Generate ELF shared libraries and allow multi-abi libs in APKs and App bundles (#33696)

* Gradle generates ELF shared libraries instead of AOT snapshots.
* `flutter build apk/appbundle` supports multiple `--target-platform` and defaults to `android-arm` and `android-arm64`.
*  `flutter build apk` now has a flag called `--split-per-abi`.

dev/devicelab/pubspec.yaml

@@ -5,7 +5,7 @@ homepage: https://github.com/flutter/flutter
 
 environment:
   # The pub client defaults to an <2.0.0 sdk constraint which we need to explicitly overwrite.
-  sdk: ">=2.2.2 <3.0.0"
+  sdk: ">=2.3.0 <3.0.0"
 
 dependencies:
   args: 1.5.2

packages/flutter_tools/lib/src/android/android_device.dart

@@ -388,18 +388,27 @@ class AndroidDevice extends Device {
     if (!await _checkForSupportedAdbVersion() || !await _checkForSupportedAndroidVersion())
       return LaunchResult.failed();
 
-    final TargetPlatform devicePlatform = await targetPlatform;
-    if (!(devicePlatform == TargetPlatform.android_arm ||
-          devicePlatform == TargetPlatform.android_arm64) &&
-        !(debuggingOptions.buildInfo.isDebug ||
-          debuggingOptions.buildInfo.isDynamic)) {
-      printError('Profile and release builds are only supported on ARM targets.');
+
+    if (!debuggingOptions.buildInfo.isDebug &&
+          !debuggingOptions.buildInfo.isDynamic) {
+      printError('Profile and release builds are only supported.');
       return LaunchResult.failed();
     }
 
-    BuildInfo buildInfo = debuggingOptions.buildInfo;
-    if (buildInfo.targetPlatform == null && devicePlatform == TargetPlatform.android_arm64)
-      buildInfo = buildInfo.withTargetPlatform(TargetPlatform.android_arm64);
+    final TargetPlatform devicePlatform = await targetPlatform;
+
+    AndroidArch androidArch;
+    switch (devicePlatform) {
+      case TargetPlatform.android_arm:
+        androidArch = AndroidArch.armeabi_v7a;
+        break;
+      case TargetPlatform.android_arm64:
+        androidArch = AndroidArch.arm64_v8a;
+        break;
+      default:
+        printError('ARM targets are only supported.');
+        return LaunchResult.failed();
+    }
 
     if (!prebuiltApplication || androidSdk.licensesAvailable && androidSdk.latestVersion == null) {
       printTrace('Building APK');
@@ -407,7 +416,9 @@ class AndroidDevice extends Device {
       await buildApk(
           project: project,
           target: mainPath,
-          buildInfo: buildInfo,
+          androidBuildInfo: AndroidBuildInfo(debuggingOptions.buildInfo,
+            targetArchs: <AndroidArch>[androidArch]
+          ),
       );
       // Package has been built, so we can get the updated application ID and
       // activity name from the .apk.

packages/flutter_tools/lib/src/android/apk.dart

@@ -16,7 +16,7 @@ import 'gradle.dart';
 Future<void> buildApk({
   @required FlutterProject project,
   @required String target,
-  BuildInfo buildInfo = BuildInfo.debug,
+  @required AndroidBuildInfo androidBuildInfo,
 }) async {
   if (!project.android.isUsingGradle) {
     throwToolExit(
@@ -33,7 +33,7 @@ Future<void> buildApk({
 
   await buildGradleProject(
     project: project,
-    buildInfo: buildInfo,
+    androidBuildInfo: androidBuildInfo,
     target: target,
     isBuildingBundle: false,
   );

packages/flutter_tools/lib/src/android/app_bundle.dart

@@ -17,7 +17,7 @@ import 'gradle.dart';
 Future<void> buildAppBundle({
   @required FlutterProject project,
   @required String target,
-  BuildInfo buildInfo = BuildInfo.debug,
+  @required AndroidBuildInfo androidBuildInfo,
 }) async {
   if (!project.android.isUsingGradle) {
     throwToolExit(
@@ -42,7 +42,7 @@ Future<void> buildAppBundle({
 
   return buildGradleProject(
     project: project,
-    buildInfo: buildInfo,
+    androidBuildInfo: androidBuildInfo,
     target: target,
     isBuildingBundle: true,
   );

packages/flutter_tools/lib/src/android/gradle.dart

@@ -15,6 +15,7 @@ import '../base/logger.dart';
 import '../base/os.dart';
 import '../base/platform.dart';
 import '../base/process.dart';
+import '../base/terminal.dart';
 import '../base/utils.dart';
 import '../build_info.dart';
 import '../cache.dart';
@@ -318,7 +319,7 @@ void _exitIfNoAndroidSdk() {
 
