[flutter_tool] Use engine flutter_runner prebuilts (#43381)

* [flutter_tool] Use engine flutter_runner prebuilts

* Update packages/flutter_tools/lib/src/fuchsia/fuchsia_build.dart

Co-Authored-By: Jonah Williams <jonahwilliams@google.com>

examples/stocks/fuchsia/meta/stocks.cmx

@@ -0,0 +1,22 @@
+{
+    "program": {
+        "data": "data/stocks"
+    },
+    "sandbox": {
+        "services": [
+            "fuchsia.cobalt.LoggerFactory",
+            "fuchsia.fonts.Provider",
+            "fuchsia.logger.LogSink",
+            "fuchsia.modular.Clipboard",
+            "fuchsia.modular.ContextWriter",
+            "fuchsia.modular.DeviceMap",
+            "fuchsia.modular.ModuleContext",
+            "fuchsia.sys.Environment",
+            "fuchsia.sys.Launcher",
+            "fuchsia.testing.runner.TestRunner",
+            "fuchsia.ui.input.ImeService",
+            "fuchsia.ui.policy.Presenter",
+            "fuchsia.ui.scenic.Scenic"
+        ]
+    }
+}

packages/flutter_tools/lib/src/application_package.dart

@@ -69,7 +69,8 @@ class ApplicationPackageFactory {
         return applicationBinary == null
             ? WindowsApp.fromWindowsProject(FlutterProject.current().windows)
             : WindowsApp.fromPrebuiltApp(applicationBinary);
-      case TargetPlatform.fuchsia:
+      case TargetPlatform.fuchsia_arm64:
+      case TargetPlatform.fuchsia_x64:
         return applicationBinary == null
             ? FuchsiaApp.fromFuchsiaProject(FlutterProject.current().fuchsia)
             : FuchsiaApp.fromPrebuiltApp(applicationBinary);
@@ -424,7 +425,8 @@ class ApplicationPackageStore {
       case TargetPlatform.ios:
         iOS ??= await IOSApp.fromIosProject(FlutterProject.current().ios);
         return iOS;
-      case TargetPlatform.fuchsia:
+      case TargetPlatform.fuchsia_arm64:
+      case TargetPlatform.fuchsia_x64:
         fuchsia ??= FuchsiaApp.fromFuchsiaProject(FlutterProject.current().fuchsia);
         return fuchsia;
       case TargetPlatform.darwin_x64:

packages/flutter_tools/lib/src/artifacts.dart

@@ -58,6 +58,12 @@ enum Artifact {
   skyEnginePath,
   /// The location of the macOS engine podspec file.
   flutterMacOSPodspec,
+
+  // Fuchsia artifacts from the engine prebuilts.
+  fuchsiaKernelCompiler,
+  fuchsiaPlatformDill,
+  fuchsiaPatchedSdk,
+  fuchsiaFlutterJitRunner,
 }
 
 String _artifactToFileName(Artifact artifact, [ TargetPlatform platform, BuildMode mode ]) {
@@ -130,6 +136,17 @@ String _artifactToFileName(Artifact artifact, [ TargetPlatform platform, BuildMo
       return 'FlutterMacOS.podspec';
     case Artifact.webPlatformKernelDill:
       return 'flutter_ddc_sdk.dill';
+    case Artifact.fuchsiaKernelCompiler:
+      return 'kernel_compiler.snapshot';
+    case Artifact.fuchsiaPlatformDill:
+      return 'platform_strong.dill';
+    case Artifact.fuchsiaPatchedSdk:
+      return 'flutter_runner_patched_sdk';
+    case Artifact.fuchsiaFlutterJitRunner:
+      if (mode == BuildMode.debug || mode == BuildMode.profile) {
+        return 'flutter_jit_runner-0.far';
+      }
+      return 'flutter_jit_product_runner-0.far';
   }
   assert(false, 'Invalid artifact $artifact.');
   return null;
@@ -190,8 +207,10 @@ class CachedArtifacts extends Artifacts {
         return _getIosArtifactPath(artifact, platform, mode);
       case TargetPlatform.darwin_x64:
         return _getDarwinArtifactPath(artifact, platform, mode);
+      case TargetPlatform.fuchsia_arm64:
+      case TargetPlatform.fuchsia_x64:
+        return _getFuchsiaArtifactPath(artifact, platform, mode);
       case TargetPlatform.linux_x64:
-      case TargetPlatform.fuchsia:
       case TargetPlatform.windows_x64:
       case TargetPlatform.tester:
       case TargetPlatform.web_javascript:
@@ -258,6 +277,28 @@ class CachedArtifacts extends Artifacts {
     }
   }
 
+  String _getFuchsiaArtifactPath(Artifact artifact, TargetPlatform platform, BuildMode mode) {
+    final String artifactFileName = _artifactToFileName(artifact, platform, mode);
+    final String root = fs.path.join(
+      cache.getArtifactDirectory('flutter_runner').path,
+      'flutter',
+      fuchsiaArchForTargetPlatform(platform),
+      getNameForBuildMode(mode),
+    );
+    switch (artifact) {
+      case Artifact.fuchsiaKernelCompiler:
+        return fs.path.join(root, 'jit', 'dart_binaries', artifactFileName);
+      case Artifact.fuchsiaPlatformDill:
+        return fs.path.join(root, 'jit', 'flutter_runner_patched_sdk', artifactFileName);
+      case Artifact.fuchsiaPatchedSdk:
+      case Artifact.fuchsiaFlutterJitRunner:
+        return fs.path.join(root, 'jit', artifactFileName);
+      default:
+        assert(false, 'Artifact $artifact not available for platform $platform.');
+        return null;
+    }
+  }
+
   String _getFlutterPatchedSdkPath(BuildMode mode) {
     final String engineArtifactsPath = cache.getArtifactDirectory('engine').path;
     return fs.path.join(engineArtifactsPath, 'common',
@@ -339,7 +380,8 @@ class CachedArtifacts extends Artifacts {
         }
         final String suffix = mode != BuildMode.debug ? '-${snakeCase(getModeName(mode), '-')}' : '';
         return fs.path.join(engineDir, platformName + suffix);
-      case TargetPlatform.fuchsia:
+      case TargetPlatform.fuchsia_arm64:
+      case TargetPlatform.fuchsia_x64:
       case TargetPlatform.tester:
       case TargetPlatform.web_javascript:
         assert(mode == null, 'Platform $platform does not support different build modes.');
@@ -430,6 +472,12 @@ class LocalEngineArtifacts extends Artifacts {
         return fs.path.join(_hostEngineOutPath, _artifactToFileName(artifact));
       case Artifact.webPlatformKernelDill:
         return fs.path.join(_getFlutterWebSdkPath(), 'kernel', _artifactToFileName(artifact));
+      case Artifact.fuchsiaKernelCompiler:
+      case Artifact.fuchsiaPlatformDill:
+      case Artifact.fuchsiaPatchedSdk:
+      case Artifact.fuchsiaFlutterJitRunner:
+        assert(false, 'Invalid local engine artifact $artifact.');
+        return null;
     }
     assert(false, 'Invalid artifact $artifact.');
     return null;

