vercel-labs/scriptc v0.4.6

on GitHub

0.4.6

Highlights

• Node islands: programs can load Node.js in-process on first use and run npm packages that scriptc doesn't compile in Node islands.
  • Native values, closures and promises pass into islands by reference, and island handles, classes and collections can be used from compiled code.
  • Modules are shared between a program and its islands, and island modules are evaluated only when the program uses them.
  • Once Node loads, the runtime's event loop runs on Node's libuv, and programs exit cleanly with Node loaded.
• New options:
  • --exceptions=rare unwinds through recursive functions instead of checking a status after each call.
  • --static builds static Linux executables (opt-in).
  • --large-pages moves executable code onto huge pages; --cpu-dispatch adds x86-64-v3 copies of hot functions.
  • Type patches replace a package's declaration files or supply missing declarations.
  • The shape overlay types JavaScript from facts the compiler proves (opt-in).
• Faster programs:
  • Exceptions raise through cached unwind plans on x86-64 Linux, and every native function has an unwind table entry.
  • Ordinary objects are stored as a layout plus value slots; unions of classes are the instance pointer itself; class instances that stay in their frame use frame storage.
  • Object groups that die together are allocated in arenas, and the cycle collector does cheaper trial deletion and adapts its nursery trigger.
  • The speed runtime is optimized with a committed runtime profile, and Math functions are computed as V8 does, with libm linked only when needed.
  • Loops: short constant-count loops run together, for and while loops are versioned on the ranges their locals enter with, counted loops unroll by the period of a guard, and small leaf functions called from loops are inlined.
  • Typed arrays: header fields are read once at a speculative loop's entry, products under bitwise operators stay in 32 bits, and shared typed-array elements are read and written with plain accesses at a counted loop's counter.
  • Strings: UTF-16 indexes of long non-ASCII strings map in constant time, ASCII case converts eight bytes at a time, template literals allocate at their exact length, and strings iterate over their bytes.
  • Untyped code: class instance fields are read inline at dynamic property sites with two inline-cache entries, native arrays iterate without type-name scans, and numbers pass to directly called untyped functions as JavaScript values.
  • I/O: fs thread-pool completions and pool-thread writes make fewer syscalls; sockets, clients and agent entries register in constant time; fetch() reuses keep-alive connections; web streams, WritableStream and TransformStream run natively.
  • Large executables map their text with 2 MiB pages, and freed heap pages are returned to the system after the frontend is disposed.
• Faster builds:
  • Small release and speed programs compile in balanced partitions, the entry module's top-level code gets its own partition, and unchanged partitions stay cached across edits.
  • Optimized executables that stay one partition generate code concurrently, and emission's workers stay busy.
  • The native compiler is laid out by context-sensitive profiles collected in two phases.
  • Type checking uses a shared tsc-ts server by default on Linux and macOS, and lib diagnostics are reused across options and module sets that cannot change them.
  • Rebuilds skip the helper version probe and the digests of unchanged files, and the CLI links without huge text pages, so cold builds use less memory.
• Node.js parity:
  • Error.captureStackTrace, Node's navigator, builtin globals read through the global object, and unhandled rejections reported in programs without async work.
  • node:zlib is built on the zlib Node bundles; Response.clone and Request.clone work on typed values; fetch bodies have the members of a web ReadableStream; redirects whose chunked body has not ended are followed.
  • Classes that extend Array compile; strings spread into their code points; frozen checked records stay frozen; sloppy-mode this is the global object.
  • util.format runtime format strings, inspect.custom and colors, and untyped promisify.
• TypeScript: scriptc reads TypeScript 7.1's binary AST format and API server beside 7.0's, and tsc-ts is updated to 0.0.10.