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

@@ -111,7 +111,9 @@ 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) {
-    localsBuffer.writeln('export "$line"');
+    if (!line.contains('[')) { // Exported conditional Xcode build settings do not work.
+      localsBuffer.writeln('export "$line"');
+    }
   }
 
   final File generatedModuleBuildPhaseScript = useMacOSConfig
@@ -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(