packages/flutter_tools/lib/src/build_info.dart

@@ -314,7 +314,8 @@ enum TargetPlatform {
   darwin_x64,
   linux_x64,
   windows_x64,
-  fuchsia,
+  fuchsia_arm64,
+  fuchsia_x64,
   tester,
   web_javascript,
 }
@@ -382,8 +383,10 @@ String getNameForTargetPlatform(TargetPlatform platform) {
       return 'linux-x64';
     case TargetPlatform.windows_x64:
       return 'windows-x64';
-    case TargetPlatform.fuchsia:
-      return 'fuchsia';
+    case TargetPlatform.fuchsia_arm64:
+      return 'fuchsia-arm64';
+    case TargetPlatform.fuchsia_x64:
+      return 'fuchsia-x64';
     case TargetPlatform.tester:
       return 'flutter-tester';
     case TargetPlatform.web_javascript:
@@ -403,6 +406,10 @@ TargetPlatform getTargetPlatformForName(String platform) {
       return TargetPlatform.android_x64;
     case 'android-x86':
       return TargetPlatform.android_x86;
+    case 'fuchsia-arm64':
+      return TargetPlatform.fuchsia_arm64;
+    case 'fuchsia-x64':
+      return TargetPlatform.fuchsia_x64;
     case 'ios':
       return TargetPlatform.ios;
     case 'darwin-x64':
@@ -463,6 +470,18 @@ String getPlatformNameForAndroidArch(AndroidArch arch) {
   return null;
 }
 
+String fuchsiaArchForTargetPlatform(TargetPlatform targetPlatform) {
+  switch (targetPlatform) {
+    case TargetPlatform.fuchsia_arm64:
+      return 'arm64';
+    case TargetPlatform.fuchsia_x64:
+      return 'x64';
+    default:
+      assert(false);
+      return null;
+  }
+}
+
 HostPlatform getCurrentHostPlatform() {
   if (platform.isMacOS) {
     return HostPlatform.darwin_x64;

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

@@ -10,6 +10,7 @@ import '../base/platform.dart';
 import '../build_info.dart';
 import '../cache.dart';
 import '../fuchsia/fuchsia_build.dart';
+import '../fuchsia/fuchsia_pm.dart';
 import '../project.dart';
 import '../runner/flutter_command.dart' show FlutterCommandResult;
 import 'build.dart';
@@ -19,6 +20,17 @@ class BuildFuchsiaCommand extends BuildSubCommand {
   BuildFuchsiaCommand({bool verboseHelp = false}) {
     usesTargetOption();
     addBuildModeFlags(verboseHelp: verboseHelp);
+    argParser.addOption(
+      'runner-source',
+      help: 'The package source to use for the flutter_runner. '
+            '"${FuchsiaPackageServer.deviceHost}" implies using a runner already on the device. '
+            '"${FuchsiaPackageServer.toolHost}" implies using a runner distributed with Flutter.',
+      allowed: <String>[
+        FuchsiaPackageServer.deviceHost,
+        FuchsiaPackageServer.toolHost,
+      ],
+      defaultsTo: FuchsiaPackageServer.toolHost,
+    );
   }
 
   @override
@@ -34,7 +46,7 @@ class BuildFuchsiaCommand extends BuildSubCommand {
   };
 
   @override
-  String get description => 'build the Fuchsia target (Experimental).';
+  String get description => 'Build the Fuchsia target (Experimental).';
 
   @override
   Future<FlutterCommandResult> runCommand() async {
@@ -42,22 +54,24 @@ class BuildFuchsiaCommand extends BuildSubCommand {
     final BuildInfo buildInfo = getBuildInfo();
     final FlutterProject flutterProject = FlutterProject.current();
     if (!platform.isLinux && !platform.isMacOS) {
-      throwToolExit('"build Fuchsia" only supported on Linux and MacOS hosts.');
+      throwToolExit('"build fuchsia" is only supported on Linux and MacOS hosts.');
     }
     if (!flutterProject.fuchsia.existsSync()) {
-      throwToolExit('No Fuchsia project configured.');
+      throwToolExit('No Fuchsia project is configured.');
     }
     final String appName = flutterProject.fuchsia.project.manifest.appName;
     final String cmxPath = fs.path.join(
         flutterProject.fuchsia.meta.path, '$appName.cmx');
     final File cmxFile = fs.file(cmxPath);
     if (!cmxFile.existsSync()) {
-      throwToolExit('Fuchsia build requires a .cmx file at $cmxPath for the app');
+      throwToolExit('The Fuchsia build requires a .cmx file at $cmxPath for the app.');
     }
     await buildFuchsia(
-        fuchsiaProject: flutterProject.fuchsia,
-        target: targetFile,
-        buildInfo: buildInfo);
+      fuchsiaProject: flutterProject.fuchsia,
+      target: targetFile,
+      buildInfo: buildInfo,
+      runnerPackageSource: argResults['runner-source'],
+    );
     return null;
   }
 }

