add workers-gen-go-command

cmd/workers-gen-go/assets/common/polyfill_performance.js

@@ -0,0 +1,36 @@
+// @license http://opensource.org/licenses/MIT
+// copyright Paul Irish 2015
+
+
+// Date.now() is supported everywhere except IE8. For IE8 we use the Date.now polyfill
+//   github.com/Financial-Times/polyfill-service/blob/master/polyfills/Date.now/polyfill.js
+// as Safari 6 doesn't have support for NavigationTiming, we use a Date.now() timestamp for relative values
+
+// if you want values similar to what you'd get with real perf.now, place this towards the head of the page
+// but in reality, you're just getting the delta between now() calls, so it's not terribly important where it's placed
+
+
+(function(){
+
+  if ("performance" in globalThis == false) {
+      globalThis.performance = {};
+  }
+  
+  Date.now = (Date.now || function () {  // thanks IE8
+	  return new Date().getTime();
+  });
+
+  if ("now" in globalThis.performance == false){
+    
+    var nowOffset = Date.now();
+    
+    if (performance.timing && performance.timing.navigationStart){
+      nowOffset = performance.timing.navigationStart
+    }
+
+    globalThis.performance.now = function now(){
+      return Date.now() - nowOffset;
+    }
+  }
+
+})();

cmd/workers-gen-go/assets/common/shim.mjs

@@ -0,0 +1,19 @@
+import "./polyfill_performance.js";
+import "./wasm_exec.js";
+import mod from "./app.wasm";
+
+const go = new Go();
+
+async function run() {
+  const readyPromise = new Promise((resolve) => {
+    globalThis.ready = resolve;
+  });
+  const instance = new WebAssembly.Instance(mod, go.importObject);
+  go.run(instance);
+  await readyPromise;
+}
+
+export async function fetch(req, env, ctx) {
+  await run();
+  return handleRequest(req, { env, ctx });
+}

cmd/workers-gen-go/assets/common/worker.mjs

@@ -0,0 +1,3 @@
+import * as imports from "./shim.mjs";
+
+export default { fetch: imports.fetch }

cmd/workers-gen-go/assets/wasm_exec_go.js

@@ -0,0 +1,554 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+"use strict";
+
+(() => {
+	const enosys = () => {
+		const err = new Error("not implemented");
+		err.code = "ENOSYS";
+		return err;
+	};
+
+	if (!globalThis.fs) {
+		let outputBuf = "";
+		globalThis.fs = {
+			constants: { O_WRONLY: -1, O_RDWR: -1, O_CREAT: -1, O_TRUNC: -1, O_APPEND: -1, O_EXCL: -1 }, // unused
+			writeSync(fd, buf) {
+				outputBuf += decoder.decode(buf);
+				const nl = outputBuf.lastIndexOf("\n");
+				if (nl != -1) {
+					console.log(outputBuf.substr(0, nl));
+					outputBuf = outputBuf.substr(nl + 1);
+				}
+				return buf.length;
+			},
+			write(fd, buf, offset, length, position, callback) {
+				if (offset !== 0 || length !== buf.length || position !== null) {
+					callback(enosys());
+					return;
+				}
+				const n = this.writeSync(fd, buf);
+				callback(null, n);
+			},
+			chmod(path, mode, callback) { callback(enosys()); },
+			chown(path, uid, gid, callback) { callback(enosys()); },
+			close(fd, callback) { callback(enosys()); },
+			fchmod(fd, mode, callback) { callback(enosys()); },
+			fchown(fd, uid, gid, callback) { callback(enosys()); },
+			fstat(fd, callback) { callback(enosys()); },
+			fsync(fd, callback) { callback(null); },
+			ftruncate(fd, length, callback) { callback(enosys()); },
+			lchown(path, uid, gid, callback) { callback(enosys()); },
+			link(path, link, callback) { callback(enosys()); },
+			lstat(path, callback) { callback(enosys()); },
+			mkdir(path, perm, callback) { callback(enosys()); },
+			open(path, flags, mode, callback) { callback(enosys()); },
+			read(fd, buffer, offset, length, position, callback) { callback(enosys()); },
+			readdir(path, callback) { callback(enosys()); },
+			readlink(path, callback) { callback(enosys()); },
+			rename(from, to, callback) { callback(enosys()); },
+			rmdir(path, callback) { callback(enosys()); },
+			stat(path, callback) { callback(enosys()); },
+			symlink(path, link, callback) { callback(enosys()); },
+			truncate(path, length, callback) { callback(enosys()); },
+			unlink(path, callback) { callback(enosys()); },
+			utimes(path, atime, mtime, callback) { callback(enosys()); },
+		};
+	}
+
+	if (!globalThis.process) {
+		globalThis.process = {
