Support a configurable build directory (#5601)

This change adds a top-level getBuildDirectory func and funcs for
android, aot, asset, ios build products.

Developers may now add a "build-dir" mapping to their
~/.flutter_settings (JSON format) config file. Output directory is
relative to the main flutter application directory.

This change also changes the default build directory for iOS builds to a
subdirectory of the configured build directory, 'build/ios' by default.

packages/flutter_tools/bin/xcode_backend.sh

@@ -65,7 +65,7 @@ BuildApp() {
 
   AssertExists ${target_path}
 
-  local build_dir=${SYMROOT:-build}
+  local build_dir=${FLUTTER_BUILD_DIR:-build}
   local local_engine_flag=""
   if [[ -n "$LOCAL_ENGINE" ]]; then
     local_engine_flag="--local-engine=$LOCAL_ENGINE"

packages/flutter_tools/lib/src/application_package.dart

@@ -83,7 +83,7 @@ class AndroidApk extends ApplicationPackage {
       apkPath = gradleAppOut;
     } else {
       manifestPath = path.join('android', 'AndroidManifest.xml');
-      apkPath = path.join('build', 'app.apk');
+      apkPath = path.join(getAndroidBuildDirectory(), 'app.apk');
     }
 
     if (!FileSystemEntity.isFileSync(manifestPath))
@@ -157,7 +157,7 @@ class IOSApp extends ApplicationPackage {
   String get deviceBundlePath => _buildAppPath('iphoneos');
 
   String _buildAppPath(String type) {
-    return path.join(appDirectory, 'build', 'Release-$type', kBundleName);
+    return path.join(getIosBuildDirectory(), 'Release-$type', kBundleName);
   }
 }
 

packages/flutter_tools/lib/src/asset.dart

@@ -10,6 +10,7 @@ import 'package:json_schema/json_schema.dart';
 import 'package:path/path.dart' as path;
 import 'package:yaml/yaml.dart';
 
+import 'build_info.dart';
 import 'cache.dart';
 import 'dart/package_map.dart';
 import 'globals.dart';
@@ -48,7 +49,6 @@ class AssetBundle {
   final Set<AssetBundleEntry> entries = new Set<AssetBundleEntry>();
 
   static const String defaultManifestPath = 'flutter.yaml';
-  static const String defaultWorkingDirPath = 'build/flx';
   static const String _kFontSetMaterial = 'material';
   static const String _kFontSetRoboto = 'roboto';
 
@@ -67,10 +67,11 @@ class AssetBundle {
 
   Future<int> build({
     String manifestPath: defaultManifestPath,
-    String workingDirPath: defaultWorkingDirPath,
+    String workingDirPath,
     bool includeRobotoFonts: true,
     bool reportLicensedPackages: false
   }) async {
+    workingDirPath ??= getAssetBuildDirectory();
     Object manifest = _loadFlutterYamlManifest(manifestPath);
     if (manifest == null) {
       // No manifest file found for this application.
@@ -94,7 +95,7 @@ class AssetBundle {
       packageMap,
       manifestDescriptor,
       assetBasePath,
-      excludeDirs: <String>[workingDirPath, path.join(assetBasePath, 'build')]
+      excludeDirs: <String>[workingDirPath, getBuildDirectory()]
     );
 
     if (assetVariants == null)

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

@@ -19,6 +19,8 @@ class Config {
   static Config get instance => context[Config] ?? (context[Config] = new Config());
 
   File _configFile;
+  String get configPath => _configFile.path;
+
   Map<String, dynamic> _values = <String, dynamic>{};
 
   Iterable<String> get keys => _values.keys;

packages/flutter_tools/lib/src/build_info.dart

@@ -4,6 +4,8 @@
 
 import 'dart:io';
 
+import 'package:path/path.dart' as path;
+
 import 'base/utils.dart';
 import 'globals.dart';
 
