package.json: add go.toolsManagement.go

This new setting allows users to specify the go command
for tools installation.

The go version selected for go.toolsManagement.go is not yet
used for version check in goInstallTools.ts inspectGoToolVersion yet.

For #825

Change-Id: Ic7a401b2089fe1e412ede32be474ee0f309c32d4
Reviewed-on: https://go-review.googlesource.com/c/vscode-go/+/387956
Trust: Hyang-Ah Hana Kim <hyangah@gmail.com>
Reviewed-by: Suzy Mueller <suzmue@golang.org>

Author: hyangah

Diff for: docs/settings.md

@@ -454,6 +454,11 @@ Allowed Options:
 
 
 Default: `"proxy"`
+### `go.toolsManagement.go`
+
+The path to the `go` binary used to install the Go tools. If it's empty, the same `go` binary chosen for the project will be used for tool installation.
+
+Default: `""`
 ### `go.trace.server`
 
 Trace the communication between VS Code and the Go language server.<br/>

Diff for: package.json

@@ -116,7 +116,8 @@
         "go.goroot",
         "go.inferGopath",
         "go.toolsGopath",
-        "go.toolsEnvVars"
+        "go.toolsEnvVars",
+        "go.toolsManagement.go"
       ]
     }
   },
@@ -1528,6 +1529,12 @@
           "description": "The logging level the extension logs at, defaults to 'error'",
           "scope": "machine-overridable"
         },
+        "go.toolsManagement.go": {
+          "type": "string",
+          "default": "",
+          "description": "The path to the `go` binary used to install the Go tools. If it's empty, the same `go` binary chosen for the project will be used for tool installation.",
+          "scope": "machine-overridable"
+        },
         "go.toolsManagement.checkForUpdates": {
           "type": "string",
           "default": "proxy",

Diff for: src/goEnvironmentStatus.ts

@@ -213,18 +213,13 @@ async function downloadGo(goOption: GoEnvironmentOption): Promise<GoEnvironmentO
 			outputChannel.clear();
 			outputChannel.show();
 			outputChannel.appendLine(`go install ${goOption.binpath}@latest`);
-			const result = await installTool(
-				{
-					name: newExecutableName,
-					importPath: goOption.binpath,
-					modulePath: goOption.binpath,
-					description: newExecutableName,
-					isImportant: false
-				},
-				await getGoVersion(),
-				toolInstallationEnvironment(),
-				true
-			);
+			const result = await installTool({
+				name: newExecutableName,
+				importPath: goOption.binpath,
+				modulePath: goOption.binpath,
+				description: newExecutableName,
+				isImportant: false
+			});
 			if (result) {
 				outputChannel.appendLine(`Error installing ${goOption.binpath}: ${result}`);
 				throw new Error('Could not install ${goOption.binpath}');

Diff for: src/goInstallTools.ts

@@ -39,7 +39,7 @@ import {
 	GoVersion,
 	rmdirRecursive
 } from './util';
-import { correctBinname, envPath, getCurrentGoRoot, setCurrentGoRoot } from './utils/pathUtils';
+import { correctBinname, envPath, executableFileExists, getCurrentGoRoot, setCurrentGoRoot } from './utils/pathUtils';
 import util = require('util');
 import vscode = require('vscode');
 
@@ -96,12 +96,30 @@ export async function installAllTools(updateExistingToolsOnly = false) {
 	);
 }
 
+export async function getGoForInstall(goVersion?: GoVersion, silent?: boolean): Promise<GoVersion> {
+	const configured = getGoConfig().get<string>('toolsManagement.go');
+	if (!configured) {
+		return goVersion;
+	}
+	if (executableFileExists(configured)) {
+		const go = await getGoVersion(configured);
+		if (go) return go;
+	}
+	if (!silent) {
+		outputChannel.appendLine(
+			`Ignoring misconfigured 'go.toolsManagement.go' (${configured}). Provide a valid Go command.`
+		);
+	}
+	return goVersion;
+}
+
 /**
  * Installs given array of missing tools. If no input is given, the all tools are installed
  *
  * @param missing array of tool names and optionally, their versions to be installed.
  *                If a tool's version is not specified, it will install the latest.
- * @param goVersion version of Go that affects how to install the tool. (e.g. modules vs legacy GOPATH mode)
+ * @param goVersion version of Go used in the project. If go used for tools installation
+ *                is not configured or misconfigured, this is used as a fallback.
  * @returns a list of tools that failed to install.
  */
 export async function installTools(
@@ -118,6 +136,7 @@ export async function installTools(
 	}
 	outputChannel.clear();
 
+	const goForInstall = await getGoForInstall(goVersion);
 	const envForTools = toolInstallationEnvironment();
 	const toolsGopath = envForTools['GOPATH'];
 	let envMsg = `Tools environment: GOPATH=${toolsGopath}`;
@@ -162,7 +181,7 @@ export async function installTools(
 	for (const tool of missing) {
 		const modulesOffForTool = modulesOff;
 
-		const failed = await installTool(tool, goVersion, envForTools, !modulesOffForTool);
+		const failed = await installToolWithGo(tool, goForInstall, envForTools, !modulesOffForTool);
 		if (failed) {
 			failures.push({ tool, reason: failed });
 		} else if (tool.name === 'gopls') {
@@ -201,9 +220,17 @@ async function tmpDirForToolInstallation() {
 	return toolsTmpDir;
 }
 
-export async function installTool(
+// installTool installs the specified tool.
+export async function installTool(tool: ToolAtVersion): Promise<string> {
+	const goVersion = await getGoForInstall(await getGoVersion());
+	const envForTools = toolInstallationEnvironment();
+
+	return await installToolWithGo(tool, goVersion, envForTools, true);
+}
+
+async function installToolWithGo(
 	tool: ToolAtVersion,
-	goVersion: GoVersion,
+	goVersion: GoVersion, // go version to be used for installation.
 	envForTools: NodeJS.Dict<string>,
 	modulesOn: boolean
 ): Promise<string> {