 Future<void> buildGradleProject({
   @required FlutterProject project,
-  @required BuildInfo buildInfo,
+  @required AndroidBuildInfo androidBuildInfo,
   @required String target,
   @required bool isBuildingBundle,
 }) async {
@@ -330,7 +331,7 @@ Future<void> buildGradleProject({
   // and can be overwritten with flutter build command.
   // The default Gradle script reads the version name and number
   // from the local.properties file.
-  updateLocalProperties(project: project, buildInfo: buildInfo);
+  updateLocalProperties(project: project, buildInfo: androidBuildInfo.buildInfo);
 
   final String gradle = await _ensureGradle(project);
 
@@ -342,7 +343,7 @@ Future<void> buildGradleProject({
     case FlutterPluginVersion.managed:
       // Fall through. Managed plugin builds the same way as plugin v2.
     case FlutterPluginVersion.v2:
-      return _buildGradleProjectV2(project, gradle, buildInfo, target, isBuildingBundle);
+      return _buildGradleProjectV2(project, gradle, androidBuildInfo, target, isBuildingBundle);
   }
 }
 
@@ -391,11 +392,12 @@ String _calculateSha(File file) {
 Future<void> _buildGradleProjectV2(
   FlutterProject flutterProject,
   String gradle,
-  BuildInfo buildInfo,
+  AndroidBuildInfo androidBuildInfo,
   String target,
   bool isBuildingBundle,
 ) async {
   final GradleProject project = await _gradleProject();
+  final BuildInfo buildInfo = androidBuildInfo.buildInfo;
 
   String assembleTask;
 
@@ -453,12 +455,13 @@ Future<void> _buildGradleProjectV2(
     command.add('-Pfilesystem-roots=${buildInfo.fileSystemRoots.join('|')}');
   if (buildInfo.fileSystemScheme != null)
     command.add('-Pfilesystem-scheme=${buildInfo.fileSystemScheme}');
-  if (buildInfo.buildSharedLibrary) {
-    command.add('-Pbuild-shared-library=true');
+  if (androidBuildInfo.splitPerAbi)
+    command.add('-Psplit-per-abi=true');
+  if (androidBuildInfo.targetArchs.isNotEmpty) {
+    final String targetPlatforms = androidBuildInfo.targetArchs
+        .map(getPlatformNameForAndroidArch).join(',');
+    command.add('-Ptarget-platform=$targetPlatforms');
   }
-  if (buildInfo.targetPlatform != null)
-    command.add('-Ptarget-platform=${getNameForTargetPlatform(buildInfo.targetPlatform)}');
-
   command.add(assembleTask);
   bool potentialAndroidXFailure = false;
   final Stopwatch sw = Stopwatch()..start();
@@ -508,24 +511,27 @@ Future<void> _buildGradleProjectV2(
   flutterUsage.sendTiming('build', 'gradle-v2', Duration(milliseconds: sw.elapsedMilliseconds));
 
   if (!isBuildingBundle) {
-    final File apkFile = _findApkFile(project, buildInfo);
-    if (apkFile == null)
+    final Iterable<File> apkFiles = _findApkFiles(project, androidBuildInfo);
+    if (apkFiles.isEmpty)
       throwToolExit('Gradle build failed to produce an Android package.');
-    // Copy the APK to app.apk, so `flutter run`, `flutter install`, etc. can find it.
-    apkFile.copySync(project.apkDirectory.childFile('app.apk').path);
+    // Copy the first APK to app.apk, so `flutter run`, `flutter install`, etc. can find it.
+    // TODO(blasten): Handle multiple APKs.
+    apkFiles.first.copySync(project.apkDirectory.childFile('app.apk').path);
 
     printTrace('calculateSha: ${project.apkDirectory}/app.apk');
     final File apkShaFile = project.apkDirectory.childFile('app.apk.sha1');
-    apkShaFile.writeAsStringSync(_calculateSha(apkFile));
+    apkShaFile.writeAsStringSync(_calculateSha(apkFiles.first));
 
-    String appSize;
-    if (buildInfo.mode == BuildMode.debug) {
-      appSize = '';
-    } else {
-      appSize = ' (${getSizeAsMB(apkFile.lengthSync())})';
+    for (File apkFile in apkFiles) {
+      String appSize;
+      if (buildInfo.mode == BuildMode.debug) {
+        appSize = '';
+      } else {
+        appSize = ' (${getSizeAsMB(apkFile.lengthSync())})';
+      }
+      printStatus('Built ${fs.path.relative(apkFile.path)}$appSize.',
+          color: TerminalColor.green);
     }
-    printStatus('Built ${fs.path.relative(apkFile.path)}$appSize.');
-
   } else {
     final File bundleFile = _findBundleFile(project, buildInfo);
     if (bundleFile == null)
@@ -537,28 +543,38 @@ Future<void> _buildGradleProjectV2(
     } else {
       appSize = ' (${getSizeAsMB(bundleFile.lengthSync())})';
     }
-    printStatus('Built ${fs.path.relative(bundleFile.path)}$appSize.');
+    printStatus('Built ${fs.path.relative(bundleFile.path)}$appSize.',
+        color: TerminalColor.green);
   }
 }
 
