a loop calls it, or when it calls itself (lowering/dynamic-tier.ts).
- A function is named only when its source says why its values are
  untyped: an `any` (for a for...of variable, the value it iterates), an
  untyped JSON.parse result, or an untyped JavaScript file. Generated
  %dyn.* helpers, module top levels and functions that are dynamic for an
  operation without a static lowering are left out.
- At most five functions are named, most likely hot first, with the
  total; dynamic-tier code in npm packages is counted per package on one
  line. All of the warning's text is in diagnostics/dynamic-tier.ts.
- SC6101 opens the SC61xx band, performance notes, with a new
  "performance" category in the diagnostics envelope; SC60xx stay the
  divergences.
- scriptc build prints it after the divergence warnings, and the
  executable cache stores it with the entry, so a cached build (including
  the CLI's routed fast path) repeats it. scriptc coverage reports it, and
  a comment-only edit no longer replays a verdict that carries it, since
  its text holds line numbers.
- --no-dynamic-tier-warning leaves it out of build and coverage;
  coverage --fail-on=dynamic fails on it.
- Docs: coverage.mdx (Dynamic tier, Gating builds and CI, the envelope
  categories) and cli.mdx.
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scriptc

Vercel Labs Experiment npm version: scriptc License: Apache-2.0 npm downloads per month: scriptc

scriptc compiles TypeScript and JavaScript to native executables and WebAssembly. It uses the types checked by the TypeScript compiler to generate machine code, and the output runs without Node.js installed. npm packages your program imports compile along with it. Code scriptc can't compile is reported at build time with a diagnostic and, where available, a rewrite hint.

scriptc is experimental and supports a subset of JavaScript, TypeScript, and Node.js APIs. Run scriptc coverage on an existing program to see how much of it compiles, and see the limitations and Node.js compatibility reference for details.

Installation

Install with Node.js 24 or later and npm:

$ npm install -g scriptc

The installed compiler runs natively on macOS, Linux, and Windows. Node.js is needed only to install it and to run WASI modules with scriptc run. Standalone compiler archives are also available from GitHub Releases.

Building executables requires a linker and the platform SDK or sysroot. See the quickstart for prerequisites and platform support for host requirements, cross-compilation, and WebAssembly.

Build a program

Create hello.ts:

const who = process.argv.length > 2 ? process.argv[2] : "world";
console.log(`hello, ${who}`);

scriptc run compiles the file and runs the result:

$ scriptc run hello.ts
hello, world

scriptc build writes an executable:

$ scriptc build hello.ts -o hello >/dev/null
$ ./hello scriptc
hello, scriptc

These examples use POSIX shell syntax. On Windows, build hello.exe and run it with .\hello.exe.

Use scriptc coverage hello.ts to check what compiles before you build. See coverage reports for details.

Use Node APIs

Supported Node APIs compile to the native runtime. For example, server.ts:

import { createServer } from "node:http";

const server = createServer((req, res) => {
  res.setHeader("content-type", "application/json");
  res.end(JSON.stringify({ path: req.url }));
});

server.listen(8080, () => {
  console.log("listening on http://localhost:8080");
});
$ scriptc build server.ts -o server >/dev/null
$ ./server
listening on http://localhost:8080

Use npm packages

npm packages compile into the executable with your code, so it doesn't read node_modules at runtime.

Create cli.ts:

import pc from "picocolors";

console.log(pc.green("hello from scriptc"));
$ npm install picocolors
$ scriptc build cli.ts -o cli >/dev/null
$ ./cli
hello from scriptc

Package support is partial. See npm dependencies for which packages compile and how to check them.

Documentation

Contributing

See CONTRIBUTING.md for source setup, testing, native artifact builds, and docs development.

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Description
GitHub Trending: vercel-labs/scriptc
Readme Apache-2.0
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C 24.1%
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