misc/wasm: pollute global JS namespace less

This commit changes wasm_exec.js so it only puts the single
name "go" into the global namespace. Other names became private
or were turned into a property/method of "go".

Change-Id: I633829dfd3c06936f092c0a14b9978bf855e41fe
Reviewed-on: https://go-review.googlesource.com/112980Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Agniva De Sarker <agniva.quicksilver@gmail.com>

misc/wasm/wasm_exec.html

@@ -17,14 +17,14 @@ license that can be found in the LICENSE file.
 		async function loadAndCompile() {
 			let resp = await fetch("test.wasm");
 			let bytes = await resp.arrayBuffer();
-			await compile(bytes);
+			await go.compile(bytes);
 			document.getElementById("runButton").disabled = false;
 		}
 
 		loadAndCompile();
 	</script>
 
-	<button onClick="console.clear(); run();" id="runButton" disabled>Run</button>
+	<button onClick="console.clear(); go.run();" id="runButton" disabled>Run</button>
 </body>
 
 </html>

misc/wasm/wasm_exec.js

@@ -2,10 +2,12 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-let args = ["js"];
+(() => {
+	let args = ["js"];
 
-// Map web browser API and Node.js API to a single common API (preferring web standards over Node.js API).
-if (typeof process !== "undefined") { // detect Node.js
+	// Map web browser API and Node.js API to a single common API (preferring web standards over Node.js API).
+	const isNodeJS = typeof process !== "undefined";
+	if (isNodeJS) {
 		if (process.argv.length < 3) {
 			process.stderr.write("usage: go_js_wasm_exec [wasm binary]\n");
 			process.exit(1);
@@ -35,12 +37,7 @@ if (typeof process !== "undefined") { // detect Node.js
 		const util = require("util");
 		global.TextEncoder = util.TextEncoder;
 		global.TextDecoder = util.TextDecoder;
-
-	compileAndRun(fs.readFileSync(process.argv[2])).catch((err) => {
-		console.error(err);
-		process.exit(1);
-	});
-} else {
+	} else {
 		window.global = window;
 
 		global.process = {
@@ -65,40 +62,40 @@ if (typeof process !== "undefined") { // detect Node.js
 				return buf.length;
 			},
 		};
-}
+	}
 
-const encoder = new TextEncoder("utf-8");
-const decoder = new TextDecoder("utf-8");
+	const encoder = new TextEncoder("utf-8");
+	const decoder = new TextDecoder("utf-8");
 
-let mod, inst;
-let values = []; // TODO: garbage collection
+	let mod, inst;
+	let values = []; // TODO: garbage collection
 
-function mem() {
+	const mem = () => {
 		// The buffer may change when requesting more memory.
 		return new DataView(inst.exports.mem.buffer);
-}
+	}
 
-function setInt64(addr, v) {
+	const setInt64 = (addr, v) => {
 		mem().setUint32(addr + 0, v, true);
 		if (v >= 0) {
 			mem().setUint32(addr + 4, v / 4294967296, true);
 		} else {
 			mem().setUint32(addr + 4, -1, true); // FIXME
 		}
-}
+	}
 
-function getInt64(addr) {
+	const getInt64 = (addr) => {
 		const low = mem().getUint32(addr + 0, true);
 		const high = mem().getInt32(addr + 4, true);
 		return low + high * 4294967296;
-}
+	}
 
-function loadValue(addr) {
+	const loadValue = (addr) => {
 		const id = mem().getUint32(addr, true);
 		return values[id];
-}
+	}
 
-function storeValue(addr, v) {
+	const storeValue = (addr, v) => {
 		if (v === undefined) {
 			mem().setUint32(addr, 0, true);
 			return;
@@ -109,15 +106,15 @@ function storeValue(addr, v) {
 		}
 		values.push(v);
 		mem().setUint32(addr, values.length - 1, true);
-}
+	}
 
-function loadSlice(addr) {
+	const loadSlice = (addr) => {
 		const array = getInt64(addr + 0);
 		const len = getInt64(addr + 8);
 		return new Uint8Array(inst.exports.mem.buffer, array, len);
-}
+	}
 
-function loadSliceOfValues(addr) {
+	const loadSliceOfValues = (addr) => {
 		const array = getInt64(addr + 0);
 		const len = getInt64(addr + 8);
 		const a = new Array(len);
@@ -126,33 +123,34 @@ function loadSliceOfValues(addr) {
 			a[i] = values[id];
 		}
 		return a;
-}
+	}
 
-function loadString(addr) {
+	const loadString = (addr) => {
 		const saddr = getInt64(addr + 0);
 		const len = getInt64(addr + 8);
 		return decoder.decode(new DataView(inst.exports.mem.buffer, saddr, len));
-}
+	}
 
-async function compileAndRun(source) {
-	await compile(source);
-	await run();
-}
+	global.go = {
+		async compileAndRun(source) {
+			await go.compile(source);
+			await go.run();
+		},
 
-async function compile(source) {
+		async compile(source) {
 			mod = await WebAssembly.compile(source);
-}
+		},
 
-async function run() {
+		async run() {
 			let importObject = {
 				go: {
 					// func wasmExit(code int32)
-			"runtime.wasmExit": function (sp) {
+					"runtime.wasmExit": (sp) => {
 						process.exit(mem().getInt32(sp + 8, true));
 					},
 
 					// func wasmWrite(fd uintptr, p unsafe.Pointer, n int32)
-			"runtime.wasmWrite": function (sp) {
+					"runtime.wasmWrite": (sp) => {
 						const fd = getInt64(sp + 8);
 						const p = getInt64(sp + 16);
 						const n = mem().getInt32(sp + 24, true);
@@ -160,59 +158,59 @@ async function run() {
 					},
 
