Exclude arm64 from valid iOS simulators (#73828)

dev/integration_tests/ios_host_app/Host.xcodeproj/project.pbxproj

@@ -447,6 +447,7 @@
 				DEBUG_INFORMATION_FORMAT = dwarf;
 				ENABLE_STRICT_OBJC_MSGSEND = YES;
 				ENABLE_TESTABILITY = YES;
+				"EXCLUDED_ARCHS[sdk=iphonesimulator*]" = arm64;
 				GCC_C_LANGUAGE_STANDARD = gnu11;
 				GCC_DYNAMIC_NO_PIC = NO;
 				GCC_NO_COMMON_BLOCKS = YES;

dev/integration_tests/ios_host_app_swift/Host.xcodeproj/project.pbxproj

@@ -3,7 +3,7 @@
 	archiveVersion = 1;
 	classes = {
 	};
-	objectVersion = 50;
+	objectVersion = 51;
 	objects = {
 
 /* Begin PBXBuildFile section */
@@ -56,7 +56,6 @@
 				5EF266650049BC10ECFD8C86 /* Pods-Host.debug.xcconfig */,
 				A412A4193ADC80C963762A82 /* Pods-Host.release.xcconfig */,
 			);
-			name = Pods;
 			path = Pods;
 			sourceTree = "<group>";
 		};
@@ -200,7 +199,7 @@
 			name = "[CP-User] Run Flutter Build hello Script";
 			runOnlyForDeploymentPostprocessing = 0;
 			shellPath = /bin/sh;
-			shellScript = "set -e\nset -u\nsource \"${SRCROOT}/../hello/.ios/Flutter/flutter_export_environment.sh\"\n\"$FLUTTER_ROOT\"/packages/flutter_tools/bin/xcode_backend.sh build";
+			shellScript = "set -e\nset -u\nsource \"${SRCROOT}/../hello/.ios/Flutter/flutter_export_environment.sh\"\n\"$FLUTTER_ROOT\"/packages/flutter_tools/bin/xcode_backend.sh build\n";
 		};
 		96286B727046BA8457A788D0 /* [CP] Copy Pods Resources */ = {
 			isa = PBXShellScriptBuildPhase;
@@ -391,6 +390,7 @@
 			buildSettings = {
 				ASSETCATALOG_COMPILER_APPICON_NAME = AppIcon;
 				CODE_SIGN_STYLE = Automatic;
+				"EXCLUDED_ARCHS[sdk=iphonesimulator*]" = arm64;
 				INFOPLIST_FILE = Host/Info.plist;
 				LD_RUNPATH_SEARCH_PATHS = (
 					"$(inherited)",

packages/flutter_tools/bin/podhelper.rb

@@ -68,6 +68,9 @@ def flutter_additional_ios_build_settings(target)
     # When deleted, the deployment version will inherit from the higher version derived from the 'Runner' target.
     # If the pod only supports a higher version, do not delete to correctly produce an error.
     build_configuration.build_settings.delete 'IPHONEOS_DEPLOYMENT_TARGET' if inherit_deployment_target
+
+    # Apple Silicon ARM simulators not yet supported.
+    build_configuration.build_settings['EXCLUDED_ARCHS[sdk=iphonesimulator*]'] = 'arm64 i386'
   end
 end
 

packages/flutter_tools/lib/src/ios/mac.dart

@@ -255,7 +255,7 @@ Future<XcodeBuildResult> buildXcodeProject({
     if (buildForDevice) {
       buildCommands.addAll(<String>['-sdk', 'iphoneos']);
     } else {
-      buildCommands.addAll(<String>['-sdk', 'iphonesimulator', '-arch', 'x86_64']);
+      buildCommands.addAll(<String>['-sdk', 'iphonesimulator']);
     }
   }
 

packages/flutter_tools/lib/src/ios/xcodeproj.dart

@@ -111,8 +111,10 @@ void _updateGeneratedEnvironmentVariablesScript({
   localsBuffer.writeln('#!/bin/sh');
   localsBuffer.writeln('# This is a generated file; do not edit or check into version control.');
   for (final String line in xcodeBuildSettings) {
+    if (!line.contains('[')) { // Exported conditional Xcode build settings do not work.
       localsBuffer.writeln('export "$line"');
     }
+  }
 
   final File generatedModuleBuildPhaseScript = useMacOSConfig
     ? project.macos.generatedEnvironmentVariableExportScript
@@ -226,6 +228,9 @@ List<String> _xcodeBuildSettingsLines({
   if (useMacOSConfig) {
     // ARM not yet supported https://github.com/flutter/flutter/issues/69221
     xcodeBuildSettings.add('EXCLUDED_ARCHS=arm64');
+  } else {
+    // Apple Silicon ARM simulators not yet supported.
+    xcodeBuildSettings.add('EXCLUDED_ARCHS[sdk=iphonesimulator*]=arm64 i386');
   }
 
   for (final MapEntry<String, String> config in buildInfo.toEnvironmentConfig().entries) {

