[objective_c] Fix older XCode builds (#2866)

Author: liamappelbe

.github/workflows/objective_c.yaml

@@ -87,11 +87,20 @@ jobs:
     defaults:
       run:
         working-directory: pkgs/objective_c/example/flutter_app
+    strategy:
+      fail-fast: false
+      matrix:
+        xcode_version: ["16.1", "26.1.1"]
+        ios_version: ["18.1"]
     steps:
       - uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3
       - uses: subosito/flutter-action@fd55f4c5af5b953cc57a2be44cb082c8f6635e8e
         with:
           channel: stable
+      - name: Select the XCode version
+        run: sudo xcode-select -switch /Applications/Xcode_${{ matrix.xcode_version }}.app/Contents/Developer
+      - name: Install iOS SDK
+        run: xcodebuild -downloadPlatform iOS -buildVersion ${{ matrix.ios_version }}
       - name: Install dependencies
         run: flutter pub get
       - name: Build the example app for macos

pkgs/objective_c/CHANGELOG.md

@@ -1,3 +1,8 @@
+## 9.2.2
+
+- Fix a [bug](https://github.com/dart-lang/http/issues/1861) where the build
+  failed on older versions of XCode.
+
 ## 9.2.1
 
 - Fix [bug](https://github.com/dart-lang/native/issues/2824) where the build

pkgs/objective_c/hook/build.dart

@@ -11,13 +11,11 @@ import 'package:native_toolchain_c/src/cbuilder/compiler_resolver.dart';
 
 const objCFlags = ['-x', 'objective-c', '-fobjc-arc'];
 
-String sdkPath = firstLineOfStdout('xcrun', ['--show-sdk-path']);
-
 const assetName = 'objective_c.dylib';
 
 // TODO(https://github.com/dart-lang/native/issues/2272): Remove this from the
 // main build.
-const extraCFiles = ['test/util.c'];
+const testFiles = ['test/util.c'];
 
 final logger = Logger('')
   ..level = Level.INFO
@@ -33,20 +31,21 @@ void main(List<String> args) async {
     }
 
     const supportedOSs = {OS.iOS, OS.macOS};
-    final os = input.config.code.targetOS;
+    final codeConfig = input.config.code;
+    final os = codeConfig.targetOS;
     if (!supportedOSs.contains(os)) {
       // Nothing to do.
       return;
     }
 
-    if (input.config.code.linkModePreference == LinkModePreference.static) {
+    if (codeConfig.linkModePreference == LinkModePreference.static) {
       throw UnsupportedError('LinkModePreference.static is not supported.');
     }
 
     final packageName = input.packageName;
     final assetPath = input.outputDirectory.resolve(assetName);
     final srcDir = Directory.fromUri(input.packageRoot.resolve('src/'));
-    final target = toTargetTriple(input.config.code);
+    final target = toTargetTriple(codeConfig);
 
     final cFiles = <String>[];
     final mFiles = <String>[];
@@ -60,9 +59,15 @@ void main(List<String> args) async {
       }
     }
 
-    cFiles.addAll(extraCFiles.map((f) => input.packageRoot.resolve(f).path));
+    // Only include the test utils on mac OS. They use memory functions that
+    // aren't supported on iOS, like mach_vm_region. We don't need them on iOS
+    // anyway since we only run memory tests on mac.
+    if (os == OS.macOS) {
+      cFiles.addAll(testFiles.map((f) => input.packageRoot.resolve(f).path));
+    }
 
-    final cFlags = <String>['-isysroot', sdkPath, '-target', target];
+    final sysroot = sdkPath(codeConfig);
+    final cFlags = <String>['-isysroot', sysroot, '-target', target];
     final mFlags = [...cFlags, ...objCFlags];
     final linkFlags = cFlags;
 
@@ -142,6 +147,21 @@ class Builder {
   }
 }
 
+String sdkPath(CodeConfig codeConfig) {
+  final String target;
+  if (codeConfig.targetOS == OS.iOS) {
+    if (codeConfig.iOS.targetSdk == IOSSdk.iPhoneOS) {
+      target = 'iphoneos';
+    } else {
+      target = 'iphonesimulator';
+    }
+  } else {
+    assert(codeConfig.targetOS == OS.macOS);
+    target = 'macosx';
+  }
+  return firstLineOfStdout('xcrun', ['--show-sdk-path', '--sdk', target]);
+}
+
 String firstLineOfStdout(String cmd, List<String> args) {
   final result = Process.runSync(cmd, args);
   assert(result.exitCode == 0);

pkgs/objective_c/pubspec.yaml

@@ -4,7 +4,7 @@
 
 name: objective_c
 description: 'A library to access Objective C from Flutter that acts as a support library for package:ffigen.'
-version: 9.2.1
+version: 9.2.2
 repository: https://github.com/dart-lang/native/tree/main/pkgs/objective_c
 issue_tracker: https://github.com/dart-lang/native/issues?q=is%3Aissue+is%3Aopen+label%3Apackage%3Aobjective_c