+			getuid() { return -1; },
+			getgid() { return -1; },
+			geteuid() { return -1; },
+			getegid() { return -1; },
+			getgroups() { throw enosys(); },
+			pid: -1,
+			ppid: -1,
+			umask() { throw enosys(); },
+			cwd() { throw enosys(); },
+			chdir() { throw enosys(); },
+		}
+	}
+
+	if (!globalThis.crypto) {
+		throw new Error("globalThis.crypto is not available, polyfill required (crypto.getRandomValues only)");
+	}
+
+	if (!globalThis.performance) {
+		throw new Error("globalThis.performance is not available, polyfill required (performance.now only)");
+	}
+
+	if (!globalThis.TextEncoder) {
+		throw new Error("globalThis.TextEncoder is not available, polyfill required");
+	}
+
+	if (!globalThis.TextDecoder) {
+		throw new Error("globalThis.TextDecoder is not available, polyfill required");
+	}
+
+	const encoder = new TextEncoder("utf-8");
+	const decoder = new TextDecoder("utf-8");
+
+	globalThis.Go = class {
+		constructor() {
+			this.argv = ["js"];
+			this.env = {};
+			this.exit = (code) => {
+				if (code !== 0) {
+					console.warn("exit code:", code);
+				}
+			};
+			this._exitPromise = new Promise((resolve) => {
+				this._resolveExitPromise = resolve;
+			});
+			this._pendingEvent = null;
+			this._scheduledTimeouts = new Map();
+			this._nextCallbackTimeoutID = 1;
+
+			const setInt64 = (addr, v) => {
+				this.mem.setUint32(addr + 0, v, true);
+				this.mem.setUint32(addr + 4, Math.floor(v / 4294967296), true);
+			}
+
+			const getInt64 = (addr) => {
+				const low = this.mem.getUint32(addr + 0, true);
+				const high = this.mem.getInt32(addr + 4, true);
+				return low + high * 4294967296;
+			}
+
+			const loadValue = (addr) => {
+				const f = this.mem.getFloat64(addr, true);
+				if (f === 0) {
+					return undefined;
+				}
+				if (!isNaN(f)) {
+					return f;
+				}
+
+				const id = this.mem.getUint32(addr, true);
+				return this._values[id];
+			}
+
+			const storeValue = (addr, v) => {
+				const nanHead = 0x7FF80000;
+
+				if (typeof v === "number" && v !== 0) {
+					if (isNaN(v)) {
+						this.mem.setUint32(addr + 4, nanHead, true);
+						this.mem.setUint32(addr, 0, true);
+						return;
+					}
+					this.mem.setFloat64(addr, v, true);
+					return;
+				}
+
+				if (v === undefined) {
+					this.mem.setFloat64(addr, 0, true);
+					return;
+				}
+
+				let id = this._ids.get(v);
+				if (id === undefined) {
+					id = this._idPool.pop();
+					if (id === undefined) {
+						id = this._values.length;
+					}
+					this._values[id] = v;
+					this._goRefCounts[id] = 0;
+					this._ids.set(v, id);
+				}
+				this._goRefCounts[id]++;
+				let typeFlag = 0;
+				switch (typeof v) {
+					case "object":
+						if (v !== null) {
+							typeFlag = 1;
+						}
+						break;
+					case "string":
+						typeFlag = 2;
+						break;
+					case "symbol":
+						typeFlag = 3;
+						break;
+					case "function":
+						typeFlag = 4;
+						break;
+				}
+				this.mem.setUint32(addr + 4, nanHead | typeFlag, true);
+				this.mem.setUint32(addr, id, true);
+			}
+
+			const loadSlice = (addr) => {
+				const array = getInt64(addr + 0);
+				const len = getInt64(addr + 8);
+				return new Uint8Array(this._inst.exports.mem.buffer, array, len);
+			}
+
+			const loadSliceOfValues = (addr) => {
+				const array = getInt64(addr + 0);
+				const len = getInt64(addr + 8);
+				const a = new Array(len);
+				for (let i = 0; i < len; i++) {
+					a[i] = loadValue(array + i * 8);
+				}
+				return a;
+			}
+
+			const loadString = (addr) => {
+				const saddr = getInt64(addr + 0);
+				const len = getInt64(addr + 8);
+				return decoder.decode(new DataView(this._inst.exports.mem.buffer, saddr, len));
+			}
+
+			const timeOrigin = Date.now() - performance.now();
+			this.importObject = {
+				go: {
+					// Go's SP does not change as long as no Go code is running. Some operations (e.g. calls, getters and setters)
+					// may synchronously trigger a Go event handler. This makes Go code get executed in the middle of the imported
+					// function. A goroutine can switch to a new stack if the current stack is too small (see morestack function).
+					// This changes the SP, thus we have to update the SP used by the imported function.
