From 4ad9bd86430eb3ac705fccbbad0a86ddb542914b Mon Sep 17 00:00:00 2001
From: Ayke van Laethem <aykevanlaethem@gmail.com>
Date: Wed, 6 Mar 2019 17:53:47 +0100
Subject: [PATCH] wasm: ignore arguments and environment variables

The wasm_exec.js file copied from the main Go repository did write those
values to address 4096 in linear memory, which led to memory corruption
in linear memory. Remove these things for now, until they're actually
supported, if support is ever added.
---
 targets/wasm_exec.js | 44 ++------------------------------------------
 1 file changed, 2 insertions(+), 42 deletions(-)

diff --git a/targets/wasm_exec.js b/targets/wasm_exec.js
index 0fc92305..87522fa9 100644
--- a/targets/wasm_exec.js
+++ b/targets/wasm_exec.js
@@ -73,13 +73,6 @@
 
 	global.Go = class {
 		constructor() {
-			this.argv = ["js"];
-			this.env = {};
-			this.exit = (code) => {
-				if (code !== 0) {
-					console.warn("exit code:", code);
-				}
-			};
 			this._callbackTimeouts = new Map();
 			this._nextCallbackTimeoutID = 1;
 
@@ -342,36 +335,6 @@
 
 			const mem = new DataView(this._inst.exports.memory.buffer)
 
-			// 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(mem.buffer, offset, str.length + 1).set(encoder.encode(str + "\0"));
-				offset += str.length + (8 - (str.length % 8));
-				return ptr;
-			};
-
-			const argc = this.argv.length;
-
-			const argvPtrs = [];
-			this.argv.forEach((arg) => {
-				argvPtrs.push(strPtr(arg));
-			});
-
-			const keys = Object.keys(this.env).sort();
-			argvPtrs.push(keys.length);
-			keys.forEach((key) => {
-				argvPtrs.push(strPtr(`${key}=${this.env[key]}`));
-			});
-
-			const argv = offset;
-			argvPtrs.forEach((ptr) => {
-				mem.setUint32(offset, ptr, true);
-				mem.setUint32(offset + 4, 0, true);
-				offset += 8;
-			});
-
 			while (true) {
 				const callbackPromise = new Promise((resolve) => {
 					this._resolveCallbackPromise = () => {
@@ -381,7 +344,7 @@
 						setTimeout(resolve, 0); // make sure it is asynchronous
 					};
 				});
-				this._inst.exports.cwa_main(argc, argv);
+				this._inst.exports.cwa_main();
 				if (this.exited) {
 					break;
 				}
@@ -413,15 +376,12 @@
 	}
 
 	if (isNodeJS) {
-		if (process.argv.length < 3) {
+		if (process.argv.length != 3) {
 			process.stderr.write("usage: go_js_wasm_exec [wasm binary] [arguments]\n");
 			process.exit(1);
 		}
 
 		const go = new Go();
-		go.argv = process.argv.slice(2);
-		go.env = 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 callback is pending
 				if (code === 0 && !go.exited) {