packages/flutter_tools/lib/src/device.dart

@@ -178,7 +178,8 @@ class DeviceManager {
     if (hasSpecifiedAllDevices) {
       devices = <Device>[
         for (Device device in devices)
-          if (await device.targetPlatform != TargetPlatform.fuchsia &&
+          if (await device.targetPlatform != TargetPlatform.fuchsia_arm64 &&
+              await device.targetPlatform != TargetPlatform.fuchsia_x64 &&
               await device.targetPlatform != TargetPlatform.web_javascript)
             device,
       ];
@@ -339,7 +340,8 @@ abstract class Device {
       case TargetPlatform.darwin_x64:
       case TargetPlatform.linux_x64:
       case TargetPlatform.windows_x64:
-      case TargetPlatform.fuchsia:
+      case TargetPlatform.fuchsia_arm64:
+      case TargetPlatform.fuchsia_x64:
       default:
         return false;
     }

packages/flutter_tools/lib/src/fuchsia/fuchsia_build.dart

@@ -38,6 +38,7 @@ Future<void> buildFuchsia({
   @required FuchsiaProject fuchsiaProject,
   @required String target, // E.g., lib/main.dart
   BuildInfo buildInfo = BuildInfo.debug,
+  String runnerPackageSource = FuchsiaPackageServer.toolHost,
 }) async {
   final Directory outDir = fs.directory(getFuchsiaBuildDirectory());
   if (!outDir.existsSync()) {
@@ -50,7 +51,7 @@ Future<void> buildFuchsia({
   await _timedBuildStep('fuchsia-build-assets',
     () => _buildAssets(fuchsiaProject, target, buildInfo));
   await _timedBuildStep('fuchsia-build-package',
-    () => _buildPackage(fuchsiaProject, target, buildInfo));
+    () => _buildPackage(fuchsiaProject, target, buildInfo, runnerPackageSource));
 }
 
 Future<void> _buildAssets(
@@ -85,7 +86,7 @@ Future<void> _buildAssets(
   await outFile.close();
 }
 
-void _rewriteCmx(BuildMode mode, File src, File dst) {
+void _rewriteCmx(BuildMode mode, String runnerPackageSource, File src, File dst) {
   final Map<String, dynamic> cmx = json.decode(src.readAsStringSync());
   // If the app author has already specified the runner in the cmx file, then
   // do not override it with something else.
@@ -106,7 +107,7 @@ void _rewriteCmx(BuildMode mode, File src, File dst) {
       throwToolExit('Fuchsia does not support build mode "$mode"');
       break;
   }
-  cmx['runner'] = 'fuchsia-pkg://fuchsia.com/$runner#meta/$runner.cmx';
+  cmx['runner'] = 'fuchsia-pkg://$runnerPackageSource/$runner#meta/$runner.cmx';
   dst.writeAsStringSync(json.encode(cmx));
 }
 
@@ -115,6 +116,7 @@ Future<void> _buildPackage(
   FuchsiaProject fuchsiaProject,
   String target, // lib/main.dart
   BuildInfo buildInfo,
+  String runnerPackageSource,
 ) async {
   final String outDir = getFuchsiaBuildDirectory();
   final String pkgDir = fs.path.join(outDir, 'pkg');
@@ -132,7 +134,7 @@ Future<void> _buildPackage(
   final File srcCmx =
       fs.file(fs.path.join(fuchsiaProject.meta.path, '$appName.cmx'));
   final File dstCmx = fs.file(fs.path.join(outDir, '$appName.cmx'));
-  _rewriteCmx(buildInfo.mode, srcCmx, dstCmx);
+  _rewriteCmx(buildInfo.mode, runnerPackageSource, srcCmx, dstCmx);
 
   // Concatenate dilpmanifest and pkgassets into package_manifest.
   final File manifestFile = fs.file(packageManifest);

packages/flutter_tools/lib/src/fuchsia/fuchsia_device.dart

@@ -272,13 +272,15 @@ class FuchsiaDevice extends Device {
       }
 
       // Start up a package server.
-      const String packageServerName = 'flutter_tool';
+      const String packageServerName = FuchsiaPackageServer.toolHost;
       fuchsiaPackageServer = FuchsiaPackageServer(
           packageRepo.path, packageServerName, host, port);
       if (!await fuchsiaPackageServer.start()) {
         printError('Failed to start the Fuchsia package server');
         return LaunchResult.failed();
       }
+
+      // Serve the application's package.
       final File farArchive = package.farArchive(
           debuggingOptions.buildInfo.mode);
       if (!await fuchsiaPackageServer.addPackage(farArchive)) {
@@ -286,6 +288,17 @@ class FuchsiaDevice extends Device {
         return LaunchResult.failed();
       }
 
+      // Serve the flutter_runner.
+      final File flutterRunnerArchive = fs.file(artifacts.getArtifactPath(
+        Artifact.fuchsiaFlutterJitRunner,
+        platform: await targetPlatform,
+        mode: debuggingOptions.buildInfo.mode,
+      ));
+      if (!await fuchsiaPackageServer.addPackage(flutterRunnerArchive)) {
+        printError('Failed to add flutter_runner package to the package server');
+        return LaunchResult.failed();
+      }
+
       // Teach the package controller about the package server.
       if (!await fuchsiaDeviceTools.amberCtl.addRepoCfg(this, fuchsiaPackageServer)) {
         printError('Failed to teach amber about the package server');
@@ -293,6 +306,18 @@ class FuchsiaDevice extends Device {
       }
       serverRegistered = true;
 
+      // Tell the package controller to prefetch the flutter_runner.
+      String flutterRunnerName = 'flutter_jit_runner';
+      if (!debuggingOptions.buildInfo.isDebug &&
+          !debuggingOptions.buildInfo.isProfile) {
+        flutterRunnerName = 'flutter_jit_product_runner';
+      }
+      if (!await fuchsiaDeviceTools.amberCtl.pkgCtlResolve(
+          this, fuchsiaPackageServer, flutterRunnerName)) {
+        printError('Failed to get pkgctl to prefetch the flutter_runner');
+        return LaunchResult.failed();
+      }
+
       // Tell the package controller to prefetch the app.
       if (!await fuchsiaDeviceTools.amberCtl.pkgCtlResolve(
           this, fuchsiaPackageServer, appName)) {
@@ -353,8 +378,30 @@ class FuchsiaDevice extends Device {
     return true;
   }
 
