Native assets support for Windows (#134203)

Support for FFI calls with `@Native external` functions through Native assets on Windows. This enables bundling native code without any build-system boilerplate code.

For more info see:

* https://github.com/flutter/flutter/issues/129757

### Implementation details for Windows.

Mainly follows the design of https://github.com/flutter/flutter/pull/134031.

Specifically for Windows in this PR is the logic for finding the compiler `cl.exe` and environment variables that contain the paths to the Windows headers `vcvars.bat` based on `vswhere.exe`.

packages/flutter_tools/lib/src/build_system/targets/native_assets.dart

@@ -16,6 +16,7 @@ import '../../linux/native_assets.dart';
 import '../../macos/native_assets.dart';
 import '../../macos/xcode.dart';
 import '../../native_assets.dart';
+import '../../windows/native_assets.dart';
 import '../build_system.dart';
 import '../depfile.dart';
 import '../exceptions.dart';
@@ -134,6 +135,20 @@ class NativeAssets extends Target {
           fileSystem: fileSystem,
           buildRunner: buildRunner,
         );
+      case TargetPlatform.windows_x64:
+        final String? environmentBuildMode = environment.defines[kBuildMode];
+        if (environmentBuildMode == null) {
+          throw MissingDefineException(kBuildMode, name);
+        }
+        final BuildMode buildMode = BuildMode.fromCliName(environmentBuildMode);
+        (_, dependencies) = await buildNativeAssetsWindows(
+          targetPlatform: targetPlatform,
+          buildMode: buildMode,
+          projectUri: projectUri,
+          yamlParentDirectory: environment.buildDir.uri,
+          fileSystem: fileSystem,
+          buildRunner: buildRunner,
+        );
       case TargetPlatform.tester:
         if (const LocalPlatform().isMacOS) {
           (_, dependencies) = await buildNativeAssetsMacOS(
@@ -154,6 +169,15 @@ class NativeAssets extends Target {
             buildRunner: buildRunner,
             flutterTester: true,
           );
+        } else if (const LocalPlatform().isWindows) {
+          (_, dependencies) = await buildNativeAssetsWindows(
+            buildMode: BuildMode.debug,
+            projectUri: projectUri,
+            yamlParentDirectory: environment.buildDir.uri,
+            fileSystem: fileSystem,
+            buildRunner: buildRunner,
+            flutterTester: true,
+          );
         } else {
           // TODO(dacoharkes): Implement other OSes. https://github.com/flutter/flutter/issues/129757
           // Write the file we claim to have in the [outputs].
@@ -168,7 +192,6 @@ class NativeAssets extends Target {
       case TargetPlatform.fuchsia_arm64:
       case TargetPlatform.fuchsia_x64:
       case TargetPlatform.web_javascript:
-      case TargetPlatform.windows_x64:
         // TODO(dacoharkes): Implement other OSes. https://github.com/flutter/flutter/issues/129757
         // Write the file we claim to have in the [outputs].
         await writeNativeAssetsYaml(<Asset>[], environment.buildDir.uri, fileSystem);

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

@@ -27,7 +27,7 @@ Future<Uri?> dryRunNativeAssetsIOS({
     return null;
   }
 
-  final Uri buildUri_ = nativeAssetsBuildUri(projectUri, OS.iOS);
+  final Uri buildUri = nativeAssetsBuildUri(projectUri, OS.iOS);
   final Iterable<Asset> assetTargetLocations = await dryRunNativeAssetsIOSInternal(
     fileSystem,
     projectUri,
@@ -35,7 +35,7 @@ Future<Uri?> dryRunNativeAssetsIOS({
   );
   final Uri nativeAssetsUri = await writeNativeAssetsYaml(
     assetTargetLocations,
-    buildUri_,
+    buildUri,
     fileSystem,
   );
   return nativeAssetsUri;
@@ -46,17 +46,17 @@ Future<Iterable<Asset>> dryRunNativeAssetsIOSInternal(
   Uri projectUri,
   NativeAssetsBuildRunner buildRunner,
 ) async {
-  const OS targetOs = OS.iOS;
-  globals.logger.printTrace('Dry running native assets for $targetOs.');
+  const OS targetOS = OS.iOS;
+  globals.logger.printTrace('Dry running native assets for $targetOS.');
   final List<Asset> nativeAssets = (await buildRunner.dryRun(
     linkModePreference: LinkModePreference.dynamic,
-    targetOs: targetOs,
+    targetOS: targetOS,
     workingDirectory: projectUri,
     includeParentEnvironment: true,
   ))
       .assets;
   ensureNoLinkModeStatic(nativeAssets);
-  globals.logger.printTrace('Dry running native assets for $targetOs done.');
+  globals.logger.printTrace('Dry running native assets for $targetOS done.');
   final Iterable<Asset> assetTargetLocations = _assetTargetLocations(nativeAssets).values;
   return assetTargetLocations;
 }
@@ -80,8 +80,8 @@ Future<List<Uri>> buildNativeAssetsIOS({
   final List<Target> targets = darwinArchs.map(_getNativeTarget).toList();
   final native_assets_cli.BuildMode buildModeCli = nativeAssetsBuildMode(buildMode);
 
-  const OS targetOs = OS.iOS;
-  final Uri buildUri_ = nativeAssetsBuildUri(projectUri, targetOs);
+  const OS targetOS = OS.iOS;
+  final Uri buildUri = nativeAssetsBuildUri(projectUri, targetOS);
   final IOSSdk iosSdk = _getIOSSdk(environmentType);
 
   globals.logger.printTrace('Building native assets for $targets $buildModeCli.');
@@ -104,7 +104,7 @@ Future<List<Uri>> buildNativeAssetsIOS({
   globals.logger.printTrace('Building native assets for $targets done.');
   final Map<AssetPath, List<Asset>> fatAssetTargetLocations = _fatAssetTargetLocations(nativeAssets);
   await copyNativeAssetsMacOSHost(
-    buildUri_,
+    buildUri,
     fatAssetTargetLocations,
     codesignIdentity,
     buildMode,

