Native assets: package in framework on iOS and MacOS (#140907)

Packages the native assets for iOS and MacOS in frameworks.

Issue:

* flutter/flutter#140544
* flutter/flutter#129757

## Details

* [x] This packages dylibs from the native assets feature in frameworks. It packages every dylib in a separate framework.
* [x] The dylib name is updated to use `@rpath` instead of `@executable_path`.
* [x] The dylibs for flutter-tester are no longer modified to change the install name. (Previously it was wrongly updating the install name to the location the dylib would have once deployed in an app.)
* [x] Use symlinking on MacOS.

Author: dcharkes

dev/devicelab/bin/tasks/module_test_ios.dart

@@ -250,9 +250,7 @@ dependencies:
       checkDirectoryNotExists(path.join(ephemeralIOSHostApp.path, 'Frameworks', '$dartPluginName.framework'));
 
       // Native assets embedded, no embedded framework.
-      const String libFfiPackageDylib = 'lib$ffiPackageName.dylib';
-      checkFileExists(path.join(ephemeralIOSHostApp.path, 'Frameworks', libFfiPackageDylib));
-      checkDirectoryNotExists(path.join(ephemeralIOSHostApp.path, 'Frameworks', '$ffiPackageName.framework'));
+      checkFileExists(path.join(ephemeralIOSHostApp.path, 'Frameworks', '$ffiPackageName.framework', ffiPackageName));
 
       section('Clean and pub get module');
 
@@ -385,7 +383,8 @@ end
 
       checkFileExists(path.join(
         hostFrameworksDirectory,
-        libFfiPackageDylib,
+        '$ffiPackageName.framework',
+        ffiPackageName,
       ));
 
       section('Check the NOTICE file is correct');
@@ -491,7 +490,8 @@ end
         checkFileExists(path.join(
           archivedAppPath,
           'Frameworks',
-          libFfiPackageDylib,
+          '$ffiPackageName.framework',
+          ffiPackageName,
         ));
 
         // The host app example builds plugins statically, url_launcher_ios.framework

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

@@ -106,7 +106,7 @@ Future<List<Uri>> buildNativeAssetsIOS({
   ensureNoLinkModeStatic(nativeAssets);
   globals.logger.printTrace('Building native assets for $targets done.');
   final Map<AssetPath, List<Asset>> fatAssetTargetLocations = _fatAssetTargetLocations(nativeAssets);
-  await copyNativeAssetsMacOSHost(
+  await _copyNativeAssetsIOS(
     buildUri,
     fatAssetTargetLocations,
     codesignIdentity,
@@ -145,21 +145,25 @@ Target _getNativeTarget(DarwinArch darwinArch) {
 }
 
 Map<AssetPath, List<Asset>> _fatAssetTargetLocations(List<Asset> nativeAssets) {
+  final Set<String> alreadyTakenNames = <String>{};
   final Map<AssetPath, List<Asset>> result = <AssetPath, List<Asset>>{};
   for (final Asset asset in nativeAssets) {
-    final AssetPath path = _targetLocationIOS(asset).path;
+    final AssetPath path = _targetLocationIOS(asset, alreadyTakenNames).path;
     result[path] ??= <Asset>[];
     result[path]!.add(asset);
   }
   return result;
 }
 
-Map<Asset, Asset> _assetTargetLocations(List<Asset> nativeAssets) => <Asset, Asset>{
-  for (final Asset asset in nativeAssets)
-    asset: _targetLocationIOS(asset),
-};
+Map<Asset, Asset> _assetTargetLocations(List<Asset> nativeAssets) {
+  final Set<String> alreadyTakenNames = <String>{};
+  return <Asset, Asset>{
+    for (final Asset asset in nativeAssets)
+      asset: _targetLocationIOS(asset, alreadyTakenNames),
+  };
+}
 
