misc/wasm/wasm_exec.js - go - Git at Google

 // 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.

 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
 	if (process.argv.length < 3) {
 		process.stderr.write("usage: go_js_wasm_exec [wasm binary]\n");
 		process.exit(1);
 	}

 	args = args.concat(process.argv.slice(3));
 	global.require = require;

 	global.fs = require("fs");

 	const nodeCrypto = require("crypto");
 	global.crypto = {
 		getRandomValues(b) {
 			nodeCrypto.randomFillSync(b);
 		},
 	};

 	const now = () => {
 		const [sec, nsec] = process.hrtime();
 		return sec * 1000 + nsec / 1000000;
 	};
 	global.performance = {
 		timeOrigin: Date.now() - now(),
 		now: now,
 	};

 	const util = require("util");
 	global.TextEncoder = util.TextEncoder;
 	global.TextDecoder = util.TextDecoder;

 	compileAndRun(fs.readFileSync(process.argv[2])).catch((err) => {
 		console.error(err);
 	});
 } else {
 	window.global = window;

 	global.process = {
 		env: {},
 		exit(code) {
 			if (code !== 0) {
 				console.warn("exit code:", code);
 			}
 		},
 	};

 	let outputBuf = "";
 	global.fs = {
 		constants: {},
 		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;
 		},
 	};
 }

 const encoder = new TextEncoder("utf-8");
 const decoder = new TextDecoder("utf-8");

 let mod, inst;
 let values = []; // TODO: garbage collection

 function mem() {
 	// The buffer may change when requesting more memory.
 	return new DataView(inst.exports.mem.buffer);
 }

 function 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 low = mem().getUint32(addr + 0, true);
 	const high = mem().getInt32(addr + 4, true);
 	return low + high * 4294967296;
 }

 function loadValue(addr) {
 	const id = mem().getUint32(addr, true);
 	return values[id];
 }

 function storeValue(addr, v) {
 	if (v === undefined) {
 		mem().setUint32(addr, 0, true);
 		return;
 	}
 	if (v === null) {
 		mem().setUint32(addr, 1, true);
 		return;
 	}
 	values.push(v);
 	mem().setUint32(addr, values.length - 1, true);
 }

 function 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 array = getInt64(addr + 0);
 	const len = getInt64(addr + 8);
 	const a = new Array(len);
 	for (let i = 0; i < len; i++) {
 		const id = mem().getUint32(array + i * 4, true);
 		a[i] = values[id];
 	}
 	return a;
 }

 function 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();
 }

 async function compile(source) {
 	mod = await WebAssembly.compile(source);
 }

 async function run() {
 	let importObject = {
 		js: {
 			// func wasmexit(code int32)
 			"runtime.wasmexit": function (sp) {
 				process.exit(mem().getInt32(sp + 8, true));
 			},

 			// func wasmwrite(fd uintptr, p unsafe.Pointer, n int32)
 			"runtime.wasmwrite": function (sp) {
 				const fd = getInt64(sp + 8);
 				const p = getInt64(sp + 16);
 				const n = mem().getInt32(sp + 24, true);
 				fs.writeSync(fd, new Uint8Array(inst.exports.mem.buffer, p, n));
 			},

 			// func nanotime() int64
 			"runtime.nanotime": function (sp) {
 				setInt64(sp + 8, (performance.timeOrigin + performance.now()) * 1000000);
 			},

 			// func walltime() (sec int64, nsec int32)
 			"runtime.walltime": function (sp) {
 				const msec = (new Date).getTime();
 				setInt64(sp + 8, msec / 1000);
 				mem().setInt32(sp + 16, (msec % 1000) * 1000000, true);
 			},

 			// func boolVal(value bool) Value
 			"runtime/js.boolVal": function (sp) {
 				storeValue(sp + 16, mem().getUint8(sp + 8) !== 0);
 			},

 			// func intVal(value int) Value
 			"runtime/js.intVal": function (sp) {
 				storeValue(sp + 16, getInt64(sp + 8));
 			},

 			// func floatVal(value float64) Value
 			"runtime/js.floatVal": function (sp) {
 				storeValue(sp + 16, mem().getFloat64(sp + 8, true));
 			},

 			// func stringVal(value string) Value
 			"runtime/js.stringVal": function (sp) {
 				storeValue(sp + 24, loadString(sp + 8));
 			},

 			// func (v Value) Get(key string) Value
 			"runtime/js.Value.Get": function (sp) {
 				storeValue(sp + 32, Reflect.get(loadValue(sp + 8), loadString(sp + 16)));
 			},