packages/flutter_tools/test/general.shard/ios/xcodeproj_test.dart

@@ -671,12 +671,14 @@ Information about project "Runner":
 
       final String contents = config.readAsStringSync();
       expect(contents.contains('ARCHS=armv7'), isTrue);
+      expect(contents.contains('EXCLUDED_ARCHS[sdk=iphonesimulator*]=arm64 i386'), isTrue);
 
       final File buildPhaseScript = fs.file('path/to/project/ios/Flutter/flutter_export_environment.sh');
       expect(buildPhaseScript.existsSync(), isTrue);
 
       final String buildPhaseScriptContents = buildPhaseScript.readAsStringSync();
       expect(buildPhaseScriptContents.contains('ARCHS=armv7'), isTrue);
+      expect(buildPhaseScriptContents.contains('EXCLUDED_ARCHS'), isFalse);
     });
 
     testUsingOsxContext('sets TRACK_WIDGET_CREATION=true when trackWidgetCreation is true', () async {

packages/flutter_tools/test/integration.shard/build_ios_config_only_test.dart

@@ -43,10 +43,7 @@ void main() {
 
     // Config is updated if command succeeded.
     expect(generatedConfig, exists);
-    expect(generatedConfig.readAsStringSync(), allOf(
-      contains('DART_OBFUSCATION=true'),
-      isNot(contains('EXCLUDED_ARCHS')),
-    ));
+    expect(generatedConfig.readAsStringSync(), contains('DART_OBFUSCATION=true'));
 
     // file that only exists if app was fully built.
     final File frameworkPlist = fileSystem.file(

packages/flutter_tools/test/integration.shard/ios_content_validation_test.dart

@@ -14,13 +14,40 @@ import '../src/darwin_common.dart';
 import 'test_utils.dart';
 
 void main() {
-  for (final BuildMode buildMode in <BuildMode>[BuildMode.debug, BuildMode.release]) {
-    group(buildMode.name, () {
+  group('iOS app validation', () {
     String flutterRoot;
     String projectRoot;
     String flutterBin;
     Directory tempDir;
 
+    setUpAll(() {
+      flutterRoot = getFlutterRoot();
+      tempDir = createResolvedTempDirectorySync('ios_content_validation.');
+      flutterBin = fileSystem.path.join(
+        flutterRoot,
+        'bin',
+        'flutter',
+      );
+
+      processManager.runSync(<String>[
+        flutterBin,
+        ...getLocalEngineArguments(),
+        'create',
+        '--platforms=ios',
+        '-i',
+        'objc',
+        'hello',
+      ], workingDirectory: tempDir.path);
+
+      projectRoot = tempDir.childDirectory('hello').path;
+    });
+
+    tearDownAll(() {
+      tryToDelete(tempDir);
+    });
+
+    for (final BuildMode buildMode in <BuildMode>[BuildMode.debug, BuildMode.release]) {
+      group('build in ${buildMode.name} mode', () {
         Directory buildPath;
         Directory outputApp;
         Directory frameworkDirectory;
@@ -79,10 +106,6 @@ void main() {
           outputAppFrameworkBinary = outputAppFramework.childFile('App');
         });
 
-      tearDownAll(() {
-        tryToDelete(tempDir);
-      });
-
         testWithoutContext('flutter build ios builds a valid app', () {
           // Should only contain Flutter.framework and App.framework.
           expect(frameworkDirectory.listSync().length, 2);
@@ -205,9 +228,44 @@ void main() {
           ]);
           expect(grepResult.stdout, isNot(contains('matches')));
         });
+      });
+    }
+
+    testWithoutContext('build for simulator with all available architectures', () {
+      final ProcessResult buildSimulator = processManager.runSync(
+        <String>[
+          flutterBin,
+          ...getLocalEngineArguments(),
+          'build',
+          'ios',
+          '--simulator',
+          '--verbose',
+          '--no-codesign',
+        ],
+        workingDirectory: projectRoot,
+        environment: <String, String>{
+          'FLUTTER_XCODE_ONLY_ACTIVE_ARCH': 'NO',
         },
-      skip: !platform.isMacOS,
-      timeout: const Timeout(Duration(minutes: 5)),
       );
-  }
+      // This test case would fail if arm64 or i386 were not excluded.
+      expect(buildSimulator.exitCode, 0);
+
+      final File simulatorAppFrameworkBinary = fileSystem.file(fileSystem.path.join(
+        projectRoot,
+        'build',
+        'ios',
+        'iphonesimulator',
+        'Runner.app',
+        'Frameworks',
+        'App.framework',
+        'App',
+      ));
+      expect(simulatorAppFrameworkBinary, exists);
+      final ProcessResult archs = processManager.runSync(
+        <String>['file', simulatorAppFrameworkBinary.path],
+      );
+      expect(archs.stdout, contains('Mach-O 64-bit dynamically linked shared library x86_64'));
+    });
+  }, skip: !platform.isMacOS, timeout: const Timeout(Duration(minutes: 5))
+  );
 }