-File _findApkFile(GradleProject project, BuildInfo buildInfo) {
-  final String apkFileName = project.apkFileFor(buildInfo);
-  if (apkFileName == null)
-    return null;
-  File apkFile = fs.file(fs.path.join(project.apkDirectory.path, apkFileName));
-  if (apkFile.existsSync())
-    return apkFile;
-  final String modeName = camelCase(buildInfo.modeName);
-  apkFile = fs.file(fs.path.join(project.apkDirectory.path, modeName, apkFileName));
-  if (apkFile.existsSync())
-    return apkFile;
-  if (buildInfo.flavor != null) {
-    // Android Studio Gradle plugin v3 adds flavor to path.
-    apkFile = fs.file(fs.path.join(project.apkDirectory.path, buildInfo.flavor, modeName, apkFileName));
+Iterable<File> _findApkFiles(GradleProject project, AndroidBuildInfo androidBuildInfo) {
+  final Iterable<String> apkFileNames = project.apkFilesFor(androidBuildInfo);
+  if (apkFileNames.isEmpty)
+    return const <File>[];
+
+  return apkFileNames.map<File>((String apkFileName) {
+    File apkFile = project.apkDirectory.childFile(apkFileName);
     if (apkFile.existsSync())
       return apkFile;
-  }
-  return null;
+    final BuildInfo buildInfo = androidBuildInfo.buildInfo;
+    final String modeName = camelCase(buildInfo.modeName);
+    apkFile = project.apkDirectory
+        .childDirectory(modeName)
+        .childFile(apkFileName);
+    if (apkFile.existsSync())
+      return apkFile;
+    if (buildInfo.flavor != null) {
+      // Android Studio Gradle plugin v3 adds flavor to path.
+      apkFile = project.apkDirectory
+          .childDirectory(buildInfo.flavor)
+          .childDirectory(modeName)
+          .childFile(apkFileName);
+      if (apkFile.existsSync())
+        return apkFile;
+    }
+    return null;
+  });
 }
 
 File _findBundleFile(GradleProject project, BuildInfo buildInfo) {
@@ -567,12 +583,12 @@ File _findBundleFile(GradleProject project, BuildInfo buildInfo) {
   if (bundleFileName == null)
     return null;
   final String modeName = camelCase(buildInfo.modeName);
-  File bundleFile = fs.file(fs.path.join(project.bundleDirectory.path, modeName, bundleFileName));
+  File bundleFile = project.bundleDirectory.childDirectory(modeName).childFile(bundleFileName);
   if (bundleFile.existsSync())
     return bundleFile;
   if (buildInfo.flavor != null) {
     // Android Studio Gradle plugin v3 adds the flavor to the path. For the bundle the folder name is the flavor plus the mode name.
-    bundleFile = fs.file(fs.path.join(project.bundleDirectory.path, buildInfo.flavor + modeName, bundleFileName));
+    bundleFile = project.bundleDirectory.childDirectory(buildInfo.flavor + modeName).childFile(bundleFileName);
     if (bundleFile.existsSync())
       return bundleFile;
   }
@@ -661,13 +677,20 @@ class GradleProject {
     return 'assemble${toTitleCase(productFlavor)}${toTitleCase(buildType)}';
   }
 
-  String apkFileFor(BuildInfo buildInfo) {
-    final String buildType = _buildTypeFor(buildInfo);
-    final String productFlavor = _productFlavorFor(buildInfo);
+  Iterable<String> apkFilesFor(AndroidBuildInfo androidBuildInfo) {
+    final String buildType = _buildTypeFor(androidBuildInfo.buildInfo);
+    final String productFlavor = _productFlavorFor(androidBuildInfo.buildInfo);
     if (buildType == null || productFlavor == null)
-      return null;
+      return const <String>[];
+
     final String flavorString = productFlavor.isEmpty ? '' : '-' + productFlavor;
-    return 'app$flavorString-$buildType.apk';
+    if (androidBuildInfo.splitPerAbi) {
+      return androidBuildInfo.targetArchs.map<String>((AndroidArch arch) {
+        final String abi = getNameForAndroidArch(arch);
+        return 'app$flavorString-$abi-$buildType.apk';
+      });
+    }
+    return <String>['app$flavorString-$buildType.apk'];
   }
 