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

@@ -2,9 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-import 'package:native_assets_builder/native_assets_builder.dart' show BuildResult;
 import 'package:native_assets_cli/native_assets_cli.dart' hide BuildMode;
-import 'package:native_assets_cli/native_assets_cli.dart' as native_assets_cli;
 
 import '../base/common.dart';
 import '../base/file_system.dart';
@@ -22,24 +20,14 @@ Future<Uri?> dryRunNativeAssetsLinux({
   required Uri projectUri,
   bool flutterTester = false,
   required FileSystem fileSystem,
-}) async {
-  if (!await nativeBuildRequired(buildRunner)) {
-    return null;
-  }
-
-  final Uri buildUri_ = nativeAssetsBuildUri(projectUri, OS.linux);
-  final Iterable<Asset> nativeAssetPaths = await dryRunNativeAssetsLinuxInternal(
-    fileSystem,
-    projectUri,
-    flutterTester,
-    buildRunner,
-  );
-  final Uri nativeAssetsUri = await writeNativeAssetsYaml(
-    nativeAssetPaths,
-    buildUri_,
-    fileSystem,
+}) {
+  return dryRunNativeAssetsSingleArchitecture(
+    buildRunner: buildRunner,
+    projectUri: projectUri,
+    flutterTester: flutterTester,
+    fileSystem: fileSystem,
+    os: OS.linux,
   );
-  return nativeAssetsUri;
 }
 
 Future<Iterable<Asset>> dryRunNativeAssetsLinuxInternal(
@@ -47,33 +35,16 @@ Future<Iterable<Asset>> dryRunNativeAssetsLinuxInternal(
   Uri projectUri,
   bool flutterTester,
   NativeAssetsBuildRunner buildRunner,
-) async {
-  const OS targetOs = OS.linux;
-  final Uri buildUri_ = nativeAssetsBuildUri(projectUri, targetOs);
-
-  globals.logger.printTrace('Dry running native assets for $targetOs.');
-  final List<Asset> nativeAssets = (await buildRunner.dryRun(
-    linkModePreference: LinkModePreference.dynamic,
-    targetOs: targetOs,
-    workingDirectory: projectUri,
-    includeParentEnvironment: true,
-  ))
-      .assets;
-  ensureNoLinkModeStatic(nativeAssets);
-  globals.logger.printTrace('Dry running native assets for $targetOs done.');
-  final Uri? absolutePath = flutterTester ? buildUri_ : null;
-  final Map<Asset, Asset> assetTargetLocations = _assetTargetLocations(nativeAssets, absolutePath);
-  final Iterable<Asset> nativeAssetPaths = assetTargetLocations.values;
-  return nativeAssetPaths;
+) {
+  return dryRunNativeAssetsSingleArchitectureInternal(
+    fileSystem,
+    projectUri,
+    flutterTester,
+    buildRunner,
+    OS.linux,
+  );
 }
 