+  TargetPlatform _targetPlatform;
+
+  Future<TargetPlatform> _queryTargetPlatform() async {
+    final RunResult result = await shell('uname -m');
+    if (result.exitCode != 0) {
+      printError('Could not determine Fuchsia target platform type:\n$result\n'
+                 'Defaulting to arm64.');
+      return TargetPlatform.fuchsia_arm64;
+    }
+    final String machine = result.stdout.trim();
+    switch (machine) {
+      case 'aarch64':
+        return TargetPlatform.fuchsia_arm64;
+      case 'x86_64':
+        return TargetPlatform.fuchsia_x64;
+      default:
+        printError('Unknown Fuchsia target platform "$machine". '
+                   'Defaulting to arm64.');
+        return TargetPlatform.fuchsia_arm64;
+    }
+  }
+
   @override
-  Future<TargetPlatform> get targetPlatform async => TargetPlatform.fuchsia;
+  Future<TargetPlatform> get targetPlatform async => _targetPlatform ??= await _queryTargetPlatform();
 
   @override
   Future<String> get sdkNameAndVersion async {
@@ -389,8 +436,16 @@ class FuchsiaDevice extends Device {
   OverrideArtifacts get artifactOverrides {
     return _artifactOverrides ??= OverrideArtifacts(
       parent: Artifacts.instance,
-      platformKernelDill: fuchsiaArtifacts.platformKernelDill,
-      flutterPatchedSdk: fuchsiaArtifacts.flutterPatchedSdk,
+      platformKernelDill: fs.file(artifacts.getArtifactPath(
+        Artifact.fuchsiaPlatformDill,
+        platform: TargetPlatform.fuchsia_x64,
+        mode: BuildMode.debug,
+      )),
+      flutterPatchedSdk: fs.file(artifacts.getArtifactPath(
+        Artifact.fuchsiaPatchedSdk,
+        platform: TargetPlatform.fuchsia_x64,
+        mode: BuildMode.debug,
+      )),
     );
   }
   OverrideArtifacts _artifactOverrides;
@@ -535,7 +590,7 @@ class FuchsiaIsolateDiscoveryProtocol {
       'Waiting for a connection from $_isolateName on ${_device.name}...',
       timeout: null, // could take an arbitrary amount of time
     );
-    _pollingTimer ??= Timer(_pollDuration, _findIsolate);
+    unawaited(_findIsolate());  // Completes the _foundUri Future.
     return _foundUri.future.then((Uri uri) {
       _uri = uri;
       return uri;

packages/flutter_tools/lib/src/fuchsia/fuchsia_kernel_compiler.dart

@@ -15,8 +15,6 @@ import '../convert.dart';
 import '../globals.dart';
 import '../project.dart';
 
-import 'fuchsia_sdk.dart';
-
 /// This is a simple wrapper around the custom kernel compiler from the Fuchsia
 /// SDK.
 class FuchsiaKernelCompiler {
@@ -30,20 +28,32 @@ class FuchsiaKernelCompiler {
     BuildInfo buildInfo = BuildInfo.debug,
   }) async {
     // TODO(zra): Use filesystem root and scheme information from buildInfo.
-    if (fuchsiaArtifacts.kernelCompiler == null) {
-      throwToolExit('Fuchisa kernel compiler not found');
-    }
     const String multiRootScheme = 'main-root';
     final String packagesFile = fuchsiaProject.project.packagesFile.path;
     final String outDir = getFuchsiaBuildDirectory();
     final String appName = fuchsiaProject.project.manifest.appName;
     final String fsRoot = fuchsiaProject.project.directory.path;
-    final String relativePackagesFile =
-        fs.path.relative(packagesFile, from: fsRoot);
+    final String relativePackagesFile = fs.path.relative(packagesFile, from: fsRoot);
     final String manifestPath = fs.path.join(outDir, '$appName.dilpmanifest');
+    final String kernelCompiler = artifacts.getArtifactPath(
+      Artifact.fuchsiaKernelCompiler,
+      platform: TargetPlatform.fuchsia_x64,  // This file is not arch-specific.
+      mode: BuildMode.debug,
+    );
+    if (!fs.isFileSync(kernelCompiler)) {
+      throwToolExit('Fuchisa kernel compiler not found at "$kernelCompiler"');
+    }
+    final String platformDill = artifacts.getArtifactPath(
+      Artifact.fuchsiaPlatformDill,
+      platform: TargetPlatform.fuchsia_x64,  // This file is not arch-specific.
+      mode: buildInfo.mode,
+    );
+    if (!fs.isFileSync(platformDill)) {
+      throwToolExit('Fuchisa platform file not found at "$platformDill"');
+    }
     List<String> flags = <String>[
       '--target', 'flutter_runner',
-      '--platform', fuchsiaArtifacts.platformKernelDill.path,
+      '--platform', platformDill,
       '--filesystem-scheme', 'main-root',
       '--filesystem-root', fsRoot,
       '--packages', '$multiRootScheme:///$relativePackagesFile',
@@ -82,7 +92,7 @@ class FuchsiaKernelCompiler {
 
     final List<String> command = <String>[
       artifacts.getArtifactPath(Artifact.engineDartBinary),
-      fuchsiaArtifacts.kernelCompiler.path,
+      artifacts.getArtifactPath(Artifact.fuchsiaKernelCompiler),
       ...flags,
     ];
     final Process process = await processUtils.start(command);

packages/flutter_tools/lib/src/fuchsia/fuchsia_pm.dart

@@ -178,6 +178,9 @@ class FuchsiaPM {
 class FuchsiaPackageServer {
   FuchsiaPackageServer(this._repo, this.name, this._host, this._port);
 
+  static const String deviceHost = 'fuchsia.com';
+  static const String toolHost = 'flutter_tool';
+
   final String _repo;
   final String _host;
   final int _port;

packages/flutter_tools/lib/src/fuchsia/fuchsia_sdk.dart

@@ -102,9 +102,6 @@ class FuchsiaArtifacts {
   FuchsiaArtifacts({
     this.sshConfig,
     this.devFinder,
-    this.platformKernelDill,
-    this.flutterPatchedSdk,
-    this.kernelCompiler,
     this.pm,
   });
 
