Make tools re-compiling warnings scoped by toolsGopath (#1589)

* Make tools re-compiling warnings scoped by toolsGopath

When switching between workspaces with different goroot and toolsGopath
settings, the editor is suggesting that re-compiling tools is required
because the GOROOT state is global and not toolsGopath-aware.

This makes the global context a map keyed on toolsGopath.

* Apply pascal case to interface name

* Minor fixes

src/goMain.ts

@@ -66,36 +66,45 @@ export function activate(ctx: vscode.ExtensionContext): void {
 	let useLangServer = vscode.workspace.getConfiguration('go')['useLanguageServer'];
 	setGlobalState(ctx.globalState);
 
-	updateGoPathGoRootFromConfig().then(() => {
+	updateGoPathGoRootFromConfig().then(async () => {
 		const updateToolsCmdText = 'Update tools';
-		const prevGoroot = ctx.globalState.get('goroot');
-		const currentGoroot = process.env['GOROOT'];
-		if (prevGoroot !== currentGoroot && prevGoroot) {
-			vscode.window.showInformationMessage('Your goroot is different than before, a few Go tools may need recompiling', updateToolsCmdText).then(selected => {
+		interface GoInfo {
+			goroot: string;
+			version: string;
+		}
+		const toolsGoInfo: { [id: string]: GoInfo; } = ctx.globalState.get('toolsGoInfo') || {};
+		const toolsGopath = getToolsGopath() || getCurrentGoPath();
+		if (!toolsGoInfo[toolsGopath]) {
+			toolsGoInfo[toolsGopath] = { goroot: null, version: null };
+		}
+		const prevGoroot = toolsGoInfo[toolsGopath].goroot;
+		const currentGoroot: string = process.env['GOROOT'];
+		if (prevGoroot && prevGoroot !== currentGoroot) {
+			vscode.window.showInformationMessage(`Your current goroot (${currentGoroot}) is different than before (${prevGoroot}), a few Go tools may need recompiling`, updateToolsCmdText).then(selected => {
 				if (selected === updateToolsCmdText) {
 					installAllTools(true);
 				}
 			});
 		} else {
-			getGoVersion().then(currentVersion => {
-				if (currentVersion) {
-					const prevVersion = ctx.globalState.get('goVersion');
-					const currVersionString = `${currentVersion.major}.${currentVersion.minor}`;
-
-					if (prevVersion !== currVersionString) {
-						if (prevVersion) {
-							vscode.window.showInformationMessage('Your Go version is different than before, few Go tools may need re-compiling', updateToolsCmdText).then(selected => {
-								if (selected === updateToolsCmdText) {
-									installAllTools(true);
-								}
-							});
-						}
-						ctx.globalState.update('goVersion', currVersionString);
+			const currentVersion = await getGoVersion();
+			if (currentVersion) {
+				const prevVersion = toolsGoInfo[toolsGopath].version;
+				const currVersionString = `${currentVersion.major}.${currentVersion.minor}`;
+
+				if (prevVersion !== currVersionString) {
+					if (prevVersion) {
+						vscode.window.showInformationMessage('Your Go version is different than before, few Go tools may need re-compiling', updateToolsCmdText).then(selected => {
+							if (selected === updateToolsCmdText) {
+								installAllTools(true);
+							}
+						});
 					}
+					toolsGoInfo[toolsGopath].version = currVersionString;
 				}
-			});
+			}
 		}
-		ctx.globalState.update('goroot', currentGoroot);
+		toolsGoInfo[toolsGopath].goroot = currentGoroot;
+		ctx.globalState.update('toolsGoInfo', toolsGoInfo);
 
 		offerToInstallTools();
 		if (checkLanguageServer()) {