-/// Builds native assets.
-///
-/// If [targetPlatform] is omitted, the current target architecture is used.
-///
-/// If [flutterTester] is true, absolute paths are emitted in the native
-/// assets mapping. This can be used for JIT mode without sandbox on the host.
-/// This is used in `flutter test` and `flutter run -d flutter-tester`.
 Future<(Uri? nativeAssetsYaml, List<Uri> dependencies)> buildNativeAssetsLinux({
   required NativeAssetsBuildRunner buildRunner,
   TargetPlatform? targetPlatform,
@@ -82,127 +53,16 @@ Future<(Uri? nativeAssetsYaml, List<Uri> dependencies)> buildNativeAssetsLinux({
   bool flutterTester = false,
   Uri? yamlParentDirectory,
   required FileSystem fileSystem,
-}) async {
-  const OS targetOs = OS.linux;
-  final Uri buildUri_ = nativeAssetsBuildUri(projectUri, targetOs);
-  final Directory buildDir = fileSystem.directory(buildUri_);
-  if (!await buildDir.exists()) {
-    // CMake requires the folder to exist to do copying.
-    await buildDir.create(recursive: true);
-  }
-  if (!await nativeBuildRequired(buildRunner)) {
-    final Uri nativeAssetsYaml = await writeNativeAssetsYaml(<Asset>[], yamlParentDirectory ?? buildUri_, fileSystem);
-    return (nativeAssetsYaml, <Uri>[]);
-  }
-
-  final Target target = targetPlatform != null ? _getNativeTarget(targetPlatform) : Target.current;
-  final native_assets_cli.BuildMode buildModeCli = nativeAssetsBuildMode(buildMode);
-
-  globals.logger.printTrace('Building native assets for $target $buildModeCli.');
-  final BuildResult result = await buildRunner.build(
-    linkModePreference: LinkModePreference.dynamic,
-    target: target,
-    buildMode: buildModeCli,
-    workingDirectory: projectUri,
-    includeParentEnvironment: true,
-    cCompilerConfig: await buildRunner.cCompilerConfig,
-  );
-  final List<Asset> nativeAssets = result.assets;
-  final Set<Uri> dependencies = result.dependencies.toSet();
-  ensureNoLinkModeStatic(nativeAssets);
-  globals.logger.printTrace('Building native assets for $target done.');
-  final Uri? absolutePath = flutterTester ? buildUri_ : null;
-  final Map<Asset, Asset> assetTargetLocations = _assetTargetLocations(nativeAssets, absolutePath);
-  await _copyNativeAssetsLinux(
-    buildUri_,
-    assetTargetLocations,
-    buildMode,
-    fileSystem,
-  );
-  final Uri nativeAssetsUri = await writeNativeAssetsYaml(
-    assetTargetLocations.values,
-    yamlParentDirectory ?? buildUri_,
-    fileSystem,
+}) {
+  return buildNativeAssetsSingleArchitecture(
+    buildRunner: buildRunner,
+    targetPlatform: targetPlatform,
+    projectUri: projectUri,
+    buildMode: buildMode,
+    flutterTester: flutterTester,
+    yamlParentDirectory: yamlParentDirectory,
+    fileSystem: fileSystem,
   );
-  return (nativeAssetsUri, dependencies.toList());
-}
-
-Map<Asset, Asset> _assetTargetLocations(
-  List<Asset> nativeAssets,
-  Uri? absolutePath,
-) =>
-    <Asset, Asset>{
-      for (final Asset asset in nativeAssets) asset: _targetLocationLinux(asset, absolutePath),
-    };
-
-Asset _targetLocationLinux(Asset asset, Uri? absolutePath) {
-  final AssetPath path = asset.path;
-  switch (path) {
-    case AssetSystemPath _:
-    case AssetInExecutable _:
-    case AssetInProcess _:
-      return asset;
-    case AssetAbsolutePath _:
-      final String fileName = path.uri.pathSegments.last;
-      Uri uri;
-      if (absolutePath != null) {
-        // Flutter tester needs full host paths.
-        uri = absolutePath.resolve(fileName);
-      } else {
-        // 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);
-      }
-      return asset.copyWith(path: AssetAbsolutePath(uri));
-  }
-  throw Exception('Unsupported asset path type ${path.runtimeType} in asset $asset');
-}
-
-/// Extract the [Target] from a [TargetPlatform].
-Target _getNativeTarget(TargetPlatform targetPlatform) {
-  switch (targetPlatform) {
-    case TargetPlatform.linux_x64:
-      return Target.linuxX64;
-    case TargetPlatform.linux_arm64:
-      return Target.linuxArm64;
-    case TargetPlatform.android:
-    case TargetPlatform.ios:
-    case TargetPlatform.darwin:
-    case TargetPlatform.windows_x64:
-    case TargetPlatform.fuchsia_arm64:
-    case TargetPlatform.fuchsia_x64:
-    case TargetPlatform.tester:
-    case TargetPlatform.web_javascript:
-    case TargetPlatform.android_arm:
-    case TargetPlatform.android_arm64:
-    case TargetPlatform.android_x64:
-    case TargetPlatform.android_x86:
-      throw Exception('Unknown targetPlatform: $targetPlatform.');
-  }
-}
-
-Future<void> _copyNativeAssetsLinux(
-  Uri buildUri,
-  Map<Asset, Asset> assetTargetLocations,
-  BuildMode buildMode,
-  FileSystem fileSystem,
-) async {
-  if (assetTargetLocations.isNotEmpty) {
-    globals.logger.printTrace('Copying native assets to ${buildUri.toFilePath()}.');
-    final Directory buildDir = fileSystem.directory(buildUri.toFilePath());
-    if (!buildDir.existsSync()) {
-      buildDir.createSync(recursive: true);
-    }
-    for (final MapEntry<Asset, Asset> assetMapping in assetTargetLocations.entries) {
-      final Uri source = (assetMapping.key.path as AssetAbsolutePath).uri;
-      final Uri target = (assetMapping.value.path as AssetAbsolutePath).uri;
-      final Uri targetUri = buildUri.resolveUri(target);
-      final String targetFullPath = targetUri.toFilePath();
-      await fileSystem.file(source).copy(targetFullPath);
-    }
-    globals.logger.printTrace('Copying native assets done.');
-  }
 }
 
 /// Flutter expects `clang++` to be on the path on Linux hosts.

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

@@ -27,9 +27,9 @@ Future<Uri?> dryRunNativeAssetsMacOS({
     return null;
   }
 
-  final Uri buildUri_ = nativeAssetsBuildUri(projectUri, OS.macOS);
+  final Uri buildUri = nativeAssetsBuildUri(projectUri, OS.macOS);
   final Iterable<Asset> nativeAssetPaths = await dryRunNativeAssetsMacOSInternal(fileSystem, projectUri, flutterTester, buildRunner);
-  final Uri nativeAssetsUri = await writeNativeAssetsYaml(nativeAssetPaths, buildUri_, fileSystem);
+  final Uri nativeAssetsUri = await writeNativeAssetsYaml(nativeAssetPaths, buildUri, fileSystem);
   return nativeAssetsUri;
 }
 
@@ -39,20 +39,20 @@ Future<Iterable<Asset>> dryRunNativeAssetsMacOSInternal(
   bool flutterTester,
   NativeAssetsBuildRunner buildRunner,
 ) async {
-  const OS targetOs = OS.macOS;
-  final Uri buildUri_ = nativeAssetsBuildUri(projectUri, targetOs);
+  const OS targetOS = OS.macOS;
+  final Uri buildUri = nativeAssetsBuildUri(projectUri, targetOS);
 