+
+					// func wasmExit(code int32)
+					"runtime.wasmExit": (sp) => {
+						sp >>>= 0;
+						const code = this.mem.getInt32(sp + 8, true);
+						this.exited = true;
+						delete this._inst;
+						delete this._values;
+						delete this._goRefCounts;
+						delete this._ids;
+						delete this._idPool;
+						this.exit(code);
+					},
+
+					// func wasmWrite(fd uintptr, p unsafe.Pointer, n int32)
+					"runtime.wasmWrite": (sp) => {
+						sp >>>= 0;
+						const fd = getInt64(sp + 8);
+						const p = getInt64(sp + 16);
+						const n = this.mem.getInt32(sp + 24, true);
+						fs.writeSync(fd, new Uint8Array(this._inst.exports.mem.buffer, p, n));
+					},
+
+					// func resetMemoryDataView()
+					"runtime.resetMemoryDataView": (sp) => {
+						sp >>>= 0;
+						this.mem = new DataView(this._inst.exports.mem.buffer);
+					},
+
+					// func nanotime1() int64
+					"runtime.nanotime1": (sp) => {
+						sp >>>= 0;
+						setInt64(sp + 8, (timeOrigin + performance.now()) * 1000000);
+					},
+
+					// func walltime() (sec int64, nsec int32)
+					"runtime.walltime": (sp) => {
+						sp >>>= 0;
+						const msec = (new Date).getTime();
+						setInt64(sp + 8, msec / 1000);
+						this.mem.setInt32(sp + 16, (msec % 1000) * 1000000, true);
+					},
+
+					// func scheduleTimeoutEvent(delay int64) int32
+					"runtime.scheduleTimeoutEvent": (sp) => {
+						sp >>>= 0;
+						const id = this._nextCallbackTimeoutID;
+						this._nextCallbackTimeoutID++;
+						this._scheduledTimeouts.set(id, setTimeout(
+							() => {
+								this._resume();
+								while (this._scheduledTimeouts.has(id)) {
+									// for some reason Go failed to register the timeout event, log and try again
+									// (temporary workaround for https://github.com/golang/go/issues/28975)
+									console.warn("scheduleTimeoutEvent: missed timeout event");
+									this._resume();
+								}
+							},
+							getInt64(sp + 8) + 1, // setTimeout has been seen to fire up to 1 millisecond early
+						));
+						this.mem.setInt32(sp + 16, id, true);
+					},
+
+					// func clearTimeoutEvent(id int32)
+					"runtime.clearTimeoutEvent": (sp) => {
+						sp >>>= 0;
+						const id = this.mem.getInt32(sp + 8, true);
+						clearTimeout(this._scheduledTimeouts.get(id));
+						this._scheduledTimeouts.delete(id);
+					},
+
+					// func getRandomData(r []byte)
+					"runtime.getRandomData": (sp) => {
+						sp >>>= 0;
+						crypto.getRandomValues(loadSlice(sp + 8));
+					},
+
+					// func finalizeRef(v ref)
+					"syscall/js.finalizeRef": (sp) => {
+						sp >>>= 0;
+						const id = this.mem.getUint32(sp + 8, true);
+						this._goRefCounts[id]--;
+						if (this._goRefCounts[id] === 0) {
+							const v = this._values[id];
+							this._values[id] = null;
+							this._ids.delete(v);
+							this._idPool.push(id);
+						}
+					},
+
+					// func stringVal(value string) ref
+					"syscall/js.stringVal": (sp) => {
+						sp >>>= 0;
+						storeValue(sp + 24, loadString(sp + 8));
+					},
+
+					// func valueGet(v ref, p string) ref
+					"syscall/js.valueGet": (sp) => {
+						sp >>>= 0;
+						const result = Reflect.get(loadValue(sp + 8), loadString(sp + 16));
+						sp = this._inst.exports.getsp() >>> 0; // see comment above
+						storeValue(sp + 32, result);
+					},
+
+					// func valueSet(v ref, p string, x ref)
+					"syscall/js.valueSet": (sp) => {
+						sp >>>= 0;
+						Reflect.set(loadValue(sp + 8), loadString(sp + 16), loadValue(sp + 32));
+					},
+
+					// func valueDelete(v ref, p string)
+					"syscall/js.valueDelete": (sp) => {
+						sp >>>= 0;
+						Reflect.deleteProperty(loadValue(sp + 8), loadString(sp + 16));
+					},
+
+					// func valueIndex(v ref, i int) ref
+					"syscall/js.valueIndex": (sp) => {
+						sp >>>= 0;
+						storeValue(sp + 24, Reflect.get(loadValue(sp + 8), getInt64(sp + 16)));
+					},
+
+					// valueSetIndex(v ref, i int, x ref)
+					"syscall/js.valueSetIndex": (sp) => {
+						sp >>>= 0;
+						Reflect.set(loadValue(sp + 8), getInt64(sp + 16), loadValue(sp + 24));
+					},
+
+					// func valueCall(v ref, m string, args []ref) (ref, bool)
+					"syscall/js.valueCall": (sp) => {
+						sp >>>= 0;
+						try {
+							const v = loadValue(sp + 8);
+							const m = Reflect.get(v, loadString(sp + 16));
+							const args = loadSliceOfValues(sp + 32);
+							const result = Reflect.apply(m, v, args);
+							sp = this._inst.exports.getsp() >>> 0; // see comment above
+							storeValue(sp + 56, result);
+							this.mem.setUint8(sp + 64, 1);
+						} catch (err) {
+							sp = this._inst.exports.getsp() >>> 0; // see comment above
+							storeValue(sp + 56, err);
+							this.mem.setUint8(sp + 64, 0);
+						}
+					},
+
+					// func valueInvoke(v ref, args []ref) (ref, bool)
+					"syscall/js.valueInvoke": (sp) => {
+						sp >>>= 0;
+						try {
+							const v = loadValue(sp + 8);
+							const args = loadSliceOfValues(sp + 16);
+							const result = Reflect.apply(v, undefined, args);
+							sp = this._inst.exports.getsp() >>> 0; // see comment above
+							storeValue(sp + 40, result);
+							this.mem.setUint8(sp + 48, 1);
+						} catch (err) {
+							sp = this._inst.exports.getsp() >>> 0; // see comment above
+							storeValue(sp + 40, err);
+							this.mem.setUint8(sp + 48, 0);
+						}
+					},
+
+					// func valueNew(v ref, args []ref) (ref, bool)