@@ -119,19 +116,6 @@ class FuchsiaArtifacts {
       // Don't try to find the artifacts on platforms that are not supported.
       return FuchsiaArtifacts();
     }
-    final String fuchsia = Cache.instance.getArtifactDirectory('fuchsia').path;
-    final String tools = fs.path.join(fuchsia, 'tools');
-    final String dartPrebuilts = fs.path.join(tools, 'dart_prebuilts');
-
-    final File devFinder = fs.file(fs.path.join(tools, 'dev_finder'));
-    final File platformDill = fs.file(fs.path.join(
-          dartPrebuilts, 'flutter_runner', 'platform_strong.dill'));
-    final File patchedSdk = fs.file(fs.path.join(
-          dartPrebuilts, 'flutter_runner'));
-    final File kernelCompiler = fs.file(fs.path.join(
-          dartPrebuilts, 'kernel_compiler.snapshot'));
-    final File pm = fs.file(fs.path.join(tools, 'pm'));
-
     // If FUCHSIA_BUILD_DIR is defined, then look for the ssh_config dir
     // relative to it. Next, if FUCHSIA_SSH_CONFIG is defined, then use it.
     // TODO(zra): Consider passing the ssh config path in with a flag.
@@ -142,12 +126,15 @@ class FuchsiaArtifacts {
     } else if (platform.environment.containsKey(_kFuchsiaSshConfig)) {
       sshConfig = fs.file(platform.environment[_kFuchsiaSshConfig]);
     }
+
+    final String fuchsia = Cache.instance.getArtifactDirectory('fuchsia').path;
+    final String tools = fs.path.join(fuchsia, 'tools');
+    final File devFinder = fs.file(fs.path.join(tools, 'dev_finder'));
+    final File pm = fs.file(fs.path.join(tools, 'pm'));
+
     return FuchsiaArtifacts(
       sshConfig: sshConfig,
       devFinder: devFinder.existsSync() ? devFinder : null,
-      platformKernelDill: platformDill.existsSync() ? platformDill : null,
-      flutterPatchedSdk: patchedSdk.existsSync() ? patchedSdk : null,
-      kernelCompiler: kernelCompiler.existsSync() ? kernelCompiler : null,
       pm: pm.existsSync() ? pm : null,
     );
   }
@@ -163,15 +150,6 @@ class FuchsiaArtifacts {
   /// Fuchsia devices.
   final File devFinder;
 
-  /// The location of the Fuchsia-specific platform dill.
-  final File platformKernelDill;
-
-  /// The directory containing [platformKernelDill].
-  final File flutterPatchedSdk;
-
-  /// The snapshot of the Fuchsia kernel compiler.
-  final File kernelCompiler;
-
   /// The pm tool.
   final File pm;
 }

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

@@ -734,7 +734,8 @@ DevelopmentArtifact _artifactFromTargetPlatform(TargetPlatform targetPlatform) {
         return DevelopmentArtifact.linux;
       }
       return null;
-    case TargetPlatform.fuchsia:
+    case TargetPlatform.fuchsia_arm64:
+    case TargetPlatform.fuchsia_x64:
     case TargetPlatform.tester:
       // No artifacts currently supported.
       return null;

packages/flutter_tools/test/commands.shard/hermetic/build_fuchsia_test.dart

@@ -27,23 +27,18 @@ void main() {
   MockPlatform linuxPlatform;
   MockPlatform windowsPlatform;
   MockFuchsiaSdk fuchsiaSdk;
-  MockFuchsiaArtifacts fuchsiaArtifacts;
-  MockFuchsiaArtifacts fuchsiaArtifactsNoCompiler;
 
   setUp(() {
     linuxPlatform = MockPlatform();
     windowsPlatform = MockPlatform();
     fuchsiaSdk = MockFuchsiaSdk();
-    fuchsiaArtifacts = MockFuchsiaArtifacts();
-    fuchsiaArtifactsNoCompiler = MockFuchsiaArtifacts();
 
     when(linuxPlatform.isLinux).thenReturn(true);
     when(linuxPlatform.isWindows).thenReturn(false);
+    when(linuxPlatform.isMacOS).thenReturn(false);
     when(windowsPlatform.isWindows).thenReturn(true);
     when(windowsPlatform.isLinux).thenReturn(false);
     when(windowsPlatform.isMacOS).thenReturn(false);
-    when(fuchsiaArtifacts.kernelCompiler).thenReturn(MockFile());
-    when(fuchsiaArtifactsNoCompiler.kernelCompiler).thenReturn(null);
   });
 
   group('Fuchsia build fails gracefully when', () {
@@ -58,7 +53,6 @@ void main() {
       Platform: () => linuxPlatform,
       FileSystem: () => MemoryFileSystem(),
       ProcessManager: () => FakeProcessManager.any(),
-      FuchsiaArtifacts: () => fuchsiaArtifacts,
     });
 
     testUsingContext('there is no cmx file', () async {
@@ -76,7 +70,6 @@ void main() {
       Platform: () => linuxPlatform,
       FileSystem: () => MemoryFileSystem(),
       ProcessManager: () => FakeProcessManager.any(),
-      FuchsiaArtifacts: () => fuchsiaArtifacts,
     });
 
     testUsingContext('on Windows platform', () async {
@@ -99,7 +92,6 @@ void main() {
       Platform: () => windowsPlatform,
       FileSystem: () => MemoryFileSystem(),
       ProcessManager: () => FakeProcessManager.any(),
-      FuchsiaArtifacts: () => fuchsiaArtifacts,
     });
 
     testUsingContext('there is no Fuchsia kernel compiler', () async {
@@ -122,7 +114,6 @@ void main() {
       Platform: () => linuxPlatform,
       FileSystem: () => MemoryFileSystem(),
       ProcessManager: () => FakeProcessManager.any(),
-      FuchsiaArtifacts: () => fuchsiaArtifactsNoCompiler,
     });
   });
 
