Add quick switcher between iOS and macOS targets

package.json

@@ -44,6 +44,11 @@
         "title": "Clean Build",
         "category": "Swift"
       },
+      {
+        "command": "swift.switchPlatform",
+        "title": "Switch Target",
+        "category": "Swift"
+      },
       {
         "command": "swift.resetPackage",
         "title": "Reset Package Dependencies",
@@ -245,6 +250,10 @@
           "command": "swift.cleanBuild",
           "when": "swift.hasPackage"
         },
+        {
+          "command": "swift.switchPlatform",
+          "when": "isMac"
+        },
         {
           "command": "swift.resetPackage",
           "when": "swift.hasPackage"

src/commands.ts

@@ -19,8 +19,11 @@ import { FolderEvent, WorkspaceContext } from "./WorkspaceContext";
 import { createSwiftTask, SwiftTaskProvider } from "./SwiftTaskProvider";
 import { FolderContext } from "./FolderContext";
 import { PackageNode } from "./ui/PackageDependencyProvider";
+import { withQuickPick } from "./ui/QuickPick";
 import { execSwift } from "./utilities/utilities";
 import { Version } from "./utilities/version";
+import { DarwinCompatibleTarget, SwiftToolchain } from "./toolchain/toolchain";
+import configuration from "./configuration";
 
 /**
  * References:
@@ -428,6 +431,34 @@ function openInExternalEditor(packageNode: PackageNode) {
     }
 }
 
+interface DarwinQuickPickTarget extends vscode.QuickPickItem {
+    value: DarwinCompatibleTarget;
+    label: string;
+}
+
+/**
+ * Switches the target SDK to the platform selected in a QuickPick UI.
+ */
+async function switchPlatform() {
+    const onSelect = async (picked: DarwinQuickPickTarget) => {
+        const sdkForTarget = await SwiftToolchain.getSdkForTarget(picked.value);
+        if (sdkForTarget) {
+            configuration.sdk = sdkForTarget;
+        } else {
+            vscode.window.showErrorMessage("Unable to obtain requested SDK path");
+        }
+    };
+
+    await withQuickPick<DarwinQuickPickTarget>(
+        "Select a new target",
+        [
+            { value: DarwinCompatibleTarget.macOS, label: "macOS" },
+            { value: DarwinCompatibleTarget.iOS, label: "iOS" },
+        ],
+        onSelect
+    );
+}
+
 function updateAfterError(result: boolean, folderContext: FolderContext) {
     const triggerResolvedUpdatedEvent = folderContext.hasResolveErrors;
     // set has resolve errors flag
@@ -450,6 +481,8 @@ export function register(ctx: WorkspaceContext) {
         ),
         vscode.commands.registerCommand("swift.updateDependencies", () => updateDependencies(ctx)),
         vscode.commands.registerCommand("swift.cleanBuild", () => cleanBuild(ctx)),
+        // Note: This is only available on macOS (gated in `package.json`) because its the only OS that has the iOS SDK available.
+        vscode.commands.registerCommand("swift.switchPlatform", () => switchPlatform()),
         vscode.commands.registerCommand("swift.resetPackage", () => resetPackage(ctx)),
         vscode.commands.registerCommand("swift.runSingle", () => runSingleFile(ctx)),
         vscode.commands.registerCommand("swift.openPackage", () => openPackage(ctx)),

src/configuration.ts

@@ -73,6 +73,9 @@ const configuration = {
     get sdk(): string {
         return vscode.workspace.getConfiguration("swift").get<string>("SDK", "");
     },
+    set sdk(value: string) {
+        vscode.workspace.getConfiguration("swift").update("SDK", value);
+    },
     /** swift build arguments */
     get buildArguments(): string[] {
         return vscode.workspace.getConfiguration("swift").get<string[]>("buildArguments", []);

src/sourcekit-lsp/LanguageClientManager.ts

@@ -23,6 +23,7 @@ import {
     swiftDriverSDKFlags,
     buildPathFlags,
     swiftRuntimeEnv,
+    swiftDriverTargetFlags,
 } from "../utilities/utilities";
 import { Version } from "../utilities/version";
 import { FolderEvent, WorkspaceContext } from "../WorkspaceContext";
@@ -345,6 +346,7 @@ export class LanguageClientManager {
             serverPathConfig.length > 0 ? serverPathConfig : getSwiftExecutable("sourcekit-lsp");
         const sdkArguments = [
             ...swiftDriverSDKFlags(true),
+            ...swiftDriverTargetFlags(true),
             ...filterArguments(
                 configuration.buildArguments.concat(buildPathFlags()),
                 LanguageClientManager.buildArgumentFilter

src/toolchain/toolchain.ts

@@ -46,6 +46,15 @@ interface SwiftTargetInfo {
     [name: string]: string | object | undefined;
 }
 