-  globals.logger.printTrace('Dry running native assets for $targetOs.');
+  globals.logger.printTrace('Dry running native assets for $targetOS.');
   final List<Asset> nativeAssets = (await buildRunner.dryRun(
     linkModePreference: LinkModePreference.dynamic,
-    targetOs: targetOs,
+    targetOS: targetOS,
     workingDirectory: projectUri,
     includeParentEnvironment: true,
   ))
       .assets;
   ensureNoLinkModeStatic(nativeAssets);
-  globals.logger.printTrace('Dry running native assets for $targetOs done.');
-  final Uri? absolutePath = flutterTester ? buildUri_ : null;
+  globals.logger.printTrace('Dry running native assets for $targetOS done.');
+  final Uri? absolutePath = flutterTester ? buildUri : null;
   final Map<Asset, Asset> assetTargetLocations = _assetTargetLocations(nativeAssets, absolutePath);
   final Iterable<Asset> nativeAssetPaths = assetTargetLocations.values;
   return nativeAssetPaths;
@@ -75,10 +75,10 @@ Future<(Uri? nativeAssetsYaml, List<Uri> dependencies)> buildNativeAssetsMacOS({
   Uri? yamlParentDirectory,
   required FileSystem fileSystem,
 }) async {
-  const OS targetOs = OS.macOS;
-  final Uri buildUri_ = nativeAssetsBuildUri(projectUri, targetOs);
+  const OS targetOS = OS.macOS;
+  final Uri buildUri = nativeAssetsBuildUri(projectUri, targetOS);
   if (!await nativeBuildRequired(buildRunner)) {
-    final Uri nativeAssetsYaml = await writeNativeAssetsYaml(<Asset>[], yamlParentDirectory ?? buildUri_, fileSystem);
+    final Uri nativeAssetsYaml = await writeNativeAssetsYaml(<Asset>[], yamlParentDirectory ?? buildUri, fileSystem);
     return (nativeAssetsYaml, <Uri>[]);
   }
 
@@ -102,11 +102,11 @@ Future<(Uri? nativeAssetsYaml, List<Uri> dependencies)> buildNativeAssetsMacOS({
   }
   ensureNoLinkModeStatic(nativeAssets);
   globals.logger.printTrace('Building native assets for $targets done.');
-  final Uri? absolutePath = flutterTester ? buildUri_ : null;
+  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);
-  final Uri nativeAssetsUri = await writeNativeAssetsYaml(assetTargetLocations.values, yamlParentDirectory ?? buildUri_, fileSystem);
+  await copyNativeAssetsMacOSHost(buildUri, fatAssetTargetLocations, codesignIdentity, buildMode, fileSystem);
+  final Uri nativeAssetsUri = await writeNativeAssetsYaml(assetTargetLocations.values, yamlParentDirectory ?? buildUri, fileSystem);
   return (nativeAssetsUri, dependencies.toList());
 }
 

packages/flutter_tools/lib/src/migrations/cmake_native_assets_migration.dart

@@ -41,8 +41,8 @@ class CmakeNativeAssetsMigration extends ProjectMigrator {
 # Copy the native assets provided by the build.dart from all packages.
 set(NATIVE_ASSETS_DIR "\${PROJECT_BUILD_DIR}native_assets/$os/")
 install(DIRECTORY "\${NATIVE_ASSETS_DIR}"
-   DESTINATION "\${INSTALL_BUNDLE_LIB_DIR}"
-   COMPONENT Runtime)
+  DESTINATION "\${INSTALL_BUNDLE_LIB_DIR}"
+  COMPONENT Runtime)
 ''';
 
     // Insert the new command after the bundled libraries loop.

packages/flutter_tools/lib/src/test/test_compiler.dart

@@ -20,6 +20,7 @@ import '../linux/native_assets.dart';
 import '../macos/native_assets.dart';
 import '../native_assets.dart';
 import '../project.dart';
+import '../windows/native_assets.dart';
 import 'test_time_recorder.dart';
 
 /// A request to the [TestCompiler] for recompilation.
@@ -195,6 +196,14 @@ class TestCompiler {
             fileSystem: globals.fs,
             buildRunner: buildRunner,
           );
+        } else if (globals.platform.isWindows) {
+          (nativeAssetsYaml, _) = await buildNativeAssetsWindows(
+            buildMode: buildInfo.mode,
+            projectUri: projectUri,
+            flutterTester: true,
+            fileSystem: globals.fs,
+            buildRunner: buildRunner,
+          );
         } else {
           await ensureNoNativeAssetsOrOsIsSupported(
             projectUri,

packages/flutter_tools/lib/src/windows/build_windows.dart

@@ -18,6 +18,7 @@ import '../convert.dart';
 import '../flutter_plugins.dart';
 import '../globals.dart' as globals;
 import '../migrations/cmake_custom_command_migration.dart';
+import '../migrations/cmake_native_assets_migration.dart';
 import 'migrations/build_architecture_migration.dart';
 import 'migrations/show_window_migration.dart';
 import 'migrations/version_migration.dart';
@@ -61,6 +62,7 @@ Future<void> buildWindows(WindowsProject windowsProject, BuildInfo buildInfo, {
 
   final List<ProjectMigrator> migrators = <ProjectMigrator>[
     CmakeCustomCommandMigration(windowsProject, globals.logger),
+    CmakeNativeAssetsMigration(windowsProject, 'windows', globals.logger),
     VersionMigration(windowsProject, globals.logger),
     ShowWindowMigration(windowsProject, globals.logger),
     BuildArchitectureMigration(windowsProject, buildDirectory, globals.logger),

