New "build mojo" command to build flx files for Fuchsia. (#6112)

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

@@ -15,6 +15,7 @@ import 'build_apk.dart';
 import 'build_aot.dart';
 import 'build_flx.dart';
 import 'build_ios.dart';
+import 'build_mojo.dart';
 
 class BuildCommand extends FlutterCommand {
   BuildCommand({bool verboseHelp: false}) {
@@ -23,6 +24,7 @@ class BuildCommand extends FlutterCommand {
     addSubcommand(new BuildCleanCommand());
     addSubcommand(new BuildIOSCommand());
     addSubcommand(new BuildFlxCommand(verboseHelp: verboseHelp));
+    addSubcommand(new BuildMojoCommand());
   }
 
   @override

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

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'dart:async';
+
+import '../flx.dart';
+import '../globals.dart';
+import 'build.dart';
+
+const String _kOptionSnapshotter = 'snapshotter-path';
+const String _kOptionTarget = 'target';
+const String _kOptionPackages = 'packages';
+const String _kOptionOutput = 'output-file';
+const String _kOptionSnapshot = 'snapshot';
+const String _kOptionDepfile = 'depfile';
+const String _kOptionWorking = 'working-dir';
+const List<String> _kOptions = const <String>[
+  _kOptionSnapshotter,
+  _kOptionTarget,
+  _kOptionPackages,
+  _kOptionOutput,
+  _kOptionSnapshot,
+  _kOptionDepfile,
+  _kOptionWorking
+];
+
+class BuildMojoCommand extends BuildSubCommand {
+  BuildMojoCommand({bool verboseHelp: false}) {
+    argParser.addOption(_kOptionSnapshotter,
+        help: 'The snapshotter executable');
+    argParser.addOption(_kOptionTarget, help: 'The entry point into the app');
+    argParser.addOption(_kOptionPackages, help: 'The .packages file');
+    argParser.addOption(_kOptionOutput, help: 'The generated flx file');
+    argParser.addOption(_kOptionSnapshot, help: 'The generated snapshot file');
+    argParser.addOption(_kOptionDepfile, help: 'The generated dependency file');
+    argParser.addOption(_kOptionWorking,
+        help: 'The directory where to put temporary files');
+    commandValidator = () => true;
+  }
+
+  @override
+  final String name = 'mojo';
+
+  @override
+  final String description = 'Build a Flutter FLX file for Mojo.';
+
+  @override
+  final String usageFooter =
+      'FLX files are archives of your application code and resources; '
+      'they are used by the Flutter content handler.';
+
+  @override
+  Future<int> runCommand() async {
+    await super.runCommand();
+    if (_kOptions
+        .any((String option) => !argResults.options.contains(option))) {
+      printError('Missing option! All options must be specified.');
+      return 1;
+    }
+    String outputPath = argResults[_kOptionOutput];
+    return await build(
+      snapshotterPath: argResults[_kOptionSnapshotter],
+      mainPath: argResults[_kOptionTarget],
+      outputPath: outputPath,
+      snapshotPath: argResults[_kOptionSnapshot],
+      depfilePath: argResults[_kOptionDepfile],
+      workingDirPath: argResults[_kOptionWorking],
+      packagesPath: argResults[_kOptionPackages],
+      includeRobotoFonts: true,
+    ).then((int result) {
+      if (result != 0) {
+        printError('Error building $outputPath: $result.');
+      }
+      return result;
+    });
+  }
+}

packages/flutter_tools/lib/src/flx.dart

@@ -27,16 +27,20 @@ const String defaultPrivateKeyPath = 'privatekey.der';
 const String _kSnapshotKey = 'snapshot_blob.bin';
 
 Future<int> createSnapshot({
+  String snapshotterPath,
   String mainPath,
   String snapshotPath,
-  String depfilePath
+  String depfilePath,
+  String packages
 }) {
+  assert(snapshotterPath != null);
   assert(mainPath != null);
   assert(snapshotPath != null);
+  assert(packages != null);
 
   final List<String> args = <String>[
-    tools.getHostToolPath(HostTool.SkySnapshot),
-    '--packages=${path.absolute(PackageMap.globalPackagesPath)}',
+    snapshotterPath,
+    '--packages=$packages',
     '--snapshot=$snapshotPath'
   ];
   if (depfilePath != null) {
@@ -67,6 +71,7 @@ Future<String> buildFlx({
 }
 
 Future<int> build({
+  String snapshotterPath,
   String mainPath: defaultMainPath,
   String manifestPath: defaultManifestPath,
   String outputPath,
@@ -74,14 +79,17 @@ Future<int> build({
   String depfilePath,
   String privateKeyPath: defaultPrivateKeyPath,
   String workingDirPath,
+  String packagesPath,
   bool precompiledSnapshot: false,
   bool includeRobotoFonts: true,
   bool reportLicensedPackages: false
 }) async {
+  snapshotterPath ??= tools.getHostToolPath(HostTool.SkySnapshot);
   outputPath ??= defaultFlxOutputPath;
   snapshotPath ??= defaultSnapshotPath;
   depfilePath ??= defaultDepfilePath;
   workingDirPath ??= getAssetBuildDirectory();
+  packagesPath ??= path.absolute(PackageMap.globalPackagesPath);
   File snapshotFile;
 
   if (!precompiledSnapshot) {
@@ -90,9 +98,11 @@ Future<int> build({
     // In a precompiled snapshot, the instruction buffer contains script
     // content equivalents
     int result = await createSnapshot(
+      snapshotterPath: snapshotterPath,
       mainPath: mainPath,
       snapshotPath: snapshotPath,
-      depfilePath: depfilePath
+      depfilePath: depfilePath,
+      packages: packagesPath
     );
     if (result != 0) {
       printError('Failed to run the Flutter compiler. Exit code: $result');