 			// func (v Value) set(key string, value Value)
 			"runtime/js.Value.set": function (sp) {
 				Reflect.set(loadValue(sp + 8), loadString(sp + 16), loadValue(sp + 32));
 			},

 			// func (v Value) Index(i int) Value
 			"runtime/js.Value.Index": function (sp) {
 				storeValue(sp + 24, Reflect.get(loadValue(sp + 8), getInt64(sp + 16)));
 			},

 			// func (v Value) setIndex(i int, value Value)
 			"runtime/js.Value.setIndex": function (sp) {
 				Reflect.set(loadValue(sp + 8), getInt64(sp + 16), loadValue(sp + 24));
 			},

 			// func (v Value) call(name string, args []Value) (Value, bool)
 			"runtime/js.Value.call": function (sp) {
 				try {
 					const v = loadValue(sp + 8);
 					const m = Reflect.get(v, loadString(sp + 16));
 					const args = loadSliceOfValues(sp + 32);
 					storeValue(sp + 56, Reflect.apply(m, v, args));
 					mem().setUint8(sp + 60, 1);
 				} catch (err) {
 					storeValue(sp + 56, err);
 					mem().setUint8(sp + 60, 0);
 				}
 			},

 			// func (v Value) invoke(args []Value) (Value, bool)
 			"runtime/js.Value.invoke": function (sp) {
 				try {
 					const v = loadValue(sp + 8);
 					const args = loadSliceOfValues(sp + 16);
 					storeValue(sp + 40, Reflect.apply(v, undefined, args));
 					mem().setUint8(sp + 44, 1);
 				} catch (err) {
 					storeValue(sp + 40, err);
 					mem().setUint8(sp + 44, 0);
 				}
 			},

 			// func (v Value) wasmnew(args []Value) (Value, bool)
 			"runtime/js.Value.wasmnew": function (sp) {
 				try {
 					const v = loadValue(sp + 8);
 					const args = loadSliceOfValues(sp + 16);
 					storeValue(sp + 40, Reflect.construct(v, args));
 					mem().setUint8(sp + 44, 1);
 				} catch (err) {
 					storeValue(sp + 40, err);
 					mem().setUint8(sp + 44, 0);
 				}
 			},

 			// func (v Value) Float() float64
 			"runtime/js.Value.Float": function (sp) {
 				mem().setFloat64(sp + 16, parseFloat(loadValue(sp + 8)), true);
 			},

 			// func (v Value) Int() int
 			"runtime/js.Value.Int": function (sp) {
 				setInt64(sp + 16, parseInt(loadValue(sp + 8)));
 			},

 			// func (v Value) Bool() bool
 			"runtime/js.Value.Bool": function (sp) {
 				mem().setUint8(sp + 16, !!loadValue(sp + 8));
 			},

 			// func (v Value) Length() int
 			"runtime/js.Value.Length": function (sp) {
 				setInt64(sp + 16, parseInt(loadValue(sp + 8).length));
 			},

 			// func (v Value) prepareString() (Value, int)
 			"runtime/js.Value.prepareString": function (sp) {
 				const str = encoder.encode(String(loadValue(sp + 8)));
 				storeValue(sp + 16, str);
 				setInt64(sp + 24, str.length);
 			},

 			// func (v Value) loadString(b []byte)
 			"runtime/js.Value.loadString": function (sp) {
 				const str = loadValue(sp + 8);
 				loadSlice(sp + 16).set(str);
 			},

 			"debug": function (value) {
 				console.log(value);
 			},
 		}
 	};

 	inst = await WebAssembly.instantiate(mod, importObject);
 	values = [undefined, null, global, inst.exports.mem];

 	// Pass command line arguments and environment variables to WebAssembly by writing them to the linear memory.
 	let offset = 4096;

 	const strPtr = (str) => {
 		let ptr = offset;
 		new Uint8Array(inst.exports.mem.buffer, offset, str.length + 1).set(encoder.encode(str + "\0"));
 		offset += str.length + (8 - (str.length % 8));
 		return ptr;
 	};

 	const argc = args.length;

 	const argvPtrs = [];
 	args.forEach((arg) => {
 		argvPtrs.push(strPtr(arg));
 	});

 	const keys = Object.keys(process.env).sort();
 	argvPtrs.push(keys.length);
 	keys.forEach((key) => {
 		argvPtrs.push(strPtr(`${key}=${process.env[key]}`));
 	});

 	const argv = offset;
 	argvPtrs.forEach((ptr) => {
 		mem().setUint32(offset, ptr, true);
 		mem().setUint32(offset + 4, 0, true);
 		offset += 8;
 	});

 	try {
 		inst.exports.run(argc, argv);
 	} catch (err) {
 		console.error(err);
 		process.exit(1);
 	}
 }
	// 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.