   String bundleTaskFor(BuildInfo buildInfo) {

packages/flutter_tools/lib/src/base/build.dart

@@ -137,7 +137,7 @@ class AOTSnapshotter {
       final String aotSharedLibrary = fs.path.join(outputDir.path, 'app.so');
       outputPaths.add(aotSharedLibrary);
       genSnapshotArgs.add('--snapshot_kind=app-aot-elf');
-      genSnapshotArgs.add('--assembly=$aotSharedLibrary');
+      genSnapshotArgs.add('--elf=$aotSharedLibrary');
     } else {
       // Blob AOT snapshot.
       final String vmSnapshotData = fs.path.join(outputDir.path, 'vm_snapshot_data');

packages/flutter_tools/lib/src/build_info.dart

@@ -17,8 +17,6 @@ class BuildInfo {
     this.compilationTraceFilePath,
     this.extraFrontEndOptions,
     this.extraGenSnapshotOptions,
-    this.buildSharedLibrary,
-    this.targetPlatform,
     this.fileSystemRoots,
     this.fileSystemScheme,
     this.buildNumber,
@@ -50,12 +48,6 @@ class BuildInfo {
   /// Extra command-line options for gen_snapshot.
   final String extraGenSnapshotOptions;
 
-  /// Whether to prefer AOT compiling to a *so file.
-  final bool buildSharedLibrary;
-
-  /// Target platform for the build (e.g. android_arm versus android_arm64).
-  final TargetPlatform targetPlatform;
-
   /// Internal version number (not displayed to users).
   /// Each build must have a unique number to differentiate it from previous builds.
   /// It is used to determine whether one build is more recent than another, with higher numbers indicating more recent build.
@@ -98,15 +90,31 @@ class BuildInfo {
   bool get supportsSimulator => isEmulatorBuildMode(mode);
   String get modeName => getModeName(mode);
   String get friendlyModeName => getFriendlyModeName(mode);
+}
+
+/// Information about an Android build to be performed or used.
+class AndroidBuildInfo {
+  const AndroidBuildInfo(
+    this.buildInfo, {
+    this.targetArchs = const <AndroidArch>[
+      AndroidArch.armeabi_v7a,
+      AndroidArch.arm64_v8a,
+    ],
+    this.splitPerAbi = false,
+  });
 
-  BuildInfo withTargetPlatform(TargetPlatform targetPlatform) =>
-      BuildInfo(mode, flavor,
-          trackWidgetCreation: trackWidgetCreation,
-          compilationTraceFilePath: compilationTraceFilePath,
-          extraFrontEndOptions: extraFrontEndOptions,
-          extraGenSnapshotOptions: extraGenSnapshotOptions,
-          buildSharedLibrary: buildSharedLibrary,
-          targetPlatform: targetPlatform);
+  // The build info containing the mode and flavor.
+  final BuildInfo buildInfo;
+
+  /// Whether to split the shared library per ABI.
+  ///
+  /// When this is false, multiple ABIs will be contained within one primary
+  /// build artifact. When this is true, multiple build artifacts (one per ABI)
+  /// will be produced.
+  final bool splitPerAbi;
+
+  /// The target platforms for the build.
+  final Iterable<AndroidArch> targetArchs;
 }
 
 /// The type of build.
@@ -254,6 +262,13 @@ enum IOSArch {
   arm64,
 }
 
+enum AndroidArch {
+  armeabi_v7a,
+  arm64_v8a,
+  x86,
+  x86_64,
+}
+
 /// The default set of iOS device architectures to build for.
 const List<IOSArch> defaultIOSArchs = <IOSArch>[
   IOSArch.arm64,
@@ -335,6 +350,51 @@ TargetPlatform getTargetPlatformForName(String platform) {
   return null;
 }
 
+AndroidArch getAndroidArchForName(String platform) {
+  switch (platform) {
+    case 'android-arm':
+      return AndroidArch.armeabi_v7a;
+    case 'android-arm64':
+      return AndroidArch.arm64_v8a;
+    case 'android-x64':
+      return AndroidArch.x86_64;
+    case 'android-x86':
+      return AndroidArch.x86;
+  }
+  assert(false);
+  return null;
+}
+
+String getNameForAndroidArch(AndroidArch arch) {
+  switch (arch) {
+    case AndroidArch.armeabi_v7a:
+      return 'armeabi-v7a';
+    case AndroidArch.arm64_v8a:
+      return 'arm64-v8a';
+    case AndroidArch.x86_64:
+      return 'x86_64';
+    case AndroidArch.x86:
+      return 'x86';
+  }
+  assert(false);
+  return null;
+}
+
+String getPlatformNameForAndroidArch(AndroidArch arch) {
+  switch (arch) {
+    case AndroidArch.armeabi_v7a:
+      return 'android-arm';
+    case AndroidArch.arm64_v8a:
+      return 'android-arm64';
+    case AndroidArch.x86_64:
+      return 'android-x64';
+    case AndroidArch.x86:
+      return 'android-x86';
+  }
+  assert(false);
+  return null;
+}
+
 HostPlatform getCurrentHostPlatform() {
   if (platform.isMacOS)
     return HostPlatform.darwin_x64;

