Files
tinygo/targets/wasm_exec.js
Ayke van Laethem 8e7a288bb4 wasm: use wasip1 API for parameter/env passing
Instead of hardcoding the command line parameters and the environment
variables in the binary, pass them at runtime to Node.js and use the
WASIp1 API to retrieve them in wasm_exec.js.

The only real benefit right now is that it becomes possible to change
`go.argv` and `go.env` before running a wasm binary.

This also changes the syscall package for GOOS=js: it now becomes more
like a libc (using wasi-libc), which means error values like
`syscall.EEXIST` will actually match the one returned by the relevant
libc function.

Wasm binary size for packages that import the os package will be
increased somewhat.
2024-10-30 11:14:18 +01:00

574 lines
17 KiB
JavaScript

// 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("node: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("node: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("node:util").TextEncoder;
}
if (!global.TextDecoder) {
global.TextDecoder = require("node:util").TextDecoder;
}
// End of polyfills for common API.
const encoder = new TextEncoder("utf-8");
const decoder = new TextDecoder("utf-8");
let reinterpretBuf = new DataView(new ArrayBuffer(8));
var logLine = [];
global.Go = class {
constructor() {
this.argv = ["js"];
this.env = {};
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 unboxValue = (v_ref) => {
reinterpretBuf.setBigInt64(0, v_ref, true);
const f = reinterpretBuf.getFloat64(0, true);
if (f === 0) {
return undefined;
}
if (!isNaN(f)) {
return f;
}
const id = v_ref & 0xffffffffn;
return this._values[id];
}
const loadValue = (addr) => {
let v_ref = mem().getBigUint64(addr, true);
return unboxValue(v_ref);
}
const boxValue = (v) => {
const nanHead = 0x7FF80000n;
if (typeof v === "number") {
if (isNaN(v)) {
return nanHead << 32n;
}
if (v === 0) {
return (nanHead << 32n) | 1n;
}
reinterpretBuf.setFloat64(0, v, true);
return reinterpretBuf.getBigInt64(0, true);
}
switch (v) {
case undefined:
return 0n;
case null:
return (nanHead << 32n) | 2n;
case true:
return (nanHead << 32n) | 3n;
case false:
return (nanHead << 32n) | 4n;
}
let id = this._ids.get(v);
if (id === undefined) {
id = this._idPool.pop();
if (id === undefined) {
id = BigInt(this._values.length);
}
this._values[id] = v;
this._goRefCounts[id] = 0;
this._ids.set(v, id);
}
this._goRefCounts[id]++;
let typeFlag = 1n;
switch (typeof v) {
case "string":
typeFlag = 2n;
break;
case "symbol":
typeFlag = 3n;
break;
case "function":
typeFlag = 4n;
break;
}
return id | ((nanHead | typeFlag) << 32n);
}
const storeValue = (addr, v) => {
let v_ref = boxValue(v);
mem().setBigUint64(addr, v_ref, 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 storeStringArraySizes = (array, num_ptr, buf_size_ptr) => {
let buf_size = 0;
for (let s of array) {
buf_size += s.length + 1;
}
mem().setUint32(num_ptr, array.length, true);
mem().setUint32(buf_size_ptr, buf_size, true);
}
const storeStringArray = (array, ptrs_ptr, buf_ptr) => {
for (let s of array) {
// Put string data in buffer.
let data = encoder.encode(s);
let dest = new Uint8Array(this._inst.exports.memory.buffer, buf_ptr, data.length);
dest.set(data);
mem().setUint8(buf_ptr+data.length, 0);
// Put pointer to buffer in pointers array.
mem().setUint32(ptrs_ptr, buf_ptr, true);
// Advance to the next element in the array.
ptrs_ptr += 4;
buf_ptr += data.length + 1;
}
}
const envArray = () => {
let array = [];
for (let [key, value] of Object.entries(this.env)) {
array.push(`${key}=${value}`);
}
return array;
}
const timeOrigin = Date.now() - performance.now();
this.importObject = {
wasi_snapshot_preview1: {
args_sizes_get: (argc_ptr, argv_buf_size_ptr) => {
storeStringArraySizes(this.argv, argc_ptr, argv_buf_size_ptr);
return 0;
},
args_get: (argv_ptr, argv_buf_ptr) => {
storeStringArray(this.argv, argv_ptr, argv_buf_ptr);
return 0;
},
environ_get: (env_ptr, env_buf_ptr) => {
storeStringArray(envArray(), env_ptr, env_buf_ptr);
