standalone: add iOS smoke test - test ability to target iOS with Zig

test/standalone.zig

@@ -245,6 +245,10 @@ pub const build_cases = [_]BuildCase{
         .build_root = "test/standalone/compiler_rt_panic",
         .import = @import("standalone/compiler_rt_panic/build.zig"),
     },
+    .{
+        .build_root = "test/standalone/ios",
+        .import = @import("standalone/ios/build.zig"),
+    },
 };
 
 const std = @import("std");

test/standalone/ios/build.zig

@@ -0,0 +1,37 @@
+const std = @import("std");
+
+pub const requires_symlinks = true;
+pub const requires_ios_sdk = true;
+
+pub fn build(b: *std.Build) void {
+    const test_step = b.step("test", "Test it");
+    b.default_step = test_step;
+
+    const optimize: std.builtin.OptimizeMode = .Debug;
+    const target: std.zig.CrossTarget = .{
+        .cpu_arch = .aarch64,
+        .os_tag = .ios,
+    };
+    const target_info = std.zig.system.NativeTargetInfo.detect(target) catch @panic("couldn't detect native target");
+    const sdk = std.zig.system.darwin.getSdk(b.allocator, target_info.target) orelse @panic("no iOS SDK found");
+    b.sysroot = sdk.path;
+
+    const exe = b.addExecutable(.{
+        .name = "main",
+        .optimize = optimize,
+        .target = target,
+    });
+    exe.addCSourceFile(.{ .file = .{ .path = "main.m" }, .flags = &.{} });
+    exe.addSystemIncludePath(.{ .path = b.pathJoin(&.{ sdk.path, "/usr/include" }) });
+    exe.addSystemFrameworkPath(.{ .path = b.pathJoin(&.{ sdk.path, "/System/Library/Frameworks" }) });
+    exe.addLibraryPath(.{ .path = b.pathJoin(&.{ sdk.path, "/usr/lib" }) });
+    exe.linkFramework("Foundation");
+    exe.linkFramework("UIKit");
+    exe.linkLibC();
+
+    const check = exe.checkObject();
+    check.checkStart();
+    check.checkExact("cmd BUILD_VERSION");
+    check.checkExact("platform IOS");
+    test_step.dependOn(&check.step);
+}

test/standalone/ios/main.m

@@ -0,0 +1,34 @@
+#import <UIKit/UIKit.h>
+
+@interface AppDelegate : UIResponder <UIApplicationDelegate>
+@property (strong, nonatomic) UIWindow *window;
+@end
+
+int main() {
+  @autoreleasepool {
+    return UIApplicationMain(0, nil, nil, NSStringFromClass([AppDelegate class]));
+  }
+}
+
+@implementation AppDelegate
+
+- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(id)options {
+  CGRect mainScreenBounds = [[UIScreen mainScreen] bounds];
+  self.window = [[UIWindow alloc] initWithFrame:mainScreenBounds];
+  UIViewController *viewController = [[UIViewController alloc] init];
+  viewController.view.frame = mainScreenBounds;
+
+  NSString* msg = @"Hello world";
+
+  UILabel *label = [[UILabel alloc] initWithFrame:mainScreenBounds];
+  [label setText:msg];
+  [viewController.view addSubview: label];
+
+  self.window.rootViewController = viewController;
+
+  [self.window makeKeyAndVisible];
+
+  return YES;
+}
+
+@end