-Asset _targetLocationIOS(Asset asset) {
+Asset _targetLocationIOS(Asset asset, Set<String> alreadyTakenNames) {
   final AssetPath path = asset.path;
   switch (path) {
     case AssetSystemPath _:
@@ -168,7 +172,52 @@ Asset _targetLocationIOS(Asset asset) {
       return asset;
     case AssetAbsolutePath _:
       final String fileName = path.uri.pathSegments.last;
-      return asset.copyWith(path: AssetAbsolutePath(Uri(path: fileName)));
+      return asset.copyWith(
+        path: AssetAbsolutePath(frameworkUri(fileName, alreadyTakenNames)),
+      );
+  }
+  throw Exception(
+      'Unsupported asset path type ${path.runtimeType} in asset $asset');
+}
+
+/// Copies native assets into a framework per dynamic library.
+///
+/// For `flutter run -release` a multi-architecture solution is needed. So,
+/// `lipo` is used to combine all target architectures into a single file.
+///
+/// The install name is set so that it matches what the place it will
+/// be bundled in the final app.
+///
+/// Code signing is also done here, so that it doesn't have to be done in
+/// in xcode_backend.dart.
+Future<void> _copyNativeAssetsIOS(
+  Uri buildUri,
+  Map<AssetPath, List<Asset>> assetTargetLocations,
+  String? codesignIdentity,
+  BuildMode buildMode,
+  FileSystem fileSystem,
+) async {
+  if (assetTargetLocations.isNotEmpty) {
+    globals.logger
+        .printTrace('Copying native assets to ${buildUri.toFilePath()}.');
+    for (final MapEntry<AssetPath, List<Asset>> assetMapping
+        in assetTargetLocations.entries) {
+      final Uri target = (assetMapping.key as AssetAbsolutePath).uri;
+      final List<Uri> sources = <Uri>[
+        for (final Asset source in assetMapping.value)
+          (source.path as AssetAbsolutePath).uri
+      ];
+      final Uri targetUri = buildUri.resolveUri(target);
+      final File dylibFile = fileSystem.file(targetUri);
+      final Directory frameworkDir = dylibFile.parent;
+      if (!await frameworkDir.exists()) {
+        await frameworkDir.create(recursive: true);
+      }
+      await lipoDylibs(dylibFile, sources);
+      await setInstallNameDylib(dylibFile);
+      await createInfoPlist(targetUri.pathSegments.last, frameworkDir);
+      await codesignDylib(codesignIdentity, buildMode, frameworkDir);
+    }
+    globals.logger.printTrace('Copying native assets done.');
   }
-  throw Exception('Unsupported asset path type ${path.runtimeType} in asset $asset');
 }

packages/flutter_tools/lib/src/macos/native_assets.dart

@@ -108,7 +108,23 @@ Future<(Uri? nativeAssetsYaml, List<Uri> dependencies)> buildNativeAssetsMacOS({
   final Uri? absolutePath = flutterTester ? buildUri : null;
   final Map<Asset, Asset> assetTargetLocations = _assetTargetLocations(nativeAssets, absolutePath);
   final Map<AssetPath, List<Asset>> fatAssetTargetLocations = _fatAssetTargetLocations(nativeAssets, absolutePath);
-  await copyNativeAssetsMacOSHost(buildUri, fatAssetTargetLocations, codesignIdentity, buildMode, fileSystem);
+  if (flutterTester) {
+    await _copyNativeAssetsMacOSFlutterTester(
+      buildUri,
+      fatAssetTargetLocations,
+      codesignIdentity,
+      buildMode,
+      fileSystem,
+    );
+  } else {
+    await _copyNativeAssetsMacOS(
+      buildUri,
+      fatAssetTargetLocations,
+      codesignIdentity,
+      buildMode,
+      fileSystem,
+    );
+  }
   final Uri nativeAssetsUri = await writeNativeAssetsYaml(assetTargetLocations.values, yamlParentDirectory ?? buildUri, fileSystem);
   return (nativeAssetsUri, dependencies.toList());
 }
@@ -125,22 +141,40 @@ Target _getNativeTarget(DarwinArch darwinArch) {
   }
 }
 
-Map<AssetPath, List<Asset>> _fatAssetTargetLocations(List<Asset> nativeAssets, Uri? absolutePath) {
+Map<AssetPath, List<Asset>> _fatAssetTargetLocations(
+  List<Asset> nativeAssets,
+  Uri? absolutePath,
+) {
+  final Set<String> alreadyTakenNames = <String>{};
   final Map<AssetPath, List<Asset>> result = <AssetPath, List<Asset>>{};
   for (final Asset asset in nativeAssets) {
-    final AssetPath path = _targetLocationMacOS(asset, absolutePath).path;
+    final AssetPath path = _targetLocationMacOS(
+      asset,
+      absolutePath,
+      alreadyTakenNames,
+    ).path;
     result[path] ??= <Asset>[];
     result[path]!.add(asset);
   }
   return result;
 }
 
-Map<Asset, Asset> _assetTargetLocations(List<Asset> nativeAssets, Uri? absolutePath) => <Asset, Asset>{
-  for (final Asset asset in nativeAssets)
-    asset: _targetLocationMacOS(asset, absolutePath),
-};
+Map<Asset, Asset> _assetTargetLocations(
+  List<Asset> nativeAssets,
+  Uri? absolutePath,
+) {
+  final Set<String> alreadyTakenNames = <String>{};
+  return <Asset, Asset>{
+    for (final Asset asset in nativeAssets)
+      asset: _targetLocationMacOS(asset, absolutePath, alreadyTakenNames),
+  };
+}
 