@@ -233,7 +224,3 @@ class MockFuchsiaSdk extends Mock implements FuchsiaSdk {
   final FuchsiaKernelCompiler fuchsiaKernelCompiler =
       MockFuchsiaKernelCompiler();
 }
-
-class MockFile extends Mock implements File {}
-
-class MockFuchsiaArtifacts extends Mock implements FuchsiaArtifacts {}

packages/flutter_tools/test/general.shard/device_test.dart

@@ -57,7 +57,7 @@ void main() {
       webDevice = _MockDevice('webby', 'webby')
         ..targetPlatform = Future<TargetPlatform>.value(TargetPlatform.web_javascript);
       fuchsiaDevice = _MockDevice('fuchsiay', 'fuchsiay')
-        ..targetPlatform = Future<TargetPlatform>.value(TargetPlatform.fuchsia);
+        ..targetPlatform = Future<TargetPlatform>.value(TargetPlatform.fuchsia_x64);
     });
 
     testUsingContext('chooses ephemeral device', () async {

packages/flutter_tools/test/general.shard/fuchsia/fuchsia_device_test.dart

@@ -12,6 +12,7 @@ import 'package:flutter_tools/src/base/common.dart';
 import 'package:flutter_tools/src/base/context.dart';
 import 'package:flutter_tools/src/base/file_system.dart';
 import 'package:flutter_tools/src/base/io.dart';
+import 'package:flutter_tools/src/base/process.dart';
 import 'package:flutter_tools/src/base/os.dart';
 import 'package:flutter_tools/src/base/time.dart';
 import 'package:flutter_tools/src/build_info.dart';
@@ -36,8 +37,13 @@ import '../../src/context.dart';
 void main() {
   group('fuchsia device', () {
     MemoryFileSystem memoryFileSystem;
+    MockFile sshConfig;
+    MockProcessUtils mockProcessUtils;
     setUp(() {
       memoryFileSystem = MemoryFileSystem();
+      sshConfig = MockFile();
+      mockProcessUtils = MockProcessUtils();
+      when(sshConfig.absolute).thenReturn(sshConfig);
     });
 
     testUsingContext('stores the requested id and name', () {
@@ -96,44 +102,78 @@ void main() {
       FileSystem: () => memoryFileSystem,
       ProcessManager: () => FakeProcessManager.any(),
     });
+
+    testUsingContext('targetPlatform arm64 works', () async {
+      when(mockProcessUtils.run(any)).thenAnswer((Invocation _) {
+        return Future<RunResult>.value(RunResult(ProcessResult(1, 0, 'aarch64', ''), <String>['']));
+      });
+      final FuchsiaDevice device = FuchsiaDevice('123');
+      expect(await device.targetPlatform, TargetPlatform.fuchsia_arm64);
+    }, overrides: <Type, Generator>{
+      FuchsiaArtifacts: () => FuchsiaArtifacts(sshConfig: sshConfig),
+      ProcessUtils: () => mockProcessUtils,
+    });
+
+    testUsingContext('targetPlatform x64 works', () async {
+      when(mockProcessUtils.run(any)).thenAnswer((Invocation _) {
+        return Future<RunResult>.value(RunResult(ProcessResult(1, 0, 'x86_64', ''), <String>['']));
+      });
+      final FuchsiaDevice device = FuchsiaDevice('123');
+      expect(await device.targetPlatform, TargetPlatform.fuchsia_x64);
+    }, overrides: <Type, Generator>{
+      FuchsiaArtifacts: () => FuchsiaArtifacts(sshConfig: sshConfig),
+      ProcessUtils: () => mockProcessUtils,
+    });
   });
 
   group('Fuchsia device artifact overrides', () {
-    MockFile devFinder;
-    MockFile sshConfig;
-    MockFile platformDill;
-    MockFile patchedSdk;
+    MemoryFileSystem memoryFileSystem;
+    File devFinder;
+    File sshConfig;
+    File platformDill;
+    File patchedSdk;
+    MockArtifacts mockArtifacts;
 
     setUp(() {
-      devFinder = MockFile();
-      sshConfig = MockFile();
-      platformDill = MockFile();
-      patchedSdk = MockFile();
-      when(devFinder.absolute).thenReturn(devFinder);
-      when(sshConfig.absolute).thenReturn(sshConfig);
-      when(platformDill.absolute).thenReturn(platformDill);
-      when(patchedSdk.absolute).thenReturn(patchedSdk);
+      memoryFileSystem = MemoryFileSystem();
+      devFinder = memoryFileSystem.file('dev_finder');
+      sshConfig = memoryFileSystem.file('ssh_config');
+      platformDill = memoryFileSystem.file('platform_strong.dill');
+      patchedSdk = memoryFileSystem.file('flutter_runner_patched_sdk');
+
+      mockArtifacts = MockArtifacts();
+      when(mockArtifacts.getArtifactPath(
+        Artifact.fuchsiaPlatformDill,
+        platform: anyNamed('platform'),
+        mode: anyNamed('mode'),
+      )).thenReturn(platformDill.path);
+      when(mockArtifacts.getArtifactPath(
+        Artifact.fuchsiaPatchedSdk,
+        platform: anyNamed('platform'),
+        mode: anyNamed('mode'),
+      )).thenReturn(patchedSdk.path);
     });
 
     testUsingContext('exist', () async {
       final FuchsiaDevice device = FuchsiaDevice('fuchsia-device');
       expect(device.artifactOverrides, isNotNull);
-      expect(device.artifactOverrides.platformKernelDill, equals(platformDill));
-      expect(device.artifactOverrides.flutterPatchedSdk, equals(patchedSdk));
+      expect(device.artifactOverrides.platformKernelDill.path, equals(platformDill.path));
+      expect(device.artifactOverrides.flutterPatchedSdk.path, equals(patchedSdk.path));
     }, overrides: <Type, Generator>{
+      Artifacts: () => mockArtifacts,
+      FileSystem: () => memoryFileSystem,
       FuchsiaArtifacts: () => FuchsiaArtifacts(
             sshConfig: sshConfig,
             devFinder: devFinder,
-            platformKernelDill: platformDill,
-            flutterPatchedSdk: patchedSdk,
           ),
+      ProcessManager: () => FakeProcessManager.any(),
     });
 
     testUsingContext('are used', () async {
       final FuchsiaDevice device = FuchsiaDevice('fuchsia-device');
       expect(device.artifactOverrides, isNotNull);
-      expect(device.artifactOverrides.platformKernelDill, equals(platformDill));
-      expect(device.artifactOverrides.flutterPatchedSdk, equals(patchedSdk));
+      expect(device.artifactOverrides.platformKernelDill.path, equals(platformDill.path));
+      expect(device.artifactOverrides.flutterPatchedSdk.path, equals(patchedSdk.path));
       await context.run<void>(
         body: () {
           expect(Artifacts.instance.getArtifactPath(Artifact.platformKernelDill),
@@ -146,12 +186,13 @@ void main() {
         },
       );
     }, overrides: <Type, Generator>{
+      Artifacts: () => mockArtifacts,
+      FileSystem: () => memoryFileSystem,
       FuchsiaArtifacts: () => FuchsiaArtifacts(
             sshConfig: sshConfig,
             devFinder: devFinder,
-            platformKernelDill: platformDill,
-            flutterPatchedSdk: patchedSdk,
           ),
+      ProcessManager: () => FakeProcessManager.any(),
     });
   });
 