@@ -113,3 +115,34 @@ HostPlatform getCurrentHostPlatform() {
 
   return HostPlatform.linux_x64;
 }
+
+/// Returns the top-level build output directory.
+String getBuildDirectory() {
+  String buildDir = config.getValue('build-dir') ?? 'build';
+  if (path.isAbsolute(buildDir)) {
+    throw new Exception(
+        'build-dir config setting in ${config.configPath} must be relative');
+  }
+  return buildDir;
+}
+
+/// Returns the Android build output directory.
+String getAndroidBuildDirectory() {
+  // TODO(cbracken) move to android subdir.
+  return getBuildDirectory();
+}
+
+/// Returns the AOT build output directory.
+String getAotBuildDirectory() {
+  return path.join(getBuildDirectory(), 'aot');
+}
+
+/// Returns the asset build output directory.
+String getAssetBuildDirectory() {
+  return path.join(getBuildDirectory(), 'flx');
+}
+
+/// Returns the iOS build output directory.
+String getIosBuildDirectory() {
+  return path.join(getBuildDirectory(), 'ios');
+}

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

@@ -7,6 +7,7 @@ import 'dart:io';
 
 import 'package:meta/meta.dart';
 
+import '../build_info.dart';
 import '../globals.dart';
 import '../runner/flutter_command.dart';
 import '../base/utils.dart';
@@ -66,7 +67,7 @@ class BuildCleanCommand extends FlutterCommand {
 
   @override
   Future<int> runInProject() async {
-    Directory buildDir = new Directory('build');
+    Directory buildDir = new Directory(getBuildDirectory());
     printStatus("Deleting '${buildDir.path}${Platform.pathSeparator}'.");
 
     if (!buildDir.existsSync())

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

@@ -16,8 +16,6 @@ import '../globals.dart';
 import '../resident_runner.dart';
 import 'build.dart';
 
-const String _kDefaultAotOutputDir = 'build/aot';
-
 // Files generated by the ahead-of-time snapshot builder.
 const List<String> kAotSnapshotFiles = const <String>[
   'snapshot_aot_instr', 'snapshot_aot_isolate', 'snapshot_aot_rodata', 'snapshot_aot_vmisolate',
@@ -29,7 +27,7 @@ class BuildAotCommand extends BuildSubCommand {
     addBuildModeFlags();
     usesPubOption();
     argParser
-      ..addOption('output-dir', defaultsTo: _kDefaultAotOutputDir)
+      ..addOption('output-dir', defaultsTo: getAotBuildDirectory())
       ..addOption('target-platform',
         defaultsTo: 'android-arm',
         allowed: <String>['android-arm', 'ios']
@@ -82,9 +80,10 @@ Future<String> buildAotSnapshot(
   String mainPath,
   TargetPlatform platform,
   BuildMode buildMode, {
-  String outputPath: _kDefaultAotOutputDir,
+  String outputPath,
   bool interpreter: false
 }) async {
+  outputPath ??= getAotBuildDirectory();
   try {
     return _buildAotSnapshot(
       mainPath,
@@ -104,9 +103,10 @@ Future<String> _buildAotSnapshot(
   String mainPath,
   TargetPlatform platform,
   BuildMode buildMode, {
-  String outputPath: _kDefaultAotOutputDir,
+  String outputPath,
   bool interpreter: false
 }) async {
+  outputPath ??= getAotBuildDirectory();
   if (!isAotBuildMode(buildMode) && !interpreter) {
     printError('${toTitleCase(getModeName(buildMode))} mode does not support AOT compilation.');
     return null;

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

@@ -26,7 +26,6 @@ import 'build.dart';
 export '../android/android_device.dart' show AndroidDevice;
 
 const String _kDefaultAndroidManifestPath = 'android/AndroidManifest.xml';
-const String _kDefaultOutputPath = 'build/app.apk';
 const String _kDefaultResourcesPath = 'android/res';
 const String _kDefaultAssetsPath = 'android/assets';
 
@@ -39,6 +38,9 @@ const String _kDebugKeystoreKeyAlias = "chromiumdebugkey";
 // Password for the Chromium debug keystore
 const String _kDebugKeystorePassword = "chromium";
 