-Asset _targetLocationMacOS(Asset asset, Uri? absolutePath) {
+Asset _targetLocationMacOS(
+  Asset asset,
+  Uri? absolutePath,
+  Set<String> alreadyTakenNames,
+) {
   final AssetPath path = asset.path;
   switch (path) {
     case AssetSystemPath _:
@@ -157,9 +191,119 @@ Asset _targetLocationMacOS(Asset asset, Uri? absolutePath) {
         // Flutter Desktop needs "absolute" paths inside the app.
         // "relative" in the context of native assets would be relative to the
         // kernel or aot snapshot.
-        uri = Uri(path: fileName);
+        uri = frameworkUri(fileName, alreadyTakenNames);
+
       }
       return asset.copyWith(path: AssetAbsolutePath(uri));
   }
   throw Exception('Unsupported asset path type ${path.runtimeType} in asset $asset');
 }
+
+/// Copies native assets into a framework per dynamic library.
+///
+/// The framework contains symlinks according to
+/// https://developer.apple.com/library/archive/documentation/MacOSX/Conceptual/BPFrameworks/Concepts/FrameworkAnatomy.html
+///
+/// For `flutter run -release` a multi-architecture solution is needed. So,
+/// `lipo` is used to combine all target architectures into a single file.
+///
+/// The install name is set so that it matches what the place it will
+/// be bundled in the final app.
+///
+/// Code signing is also done here, so that it doesn't have to be done in
+/// in macos_assemble.sh.
+Future<void> _copyNativeAssetsMacOS(
+  Uri buildUri,
+  Map<AssetPath, List<Asset>> assetTargetLocations,
+  String? codesignIdentity,
+  BuildMode buildMode,
+  FileSystem fileSystem,
+) async {
+  if (assetTargetLocations.isNotEmpty) {
+    globals.logger.printTrace('Copying native assets to ${buildUri.toFilePath()}.');
+    for (final MapEntry<AssetPath, List<Asset>> assetMapping in assetTargetLocations.entries) {
+      final Uri target = (assetMapping.key as AssetAbsolutePath).uri;
+      final List<Uri> sources = <Uri>[
+        for (final Asset source in assetMapping.value)
+          (source.path as AssetAbsolutePath).uri,
+      ];
+      final Uri targetUri = buildUri.resolveUri(target);
+      final String name = targetUri.pathSegments.last;
+      final Directory frameworkDir = fileSystem.file(targetUri).parent;
+      if (await frameworkDir.exists()) {
+        await frameworkDir.delete(recursive: true);
+      }
+      // MyFramework.framework/                           frameworkDir
+      //   MyFramework  -> Versions/Current/MyFramework   dylibLink
+      //   Resources    -> Versions/Current/Resources     resourcesLink
+      //   Versions/                                      versionsDir
+      //     A/                                           versionADir
+      //       MyFramework                                dylibFile
+      //       Resources/                                 resourcesDir
+      //         Info.plist
+      //     Current  -> A                                currentLink
+      final Directory versionsDir = frameworkDir.childDirectory('Versions');
+      final Directory versionADir = versionsDir.childDirectory('A');
+      final Directory resourcesDir = versionADir.childDirectory('Resources');
+      await resourcesDir.create(recursive: true);
+      final File dylibFile = versionADir.childFile(name);
+      final Link currentLink = versionsDir.childLink('Current');
+      await currentLink.create(fileSystem.path.relative(
+        versionADir.path,
+        from: currentLink.parent.path,
+      ));
+      final Link resourcesLink = frameworkDir.childLink('Resources');
+      await resourcesLink.create(fileSystem.path.relative(
+        resourcesDir.path,
+        from: resourcesLink.parent.path,
+      ));
+      await lipoDylibs(dylibFile, sources);
+      final Link dylibLink = frameworkDir.childLink(name);
+      await dylibLink.create(fileSystem.path.relative(
+        versionsDir.childDirectory('Current').childFile(name).path,
+        from: dylibLink.parent.path,
+      ));
+      await setInstallNameDylib(dylibFile);
+      await createInfoPlist(name, resourcesDir);
+      await codesignDylib(codesignIdentity, buildMode, frameworkDir);
+    }
+    globals.logger.printTrace('Copying native assets done.');
+  }
+}
+
+
+/// Copies native assets for flutter tester.
+///
+/// For `flutter run -release` a multi-architecture solution is needed. So,
+/// `lipo` is used to combine all target architectures into a single file.
+///
+/// In contrast to [_copyNativeAssetsMacOS], it does not set the install name.
+///
+/// Code signing is also done here.
+Future<void> _copyNativeAssetsMacOSFlutterTester(
+  Uri buildUri,
+  Map<AssetPath, List<Asset>> assetTargetLocations,
+  String? codesignIdentity,
+  BuildMode buildMode,
+  FileSystem fileSystem,
+) async {
+  if (assetTargetLocations.isNotEmpty) {
+    globals.logger.printTrace('Copying native assets to ${buildUri.toFilePath()}.');
+    for (final MapEntry<AssetPath, List<Asset>> assetMapping in assetTargetLocations.entries) {
+      final Uri target = (assetMapping.key as AssetAbsolutePath).uri;
+      final List<Uri> sources = <Uri>[
+        for (final Asset source in assetMapping.value)
+          (source.path as AssetAbsolutePath).uri,
+      ];
+      final Uri targetUri = buildUri.resolveUri(target);
+      final File dylibFile = fileSystem.file(targetUri);
+      final Directory targetParent = dylibFile.parent;
+      if (!await targetParent.exists()) {
+        await targetParent.create(recursive: true);
+      }
+      await lipoDylibs(dylibFile, sources);
+      await codesignDylib(codesignIdentity, buildMode, dylibFile);
+    }
+    globals.logger.printTrace('Copying native assets done.');
+  }
+}