Chris Tate
fa7bc7c7a0
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.
scriptc
Compile TypeScript and JavaScript to native executables or WASI WebAssembly modules that run without Node.js installed.
$ cat fib.ts
function fib(n: number): number {
return n < 2 ? n : fib(n - 1) + fib(n - 2);
}
console.log(fib(30));
$ scriptc run fib.ts
832040
$ scriptc build fib.ts -o fib >/dev/null && ./fib
832040
scriptc compiles the same TypeScript you run on Node.js, type-checked by the TypeScript compiler. npm packages your program imports compile along with it. Code scriptc can't compile fails the build with an error code and, where available, a rewrite hint.
scriptc is experimental. See the limitations and the Node.js compatibility reference.
Install
$ npm install -g scriptc
npm installs the native compiler for your platform (macOS, Linux, or Windows). Node.js 24 or later is needed to install it and to run WASI modules with scriptc run; compiling and running executables doesn't need Node.js.
Building executables needs a linker and the platform SDK or sysroot, such as the Xcode Command Line Tools on macOS. Set SCRIPTC_LINKER to choose the linker driver. --emit=ir|llvm|asm|obj needs no external tools. See the quickstart for details.
Commands
scriptc build <file.ts>: compile to a native executable or another artifact selected with--emit.scriptc run <file.ts>: compile and run.scriptc coverage <file.ts>: report what compiles, and explain what doesn't.scriptc build --lib --profile <profile.json>: compile a static library, or a Wasm reactor onwasm32-wasi.
See the CLI reference for every option.
Cross-compilation and WebAssembly
Set SCRIPTC_TARGET to build for another platform, for example SCRIPTC_TARGET=aarch64-linux-gnu.2.36 or SCRIPTC_TARGET=wasm32-wasi. Install the matching @scriptc/runtime-<target> package in your project, at the same version as scriptc --version, or set SCRIPTC_RUNTIME_PACK to a runtime pack directory. See platform support and WebAssembly modules.
Native code
Call C functions by declaring their signatures in TypeScript and binding them to C symbols in a manifest passed with --ffi <manifest.json>. See the Native FFI guide.
Build cache
Builds reuse a bounded persistent cache. Set SCRIPTC_NO_CACHE=1 to bypass it or SCRIPTC_CACHE_DIR to choose its location.
Docs: scriptc.dev