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

+// Copyright 2014 The Flutter 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 'package:native_assets_cli/native_assets_cli.dart' hide BuildMode;
+
+import '../base/file_system.dart';
+import '../build_info.dart';
+import '../globals.dart' as globals;
+import '../native_assets.dart';
+import 'visual_studio.dart';
+
+/// Dry run the native builds.
+///
+/// This does not build native assets, it only simulates what the final paths
+/// of all assets will be so that this can be embedded in the kernel file.
+Future<Uri?> dryRunNativeAssetsWindows({
+  required NativeAssetsBuildRunner buildRunner,
+  required Uri projectUri,
+  bool flutterTester = false,
+  required FileSystem fileSystem,
+}) {
+  return dryRunNativeAssetsSingleArchitecture(
+    buildRunner: buildRunner,
+    projectUri: projectUri,
+    flutterTester: flutterTester,
+    fileSystem: fileSystem,
+    os: OS.windows,
+  );
+}
+
+Future<Iterable<Asset>> dryRunNativeAssetsWindowsInternal(
+  FileSystem fileSystem,
+  Uri projectUri,
+  bool flutterTester,
+  NativeAssetsBuildRunner buildRunner,
+) {
+  return dryRunNativeAssetsSingleArchitectureInternal(
+    fileSystem,
+    projectUri,
+    flutterTester,
+    buildRunner,
+    OS.windows,
+  );
+}
+
+Future<(Uri? nativeAssetsYaml, List<Uri> dependencies)>
+    buildNativeAssetsWindows({
+  required NativeAssetsBuildRunner buildRunner,
+  TargetPlatform? targetPlatform,
+  required Uri projectUri,
+  required BuildMode buildMode,
+  bool flutterTester = false,
+  Uri? yamlParentDirectory,
+  required FileSystem fileSystem,
+}) {
+  return buildNativeAssetsSingleArchitecture(
+    buildRunner: buildRunner,
+    targetPlatform: targetPlatform,
+    projectUri: projectUri,
+    buildMode: buildMode,
+    flutterTester: flutterTester,
+    yamlParentDirectory: yamlParentDirectory,
+    fileSystem: fileSystem,
+  );
+}
+
+
+Future<CCompilerConfig> cCompilerConfigWindows() async {
+  final VisualStudio visualStudio = VisualStudio(
+    fileSystem: globals.fs,
+    platform: globals.platform,
+    logger: globals.logger,
+    processManager: globals.processManager,
+  );
+
+  return CCompilerConfig(
+    cc: _toOptionalFileUri(visualStudio.clPath),
+    ld: _toOptionalFileUri(visualStudio.linkPath),
+    ar: _toOptionalFileUri(visualStudio.libPath),
+    envScript: _toOptionalFileUri(visualStudio.vcvarsPath),
+    envScriptArgs: <String>[],
+  );
+}
+
+Uri? _toOptionalFileUri(String? string) {
+  if (string == null) {
+    return null;
+  }
+  return Uri.file(string);
+}

packages/flutter_tools/lib/src/windows/visual_studio.dart

@@ -184,6 +184,60 @@ class VisualStudio {
     }
   }
 
+  /// The path to cl.exe, or null if no Visual Studio installation has
+  /// the components necessary to build.
+  String? get clPath {
+    return _getMsvcBinPath('cl.exe');
+  }
+
+  /// The path to lib.exe, or null if no Visual Studio installation has
+  /// the components necessary to build.
+  String? get libPath {
+    return _getMsvcBinPath('lib.exe');
+  }
+
+  /// The path to link.exe, or null if no Visual Studio installation has
+  /// the components necessary to build.
+  String? get linkPath {
+    return _getMsvcBinPath('link.exe');
+  }
+
+  String? _getMsvcBinPath(String executable) {
+    final VswhereDetails? details = _bestVisualStudioDetails;
+    if (details == null || !details.isUsable || details.installationPath == null || details.msvcVersion == null) {
+      return null;
+    }
+
+    return _fileSystem.path.joinAll(<String>[
+      details.installationPath!,
+      'VC',
+      'Tools',
+      'MSVC',
+      details.msvcVersion!,
+      'bin',
+      'Hostx64',
+      'x64',
+      executable,
+    ]);
+  }
+
+  /// The path to vcvars64.exe, or null if no Visual Studio installation has
+  /// the components necessary to build.
+  String? get vcvarsPath {
+    final VswhereDetails? details = _bestVisualStudioDetails;
+    if (details == null || !details.isUsable || details.installationPath == null) {
+      return null;
+    }
+
+    return _fileSystem.path.joinAll(<String>[
+      details.installationPath!,
+      'VC',
+      'Auxiliary',
+      'Build',
+      'vcvars64.bat',
+    ]);
+  }
+
   /// The major version of the Visual Studio install, as an integer.
   int? get _majorVersion => fullVersion != null ? int.tryParse(fullVersion!.split('.')[0]) : null;
 
@@ -301,7 +355,12 @@ class VisualStudio {
       if (whereResult.exitCode == 0) {
         final List<Map<String, dynamic>>? installations = _tryDecodeVswhereJson(whereResult.stdout);
         if (installations != null && installations.isNotEmpty) {
-          return VswhereDetails.fromJson(validateRequirements, installations[0]);
+          final String? msvcVersion = _findMsvcVersion(installations);
+          return VswhereDetails.fromJson(
+            validateRequirements,
+            installations[0],
+            msvcVersion,
+          );
         }
       }
     } on ArgumentError {
@@ -312,6 +371,28 @@ class VisualStudio {
     return null;
   }
 
+  String? _findMsvcVersion(List<Map<String, dynamic>> installations) {
+    final String? installationPath = installations[0]['installationPath'] as String?;
+    String? msvcVersion;
+    if (installationPath != null) {
+      final Directory installationDir = _fileSystem.directory(installationPath);
+      final Directory msvcDir = installationDir
+          .childDirectory('VC')
+          .childDirectory('Tools')
+          .childDirectory('MSVC');
+      if (msvcDir.existsSync()) {
+        final Iterable<Directory> msvcVersionDirs = msvcDir.listSync().whereType<Directory>();
+        if (msvcVersionDirs.isEmpty) {
+          return null;
+        }
+        msvcVersion = msvcVersionDirs.last.uri.pathSegments
+            .where((String e) => e.isNotEmpty)
+            .last;
+      }
+    }
+    return msvcVersion;
+  }
+
   List<Map<String, dynamic>>? _tryDecodeVswhereJson(String vswhereJson) {
     List<dynamic>? result;
     FormatException? originalError;
@@ -443,12 +524,14 @@ class VswhereDetails {
     required this.isRebootRequired,
     required this.isPrerelease,
     required this.catalogDisplayVersion,
+    required this.msvcVersion,
   });
 