+// Default APK output path.
+String get _defaultOutputPath => path.join(getAndroidBuildDirectory(), 'app.apk');
+
 /// Copies files into a new directory structure.
 class _AssetBuilder {
   final Directory outDir;
@@ -174,7 +176,7 @@ class BuildApkCommand extends BuildSubCommand {
       help: 'Resources directory path.');
     argParser.addOption('output-file',
       abbr: 'o',
-      defaultsTo: _kDefaultOutputPath,
+      defaultsTo: _defaultOutputPath,
       help: 'Output APK file.');
     argParser.addOption('flx',
       abbr: 'f',
@@ -443,12 +445,14 @@ Future<int> buildAndroid(
   bool force: false,
   String manifest: _kDefaultAndroidManifestPath,
   String resources,
-  String outputFile: _kDefaultOutputPath,
+  String outputFile,
   String target,
   String flxPath,
   String aotPath,
   ApkKeystoreInfo keystore
 }) async {
+  outputFile ??= _defaultOutputPath;
+
   // Validate that we can find an android sdk.
   if (androidSdk == null) {
     printError('No Android SDK found. Try setting the ANDROID_HOME environment variable.');

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

@@ -4,6 +4,7 @@
 
 import 'dart:async';
 
+import '../build_info.dart';
 import '../flx.dart';
 import '../globals.dart';
 import 'build.dart';
@@ -20,7 +21,7 @@ class BuildFlxCommand extends BuildSubCommand {
     argParser.addOption('output-file', abbr: 'o', defaultsTo: defaultFlxOutputPath);
     argParser.addOption('snapshot', defaultsTo: defaultSnapshotPath);
     argParser.addOption('depfile', defaultsTo: defaultDepfilePath);
-    argParser.addOption('working-dir', defaultsTo: defaultWorkingDirPath);
+    argParser.addOption('working-dir', defaultsTo: getAssetBuildDirectory());
     argParser.addFlag('include-roboto-fonts', defaultsTo: true);
     argParser.addFlag('report-licensed-packages', help: 'Whether to report the names of all the packages that are included in the application\'s LICENSE file.', defaultsTo: false);
     usesPubOption();

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

@@ -15,7 +15,7 @@ import '../globals.dart';
 import '../resident_runner.dart';
 import '../runner/flutter_command.dart';
 
-const String _kDefaultBundlePath = 'build/app.flx';
+String get _defaultBundlePath => path.join(getBuildDirectory(), 'app.flx');
 
 class RunMojoCommand extends FlutterCommand {
   RunMojoCommand({ this.hidden: false }) {
@@ -140,7 +140,7 @@ class RunMojoCommand extends FlutterCommand {
 
     String targetApp = argResults['app'];
     if (targetApp == null) {
-      targetApp = _kDefaultBundlePath;
+      targetApp = _defaultBundlePath;
 
       String mainPath = findMainDartFile(argResults['target']);
 

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

@@ -6,8 +6,11 @@ import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
 
+import 'package:path/path.dart' as path;
+
 import '../base/common.dart';
 import '../base/utils.dart';
+import '../build_info.dart';
 import '../cache.dart';
 import '../globals.dart';
 import '../vmservice.dart';
@@ -153,7 +156,8 @@ class Tracing {
 /// Download the startup trace information from the given observatory client and
 /// store it to build/start_up_info.json.
 Future<Null> downloadStartupTrace(VMService observatory) async {
-  File traceInfoFile = new File('build/start_up_info.json');
+  String traceInfoFilePath = path.join(getBuildDirectory(), 'start_up_info.json');
+  File traceInfoFile = new File(traceInfoFilePath);
 
   // Delete old startup data, if any.
   if (await traceInfoFile.exists())

packages/flutter_tools/lib/src/devfs.dart

@@ -9,6 +9,7 @@ import 'dart:io';
 import 'package:path/path.dart' as path;
 
 import 'base/logger.dart';
+import 'build_info.dart';
 import 'dart/package_map.dart';
 import 'asset.dart';
 import 'globals.dart';
@@ -335,9 +336,10 @@ class DevFS {
       status = logger.startProgress('Scanning asset files...');
       // Synchronize asset bundle.
       for (AssetBundleEntry entry in bundle.entries) {
-        // We write the assets into 'build/flx' so that they are in the
-        // same location in DevFS and the iOS simulator.
-        final String devicePath = path.join('build/flx', entry.archivePath);
+        // We write the assets into the AssetBundle working dir so that they
+        // are in the same location in DevFS and the iOS simulator.
+        final String devicePath =
+            path.join(getAssetBuildDirectory(), entry.archivePath);
         _scanBundleEntry(devicePath, entry, bundleDirty);
       }
       status.stop(showElapsedTime: true);
@@ -457,7 +459,7 @@ class DevFS {
 