packages/flutter_tools/lib/src/commands/build_apk.dart

@@ -5,6 +5,9 @@
 import 'dart:async';
 
 import '../android/apk.dart';
+import '../base/terminal.dart';
+import '../build_info.dart';
+import '../globals.dart';
 import '../project.dart';
 import '../runner/flutter_command.dart' show DevelopmentArtifact, FlutterCommandResult;
 import 'build.dart';
@@ -21,12 +24,14 @@ class BuildApkCommand extends BuildSubCommand {
 
     argParser
       ..addFlag('track-widget-creation', negatable: false, hide: !verboseHelp)
-      ..addFlag('build-shared-library',
+      ..addFlag('split-per-abi',
         negatable: false,
-        help: 'Whether to prefer compiling to a *.so file (android only).',
+        help: 'Whether to split the APKs per ABIs.'
+              'To learn more, see: https://developer.android.com/studio/build/configure-apk-splits#configure-abi-split',
       )
-      ..addOption('target-platform',
-        defaultsTo: 'android-arm',
+      ..addMultiOption('target-platform',
+        splitCommas: true,
+        defaultsTo: <String>['android-arm', 'android-arm64'],
         allowed: <String>['android-arm', 'android-arm64', 'android-x86', 'android-x64'],
         help: 'The target platform for which the app is compiled.',
       );
@@ -49,10 +54,33 @@ class BuildApkCommand extends BuildSubCommand {
 
   @override
   Future<FlutterCommandResult> runCommand() async {
+    final BuildInfo buildInfo = getBuildInfo();
+    final AndroidBuildInfo androidBuildInfo = AndroidBuildInfo(buildInfo,
+      splitPerAbi: argResults['split-per-abi'],
+      targetArchs: argResults['target-platform'].map<AndroidArch>(getAndroidArchForName)
+    );
+
+    if (buildInfo.isRelease && !androidBuildInfo.splitPerAbi && androidBuildInfo.targetArchs.length > 1) {
+      final String targetPlatforms = argResults['target-platform'].join(', ');
+
+      printStatus('You are building a fat APK that includes binaries for '
+                  '$targetPlatforms.', emphasis: true, color: TerminalColor.green);
+      printStatus('If you are deploying the app to the Play Store, '
+                  'it\'s recommended to use app bundles or split the APK to reduce the APK size.', emphasis: true);
+      printStatus('To generate an app bundle, run:', emphasis: true, indent: 4);
+      printStatus('flutter build appbundle '
+                  '--target-platform ${targetPlatforms.replaceAll(' ', '')}',indent: 8);
+      printStatus('Learn more on: https://developer.android.com/guide/app-bundle',indent: 8);
+      printStatus('To split the APKs per ABI, run:', emphasis: true, indent: 4);
+      printStatus('flutter build apk '
+                  '--target-platform ${targetPlatforms.replaceAll(' ', '')} '
+                  '--split-per-abi', indent: 8);
+      printStatus('Learn more on:  https://developer.android.com/studio/build/configure-apk-splits#configure-abi-split',indent: 8);
+    }
     await buildApk(
       project: FlutterProject.current(),
       target: targetFile,
-      buildInfo: getBuildInfo(),
+      androidBuildInfo: androidBuildInfo,
     );
     return null;
   }

packages/flutter_tools/lib/src/commands/build_appbundle.dart

@@ -5,6 +5,7 @@
 import 'dart:async';
 
 import '../android/app_bundle.dart';
+import '../build_info.dart';
 import '../project.dart';
 import '../runner/flutter_command.dart' show FlutterCommandResult;
 import 'build.dart';
@@ -20,18 +21,11 @@ class BuildAppBundleCommand extends BuildSubCommand {
 
     argParser
       ..addFlag('track-widget-creation', negatable: false, hide: !verboseHelp)
-      ..addFlag(
-        'build-shared-library',
-        negatable: false,
-        help: 'Whether to prefer compiling to a *.so file (android only).',
-      )
-      ..addOption(
-        'target-platform',
+      ..addMultiOption('target-platform',
+        splitCommas: true,
+        defaultsTo: <String>['android-arm', 'android-arm64'],
         allowed: <String>['android-arm', 'android-arm64'],
-        help: 'The target platform for which the app is compiled.\n'
-            'By default, the bundle will include \'arm\' and \'arm64\', '
-            'which is the recommended configuration for app bundles.\n'
-            'For more, see https://developer.android.com/distribute/best-practices/develop/64-bit',
+        help: 'The target platform for which the app is compiled.',
       );
   }
 