+					"syscall/js.valueNew": (sp) => {
+						sp >>>= 0;
+						try {
+							const v = loadValue(sp + 8);
+							const args = loadSliceOfValues(sp + 16);
+							const result = Reflect.construct(v, args);
+							sp = this._inst.exports.getsp() >>> 0; // see comment above
+							storeValue(sp + 40, result);
+							this.mem.setUint8(sp + 48, 1);
+						} catch (err) {
+							sp = this._inst.exports.getsp() >>> 0; // see comment above
+							storeValue(sp + 40, err);
+							this.mem.setUint8(sp + 48, 0);
+						}
+					},
+
+					// func valueLength(v ref) int
+					"syscall/js.valueLength": (sp) => {
+						sp >>>= 0;
+						setInt64(sp + 16, parseInt(loadValue(sp + 8).length));
+					},
+
+					// valuePrepareString(v ref) (ref, int)
+					"syscall/js.valuePrepareString": (sp) => {
+						sp >>>= 0;
+						const str = encoder.encode(String(loadValue(sp + 8)));
+						storeValue(sp + 16, str);
+						setInt64(sp + 24, str.length);
+					},
+
+					// valueLoadString(v ref, b []byte)
+					"syscall/js.valueLoadString": (sp) => {
+						sp >>>= 0;
+						const str = loadValue(sp + 8);
+						loadSlice(sp + 16).set(str);
+					},
+
+					// func valueInstanceOf(v ref, t ref) bool
+					"syscall/js.valueInstanceOf": (sp) => {
+						sp >>>= 0;
+						this.mem.setUint8(sp + 24, (loadValue(sp + 8) instanceof loadValue(sp + 16)) ? 1 : 0);
+					},
+
+					// func copyBytesToGo(dst []byte, src ref) (int, bool)
+					"syscall/js.copyBytesToGo": (sp) => {
+						sp >>>= 0;
+						const dst = loadSlice(sp + 8);
+						const src = loadValue(sp + 32);
+						if (!(src instanceof Uint8Array || src instanceof Uint8ClampedArray)) {
+							this.mem.setUint8(sp + 48, 0);
+							return;
+						}
+						const toCopy = src.subarray(0, dst.length);
+						dst.set(toCopy);
+						setInt64(sp + 40, toCopy.length);
+						this.mem.setUint8(sp + 48, 1);
+					},
+
+					// func copyBytesToJS(dst ref, src []byte) (int, bool)
+					"syscall/js.copyBytesToJS": (sp) => {
+						sp >>>= 0;
+						const dst = loadValue(sp + 8);
+						const src = loadSlice(sp + 16);
+						if (!(dst instanceof Uint8Array || dst instanceof Uint8ClampedArray)) {
+							this.mem.setUint8(sp + 48, 0);
+							return;
+						}
+						const toCopy = src.subarray(0, dst.length);
+						dst.set(toCopy);
+						setInt64(sp + 40, toCopy.length);
+						this.mem.setUint8(sp + 48, 1);
+					},
+
+					"debug": (value) => {
+						console.log(value);
+					},
+				}
+			};
+		}
+
+		async run(instance) {
+			if (!(instance instanceof WebAssembly.Instance)) {
+				throw new Error("Go.run: WebAssembly.Instance expected");
+			}
+			this._inst = instance;
+			this.mem = new DataView(this._inst.exports.mem.buffer);
+			this._values = [ // JS values that Go currently has references to, indexed by reference id
+				NaN,
+				0,
+				null,
+				true,
+				false,
+				globalThis,
+				this,
+			];
+			this._goRefCounts = new Array(this._values.length).fill(Infinity); // number of references that Go has to a JS value, indexed by reference id
+			this._ids = new Map([ // mapping from JS values to reference ids
+				[0, 1],
+				[null, 2],
+				[true, 3],
+				[false, 4],
+				[globalThis, 5],
+				[this, 6],
+			]);
+			this._idPool = [];   // unused ids that have been garbage collected
+			this.exited = false; // whether the Go program has exited
+
+			// Pass command line arguments and environment variables to WebAssembly by writing them to the linear memory.
+			let offset = 4096;
+
+			const strPtr = (str) => {
+				const ptr = offset;
+				const bytes = encoder.encode(str + "\0");
+				new Uint8Array(this.mem.buffer, offset, bytes.length).set(bytes);
+				offset += bytes.length;
+				if (offset % 8 !== 0) {
+					offset += 8 - (offset % 8);
+				}
+				return ptr;
+			};
+
+			const argc = this.argv.length;
+
+			const argvPtrs = [];
+			this.argv.forEach((arg) => {
+				argvPtrs.push(strPtr(arg));
+			});
+			argvPtrs.push(0);
+
+			const keys = Object.keys(this.env).sort();
+			keys.forEach((key) => {
+				argvPtrs.push(strPtr(`${key}=${this.env[key]}`));
+			});
+			argvPtrs.push(0);
+
+			const argv = offset;
+			argvPtrs.forEach((ptr) => {
+				this.mem.setUint32(offset, ptr, true);
+				this.mem.setUint32(offset + 4, 0, true);
+				offset += 8;
+			});
+
+			// The linker guarantees global data starts from at least wasmMinDataAddr.
+			// Keep in sync with cmd/link/internal/ld/data.go:wasmMinDataAddr.
+			const wasmMinDataAddr = 4096 + 8192;
+			if (offset >= wasmMinDataAddr) {
+				throw new Error("total length of command line and environment variables exceeds limit");
+			}
+
+			this._inst.exports.run(argc, argv);
+			if (this.exited) {
+				this._resolveExitPromise();
+			}
+			await this._exitPromise;
+		}
+
+		_resume() {
+			if (this.exited) {
+				throw new Error("Go program has already exited");
+			}
+			this._inst.exports.resume();
+			if (this.exited) {
+				this._resolveExitPromise();
+			}
+		}
+
+		_makeFuncWrapper(id) {
+			const go = this;
+			return function () {
+				const event = { id: id, this: this, args: arguments };
+				go._pendingEvent = event;
+				go._resume();
+				return event.result;
+			};
+		}
+	}
+})();

cmd/workers-gen-go/assets/wasm_exec_tinygo.js

@@ -0,0 +1,543 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+//
+// This file has been modified for use by the TinyGo compiler.
