misc/wasm: expect environment to provide polyfills
The list of environments to support with wasm_exec.js was becoming too
large to maintain. With this change, wasm_exec.js expects that the
environment provides all necessary polyfills.
The standardized "globalThis" is used for accessing the environment.
wasm_exec.js now only provides stub fallbacks for globalThis.fs and
globalThis.process.
All code specific to Node.js is now in a separate file.
Change-Id: I076febbd94d4d7845260faad972f450f74a7b983
Reviewed-on: https://go-review.googlesource.com/c/go/+/347353
Trust: Richard Musiol <neelance@gmail.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
diff --git a/misc/wasm/go_js_wasm_exec b/misc/wasm/go_js_wasm_exec
index b700722..fcbd0e4 100755
--- a/misc/wasm/go_js_wasm_exec
+++ b/misc/wasm/go_js_wasm_exec
@@ -11,4 +11,4 @@
done
DIR="$( cd -P "$( dirname "$SOURCE" )" && pwd )"
-exec node "$DIR/wasm_exec.js" "$@"
+exec node "$DIR/wasm_exec_node.js" "$@"
diff --git a/misc/wasm/wasm_exec.js b/misc/wasm/wasm_exec.js
index e2f3cda..30044a6 100644
--- a/misc/wasm/wasm_exec.js
+++ b/misc/wasm/wasm_exec.js
@@ -1,49 +1,19 @@
// 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";
(() => {
- // Map multiple JavaScript environments to a single common API,
- // preferring web standards over Node.js API.
- //
- // Environments considered:
- // - Browsers
- // - Node.js
- // - Electron
- // - Parcel
- // - Webpack
-
- 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) {
- const fs = require("fs");
- if (typeof fs === "object" && fs !== null && Object.keys(fs).length !== 0) {
- global.fs = fs;
- }
- }
-
const enosys = () => {
const err = new Error("not implemented");
err.code = "ENOSYS";
return err;
};
- if (!global.fs) {
+ if (!globalThis.fs) {
let outputBuf = "";
- global.fs = {
+ 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);
@@ -88,8 +58,8 @@
};
}
- if (!global.process) {
- global.process = {
+ if (!globalThis.process) {
+ globalThis.process = {
getuid() { return -1; },
getgid() { return -1; },
geteuid() { return -1; },
@@ -103,47 +73,26 @@
}
}
- if (!global.crypto && global.require) {
- const nodeCrypto = require("crypto");
- global.crypto = {
- getRandomValues(b) {
- nodeCrypto.randomFillSync(b);
- },
- };
- }
- if (!global.crypto) {
- throw new Error("global.crypto is not available, polyfill required (getRandomValues only)");
+ if (!globalThis.crypto) {
+ throw new Error("globalThis.crypto is not available, polyfill required (crypto.getRandomValues only)");
}
- if (!global.performance) {
- global.performance = {
- now() {
- const [sec, nsec] = process.hrtime();
- return sec * 1000 + nsec / 1000000;
- },
- };
+ if (!globalThis.performance) {
+ throw new Error("globalThis.performance is not available, polyfill required (performance.now only)");
}
- if (!global.TextEncoder && global.require) {
- global.TextEncoder = require("util").TextEncoder;
- }
- if (!global.TextEncoder) {
- throw new Error("global.TextEncoder is not available, polyfill required");
+ if (!globalThis.TextEncoder) {
+ throw new Error("globalThis.TextEncoder is not available, polyfill required");
}
- if (!global.TextDecoder && global.require) {
- global.TextDecoder = require("util").TextDecoder;
+ if (!globalThis.TextDecoder) {
+ throw new Error("globalThis.TextDecoder is not available, polyfill required");
}
- if (!global.TextDecoder) {
- throw new Error("global.TextDecoder is not available, polyfill required");
- }
-
- // End of polyfills for common API.
const encoder = new TextEncoder("utf-8");
const decoder = new TextDecoder("utf-8");
- global.Go = class {
+ globalThis.Go = class {
constructor() {
this.argv = ["js"];
this.env = {};
@@ -518,7 +467,7 @@
null,
true,
false,
- global,
+ 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
@@ -527,7 +476,7 @@
[null, 2],
[true, 3],
[false, 4],
- [global, 5],
+ [globalThis, 5],
[this, 6],
]);
this._idPool = []; // unused ids that have been garbage collected
@@ -602,36 +551,4 @@
};
}
}
-
- if (
- typeof module !== "undefined" &&
- 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 = Object.assign({ TMPDIR: require("os").tmpdir() }, process.env);
- go.exit = process.exit;
- WebAssembly.instantiate(fs.readFileSync(process.argv[2]), go.importObject).then((result) => {
- process.on("exit", (code) => { // Node.js exits if no event handler is pending
- if (code === 0 && !go.exited) {
- // deadlock, make Go print error and stack traces
- go._pendingEvent = { id: 0 };
- go._resume();
- }
- });
- return go.run(result.instance);
- }).catch((err) => {
- console.error(err);
- process.exit(1);
- });
- }
})();
diff --git a/misc/wasm/wasm_exec_node.js b/misc/wasm/wasm_exec_node.js
new file mode 100644
index 0000000..f9200ca
--- /dev/null
+++ b/misc/wasm/wasm_exec_node.js
@@ -0,0 +1,49 @@
+// Copyright 2021 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";
+
+if (process.argv.length < 3) {
+ console.error("usage: go_js_wasm_exec [wasm binary] [arguments]");
+ process.exit(1);
+}
+
+globalThis.require = require;
+globalThis.fs = require("fs");
+globalThis.TextEncoder = require("util").TextEncoder;
+globalThis.TextDecoder = require("util").TextDecoder;
+
+globalThis.performance = {
+ now() {
+ const [sec, nsec] = process.hrtime();
+ return sec * 1000 + nsec / 1000000;
+ },
+};
+
+const crypto = require("crypto");
+globalThis.crypto = {
+ getRandomValues(b) {
+ crypto.randomFillSync(b);
+ },
+};
+
+require("./wasm_exec");
+
+const go = new Go();
+go.argv = process.argv.slice(2);
+go.env = Object.assign({ TMPDIR: require("os").tmpdir() }, process.env);
+go.exit = process.exit;
+WebAssembly.instantiate(fs.readFileSync(process.argv[2]), go.importObject).then((result) => {
+ process.on("exit", (code) => { // Node.js exits if no event handler is pending
+ if (code === 0 && !go.exited) {
+ // deadlock, make Go print error and stack traces
+ go._pendingEvent = { id: 0 };
+ go._resume();
+ }
+ });
+ return go.run(result.instance);
+}).catch((err) => {
+ console.error(err);
+ process.exit(1);
+});