@@ -339,15 +380,23 @@ void main() {
   });
 
   group(FuchsiaIsolateDiscoveryProtocol, () {
+    MockPortForwarder portForwarder;
+    MockVMService vmService;
+    MockVM vm;
+
+    setUp(() {
+      portForwarder = MockPortForwarder();
+      vmService = MockVMService();
+      vm = MockVM();
+
+      when(vm.vmService).thenReturn(vmService);
+      when(vmService.vm).thenReturn(vm);
+    });
+
     Future<Uri> findUri(List<MockFlutterView> views, String expectedIsolateName) {
-      final MockPortForwarder portForwarder = MockPortForwarder();
-      final MockVMService vmService = MockVMService();
-      final MockVM vm = MockVM();
-      vm.vmService = vmService;
-      vmService.vm = vm;
-      vm.views = views;
+      when(vm.views).thenReturn(views);
       for (MockFlutterView view in views) {
-        view.owner = vm;
+        when(view.owner).thenReturn(vm);
       }
       final MockFuchsiaDevice fuchsiaDevice =
           MockFuchsiaDevice('123', portForwarder, false);
@@ -404,11 +453,47 @@ void main() {
     FakeOperatingSystemUtils osUtils;
     FakeFuchsiaDeviceTools fuchsiaDeviceTools;
     MockFuchsiaSdk fuchsiaSdk;
+    MockFuchsiaArtifacts fuchsiaArtifacts;
+    MockArtifacts mockArtifacts;
+
+    File compilerSnapshot;
+    File platformDill;
+    File patchedSdk;
+    File runner;
+
     setUp(() {
       memoryFileSystem = MemoryFileSystem();
       osUtils = FakeOperatingSystemUtils();
       fuchsiaDeviceTools = FakeFuchsiaDeviceTools();
       fuchsiaSdk = MockFuchsiaSdk();
+      fuchsiaArtifacts = MockFuchsiaArtifacts();
+
+      compilerSnapshot = memoryFileSystem.file('kernel_compiler.snapshot')..createSync();
+      platformDill = memoryFileSystem.file('platform_strong.dill')..createSync();
+      patchedSdk = memoryFileSystem.file('flutter_runner_patched_sdk')..createSync();
+      runner = memoryFileSystem.file('flutter_jit_runner')..createSync();
+
+      mockArtifacts = MockArtifacts();
+      when(mockArtifacts.getArtifactPath(
+        Artifact.fuchsiaKernelCompiler,
+        platform: anyNamed('platform'),
+        mode: anyNamed('mode'),
+      )).thenReturn(compilerSnapshot.path);
+      when(mockArtifacts.getArtifactPath(
+        Artifact.fuchsiaPlatformDill,
+        platform: anyNamed('platform'),
+        mode: anyNamed('mode'),
+      )).thenReturn(platformDill.path);
+      when(mockArtifacts.getArtifactPath(
+        Artifact.fuchsiaPatchedSdk,
+        platform: anyNamed('platform'),
+        mode: anyNamed('mode'),
+      )).thenReturn(patchedSdk.path);
+      when(mockArtifacts.getArtifactPath(
+        Artifact.fuchsiaFlutterJitRunner,
+        platform: anyNamed('platform'),
+        mode: anyNamed('mode'),
+      )).thenReturn(runner.path);
     });
 
     Future<LaunchResult> setupAndStartApp({
@@ -434,11 +519,12 @@ void main() {
         app = BuildableFuchsiaApp(project: FlutterProject.current().fuchsia);
       }
 
-      final DebuggingOptions debuggingOptions =
-          DebuggingOptions.disabled(BuildInfo(mode, null));
-      return await device.startApp(app,
-          prebuiltApplication: prebuilt,
-          debuggingOptions: debuggingOptions);
+      final DebuggingOptions debuggingOptions = DebuggingOptions.disabled(BuildInfo(mode, null));
+      return await device.startApp(
+        app,
+        prebuiltApplication: prebuilt,
+        debuggingOptions: debuggingOptions,
+      );
     }
 