   /// Create a `VswhereDetails` from the JSON output of vswhere.exe.
   factory VswhereDetails.fromJson(
     bool meetsRequirements,
-    Map<String, dynamic> details
+    Map<String, dynamic> details,
+    String? msvcVersion,
   ) {
     final Map<String, dynamic>? catalog = details['catalog'] as Map<String, dynamic>?;
 
@@ -467,6 +550,8 @@ class VswhereDetails {
       // contain replacement characters.
       displayName: details['displayName'] as String?,
       catalogDisplayVersion: catalog == null ? null : catalog['productDisplayVersion'] as String?,
+
+      msvcVersion: msvcVersion,
     );
   }
 
@@ -511,6 +596,9 @@ class VswhereDetails {
   /// The user-friendly version.
   final String? catalogDisplayVersion;
 
+  /// The MSVC versions.
+  final String? msvcVersion;
+
   /// Checks if the Visual Studio installation can be used by Flutter.
   ///
   /// Returns false if the installation has issues the user must resolve.

packages/flutter_tools/templates/app_shared/windows.tmpl/CMakeLists.txt.tmpl

@@ -91,6 +91,12 @@ if(PLUGIN_BUNDLED_LIBRARIES)
     COMPONENT Runtime)
 endif()
 
+# Copy the native assets provided by the build.dart from all packages.
+set(NATIVE_ASSETS_DIR "${PROJECT_BUILD_DIR}native_assets/windows/")
+install(DIRECTORY "${NATIVE_ASSETS_DIR}"
+   DESTINATION "${INSTALL_BUNDLE_LIB_DIR}"
+   COMPONENT Runtime)
+
 # Fully re-copy the assets directory on each build to avoid having stale files
 # from a previous install.
 set(FLUTTER_ASSET_DIR_NAME "flutter_assets")

packages/flutter_tools/templates/package_ffi/pubspec.yaml.tmpl

@@ -10,7 +10,7 @@ dependencies:
   cli_config: ^0.1.1
   logging: ^1.1.1
   native_assets_cli: ^0.2.0
-  native_toolchain_c: ^0.2.0
+  native_toolchain_c: ^0.2.3
 
 dev_dependencies:
   ffi: ^2.0.2

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

@@ -49,7 +49,7 @@ class FakeNativeAssetsBuildRunner implements NativeAssetsBuildRunner {
   Future<native_assets_builder.DryRunResult> dryRun({
     required bool includeParentEnvironment,
     required LinkModePreference linkModePreference,
-    required OS targetOs,
+    required OS targetOS,
     required Uri workingDirectory,
   }) async {
     dryRunInvocations++;

packages/flutter_tools/test/general.shard/ios/native_assets_test.dart

@@ -142,6 +142,13 @@ void main() {
         ),
       ),
     );
+    expect(
+      (globals.logger as BufferLogger).traceText,
+      stringContainsInOrder(<String>[
+        'Dry running native assets for ios.',
+        'Dry running native assets for ios done.',
+      ]),
+    );
     expect(
       nativeAssetsYaml,
       projectUri.resolve('build/native_assets/ios/native_assets.yaml'),
@@ -259,13 +266,20 @@ void main() {
             Asset(
               id: 'package:bar/bar.dart',
               linkMode: LinkMode.dynamic,
-              target: native_assets_cli.Target.macOSArm64,
+              target: native_assets_cli.Target.iOSArm64,
               path: AssetAbsolutePath(Uri.file('bar.dylib')),
             ),
           ],
         ),
       ),
     );
+    expect(
+      (globals.logger as BufferLogger).traceText,
+      stringContainsInOrder(<String>[
+        'Building native assets for [ios_arm64] debug.',
+        'Building native assets for [ios_arm64] done.',
+      ]),
+    );
     expect(
       environment.buildDir.childFile('native_assets.yaml'),
       exists,

packages/flutter_tools/test/general.shard/linux/native_assets_test.dart

@@ -180,6 +180,13 @@ void main() {
         ),
       ),
     );
+    expect(
+      (globals.logger as BufferLogger).traceText,
+      stringContainsInOrder(<String>[
+        'Dry running native assets for linux.',
+        'Dry running native assets for linux done.',
+      ]),
+    );
     expect(
       nativeAssetsYaml,
       projectUri.resolve('build/native_assets/linux/native_assets.yaml'),
@@ -222,6 +229,7 @@ void main() {
     await packageConfig.parent.create();
     await packageConfig.create();
     final (Uri? nativeAssetsYaml, _) = await buildNativeAssetsLinux(
+      targetPlatform: TargetPlatform.linux_x64,
       projectUri: projectUri,
       buildMode: BuildMode.debug,
       fileSystem: fileSystem,
@@ -257,16 +265,14 @@ void main() {
       FeatureFlags: () => TestFeatureFlags(isNativeAssetsEnabled: true),
       ProcessManager: () => FakeProcessManager.empty(),
     }, () async {
-      if (const LocalPlatform().isWindows) {
-        return; // Backslashes in commands, but we will never run these commands on Windows.
-      }
-      final File packageConfig = environment.projectDir.childFile('.dart_tool/package_config.json');
+      final File packageConfig = environment.projectDir.childDirectory('.dart_tool').childFile('package_config.json');
       await packageConfig.parent.create();
       await packageConfig.create();
       final File dylibAfterCompiling = fileSystem.file('libbar.so');
       // The mock doesn't create the file, so create it here.
       await dylibAfterCompiling.create();
       final (Uri? nativeAssetsYaml, _) = await buildNativeAssetsLinux(
+        targetPlatform: TargetPlatform.linux_x64,
         projectUri: projectUri,
         buildMode: BuildMode.debug,
         fileSystem: fileSystem,
@@ -287,6 +293,13 @@ void main() {
           ),
         ),
       );
+      expect(
+        (globals.logger as BufferLogger).traceText,
+        stringContainsInOrder(<String>[
+          'Building native assets for linux_x64 debug.',
+          'Building native assets for linux_x64 done.',
+        ]),
+      );
       expect(
         nativeAssetsYaml,
         projectUri.resolve('build/native_assets/linux/native_assets.yaml'),
@@ -297,7 +310,7 @@ void main() {
           'package:bar/bar.dart',
           if (flutterTester)
             // Tests run on host system, so the have the full path on the system.
-            '- ${projectUri.resolve('/build/native_assets/linux/libbar.so').toFilePath()}'
+            '- ${projectUri.resolve('build/native_assets/linux/libbar.so').toFilePath()}'
           else
             // Apps are a bundle with the dylibs on their dlopen path.
             '- libbar.so',
@@ -365,7 +378,6 @@ void main() {
     FileSystem: () => fileSystem,
   }, () async {
     if (!const LocalPlatform().isLinux) {
-      // TODO(dacoharkes): Implement other OSes. https://github.com/flutter/flutter/issues/129757
       return;
     }
 