},
environ_sizes_get: (env_ptr, env_buf_size_ptr) => {
storeStringArraySizes(envArray(), env_ptr, env_buf_size_ptr);
return 0;
},
// 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;
},
},
gojs: {
// 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": (v_ref) => {
// 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": (value_ptr, value_len) => {
const s = loadString(value_ptr, value_len);
return boxValue(s);
},
// func valueGet(v ref, p string) ref
"syscall/js.valueGet": (v_ref, p_ptr, p_len) => {
let prop = loadString(p_ptr, p_len);
let v = unboxValue(v_ref);
let result = Reflect.get(v, prop);
return boxValue(result);
},
// func valueSet(v ref, p string, x ref)
"syscall/js.valueSet": (v_ref, p_ptr, p_len, x_ref) => {
const v = unboxValue(v_ref);
const p = loadString(p_ptr, p_len);
const x = unboxValue(x_ref);
Reflect.set(v, p, x);
},
// func valueDelete(v ref, p string)
"syscall/js.valueDelete": (v_ref, p_ptr, p_len) => {
const v = unboxValue(v_ref);
const p = loadString(p_ptr, p_len);
Reflect.deleteProperty(v, p);
},
// func valueIndex(v ref, i int) ref
"syscall/js.valueIndex": (v_ref, i) => {
return boxValue(Reflect.get(unboxValue(v_ref), i));
},
// valueSetIndex(v ref, i int, x ref)
"syscall/js.valueSetIndex": (v_ref, i, x_ref) => {
Reflect.set(unboxValue(v_ref), i, unboxValue(x_ref));
},
// func valueCall(v ref, m string, args []ref) (ref, bool)
"syscall/js.valueCall": (ret_addr, v_ref, m_ptr, m_len, args_ptr, args_len, args_cap) => {
const v = unboxValue(v_ref);
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_ref, args_ptr, args_len, args_cap) => {
try {
const v = unboxValue(v_ref);
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_ref, args_ptr, args_len, args_cap) => {
const v = unboxValue(v_ref);
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_ref) => {
return unboxValue(v_ref).length;
},
// valuePrepareString(v ref) (ref, int)
"syscall/js.valuePrepareString": (ret_addr, v_ref) => {
const s = String(unboxValue(v_ref));
const str = encoder.encode(s);
storeValue(ret_addr, str);
mem().setInt32(ret_addr + 8, str.length, true);
},
// valueLoadString(v ref, b []byte)
"syscall/js.valueLoadString": (v_ref, slice_ptr, slice_len, slice_cap) => {
const str = unboxValue(v_ref);
loadSlice(slice_ptr, slice_len, slice_cap).set(str);
},
// func valueInstanceOf(v ref, t ref) bool
"syscall/js.valueInstanceOf": (v_ref, t_ref) => {
return unboxValue(v_ref) instanceof unboxValue(t_ref);
},
// func copyBytesToGo(dst []byte, src ref) (int, bool)
"syscall/js.copyBytesToGo": (ret_addr, dest_addr, dest_len, dest_cap, src_ref) => {
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 = unboxValue(src_ref);
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);
mem().setUint32(num_bytes_copied_addr, toCopy.length, true);
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, dst_ref, src_addr, src_len, src_cap) => {
let num_bytes_copied_addr = ret_addr;
let returned_status_addr = ret_addr + 4; // Address of returned boolean status variable
const dst = unboxValue(dst_ref);
const src = loadSlice(src_addr, src_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);
mem().setUint32(num_bytes_copied_addr, toCopy.length, true);
mem().setUint8(returned_status_addr, 1); // Return "ok" status
},
}
};
// Go 1.20 uses 'env'. Go 1.21 uses 'gojs'.
// For compatibility, we use both as long as Go 1.20 is supported.
this.importObject.env = this.importObject.gojs;
}
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
if (this._inst.exports._start) {
this._inst.exports._start();
// TODO: wait until the program exists.
await new Promise(() => {});
} else {
this._inst.exports._initialize();
}
}
_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();
go.argv = process.argv.slice(2);
go.env = process.env;
WebAssembly.instantiate(fs.readFileSync(process.argv[2]), go.importObject).then((result) => {
return go.run(result.instance);
}).catch((err) => {
console.error(err);
process.exit(1);
});
}
})();