+
+(() => {
+	// Map multiple JavaScript environments to a single common API,
+	// preferring web standards over Node.js API.
+	//
+	// Environments considered:
+	// - Browsers
+	// - Node.js
+	// - Electron
+	// - Parcel
+
+	if (typeof global !== "undefined") {
+		// global already exists
+	} else if (typeof window !== "undefined") {
+		window.global = window;
+	} else if (typeof self !== "undefined") {
+		self.global = self;
+	} else {
+		throw new Error("cannot export Go (neither global, window nor self is defined)");
+	}
+
+	/*
+	if (!global.require && typeof require !== "undefined") {
+		global.require = require;
+	}
+	*/
+
+		/*
+	if (!global.fs && global.require) {
+		global.fs = require("fs");
+	}
+	*/
+
+	const enosys = () => {
+		const err = new Error("not implemented");
+		err.code = "ENOSYS";
+		return err;
+	};
+
+	if (!global.fs) {
+		let outputBuf = "";
+		global.fs = {
+			constants: { O_WRONLY: -1, O_RDWR: -1, O_CREAT: -1, O_TRUNC: -1, O_APPEND: -1, O_EXCL: -1 }, // unused
+			writeSync(fd, buf) {
+				outputBuf += decoder.decode(buf);
+				const nl = outputBuf.lastIndexOf("\n");
+				if (nl != -1) {
+					console.log(outputBuf.substr(0, nl));
+					outputBuf = outputBuf.substr(nl + 1);
+				}
+				return buf.length;
+			},
+			write(fd, buf, offset, length, position, callback) {
+				if (offset !== 0 || length !== buf.length || position !== null) {
+					callback(enosys());
+					return;
+				}
+				const n = this.writeSync(fd, buf);
+				callback(null, n);
+			},
+			chmod(path, mode, callback) { callback(enosys()); },
+			chown(path, uid, gid, callback) { callback(enosys()); },
+			close(fd, callback) { callback(enosys()); },
+			fchmod(fd, mode, callback) { callback(enosys()); },
+			fchown(fd, uid, gid, callback) { callback(enosys()); },
+			fstat(fd, callback) { callback(enosys()); },
+			fsync(fd, callback) { callback(null); },
+			ftruncate(fd, length, callback) { callback(enosys()); },
+			lchown(path, uid, gid, callback) { callback(enosys()); },
+			link(path, link, callback) { callback(enosys()); },
+			lstat(path, callback) { callback(enosys()); },
+			mkdir(path, perm, callback) { callback(enosys()); },
+			open(path, flags, mode, callback) { callback(enosys()); },
+			read(fd, buffer, offset, length, position, callback) { callback(enosys()); },
+			readdir(path, callback) { callback(enosys()); },
+			readlink(path, callback) { callback(enosys()); },
+			rename(from, to, callback) { callback(enosys()); },
+			rmdir(path, callback) { callback(enosys()); },
+			stat(path, callback) { callback(enosys()); },
+			symlink(path, link, callback) { callback(enosys()); },
+			truncate(path, length, callback) { callback(enosys()); },
+			unlink(path, callback) { callback(enosys()); },
+			utimes(path, atime, mtime, callback) { callback(enosys()); },
+		};
+	}
+
+	if (!global.process) {
+		global.process = {
+			getuid() { return -1; },
+			getgid() { return -1; },
+			geteuid() { return -1; },
+			getegid() { return -1; },
+			getgroups() { throw enosys(); },
+			pid: -1,
+			ppid: -1,
+			umask() { throw enosys(); },
+			cwd() { throw enosys(); },
+			chdir() { throw enosys(); },
+		}
+	}
+
+	/*
+	if (!global.crypto) {
+		const nodeCrypto = require("crypto");
+		global.crypto = {
+			getRandomValues(b) {
+				nodeCrypto.randomFillSync(b);
+			},
+		};
+	}
+	*/
+
+	if (!global.performance) {
+		global.performance = {
+			now() {
+				const [sec, nsec] = process.hrtime();
+				return sec * 1000 + nsec / 1000000;
+			},
+		};
+	}
+
+	/*
+	if (!global.TextEncoder) {
+		global.TextEncoder = require("util").TextEncoder;
+	}
+
+	if (!global.TextDecoder) {
+		global.TextDecoder = require("util").TextDecoder;
+	}
+	*/
+
+	// End of polyfills for common API.
+
+	const encoder = new TextEncoder("utf-8");
+	const decoder = new TextDecoder("utf-8");
+	var logLine = [];
+
+	global.Go = class {
+		constructor() {
+			this._callbackTimeouts = new Map();
+			this._nextCallbackTimeoutID = 1;
+
+			const mem = () => {
+				// The buffer may change when requesting more memory.
