Strip WASI polyfill from non-WASI builds

Author: kateinoigakukun

Plugins/PackageToJS/Sources/PackageToJS.swift

@@ -282,7 +282,8 @@ struct PackagingPlanner {
         ]
         let (buildConfiguration, triple) = deriveBuildConfiguration()
         let conditions = [
-            "USE_SHARED_MEMORY": triple == "wasm32-unknown-wasip1-threads"
+            "USE_SHARED_MEMORY": triple == "wasm32-unknown-wasip1-threads",
+            "IS_WASI": triple.hasPrefix("wasm32-unknown-wasi"),
         ]
         return make.addTask(
             inputFiles: [selfPath, inputPath.path], inputTasks: [outputDirTask] + inputs,

Plugins/PackageToJS/Templates/index.js

@@ -1,5 +1,7 @@
 // @ts-check
-import { WASI, WASIProcExit, File, OpenFile, ConsoleStdout, PreopenDirectory } from '@bjorn3/browser_wasi_shim';
+/* #if IS_WASI */
+import { WASI, File, OpenFile, ConsoleStdout, PreopenDirectory } from '@bjorn3/browser_wasi_shim';
+/* #endif */
 import { instantiate, MODULE_PATH } from './instantiate.js';
 
 /** @type {import('./index.d').init} */
@@ -8,6 +10,7 @@ export async function init(
     imports,
     options
 ) {
+    /* #if IS_WASI */
     const wasi = new WASI(/* args */[MODULE_PATH, ...(options?.args ?? [])], /* env */[], /* fd */[
         new OpenFile(new File([])), // stdin
         ConsoleStdout.lineBuffered((stdout) => {
@@ -18,8 +21,11 @@ export async function init(
         }),
         new PreopenDirectory("/", new Map()),
     ], { debug: false })
+    /* #endif */
     const { instance, exports, swift } = await instantiate(moduleSource, imports, {
+        /* #if IS_WASI */
         wasi,
+        /* #endif */
         /* #if USE_SHARED_MEMORY */
         memory: options.memory,
         /* #endif */

Plugins/PackageToJS/Templates/instantiate.d.ts

@@ -60,7 +60,9 @@ export declare function instantiate(
     moduleSource: WebAssembly.Module | ArrayBufferView | ArrayBuffer | Response | PromiseLike<Response>,
     imports: Import,
     options: {
+        /* #if IS_WASI */
         wasi: WASI,
+        /* #endif */
         /* #if USE_SHARED_MEMORY */
         memory: WebAssembly.Memory
         /* #endif */

Plugins/PackageToJS/Templates/instantiate.js

@@ -23,18 +23,22 @@ export async function instantiate(
     imports,
     options
 ) {
+    /* #if IS_WASI */
     const { wasi } = options;
+    /* #endif */
     const instantiator = await createInstantiator(imports, options);
     const swift = new SwiftRuntime();
 
     /** @type {WebAssembly.Imports} */
     const importObject = {
         javascript_kit: swift.wasmImports,
+        /* #if IS_WASI */
         wasi_snapshot_preview1: wasi.wasiImport,
         /* #if USE_SHARED_MEMORY */ env: {
             memory: options.memory,
         },
         /* #endif */
+        /* #endif */
     };
     instantiator.addImports(importObject);
 
@@ -60,7 +64,9 @@ export async function instantiate(
     }
 
     swift.setInstance(instance);
+    /* #if IS_WASI */
     wasi.initialize(instance);
+    /* #endif */
 
     return {
         instance,