	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
	if (process.argv.length < 3) {
	process.stderr.write("usage: go_js_wasm_exec [wasm binary]\n");
	process.exit(1);
	}

	args = args.concat(process.argv.slice(3));
	global.require = require;

	global.fs = require("fs");

	const nodeCrypto = require("crypto");
	global.crypto = {
	getRandomValues(b) {
	nodeCrypto.randomFillSync(b);
	},
	};

	const now = () => {
	const [sec, nsec] = process.hrtime();
	return sec * 1000 + nsec / 1000000;
	};
	global.performance = {
	timeOrigin: Date.now() - now(),
	now: now,
	};

	const util = require("util");
	global.TextEncoder = util.TextEncoder;
	global.TextDecoder = util.TextDecoder;

	compileAndRun(fs.readFileSync(process.argv[2])).catch((err) => {
	console.error(err);
	});
	} else {
	window.global = window;

	global.process = {
	env: {},
	exit(code) {
	if (code !== 0) {
	console.warn("exit code:", code);
	}
	},
	};

	let outputBuf = "";
	global.fs = {
	constants: {},
	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;
	},
	};
	}

	const encoder = new TextEncoder("utf-8");
	const decoder = new TextDecoder("utf-8");

	let mod, inst;
	let values = []; // TODO: garbage collection

	function mem() {
	// The buffer may change when requesting more memory.
	return new DataView(inst.exports.mem.buffer);
	}

	function 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 low = mem().getUint32(addr + 0, true);
	const high = mem().getInt32(addr + 4, true);
	return low + high * 4294967296;
	}

	function loadValue(addr) {
	const id = mem().getUint32(addr, true);
	return values[id];
	}

	function storeValue(addr, v) {
	if (v === undefined) {
	mem().setUint32(addr, 0, true);
	return;
	}
	if (v === null) {
	mem().setUint32(addr, 1, true);
	return;
	}
	values.push(v);
	mem().setUint32(addr, values.length - 1, true);
	}

	function 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 array = getInt64(addr + 0);
	const len = getInt64(addr + 8);
	const a = new Array(len);
	for (let i = 0; i < len; i++) {
	const id = mem().getUint32(array + i * 4, true);
	a[i] = values[id];
	}
	return a;
	}

	function 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();
	}

	async function compile(source) {
	mod = await WebAssembly.compile(source);
	}

	async function run() {
	let importObject = {
	js: {
	// func wasmexit(code int32)
	"runtime.wasmexit": function (sp) {
	process.exit(mem().getInt32(sp + 8, true));
	},

	// func wasmwrite(fd uintptr, p unsafe.Pointer, n int32)
	"runtime.wasmwrite": function (sp) {
	const fd = getInt64(sp + 8);
	const p = getInt64(sp + 16);
	const n = mem().getInt32(sp + 24, true);
	fs.writeSync(fd, new Uint8Array(inst.exports.mem.buffer, p, n));
	},

	// func nanotime() int64
	"runtime.nanotime": function (sp) {
	setInt64(sp + 8, (performance.timeOrigin + performance.now()) * 1000000);
	},

	// func walltime() (sec int64, nsec int32)
	"runtime.walltime": function (sp) {
	const msec = (new Date).getTime();
	setInt64(sp + 8, msec / 1000);
	mem().setInt32(sp + 16, (msec % 1000) * 1000000, true);
	},

	// func boolVal(value bool) Value
	"runtime/js.boolVal": function (sp) {
	storeValue(sp + 16, mem().getUint8(sp + 8) !== 0);
	},

	// func intVal(value int) Value
	"runtime/js.intVal": function (sp) {
	storeValue(sp + 16, getInt64(sp + 8));
	},

	// func floatVal(value float64) Value
	"runtime/js.floatVal": function (sp) {
	storeValue(sp + 16, mem().getFloat64(sp + 8, true));
	},

	// func stringVal(value string) Value
	"runtime/js.stringVal": function (sp) {
	storeValue(sp + 24, loadString(sp + 8));
	},

	// func (v Value) Get(key string) Value
	"runtime/js.Value.Get": function (sp) {
	storeValue(sp + 32, Reflect.get(loadValue(sp + 8), loadString(sp + 16)));
	},