+				return new DataView(this._inst.exports.memory.buffer);
+			}
+
+			const setInt64 = (addr, v) => {
+				mem().setUint32(addr + 0, v, true);
+				mem().setUint32(addr + 4, Math.floor(v / 4294967296), true);
+			}
+
+			const getInt64 = (addr) => {
+				const low = mem().getUint32(addr + 0, true);
+				const high = mem().getInt32(addr + 4, true);
+				return low + high * 4294967296;
+			}
+
+			const loadValue = (addr) => {
+				const f = mem().getFloat64(addr, true);
+				if (f === 0) {
+					return undefined;
+				}
+				if (!isNaN(f)) {
+					return f;
+				}
+
+				const id = mem().getUint32(addr, true);
+				return this._values[id];
+			}
+
+			const storeValue = (addr, v) => {
+				const nanHead = 0x7FF80000;
+
+				if (typeof v === "number") {
+					if (isNaN(v)) {
+						mem().setUint32(addr + 4, nanHead, true);
+						mem().setUint32(addr, 0, true);
+						return;
+					}
+					if (v === 0) {
+						mem().setUint32(addr + 4, nanHead, true);
+						mem().setUint32(addr, 1, true);
+						return;
+					}
+					mem().setFloat64(addr, v, true);
+					return;
+				}
+
+				switch (v) {
+					case undefined:
+						mem().setFloat64(addr, 0, true);
+						return;
+					case null:
+						mem().setUint32(addr + 4, nanHead, true);
+						mem().setUint32(addr, 2, true);
+						return;
+					case true:
+						mem().setUint32(addr + 4, nanHead, true);
+						mem().setUint32(addr, 3, true);
+						return;
+					case false:
+						mem().setUint32(addr + 4, nanHead, true);
+						mem().setUint32(addr, 4, true);
+						return;
+				}
+
+				let id = this._ids.get(v);
+				if (id === undefined) {
+					id = this._idPool.pop();
+					if (id === undefined) {
+						id = this._values.length;
+					}
+					this._values[id] = v;
+					this._goRefCounts[id] = 0;
+					this._ids.set(v, id);
+				}
+				this._goRefCounts[id]++;
+				let typeFlag = 1;
+				switch (typeof v) {
+					case "string":
+						typeFlag = 2;
+						break;
+					case "symbol":
+						typeFlag = 3;
+						break;
+					case "function":
+						typeFlag = 4;
+						break;
+				}
+				mem().setUint32(addr + 4, nanHead | typeFlag, true);
+				mem().setUint32(addr, id, true);
+			}
+
+			const loadSlice = (array, len, cap) => {
+				return new Uint8Array(this._inst.exports.memory.buffer, array, len);
+			}
+
+			const loadSliceOfValues = (array, len, cap) => {
+				const a = new Array(len);
+				for (let i = 0; i < len; i++) {
+					a[i] = loadValue(array + i * 8);
+				}
+				return a;
+			}
+
+			const loadString = (ptr, len) => {
+				return decoder.decode(new DataView(this._inst.exports.memory.buffer, ptr, len));
+			}
+
+			const timeOrigin = Date.now() - performance.now();
+			this.importObject = {
+				wasi_snapshot_preview1: {
+					// https://github.com/WebAssembly/WASI/blob/main/phases/snapshot/docs.md#fd_write
+					fd_write: function(fd, iovs_ptr, iovs_len, nwritten_ptr) {
+						let nwritten = 0;
+						if (fd == 1) {
+							for (let iovs_i=0; iovs_i<iovs_len;iovs_i++) {
+								let iov_ptr = iovs_ptr+iovs_i*8; // assuming wasm32
+								let ptr = mem().getUint32(iov_ptr + 0, true);
+								let len = mem().getUint32(iov_ptr + 4, true);
+								nwritten += len;
+								for (let i=0; i<len; i++) {
+									let c = mem().getUint8(ptr+i);
+									if (c == 13) { // CR
+										// ignore
+									} else if (c == 10) { // LF
+										// write line
+										let line = decoder.decode(new Uint8Array(logLine));
+										logLine = [];
+										console.log(line);
+									} else {
+										logLine.push(c);
+									}
+								}
+							}
+						} else {
+							console.error('invalid file descriptor:', fd);
+						}
+						mem().setUint32(nwritten_ptr, nwritten, true);
+						return 0;
+					},
+					fd_close: () => 0,      // dummy
+					fd_fdstat_get: () => 0, // dummy
+					fd_seek: () => 0,       // dummy
+					"proc_exit": (code) => {
+						if (global.process) {
+							// Node.js
+							process.exit(code);
+						} else {
+							// Can't exit in a browser.
+							throw 'trying to exit with code ' + code;
+						}
+					},
+					random_get: (bufPtr, bufLen) => {
+						crypto.getRandomValues(loadSlice(bufPtr, bufLen));
+						return 0;
+					},
+				},
+				env: {
+					// func ticks() float64
+					"runtime.ticks": () => {
+						return timeOrigin + performance.now();
+					},
+
+					// func sleepTicks(timeout float64)
+					"runtime.sleepTicks": (timeout) => {
+						// Do not sleep, only reactivate scheduler after the given timeout.
+						setTimeout(this._inst.exports.go_scheduler, timeout);
+					},
+
+					// func finalizeRef(v ref)
+					"syscall/js.finalizeRef": (sp) => {
+						// Note: TinyGo does not support finalizers so this should never be
+						// called.