@@ -47,10 +41,13 @@ class BuildAppBundleCommand extends BuildSubCommand {
 
   @override
   Future<FlutterCommandResult> runCommand() async {
+    final AndroidBuildInfo androidBuildInfo = AndroidBuildInfo(getBuildInfo(),
+      targetArchs: argResults['target-platform'].map<AndroidArch>(getAndroidArchForName)
+    );
     await buildAppBundle(
       project: FlutterProject.current(),
       target: targetFile,
-      buildInfo: getBuildInfo(),
+      androidBuildInfo: androidBuildInfo,
     );
     return null;
   }

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

@@ -387,8 +387,7 @@ class IOSSimulator extends Device {
     final BuildInfo debugBuildInfo = BuildInfo(BuildMode.debug, buildInfo.flavor,
         trackWidgetCreation: buildInfo.trackWidgetCreation,
         extraFrontEndOptions: buildInfo.extraFrontEndOptions,
-        extraGenSnapshotOptions: buildInfo.extraGenSnapshotOptions,
-        buildSharedLibrary: buildInfo.buildSharedLibrary);
+        extraGenSnapshotOptions: buildInfo.extraGenSnapshotOptions);
 
     final XcodeBuildResult buildResult = await buildXcodeProject(
       app: app,

packages/flutter_tools/lib/src/runner/flutter_command.dart

@@ -320,12 +320,6 @@ abstract class FlutterCommand extends Command<void> {
   }
 
   BuildInfo getBuildInfo() {
-    TargetPlatform targetPlatform;
-    if (argParser.options.containsKey('target-platform') &&
-        argResults['target-platform'] != 'default') {
-      targetPlatform = getTargetPlatformForName(argResults['target-platform']);
-    }
-
     final bool trackWidgetCreation = argParser.options.containsKey('track-widget-creation')
         ? argResults['track-widget-creation']
         : false;
@@ -362,10 +356,6 @@ abstract class FlutterCommand extends Command<void> {
       extraGenSnapshotOptions: argParser.options.containsKey(FlutterOptions.kExtraGenSnapshotOptions)
           ? argResults[FlutterOptions.kExtraGenSnapshotOptions]
           : null,
-      buildSharedLibrary: argParser.options.containsKey('build-shared-library')
-        ? argResults['build-shared-library']
-        : false,
-      targetPlatform: targetPlatform,
       fileSystemRoots: argParser.options.containsKey(FlutterOptions.kFileSystemRoot)
           ? argResults[FlutterOptions.kFileSystemRoot] : null,
       fileSystemScheme: argParser.options.containsKey(FlutterOptions.kFileSystemScheme)