   bool _shouldIgnore(String devicePath) {
     List<String> ignoredPrefixes = <String>['android/',
-                                            'build/',
+                                            getBuildDirectory(),
                                             'ios/',
                                             '.pub/'];
     for (String ignoredPrefix in ignoredPrefixes) {

packages/flutter_tools/lib/src/flx.dart

@@ -11,6 +11,7 @@ import 'asset.dart';
 import 'base/file_system.dart' show ensureDirectoryExists;
 import 'base/process.dart';
 import 'dart/package_map.dart';
+import 'build_info.dart';
 import 'globals.dart';
 import 'toolchain.dart';
 import 'zip.dart';
@@ -18,11 +19,10 @@ import 'zip.dart';
 const String defaultMainPath = 'lib/main.dart';
 const String defaultAssetBasePath = '.';
 const String defaultManifestPath = 'flutter.yaml';
-const String defaultFlxOutputPath = 'build/app.flx';
-const String defaultSnapshotPath = 'build/snapshot_blob.bin';
-const String defaultDepfilePath = 'build/snapshot_blob.bin.d';
+String get defaultFlxOutputPath => path.join(getBuildDirectory(), 'app.flx');
+String get defaultSnapshotPath => path.join(getBuildDirectory(), 'snapshot_blob.bin');
+String get defaultDepfilePath => path.join(getBuildDirectory(), 'snapshot_blob.bin.d');
 const String defaultPrivateKeyPath = 'privatekey.der';
-const String defaultWorkingDirPath = 'build/flx';
 
 const String _kSnapshotKey = 'snapshot_blob.bin';
 
@@ -47,7 +47,7 @@ Future<int> createSnapshot({
   return runCommandAndStreamOutput(args);
 }
 
-/// Build the flx in the build/ directory and return `localBundlePath` on success.
+/// Build the flx in the build directory and return `localBundlePath` on success.
 ///
 /// Return `null` on failure.
 Future<String> buildFlx({
@@ -56,30 +56,32 @@ Future<String> buildFlx({
   bool includeRobotoFonts: true
 }) async {
   int result;
-  String localBundlePath = path.join('build', 'app.flx');
-  String localSnapshotPath = path.join('build', 'snapshot_blob.bin');
   result = await build(
-    snapshotPath: localSnapshotPath,
-    outputPath: localBundlePath,
+    snapshotPath: defaultSnapshotPath,
+    outputPath: defaultFlxOutputPath,
     mainPath: mainPath,
     precompiledSnapshot: precompiledSnapshot,
     includeRobotoFonts: includeRobotoFonts
   );
-  return result == 0 ? localBundlePath : null;
+  return result == 0 ? defaultFlxOutputPath : null;
 }
 
 Future<int> build({
   String mainPath: defaultMainPath,
   String manifestPath: defaultManifestPath,
-  String outputPath: defaultFlxOutputPath,
-  String snapshotPath: defaultSnapshotPath,
-  String depfilePath: defaultDepfilePath,
+  String outputPath,
+  String snapshotPath,
+  String depfilePath,
   String privateKeyPath: defaultPrivateKeyPath,
-  String workingDirPath: defaultWorkingDirPath,
+  String workingDirPath,
   bool precompiledSnapshot: false,
   bool includeRobotoFonts: true,
   bool reportLicensedPackages: false
 }) async {
+  outputPath ??= defaultFlxOutputPath;
+  snapshotPath ??= defaultSnapshotPath;
+  depfilePath ??= defaultDepfilePath;
+  workingDirPath ??= getAssetBuildDirectory();
   File snapshotFile;
 
   if (!precompiledSnapshot) {
@@ -114,12 +116,14 @@ Future<int> build({
 Future<int> assemble({
   String manifestPath,
   File snapshotFile,
-  String outputPath: defaultFlxOutputPath,
+  String outputPath,
   String privateKeyPath: defaultPrivateKeyPath,
-  String workingDirPath: defaultWorkingDirPath,
+  String workingDirPath,
   bool includeRobotoFonts: true,
   bool reportLicensedPackages: false
 }) async {
+  outputPath ??= defaultFlxOutputPath;
+  workingDirPath ??= getAssetBuildDirectory();
   printTrace('Building $outputPath');
 