+						// console.error('syscall/js.finalizeRef not implemented');
+					},
+
+					// func stringVal(value string) ref
+					"syscall/js.stringVal": (ret_ptr, value_ptr, value_len) => {
+						const s = loadString(value_ptr, value_len);
+						storeValue(ret_ptr, s);
+					},
+
+					// func valueGet(v ref, p string) ref
+					"syscall/js.valueGet": (retval, v_addr, p_ptr, p_len) => {
+						let prop = loadString(p_ptr, p_len);
+						let value = loadValue(v_addr);
+						let result = Reflect.get(value, prop);
+						storeValue(retval, result);
+					},
+
+					// func valueSet(v ref, p string, x ref)
+					"syscall/js.valueSet": (v_addr, p_ptr, p_len, x_addr) => {
+						const v = loadValue(v_addr);
+						const p = loadString(p_ptr, p_len);
+						const x = loadValue(x_addr);
+						Reflect.set(v, p, x);
+					},
+
+					// func valueDelete(v ref, p string)
+					"syscall/js.valueDelete": (v_addr, p_ptr, p_len) => {
+						const v = loadValue(v_addr);
+						const p = loadString(p_ptr, p_len);
+						Reflect.deleteProperty(v, p);
+					},
+
+					// func valueIndex(v ref, i int) ref
+					"syscall/js.valueIndex": (ret_addr, v_addr, i) => {
+						storeValue(ret_addr, Reflect.get(loadValue(v_addr), i));
+					},
+
+					// valueSetIndex(v ref, i int, x ref)
+					"syscall/js.valueSetIndex": (v_addr, i, x_addr) => {
+						Reflect.set(loadValue(v_addr), i, loadValue(x_addr));
+					},
+
+					// func valueCall(v ref, m string, args []ref) (ref, bool)
+					"syscall/js.valueCall": (ret_addr, v_addr, m_ptr, m_len, args_ptr, args_len, args_cap) => {
+						const v = loadValue(v_addr);
+						const name = loadString(m_ptr, m_len);
+						const args = loadSliceOfValues(args_ptr, args_len, args_cap);
+						try {
+							const m = Reflect.get(v, name);
+							storeValue(ret_addr, Reflect.apply(m, v, args));
+							mem().setUint8(ret_addr + 8, 1);
+						} catch (err) {
+							storeValue(ret_addr, err);
+							mem().setUint8(ret_addr + 8, 0);
+						}
+					},
+
+					// func valueInvoke(v ref, args []ref) (ref, bool)
+					"syscall/js.valueInvoke": (ret_addr, v_addr, args_ptr, args_len, args_cap) => {
+						try {
+							const v = loadValue(v_addr);
+							const args = loadSliceOfValues(args_ptr, args_len, args_cap);
+							storeValue(ret_addr, Reflect.apply(v, undefined, args));
+							mem().setUint8(ret_addr + 8, 1);
+						} catch (err) {
+							storeValue(ret_addr, err);
+							mem().setUint8(ret_addr + 8, 0);
+						}
+					},
+
+					// func valueNew(v ref, args []ref) (ref, bool)
+					"syscall/js.valueNew": (ret_addr, v_addr, args_ptr, args_len, args_cap) => {
+						const v = loadValue(v_addr);
+						const args = loadSliceOfValues(args_ptr, args_len, args_cap);
+						try {
+							storeValue(ret_addr, Reflect.construct(v, args));
+							mem().setUint8(ret_addr + 8, 1);
+						} catch (err) {
+							storeValue(ret_addr, err);
+							mem().setUint8(ret_addr+ 8, 0);
+						}
+					},
+
+					// func valueLength(v ref) int
+					"syscall/js.valueLength": (v_addr) => {
+						return loadValue(v_addr).length;
+					},
+
+					// valuePrepareString(v ref) (ref, int)
+					"syscall/js.valuePrepareString": (ret_addr, v_addr) => {
+						const s = String(loadValue(v_addr));
+						const str = encoder.encode(s);
+						storeValue(ret_addr, str);
+						setInt64(ret_addr + 8, str.length);
+					},
+
+					// valueLoadString(v ref, b []byte)
+					"syscall/js.valueLoadString": (v_addr, slice_ptr, slice_len, slice_cap) => {
+						const str = loadValue(v_addr);
+						loadSlice(slice_ptr, slice_len, slice_cap).set(str);
+					},
+
+					// func valueInstanceOf(v ref, t ref) bool
+					"syscall/js.valueInstanceOf": (v_addr, t_addr) => {
+ 						return loadValue(v_addr) instanceof loadValue(t_addr);
+					},
+
+					// func copyBytesToGo(dst []byte, src ref) (int, bool)
+					"syscall/js.copyBytesToGo": (ret_addr, dest_addr, dest_len, dest_cap, source_addr) => {
+						let num_bytes_copied_addr = ret_addr;
+						let returned_status_addr = ret_addr + 4; // Address of returned boolean status variable
+
+						const dst = loadSlice(dest_addr, dest_len);
+						const src = loadValue(source_addr);
+						if (!(src instanceof Uint8Array || src instanceof Uint8ClampedArray)) {
+							mem().setUint8(returned_status_addr, 0); // Return "not ok" status
+							return;
+						}
+						const toCopy = src.subarray(0, dst.length);
+						dst.set(toCopy);
+						setInt64(num_bytes_copied_addr, toCopy.length);
+						mem().setUint8(returned_status_addr, 1); // Return "ok" status
+					},
+
+					// copyBytesToJS(dst ref, src []byte) (int, bool)
+					// Originally copied from upstream Go project, then modified:
+					//   https://github.com/golang/go/blob/3f995c3f3b43033013013e6c7ccc93a9b1411ca9/misc/wasm/wasm_exec.js#L404-L416
+					"syscall/js.copyBytesToJS": (ret_addr, dest_addr, source_addr, source_len, source_cap) => {
+						let num_bytes_copied_addr = ret_addr;