packages/flutter_tools/test/android/gradle_test.dart

@@ -157,16 +157,102 @@ someOtherTask
     });
     test('should provide apk file name for default build types', () {
       final GradleProject project = GradleProject(<String>['debug', 'profile', 'release'], <String>[], fs.directory('/some/dir'),fs.directory('/some/dir'));
-      expect(project.apkFileFor(BuildInfo.debug), 'app-debug.apk');
-      expect(project.apkFileFor(BuildInfo.profile), 'app-profile.apk');
-      expect(project.apkFileFor(BuildInfo.release), 'app-release.apk');
-      expect(project.apkFileFor(const BuildInfo(BuildMode.release, 'unknown')), isNull);
+      expect(project.apkFilesFor(const AndroidBuildInfo(BuildInfo.debug)).first, 'app-debug.apk');
+      expect(project.apkFilesFor(const AndroidBuildInfo(BuildInfo.profile)).first, 'app-profile.apk');
+      expect(project.apkFilesFor(const AndroidBuildInfo(BuildInfo.release)).first, 'app-release.apk');
+      expect(project.apkFilesFor(const AndroidBuildInfo(BuildInfo(BuildMode.release, 'unknown'))).isEmpty, isTrue);
     });
     test('should provide apk file name for flavored build types', () {
       final GradleProject project = GradleProject(<String>['debug', 'profile', 'release'], <String>['free', 'paid'], fs.directory('/some/dir'),fs.directory('/some/dir'));
-      expect(project.apkFileFor(const BuildInfo(BuildMode.debug, 'free')), 'app-free-debug.apk');
-      expect(project.apkFileFor(const BuildInfo(BuildMode.release, 'paid')), 'app-paid-release.apk');
-      expect(project.apkFileFor(const BuildInfo(BuildMode.release, 'unknown')), isNull);
+      expect(project.apkFilesFor(const AndroidBuildInfo(BuildInfo(BuildMode.debug, 'free'))).first, 'app-free-debug.apk');
+      expect(project.apkFilesFor(const AndroidBuildInfo(BuildInfo(BuildMode.release, 'paid'))).first, 'app-paid-release.apk');
+      expect(project.apkFilesFor(const AndroidBuildInfo(BuildInfo(BuildMode.release, 'unknown'))).isEmpty, isTrue);
+    });
+    test('should provide apks for default build types and each ABI', () {
+      final GradleProject project = GradleProject(<String>['debug', 'profile', 'release'], <String>[], fs.directory('/some/dir'),fs.directory('/some/dir'));
+      expect(project.apkFilesFor(
+        const AndroidBuildInfo(
+          BuildInfo.debug,
+            splitPerAbi: true,
+            targetArchs: <AndroidArch>[
+                AndroidArch.armeabi_v7a,
+                AndroidArch.arm64_v8a,
+              ]
+            )
+          ),
+        <String>[
+          'app-armeabi-v7a-debug.apk',
+          'app-arm64-v8a-debug.apk',
+        ]);
+
+      expect(project.apkFilesFor(
+        const AndroidBuildInfo(
+          BuildInfo.release,
+            splitPerAbi: true,
+            targetArchs: <AndroidArch>[
+                AndroidArch.armeabi_v7a,
+                AndroidArch.arm64_v8a,
+              ]
+            )
+          ),
+        <String>[
+          'app-armeabi-v7a-release.apk',
+          'app-arm64-v8a-release.apk',
+        ]);
+
+      expect(project.apkFilesFor(
+        const AndroidBuildInfo(
+          BuildInfo(BuildMode.release, 'unknown'),
+            splitPerAbi: true,
+            targetArchs: <AndroidArch>[
+                AndroidArch.armeabi_v7a,
+                AndroidArch.arm64_v8a,
+              ]
+            )
+          ).isEmpty, isTrue);
+    });
+    test('should provide apks for each ABI and flavored build types', () {
+      final GradleProject project = GradleProject(<String>['debug', 'profile', 'release'], <String>['free', 'paid'], fs.directory('/some/dir'),fs.directory('/some/dir'));
+      expect(project.apkFilesFor(
+        const AndroidBuildInfo(
+          BuildInfo(BuildMode.debug, 'free'),
+            splitPerAbi: true,
+            targetArchs: <AndroidArch>[
+                AndroidArch.armeabi_v7a,
+                AndroidArch.arm64_v8a,
+              ]
+            )
+          ),
+        <String>[
+          'app-free-armeabi-v7a-debug.apk',
+          'app-free-arm64-v8a-debug.apk',
+        ]);
+
+      expect(project.apkFilesFor(
+        const AndroidBuildInfo(
+          BuildInfo(BuildMode.release, 'paid'),
+            splitPerAbi: true,
+            targetArchs: <AndroidArch>[
+                AndroidArch.armeabi_v7a,
+                AndroidArch.arm64_v8a,
+              ]
+            )
+          ),
+        <String>[
+          'app-paid-armeabi-v7a-release.apk',
+          'app-paid-arm64-v8a-release.apk',
+        ]);
+
+      expect(project.apkFilesFor(
+        const AndroidBuildInfo(
+          BuildInfo(BuildMode.release, 'unknown'),
+            splitPerAbi: true,
+            targetArchs: <AndroidArch>[
+                AndroidArch.armeabi_v7a,
+                AndroidArch.arm64_v8a,
+              ]
+            )
+          ).isEmpty, isTrue);
     });
     test('should provide bundle file name for default build types', () {
       final GradleProject project = GradleProject(<String>['debug', 'profile', 'release'], <String>[], fs.directory('/some/dir'),fs.directory('/some/dir'));

packages/flutter_tools/test/base/build_test.dart

@@ -80,7 +80,7 @@ void main() {
     });
   });
 
-  group('Snapshotter - iOS AOT', () {
+  group('Snapshotter - AOT', () {
     const String kSnapshotDart = 'snapshot.dart';
     String skyEnginePath;
 
@@ -395,10 +395,11 @@ void main() {
       ]);
     }, overrides: contextOverrides);
 
-    testUsingContext('returns failure if buildSharedLibrary is true but no NDK is found', () async {
-      final String outputPath = fs.path.join('build', 'foo');
+    testUsingContext('builds shared library for android-arm', () async {
+      fs.file('main.dill').writeAsStringSync('binary magic');
 
-      when(mockAndroidSdk.ndk).thenReturn(null);
+      final String outputPath = fs.path.join('build', 'foo');
+      fs.directory(outputPath).createSync(recursive: true);
 
       final int genSnapshotExitCode = await snapshotter.build(
         platform: TargetPlatform.android_arm,
@@ -409,8 +410,45 @@ void main() {
         buildSharedLibrary: true,
       );
 