+/**
+ * A Swift compilation target that can be compiled to
+ * from macOS. These are similar to XCode's target list.
+ */
+export enum DarwinCompatibleTarget {
+    iOS,
+    macOS,
+}
+
 export class SwiftToolchain {
     constructor(
         public swiftFolderPath: string,
@@ -195,8 +204,8 @@ export class SwiftToolchain {
                 if (process.env.SDKROOT) {
                     return process.env.SDKROOT;
                 }
-                const { stdout } = await execFile("xcrun", ["--sdk", "macosx", "--show-sdk-path"]);
-                return path.join(stdout.trimEnd());
+
+                return this.getSdkForTarget(DarwinCompatibleTarget.macOS);
             }
             case "win32": {
                 return process.env.SDKROOT;
@@ -205,6 +214,30 @@ export class SwiftToolchain {
         return undefined;
     }
 
+    /**
+     * @param target Target to obtain the SDK path for
+     * @returns path to the SDK for the target
+     */
+    public static async getSdkForTarget(
+        target: DarwinCompatibleTarget
+    ): Promise<string | undefined> {
+        let sdkType: string;
+        switch (target) {
+            case DarwinCompatibleTarget.macOS:
+                sdkType = "macosx";
+                break;
+            case DarwinCompatibleTarget.iOS:
+                sdkType = "iphoneos";
+                break;
+        }
+
+        // Include custom variables so that non-standard XCode installs can be better supported.
+        const { stdout } = await execFile("xcrun", ["--sdk", sdkType, "--show-sdk-path"], {
+            env: { ...process.env, ...configuration.swiftEnvironmentVariables },
+        });
+        return path.join(stdout.trimEnd());
+    }
+
     /**
      * @returns path to custom SDK
      */

src/ui/QuickPick.ts

@@ -0,0 +1,46 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the VSCode Swift open source project
+//
+// Copyright (c) 2022 the VSCode Swift project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+// See CONTRIBUTORS.txt for the list of VSCode Swift project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+
+import * as vscode from "vscode";
+
+/**
+ * Displays a QuickPick UI with the parameters and passes the result
+ * to the provided closure.
+ */
+export async function withQuickPick<T extends vscode.QuickPickItem>(
+    placeholder: string,
+    options: T[],
+    onSelect: (picked: T) => Promise<void>
+) {
+    const picker = vscode.window.createQuickPick<T>();
+
+    picker.placeholder = placeholder;
+    picker.items = options;
+
+    picker.show();
+
+    const pickedItem = await new Promise<T | undefined>(resolve => {
+        picker.onDidAccept(() => resolve(picker.selectedItems[0]));
+        picker.onDidHide(() => resolve(undefined));
+    });
+
+    picker.busy = true;
+
+    if (pickedItem) {
+        await onSelect(pickedItem);
+        picker.busy = false;
+    }
+
+    picker.dispose();
+}

src/utilities/utilities.ts

@@ -251,6 +251,36 @@ export function swiftDriverSDKFlags(indirect = false): string[] {
     return indirect ? args.flatMap(arg => ["-Xswiftc", arg]) : args;
 }
 
+/**
+ * Get target flags for swiftc
+ *
+ * @param indirect whether to pass the flags by -Xswiftc
+ */
+export function swiftDriverTargetFlags(indirect = false): string[] {
+    const IPHONE_SDK_KIND = "iPhoneOS";
+
+    let args: string[] = [];
+
+    if (configuration.sdk === "") {
+        return args;
+    }
+
+    const sdkKindParts = configuration.sdk.split("/");
+    const sdkKind = sdkKindParts[sdkKindParts.length - 1];
+    if (sdkKind.includes(IPHONE_SDK_KIND)) {
+        // Obtain the iOS version of the SDK.
+        const version = sdkKind.substring(
+            // Trim the prefix
+            sdkKind.length - IPHONE_SDK_KIND.length,
+            // Trim the `.sdk` suffix
+            sdkKind.length - 4
+        );
+        args = ["-target", `arm64-apple-ios${version}`];
+    }
+
+    return indirect ? args.flatMap(arg => ["-Xswiftc", arg]) : args;
+}
+
 /**
  * Get the file name of executable
  *