     testUsingContext('start prebuilt in release mode', () async {
@@ -447,9 +533,11 @@ void main() {
       expect(launchResult.started, isTrue);
       expect(launchResult.hasObservatory, isFalse);
     }, overrides: <Type, Generator>{
+      Artifacts: () => mockArtifacts,
       FileSystem: () => memoryFileSystem,
       ProcessManager: () => FakeProcessManager.any(),
       FuchsiaDeviceTools: () => fuchsiaDeviceTools,
+      FuchsiaArtifacts: () => fuchsiaArtifacts,
       FuchsiaSdk: () => fuchsiaSdk,
       OperatingSystemUtils: () => osUtils,
     });
@@ -472,9 +560,11 @@ void main() {
       expect(launchResult.hasObservatory, isFalse);
       expect(await device.stopApp(app), isTrue);
     }, overrides: <Type, Generator>{
+      Artifacts: () => mockArtifacts,
       FileSystem: () => memoryFileSystem,
       ProcessManager: () => FakeProcessManager.any(),
       FuchsiaDeviceTools: () => fuchsiaDeviceTools,
+      FuchsiaArtifacts: () => fuchsiaArtifacts,
       FuchsiaSdk: () => fuchsiaSdk,
       OperatingSystemUtils: () => osUtils,
     });
@@ -485,9 +575,11 @@ void main() {
       expect(launchResult.started, isTrue);
       expect(launchResult.hasObservatory, isTrue);
     }, overrides: <Type, Generator>{
+      Artifacts: () => mockArtifacts,
       FileSystem: () => memoryFileSystem,
       ProcessManager: () => FakeProcessManager.any(),
       FuchsiaDeviceTools: () => fuchsiaDeviceTools,
+      FuchsiaArtifacts: () => fuchsiaArtifacts,
       FuchsiaSdk: () => fuchsiaSdk,
       OperatingSystemUtils: () => osUtils,
     });
@@ -498,9 +590,11 @@ void main() {
       expect(launchResult.started, isTrue);
       expect(launchResult.hasObservatory, isFalse);
     }, overrides: <Type, Generator>{
+      Artifacts: () => mockArtifacts,
       FileSystem: () => memoryFileSystem,
       ProcessManager: () => FakeProcessManager.any(),
       FuchsiaDeviceTools: () => fuchsiaDeviceTools,
+      FuchsiaArtifacts: () => fuchsiaArtifacts,
       FuchsiaSdk: () => fuchsiaSdk,
       OperatingSystemUtils: () => osUtils,
     });
@@ -511,9 +605,11 @@ void main() {
       expect(launchResult.started, isTrue);
       expect(launchResult.hasObservatory, isTrue);
     }, overrides: <Type, Generator>{
+      Artifacts: () => mockArtifacts,
       FileSystem: () => memoryFileSystem,
       ProcessManager: () => FakeProcessManager.any(),
       FuchsiaDeviceTools: () => fuchsiaDeviceTools,
+      FuchsiaArtifacts: () => fuchsiaArtifacts,
       FuchsiaSdk: () => fuchsiaSdk,
       OperatingSystemUtils: () => osUtils,
     });
@@ -524,9 +620,11 @@ void main() {
       expect(launchResult.started, isFalse);
       expect(launchResult.hasObservatory, isFalse);
     }, overrides: <Type, Generator>{
+      Artifacts: () => mockArtifacts,
       FileSystem: () => memoryFileSystem,
       ProcessManager: () => FakeProcessManager.any(),
       FuchsiaDeviceTools: () => fuchsiaDeviceTools,
+      FuchsiaArtifacts: () => fuchsiaArtifacts,
       FuchsiaSdk: () => MockFuchsiaSdk(devFinder: FailingDevFinder()),
       OperatingSystemUtils: () => osUtils,
     });
@@ -537,9 +635,11 @@ void main() {
       expect(launchResult.started, isFalse);
       expect(launchResult.hasObservatory, isFalse);
     }, overrides: <Type, Generator>{
+      Artifacts: () => mockArtifacts,
       FileSystem: () => memoryFileSystem,
       ProcessManager: () => FakeProcessManager.any(),
       FuchsiaDeviceTools: () => fuchsiaDeviceTools,
+      FuchsiaArtifacts: () => fuchsiaArtifacts,
       FuchsiaSdk: () => MockFuchsiaSdk(pm: FailingPM()),
       OperatingSystemUtils: () => osUtils,
     });
@@ -550,9 +650,11 @@ void main() {
       expect(launchResult.started, isFalse);
       expect(launchResult.hasObservatory, isFalse);
     }, overrides: <Type, Generator>{
+      Artifacts: () => mockArtifacts,
       FileSystem: () => memoryFileSystem,
       ProcessManager: () => FakeProcessManager.any(),
       FuchsiaDeviceTools: () => FakeFuchsiaDeviceTools(amber: FailingAmberCtl()),
+      FuchsiaArtifacts: () => fuchsiaArtifacts,
       FuchsiaSdk: () => fuchsiaSdk,
       OperatingSystemUtils: () => osUtils,
     });
@@ -563,9 +665,11 @@ void main() {
       expect(launchResult.started, isFalse);
       expect(launchResult.hasObservatory, isFalse);
     }, overrides: <Type, Generator>{
+      Artifacts: () => mockArtifacts,
       FileSystem: () => memoryFileSystem,
       ProcessManager: () => FakeProcessManager.any(),
       FuchsiaDeviceTools: () => FakeFuchsiaDeviceTools(tiles: FailingTilesCtl()),
+      FuchsiaArtifacts: () => fuchsiaArtifacts,
       FuchsiaSdk: () => fuchsiaSdk,
       OperatingSystemUtils: () => osUtils,
     });
@@ -643,10 +747,16 @@ class FuchsiaModulePackage extends ApplicationPackage {
   final String name;
 }
 
+class MockArtifacts extends Mock implements Artifacts {}
+
+class MockFuchsiaArtifacts extends Mock implements FuchsiaArtifacts {}
+
 class MockProcessManager extends Mock implements ProcessManager {}
 
 class MockProcessResult extends Mock implements ProcessResult {}
 
+class MockProcessUtils extends Mock implements ProcessUtils {}
+
 class MockFile extends Mock implements File {}
 
 class MockProcess extends Mock implements Process {}
@@ -690,31 +800,22 @@ class MockFuchsiaDevice extends Mock implements FuchsiaDevice {
   final String id;
   @override
   final DevicePortForwarder portForwarder;
+
+  @override
+  Future<TargetPlatform> get targetPlatform async => TargetPlatform.fuchsia_arm64;
 }
 
 class MockPortForwarder extends Mock implements DevicePortForwarder {}
 
-class MockVMService extends Mock implements VMService {
-  @override
-  VM vm;
-}
+class MockVMService extends Mock implements VMService {}
 
-class MockVM extends Mock implements VM {
-  @override
-  VMService vmService;
-
-  @override
-  List<FlutterView> views;
-}
+class MockVM extends Mock implements VM {}
 
 class MockFlutterView extends Mock implements FlutterView {
   MockFlutterView(this.uiIsolate);
 
   @override
   final Isolate uiIsolate;
-
-  @override
-  ServiceObjectOwner owner;
 }
 
 class MockIsolate extends Mock implements Isolate {
@@ -731,6 +832,9 @@ class FuchsiaDeviceWithFakeDiscovery extends FuchsiaDevice {
   FuchsiaIsolateDiscoveryProtocol getIsolateDiscoveryProtocol(String isolateName) {
     return FakeFuchsiaIsolateDiscoveryProtocol();
   }
+
+  @override
+  Future<TargetPlatform> get targetPlatform async => TargetPlatform.fuchsia_arm64;
 }
 
 class FakeFuchsiaIsolateDiscoveryProtocol implements FuchsiaIsolateDiscoveryProtocol {