-      expect(genSnapshotExitCode, isNot(0));
-      expect(genSnapshot.callCount, 0);
+      expect(genSnapshotExitCode, 0);
+      expect(genSnapshot.callCount, 1);
+      expect(genSnapshot.snapshotType.platform, TargetPlatform.android_arm);
+      expect(genSnapshot.snapshotType.mode, BuildMode.release);
+      expect(genSnapshot.additionalArgs, <String>[
+        '--deterministic',
+        '--snapshot_kind=app-aot-elf',
+        '--elf=build/foo/app.so',
+        '--no-sim-use-hardfp',
+        '--no-use-integer-division',
+        'main.dill',
+      ]);
+    }, overrides: contextOverrides);
+
+    testUsingContext('builds shared library for android-arm64', () async {
+      fs.file('main.dill').writeAsStringSync('binary magic');
+
+      final String outputPath = fs.path.join('build', 'foo');
+      fs.directory(outputPath).createSync(recursive: true);
+
+      final int genSnapshotExitCode = await snapshotter.build(
+        platform: TargetPlatform.android_arm64,
+        buildMode: BuildMode.release,
+        mainPath: 'main.dill',
+        packagesPath: '.packages',
+        outputPath: outputPath,
+        buildSharedLibrary: true,
+      );
+
+      expect(genSnapshotExitCode, 0);
+      expect(genSnapshot.callCount, 1);
+      expect(genSnapshot.snapshotType.platform, TargetPlatform.android_arm64);
+      expect(genSnapshot.snapshotType.mode, BuildMode.release);
+      expect(genSnapshot.additionalArgs, <String>[
+        '--deterministic',
+        '--snapshot_kind=app-aot-elf',
+        '--elf=build/foo/app.so',
+        'main.dill',
+      ]);
     }, overrides: contextOverrides);
 
     testUsingContext('builds Android arm release AOT snapshot', () async {

packages/flutter_tools/test/ios/xcodeproj_test.dart

@@ -286,7 +286,7 @@ Information about project "Runner":
           platform: TargetPlatform.ios, mode: anyNamed('mode'))).thenReturn('engine');
       when(mockArtifacts.engineOutPath).thenReturn(fs.path.join('out', 'ios_profile_arm'));
 
-      const BuildInfo buildInfo = BuildInfo(BuildMode.debug, null, targetPlatform: TargetPlatform.ios);
+      const BuildInfo buildInfo = BuildInfo(BuildMode.debug, null);
       final FlutterProject project = FlutterProject.fromPath('path/to/project');
       await updateGeneratedXcodeProperties(
         project: project,
@@ -304,7 +304,7 @@ Information about project "Runner":
       when(mockArtifacts.getArtifactPath(Artifact.flutterFramework,
           platform: TargetPlatform.ios, mode: anyNamed('mode'))).thenReturn('engine');
       when(mockArtifacts.engineOutPath).thenReturn(fs.path.join('out', 'ios_profile_arm'));
-      const BuildInfo buildInfo = BuildInfo(BuildMode.debug, null, trackWidgetCreation: true, targetPlatform: TargetPlatform.ios);
+      const BuildInfo buildInfo = BuildInfo(BuildMode.debug, null, trackWidgetCreation: true);
       final FlutterProject project = FlutterProject.fromPath('path/to/project');
       await updateGeneratedXcodeProperties(
         project: project,
@@ -322,7 +322,7 @@ Information about project "Runner":
       when(mockArtifacts.getArtifactPath(Artifact.flutterFramework,
           platform: TargetPlatform.ios, mode: anyNamed('mode'))).thenReturn('engine');
       when(mockArtifacts.engineOutPath).thenReturn(fs.path.join('out', 'ios_profile_arm'));
-      const BuildInfo buildInfo = BuildInfo(BuildMode.debug, null, targetPlatform: TargetPlatform.ios);
+      const BuildInfo buildInfo = BuildInfo(BuildMode.debug, null);
       final FlutterProject project = FlutterProject.fromPath('path/to/project');
       await updateGeneratedXcodeProperties(
         project: project,
@@ -340,7 +340,7 @@ Information about project "Runner":
       when(mockArtifacts.getArtifactPath(Artifact.flutterFramework,
           platform: TargetPlatform.ios, mode: anyNamed('mode'))).thenReturn('engine');
       when(mockArtifacts.engineOutPath).thenReturn(fs.path.join('out', 'ios_profile'));
-      const BuildInfo buildInfo = BuildInfo(BuildMode.debug, null, targetPlatform: TargetPlatform.ios);
+      const BuildInfo buildInfo = BuildInfo(BuildMode.debug, null);
 
       final FlutterProject project = FlutterProject.fromPath('path/to/project');
       await updateGeneratedXcodeProperties(