 					// func nanotime() int64
-			"runtime.nanotime": function (sp) {
+					"runtime.nanotime": (sp) => {
 						setInt64(sp + 8, (performance.timeOrigin + performance.now()) * 1000000);
 					},
 
 					// func walltime() (sec int64, nsec int32)
-			"runtime.walltime": function (sp) {
+					"runtime.walltime": (sp) => {
 						const msec = (new Date).getTime();
 						setInt64(sp + 8, msec / 1000);
 						mem().setInt32(sp + 16, (msec % 1000) * 1000000, true);
 					},
 
 					// func boolVal(value bool) Value
-			"syscall/js.boolVal": function (sp) {
+					"syscall/js.boolVal": (sp) => {
 						storeValue(sp + 16, mem().getUint8(sp + 8) !== 0);
 					},
 
 					// func intVal(value int) Value
-			"syscall/js.intVal": function (sp) {
+					"syscall/js.intVal": (sp) => {
 						storeValue(sp + 16, getInt64(sp + 8));
 					},
 
 					// func floatVal(value float64) Value
-			"syscall/js.floatVal": function (sp) {
+					"syscall/js.floatVal": (sp) => {
 						storeValue(sp + 16, mem().getFloat64(sp + 8, true));
 					},
 
 					// func stringVal(value string) Value
-			"syscall/js.stringVal": function (sp) {
+					"syscall/js.stringVal": (sp) => {
 						storeValue(sp + 24, loadString(sp + 8));
 					},
 
 					// func (v Value) Get(key string) Value
-			"syscall/js.Value.Get": function (sp) {
+					"syscall/js.Value.Get": (sp) => {
 						storeValue(sp + 32, Reflect.get(loadValue(sp + 8), loadString(sp + 16)));
 					},
 
 					// func (v Value) set(key string, value Value)
-			"syscall/js.Value.set": function (sp) {
+					"syscall/js.Value.set": (sp) => {
 						Reflect.set(loadValue(sp + 8), loadString(sp + 16), loadValue(sp + 32));
 					},
 
 					// func (v Value) Index(i int) Value
-			"syscall/js.Value.Index": function (sp) {
+					"syscall/js.Value.Index": (sp) => {
 						storeValue(sp + 24, Reflect.get(loadValue(sp + 8), getInt64(sp + 16)));
 					},
 
 					// func (v Value) setIndex(i int, value Value)
-			"syscall/js.Value.setIndex": function (sp) {
+					"syscall/js.Value.setIndex": (sp) => {
 						Reflect.set(loadValue(sp + 8), getInt64(sp + 16), loadValue(sp + 24));
 					},
 
 					// func (v Value) call(name string, args []Value) (Value, bool)
-			"syscall/js.Value.call": function (sp) {
+					"syscall/js.Value.call": (sp) => {
 						try {
 							const v = loadValue(sp + 8);
 							const m = Reflect.get(v, loadString(sp + 16));
@@ -226,7 +224,7 @@ async function run() {
 					},
 
 					// func (v Value) invoke(args []Value) (Value, bool)
-			"syscall/js.Value.invoke": function (sp) {
+					"syscall/js.Value.invoke": (sp) => {
 						try {
 							const v = loadValue(sp + 8);
 							const args = loadSliceOfValues(sp + 16);
@@ -239,7 +237,7 @@ async function run() {
 					},
 
 					// func (v Value) new(args []Value) (Value, bool)
-			"syscall/js.Value.new": function (sp) {
+					"syscall/js.Value.new": (sp) => {
 						try {
 							const v = loadValue(sp + 8);
 							const args = loadSliceOfValues(sp + 16);
@@ -252,39 +250,39 @@ async function run() {
 					},
 
 					// func (v Value) Float() float64
-			"syscall/js.Value.Float": function (sp) {
+					"syscall/js.Value.Float": (sp) => {
 						mem().setFloat64(sp + 16, parseFloat(loadValue(sp + 8)), true);
 					},
 
 					// func (v Value) Int() int
-			"syscall/js.Value.Int": function (sp) {
+					"syscall/js.Value.Int": (sp) => {
 						setInt64(sp + 16, parseInt(loadValue(sp + 8)));
 					},
 
 					// func (v Value) Bool() bool
-			"syscall/js.Value.Bool": function (sp) {
+					"syscall/js.Value.Bool": (sp) => {
 						mem().setUint8(sp + 16, !!loadValue(sp + 8));
 					},
 
 					// func (v Value) Length() int
-			"syscall/js.Value.Length": function (sp) {
+					"syscall/js.Value.Length": (sp) => {
 						setInt64(sp + 16, parseInt(loadValue(sp + 8).length));
 					},
 
 					// func (v Value) prepareString() (Value, int)
-			"syscall/js.Value.prepareString": function (sp) {
+					"syscall/js.Value.prepareString": (sp) => {
 						const str = encoder.encode(String(loadValue(sp + 8)));
 						storeValue(sp + 16, str);
 						setInt64(sp + 24, str.length);
 					},
 
 					// func (v Value) loadString(b []byte)
-			"syscall/js.Value.loadString": function (sp) {
+					"syscall/js.Value.loadString": (sp) => {
 						const str = loadValue(sp + 8);
 						loadSlice(sp + 16).set(str);
 					},
 
-			"debug": function (value) {
+					"debug": (value) => {
 						console.log(value);
 					},
 				}
@@ -329,4 +327,13 @@ async function run() {
 				console.error(err);
 				process.exit(1);
 			}
-}
+		}
+	}
+
+	if (isNodeJS) {
+		go.compileAndRun(fs.readFileSync(process.argv[2])).catch((err) => {
+			console.error(err);
+			process.exit(1);
+		});
+	}
+})();