+						let returned_status_addr = ret_addr + 4; // Address of returned boolean status variable
+
+						const dst = loadValue(dest_addr);
+						const src = loadSlice(source_addr, source_len);
+						if (!(dst instanceof Uint8Array || dst instanceof Uint8ClampedArray)) {
+							mem().setUint8(returned_status_addr, 0); // Return "not ok" status
+							return;
+						}
+						const toCopy = src.subarray(0, dst.length);
+						dst.set(toCopy);
+						setInt64(num_bytes_copied_addr, toCopy.length);
+						mem().setUint8(returned_status_addr, 1); // Return "ok" status
+					},
+				}
+			};
+		}
+
+		async run(instance) {
+			this._inst = instance;
+			this._values = [ // JS values that Go currently has references to, indexed by reference id
+				NaN,
+				0,
+				null,
+				true,
+				false,
+				global,
+				this,
+			];
+			this._goRefCounts = []; // number of references that Go has to a JS value, indexed by reference id
+			this._ids = new Map();  // mapping from JS values to reference ids
+			this._idPool = [];      // unused ids that have been garbage collected
+			this.exited = false;    // whether the Go program has exited
+
+			const mem = new DataView(this._inst.exports.memory.buffer)
+
+			while (true) {
+				const callbackPromise = new Promise((resolve) => {
+					this._resolveCallbackPromise = () => {
+						if (this.exited) {
+							throw new Error("bad callback: Go program has already exited");
+						}
+						setTimeout(resolve, 0); // make sure it is asynchronous
+					};
+				});
+				this._inst.exports._start();
+				if (this.exited) {
+					break;
+				}
+				await callbackPromise;
+			}
+		}
+
+		_resume() {
+			if (this.exited) {
+				throw new Error("Go program has already exited");
+			}
+			this._inst.exports.resume();
+			if (this.exited) {
+				this._resolveExitPromise();
+			}
+		}
+
+		_makeFuncWrapper(id) {
+			const go = this;
+			return function () {
+				const event = { id: id, this: this, args: arguments };
+				go._pendingEvent = event;
+				go._resume();
+				return event.result;
+			};
+		}
+	}
+
+	if (
+		global.require &&
+		global.require.main === module &&
+		global.process &&
+		global.process.versions &&
+		!global.process.versions.electron
+	) {
+		if (process.argv.length != 3) {
+			console.error("usage: go_js_wasm_exec [wasm binary] [arguments]");
+			process.exit(1);
+		}
+
+		const go = new Go();
+		WebAssembly.instantiate(fs.readFileSync(process.argv[2]), go.importObject).then((result) => {
+			return go.run(result.instance);
+		}).catch((err) => {
+			console.error(err);
+			process.exit(1);
+		});
+	}
+})();

cmd/workers-gen-go/main.go

@@ -0,0 +1,107 @@
+package main
+
+import (
+	"bytes"
+	"embed"
+	"flag"
+	"fmt"
+	"io"
+	"os"
+	"path"
+)
+
+//go:embed assets
+var assets embed.FS
+
+const (
+	assetDirPath  = "assets"
+	commonDirPath = "assets/common"
+	buildDirPath  = "build"
+)
+
+func main() {
+	var mode string
+	flag.StringVar(&mode, "mode", string(ModeTinygo), `build mode: tinygo or go`)
+	flag.Parse()
+	if !Mode(mode).IsValid() {
+		flag.PrintDefaults()
+		os.Exit(1)
+		return
+	}
+	if err := runMain(Mode(mode)); err != nil {
+		fmt.Fprintf(os.Stderr, "err: %v", err)
+		os.Exit(1)
+	}
+}
+
+func runMain(mode Mode) error {
+	if err := os.RemoveAll(buildDirPath); err != nil {
+		return err
+	}
+	if err := os.MkdirAll(buildDirPath, os.ModePerm); err != nil {
+		return err
+	}
+	if err := copyWasmExecJS(mode); err != nil {
+		return err
+	}
+	if err := copyCommonAssets(); err != nil {
+		return err
+	}
+	return nil
+}
+
+func copyWasmExecJS(mode Mode) error {
+	var fileName string
+	switch mode {
+	case ModeTinygo:
+		fileName = "wasm_exec_tinygo.js"
+	case ModeGo:
+		fileName = "wasm_exec_tinygo.js"
+	default:
+		return fmt.Errorf("unexpected mode: %s", mode)
+	}
+	destPath := path.Join(buildDirPath, "wasm_exec.js")
+	originPath := path.Join(assetDirPath, fileName)
+	if err := copyFile(destPath, originPath); err != nil {
+		return err
+	}
+	return nil
+}
+
+func copyCommonAssets() error {
+	entries, err := assets.ReadDir(commonDirPath)
+	if err != nil {
+		return err
+	}
+	for _, entry := range entries {
+		destPath := path.Join(buildDirPath, entry.Name())
+		originPath := path.Join(commonDirPath, entry.Name())
+		if err := copyFile(destPath, originPath); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func copyFile(destPath, originPath string) error {
+	f, err := assets.ReadFile(originPath)
+	if err != nil {
+		return err
+	}
+	if err != nil {
+		return err
+	}
+	dest, err := os.Create(destPath)
+	if err != nil {
+		return err
+	}
+	defer dest.Close()
+	_, err = io.Copy(dest, bytes.NewReader(f))
+	if err != nil {
+		return err
+	}
+	if err != nil {
+		return err
+	}
+	return nil
+}

cmd/workers-gen-go/mode.go

@@ -0,0 +1,16 @@
+package main
+
+type Mode string
+
+const (
+	ModeGo     Mode = "go"
+	ModeTinygo Mode = "tinygo"
+)
+
+func (m Mode) IsValid() bool {
+	switch m {
+	case ModeGo, ModeTinygo:
+		return true
+	}
+	return false
+}