packages/flutter_tools/test/general.shard/macos/native_assets_test.dart

@@ -161,6 +161,13 @@ void main() {
         ),
       ),
     );
+    expect(
+      (globals.logger as BufferLogger).traceText,
+      stringContainsInOrder(<String>[
+        'Dry running native assets for macos.',
+        'Dry running native assets for macos done.',
+      ]),
+    );
     expect(
       nativeAssetsYaml,
       projectUri.resolve('build/native_assets/macos/native_assets.yaml'),
@@ -291,6 +298,13 @@ void main() {
           ),
         ),
       );
+      expect(
+        (globals.logger as BufferLogger).traceText,
+        stringContainsInOrder(<String>[
+          'Building native assets for [macos_arm64] debug.',
+          'Building native assets for [macos_arm64] done.',
+        ]),
+      );
       expect(
         nativeAssetsYaml,
         projectUri.resolve('build/native_assets/macos/native_assets.yaml'),
@@ -301,7 +315,7 @@ void main() {
           'package:bar/bar.dart',
           if (flutterTester)
             // Tests run on host system, so the have the full path on the system.
-            '- ${projectUri.resolve('/build/native_assets/macos/bar.dylib').toFilePath()}'
+            '- ${projectUri.resolve('build/native_assets/macos/bar.dylib').toFilePath()}'
           else
             // Apps are a bundle with the dylibs on their dlopen path.
             '- bar.dylib',
@@ -370,7 +384,6 @@ InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault
     ),
   }, () async {
     if (!const LocalPlatform().isMacOS) {
-      // TODO(dacoharkes): Implement other OSes. https://github.com/flutter/flutter/issues/129757
       return;
     }
 

packages/flutter_tools/test/general.shard/migrations/cmake_project_migration_test.dart

@@ -230,9 +230,9 @@ install(DIRECTORY "${NATIVE_ASSETS_DIR}"
         expect(testLogger.statusText, isEmpty);
       });
 
-      // TODO(dacoharkes): Add test for Windows when adding Windows support. https://github.com/flutter/flutter/issues/129757
-      testWithoutContext('is migrated to copy native assets', () {
-        managedCmakeFile.writeAsStringSync(r'''
+      for (final String os in <String>['linux', 'windows']) {
+        testWithoutContext('is migrated to copy native assets', () {
+          managedCmakeFile.writeAsStringSync(r'''
 foreach(bundled_library ${PLUGIN_BUNDLED_LIBRARIES})
   install(FILES "${bundled_library}"
     DESTINATION "${INSTALL_BUNDLE_LIB_DIR}"
@@ -249,38 +249,40 @@ install(DIRECTORY "${PROJECT_BUILD_DIR}/${FLUTTER_ASSET_DIR_NAME}"
   DESTINATION "${INSTALL_BUNDLE_DATA_DIR}" COMPONENT Runtime)
 ''');
 
-        final CmakeNativeAssetsMigration cmakeProjectMigration = CmakeNativeAssetsMigration(
-          mockCmakeProject,
-          'linux',
-          testLogger,
-        );
-        cmakeProjectMigration.migrate();
-
-        expect(managedCmakeFile.readAsStringSync(), r'''
-foreach(bundled_library ${PLUGIN_BUNDLED_LIBRARIES})
-  install(FILES "${bundled_library}"
-    DESTINATION "${INSTALL_BUNDLE_LIB_DIR}"
+          final CmakeNativeAssetsMigration cmakeProjectMigration = CmakeNativeAssetsMigration(
+            mockCmakeProject,
+            os,
+            testLogger,
+          );
+          cmakeProjectMigration.migrate();
+
+          expect(managedCmakeFile.readAsStringSync(), '''
+foreach(bundled_library \${PLUGIN_BUNDLED_LIBRARIES})
+  install(FILES "\${bundled_library}"
+    DESTINATION "\${INSTALL_BUNDLE_LIB_DIR}"
     COMPONENT Runtime)
 endforeach(bundled_library)
 
 # Copy the native assets provided by the build.dart from all packages.
-set(NATIVE_ASSETS_DIR "${PROJECT_BUILD_DIR}native_assets/linux/")
-install(DIRECTORY "${NATIVE_ASSETS_DIR}"
-   DESTINATION "${INSTALL_BUNDLE_LIB_DIR}"
-   COMPONENT Runtime)
+set(NATIVE_ASSETS_DIR "\${PROJECT_BUILD_DIR}native_assets/$os/")
+install(DIRECTORY "\${NATIVE_ASSETS_DIR}"
+  DESTINATION "\${INSTALL_BUNDLE_LIB_DIR}"
+  COMPONENT Runtime)
 
