WASI Snapshot Preview 1 Host

When you compile with --host wasi_snapshot_preview1, WARPO targets the WASI Snapshot Preview 1 import surface (module name wasi_snapshot_preview1).

In addition, WARPO automatically provides WASI-backed global APIs so you can write familiar code like console.log(...) and process.exit(...).

Enable The Host

In asconfig.json:

{
  "options": {
    "host": "wasi_snapshot_preview1"
  }
}

Or via CLI:

warpo assembly/index.ts -o build/app.wasm --host wasi_snapshot_preview1

Provided Globals

WARPO injects these aliases when host is wasi_snapshot_preview1:

• console (WASI-backed) from ~lib/wasi_snapshot_preview1/wasi_console/wasi_console
• process (WASI-backed) from ~lib/wasi_snapshot_preview1/wasi_process/wasi_process
• Date (WASI-backed) from ~lib/wasi_snapshot_preview1/wasi_date/wasi_Date
• performance (WASI-backed) from ~lib/wasi_snapshot_preview1/wasi_performance/wasi_performance
• crypto (WASI-backed) from ~lib/wasi_snapshot_preview1/wasi_crypto/wasi_crypto
• abort (WASI-backed) from ~lib/wasi_snapshot_preview1/wasi_internal/wasi_abort
• seed (WASI-backed) from ~lib/wasi_snapshot_preview1/wasi_internal/wasi_seed
• trace (WASI-backed) from ~lib/wasi_snapshot_preview1/wasi_internal/wasi_trace

Example

console.log("hello from WASI");
console.time("work");

console.log("argv[0] = " + (process.argv.length ? process.argv[0] : ""));
console.log("HOME = " + (process.env.has("HOME") ? process.env.get("HOME") : ""));

console.timeEnd("work");

// Exit with success
process.exit(0);