	// func (v Value) set(key string, value Value)
	"runtime/js.Value.set": function (sp) {
	Reflect.set(loadValue(sp + 8), loadString(sp + 16), loadValue(sp + 32));
	},

	// func (v Value) Index(i int) Value
	"runtime/js.Value.Index": function (sp) {
	storeValue(sp + 24, Reflect.get(loadValue(sp + 8), getInt64(sp + 16)));
	},

	// func (v Value) setIndex(i int, value Value)
	"runtime/js.Value.setIndex": function (sp) {
	Reflect.set(loadValue(sp + 8), getInt64(sp + 16), loadValue(sp + 24));
	},

	// func (v Value) call(name string, args []Value) (Value, bool)
	"runtime/js.Value.call": function (sp) {
	try {
	const v = loadValue(sp + 8);
	const m = Reflect.get(v, loadString(sp + 16));
	const args = loadSliceOfValues(sp + 32);
	storeValue(sp + 56, Reflect.apply(m, v, args));
	mem().setUint8(sp + 60, 1);
	} catch (err) {
	storeValue(sp + 56, err);
	mem().setUint8(sp + 60, 0);
	}
	},

	// func (v Value) invoke(args []Value) (Value, bool)
	"runtime/js.Value.invoke": function (sp) {
	try {
	const v = loadValue(sp + 8);
	const args = loadSliceOfValues(sp + 16);
	storeValue(sp + 40, Reflect.apply(v, undefined, args));
	mem().setUint8(sp + 44, 1);
	} catch (err) {
	storeValue(sp + 40, err);
	mem().setUint8(sp + 44, 0);
	}
	},

	// func (v Value) wasmnew(args []Value) (Value, bool)
	"runtime/js.Value.wasmnew": function (sp) {
	try {
	const v = loadValue(sp + 8);
	const args = loadSliceOfValues(sp + 16);
	storeValue(sp + 40, Reflect.construct(v, args));
	mem().setUint8(sp + 44, 1);
	} catch (err) {
	storeValue(sp + 40, err);
	mem().setUint8(sp + 44, 0);
	}
	},

	// func (v Value) Float() float64
	"runtime/js.Value.Float": function (sp) {
	mem().setFloat64(sp + 16, parseFloat(loadValue(sp + 8)), true);
	},

	// func (v Value) Int() int
	"runtime/js.Value.Int": function (sp) {
	setInt64(sp + 16, parseInt(loadValue(sp + 8)));
	},

	// func (v Value) Bool() bool
	"runtime/js.Value.Bool": function (sp) {
	mem().setUint8(sp + 16, !!loadValue(sp + 8));
	},

	// func (v Value) Length() int
	"runtime/js.Value.Length": function (sp) {
	setInt64(sp + 16, parseInt(loadValue(sp + 8).length));
	},

	// func (v Value) prepareString() (Value, int)
	"runtime/js.Value.prepareString": function (sp) {
	const str = encoder.encode(String(loadValue(sp + 8)));
	storeValue(sp + 16, str);
	setInt64(sp + 24, str.length);
	},

	// func (v Value) loadString(b []byte)
	"runtime/js.Value.loadString": function (sp) {
	const str = loadValue(sp + 8);
	loadSlice(sp + 16).set(str);
	},

	"debug": function (value) {
	console.log(value);
	},
	}
	};

	inst = await WebAssembly.instantiate(mod, importObject);
	values = [undefined, null, global, inst.exports.mem];

	// Pass command line arguments and environment variables to WebAssembly by writing them to the linear memory.
	let offset = 4096;

	const strPtr = (str) => {
	let ptr = offset;
	new Uint8Array(inst.exports.mem.buffer, offset, str.length + 1).set(encoder.encode(str + "\0"));
	offset += str.length + (8 - (str.length % 8));
	return ptr;
	};

	const argc = args.length;

	const argvPtrs = [];
	args.forEach((arg) => {
	argvPtrs.push(strPtr(arg));
	});

	const keys = Object.keys(process.env).sort();
	argvPtrs.push(keys.length);
	keys.forEach((key) => {
	argvPtrs.push(strPtr(`${key}=${process.env[key]}`));
	});

	const argv = offset;
	argvPtrs.forEach((ptr) => {
	mem().setUint32(offset, ptr, true);
	mem().setUint32(offset + 4, 0, true);
	offset += 8;
	});

	try {
	inst.exports.run(argc, argv);
	} catch (err) {
	console.error(err);
	process.exit(1);
	}
	}