 # Fully re-copy the assets directory on each build to avoid having stale files
 # from a previous install.
 set(FLUTTER_ASSET_DIR_NAME "flutter_assets")
 install(CODE "
-  file(REMOVE_RECURSE \"${INSTALL_BUNDLE_DATA_DIR}/${FLUTTER_ASSET_DIR_NAME}\")
+  file(REMOVE_RECURSE \\"\${INSTALL_BUNDLE_DATA_DIR}/\${FLUTTER_ASSET_DIR_NAME}\\")
   " COMPONENT Runtime)
-install(DIRECTORY "${PROJECT_BUILD_DIR}/${FLUTTER_ASSET_DIR_NAME}"
-  DESTINATION "${INSTALL_BUNDLE_DATA_DIR}" COMPONENT Runtime)
+install(DIRECTORY "\${PROJECT_BUILD_DIR}/\${FLUTTER_ASSET_DIR_NAME}"
+  DESTINATION "\${INSTALL_BUNDLE_DATA_DIR}" COMPONENT Runtime)
 ''');
 
-        expect(testLogger.statusText, contains('CMake missing install() NATIVE_ASSETS_DIR command, updating.'));
-      });
+          expect(testLogger.statusText,
+              contains('CMake missing install() NATIVE_ASSETS_DIR command, updating.'));
+        });
+      }
     });
   });
 }

packages/flutter_tools/test/integration.shard/native_assets_test.dart

@@ -58,8 +58,8 @@ const String packageName = 'package_with_native_assets';
 const String exampleAppName = '${packageName}_example';
 
 void main() {
-  if (!platform.isMacOS && !platform.isLinux) {
-    // TODO(dacoharkes): Implement other OSes. https://github.com/flutter/flutter/issues/129757
+  if (!platform.isMacOS && !platform.isLinux && !platform.isWindows) {
+    // TODO(dacoharkes): Implement Fuchsia. https://github.com/flutter/flutter/issues/129757
     return;
   }
 
@@ -146,9 +146,10 @@ void main() {
 
           if (device == 'macos') {
             expectDylibIsBundledMacOS(exampleDirectory, buildMode);
-          }
-          if (device == 'linux') {
+          } else if (device == 'linux') {
             expectDylibIsBundledLinux(exampleDirectory, buildMode);
+          } else if (device == 'windows') {
+            expectDylibIsBundledWindows(exampleDirectory, buildMode);
           }
           if (device == hostOs) {
             expectCCompilerIsConfigured(exampleDirectory);
@@ -205,6 +206,8 @@ void main() {
             expectDylibIsBundledIos(exampleDirectory, buildMode);
           } else if (buildSubcommand == 'linux') {
             expectDylibIsBundledLinux(exampleDirectory, buildMode);
+          } else if (buildSubcommand == 'windows') {
+            expectDylibIsBundledWindows(exampleDirectory, buildMode);
           }
           expectCCompilerIsConfigured(exampleDirectory);
         });
@@ -239,11 +242,15 @@ void main() {
             'build',
             buildSubcommand,
             if (buildSubcommand == 'ios') '--no-codesign',
+            if (buildSubcommand == 'windows') '-v' // Requires verbose mode for error.
           ],
           workingDirectory: exampleDirectory.path,
         );
         expect(result.exitCode, isNot(0));
-        expect(result.stderr, contains('link mode set to static, but this is not yet supported'));
+        expect(
+          (result.stdout as String) + (result.stderr as String),
+          contains('link mode set to static, but this is not yet supported'),
+        );
       });
     });
   }
@@ -301,14 +308,36 @@ void expectDylibIsBundledIos(Directory appDirectory, String buildMode) {
 void expectDylibIsBundledLinux(Directory appDirectory, String buildMode) {
   // Linux does not support cross compilation, so always only check current architecture.
   final String architecture = Architecture.current.dartPlatform;
-  final Directory appBundle = appDirectory.childDirectory('build/$hostOs/$architecture/$buildMode/bundle/');
+  final Directory appBundle = appDirectory
+      .childDirectory('build')
+      .childDirectory(hostOs)
+      .childDirectory(architecture)
+      .childDirectory(buildMode)
+      .childDirectory('bundle');
   expect(appBundle, exists);
-  final Directory dylibsFolder = appBundle.childDirectory('lib/');
+  final Directory dylibsFolder = appBundle.childDirectory('lib');
   expect(dylibsFolder, exists);
   final File dylib = dylibsFolder.childFile(OS.linux.dylibFileName(packageName));
   expect(dylib, exists);
 }
 
+/// Checks that dylibs are bundled.
+///
+/// Sample path: build\windows\x64\runner\Debug\my_package_example.exe
+void expectDylibIsBundledWindows(Directory appDirectory, String buildMode) {
+  // Linux does not support cross compilation, so always only check current architecture.
+  final String architecture = Architecture.current.dartPlatform;
+  final Directory appBundle = appDirectory
+      .childDirectory('build')
+      .childDirectory(hostOs)
+      .childDirectory(architecture)
+      .childDirectory('runner')
+      .childDirectory(buildMode.upperCaseFirst());
+  expect(appBundle, exists);
+  final File dylib = appBundle.childFile(OS.windows.dylibFileName(packageName));
+  expect(dylib, exists);
+}
+
 /// For `flutter build` we can't easily test whether running the app works.
 /// Check that we have the dylibs in the app.
 void expectDylibIsBundledWithFrameworks(Directory appDirectory, String buildMode, String os) {