   // Build the asset bundle.

packages/flutter_tools/lib/src/hot.dart

@@ -13,6 +13,7 @@ import 'asset.dart';
 import 'base/logger.dart';
 import 'base/process.dart';
 import 'base/utils.dart';
+import 'build_info.dart';
 import 'cache.dart';
 import 'commands/build_apk.dart';
 import 'commands/install.dart';
@@ -380,7 +381,7 @@ class HotRunner extends ResidentRunner {
     String devicePackagesPath =
         _devFS.baseUri.resolve('.packages').toFilePath();
     String deviceAssetsDirectoryPath =
-        _devFS.baseUri.resolve('build/flx').toFilePath();
+        _devFS.baseUri.resolve(getAssetBuildDirectory()).toFilePath();
     await _launchInView(deviceEntryPath,
                         devicePackagesPath,
                         deviceAssetsDirectoryPath);

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

@@ -28,6 +28,11 @@ void updateXcodeGeneratedProperties(String projectPath, BuildMode mode, String t
   // The runtime mode for the current build.
   localsBuffer.writeln('FLUTTER_BUILD_MODE=${getModeName(mode)}');
 
+  // The build outputs directory, relative to FLUTTER_APPLICATION_PATH.
+  localsBuffer.writeln('FLUTTER_BUILD_DIR=${getBuildDirectory()}');
+
+  localsBuffer.writeln('SYMROOT=\${SOURCE_ROOT}/../${getIosBuildDirectory()}');
+
   String flutterFrameworkDir = path.normalize(tools.getEngineArtifactsDirectory(TargetPlatform.ios, mode).path);
   localsBuffer.writeln('FLUTTER_FRAMEWORK_DIR=$flutterFrameworkDir');
 

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

@@ -476,7 +476,7 @@ class IOSSimulator extends Device {
 
     // Prepare launch arguments.
     List<String> args = <String>[
-      "--flx=${path.absolute(path.join('build', 'app.flx'))}",
+      "--flx=${path.absolute(path.join(getBuildDirectory(), 'app.flx'))}",
       "--dart-main=${path.absolute(mainPath)}",
       "--packages=${path.absolute('.packages')}",
     ];

packages/flutter_tools/test/devfs_test.dart

@@ -5,6 +5,7 @@
 import 'dart:io';
 
 import 'package:flutter_tools/src/asset.dart';
+import 'package:flutter_tools/src/build_info.dart';
 import 'package:flutter_tools/src/devfs.dart';
 import 'package:path/path.dart' as path;
 import 'package:test/test.dart';
@@ -59,17 +60,20 @@ void main() {
     });
     testUsingContext('add file in an asset bundle', () async {
       await devFS.update(bundle: assetBundle, bundleDirty: true);
-      expect(devFSOperations.contains('writeFile test build/flx/a.txt'), isTrue);
+      expect(devFSOperations.contains(
+          'writeFile test ${getAssetBuildDirectory()}/a.txt'), isTrue);
     });
     testUsingContext('add a file to the asset bundle', () async {
       assetBundle.entries.add(new AssetBundleEntry.fromString('b.txt', ''));
       await devFS.update(bundle: assetBundle, bundleDirty: true);
-      expect(devFSOperations.contains('writeFile test build/flx/b.txt'), isTrue);
+      expect(devFSOperations.contains(
+          'writeFile test ${getAssetBuildDirectory()}/b.txt'), isTrue);
     });
     testUsingContext('delete a file from the asset bundle', () async {
       assetBundle.entries.clear();
       await devFS.update(bundle: assetBundle, bundleDirty: true);
-      expect(devFSOperations.contains('deleteFile test build/flx/b.txt'), isTrue);
+      expect(devFSOperations.contains(
+          'deleteFile test ${getAssetBuildDirectory()}/b.txt'), isTrue);
     });
     testUsingContext('delete dev file system', () async {
       await devFS.destroy();