Enable native compilation for windows-arm64 (#137618)

It's now possible to natively compile a flutter app for
windows-arm64. Cross-compilation is not yet implemented.

Uses arm64 artifacts now available for Dart/Flutter.
Platform detection is based on Abi class, provided by Dart. Depending if
Dart is an arm64 or x64 binary, the Abi is set accordingly.
Initial bootstrap of dart artifacts (update_dart_sdk.ps1) is checking
PROCESSOR_ARCHITECTURE environment variable, which is the way to detect
host architecture on Windows.

This is available only for master channel (on other channels, it
fallbacks to windows-x64).

On windows-x64, it produces an x64 app. On windows-arm64, it produces an
arm64 app.

Author: pbo-linaro

bin/internal/update_dart_sdk.ps1

@@ -47,7 +47,22 @@ if (-not $dartSdkBaseUrl) {
 if ($engineRealm) {
     $dartSdkBaseUrl = "$dartSdkBaseUrl/$engineRealm"
 }
-$dartZipName = "dart-sdk-windows-x64.zip"
+
+# It's important to use the native Dart SDK as the default target architecture
+# for Flutter Windows builds depend on the Dart executable's architecture.
+$dartZipNameX64 = "dart-sdk-windows-x64.zip"
+$dartZipNameArm64 = "dart-sdk-windows-arm64.zip"
+$dartZipName = $dartZipNameX64
+if ($env:PROCESSOR_ARCHITECTURE -eq "ARM64") {
+    $dartSdkArm64Url = "$dartSdkBaseUrl/flutter_infra_release/flutter/$engineVersion/$dartZipNameArm64"
+    Try {
+        Invoke-WebRequest -Uri $dartSdkArm64Url -UseBasicParsing -Method Head | Out-Null
+        $dartZipName = $dartZipNameArm64
+    }
+    Catch {
+        Write-Host "The current channel's Dart SDK does not support Windows Arm64, falling back to Windows x64..."
+    }
+}
 $dartSdkUrl = "$dartSdkBaseUrl/flutter_infra_release/flutter/$engineVersion/$dartZipName"
 
 if ((Test-Path $dartSdkPath) -or (Test-Path $dartSdkLicense)) {

dev/devicelab/lib/tasks/perf_tests.dart

@@ -4,6 +4,7 @@
 
 import 'dart:async';
 import 'dart:convert' show LineSplitter, json, utf8;
+import 'dart:ffi' show Abi;
 import 'dart:io';
 import 'dart:math' as math;
 
@@ -953,11 +954,12 @@ class StartupTest {
             '--target=$target',
           ]);
           final String basename = path.basename(testDirectory);
+          final String arch = Abi.current() == Abi.windowsX64 ? 'x64': 'arm64';
           applicationBinaryPath = path.join(
             testDirectory,
             'build',
             'windows',
-            'x64',
+            arch,
             'runner',
             'Profile',
             '$basename.exe'
@@ -1763,11 +1765,12 @@ class CompileTest {
         await flutter('build', options: options);
         watch.stop();
         final String basename = path.basename(cwd);
+        final String arch = Abi.current() == Abi.windowsX64 ? 'x64': 'arm64';
         final String exePath = path.join(
           cwd,
           'build',
           'windows',
-          'x64',
+          arch,
           'runner',
           'release',
           '$basename.exe');

dev/devicelab/lib/tasks/plugin_tests.dart

@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+import 'dart:ffi';
 import 'dart:io';
 
 import 'package:path/path.dart' as path;
@@ -328,8 +329,9 @@ public class $pluginClass: NSObject, FlutterPlugin {
           throw TaskResult.failure('Platform unit tests failed');
         }
       case 'windows':
+        final String arch = Abi.current() == Abi.windowsX64 ? 'x64': 'arm64';
         if (await exec(
-          path.join(rootPath, 'build', 'windows', 'x64', 'plugins', 'plugintest', 'Release', 'plugintest_test.exe'),
+          path.join(rootPath, 'build', 'windows', arch, 'plugins', 'plugintest', 'Release', 'plugintest_test.exe'),
           <String>[],
           canFail: true,
         ) != 0) {

dev/devicelab/lib/tasks/run_tests.dart

@@ -4,6 +4,7 @@
 
 import 'dart:async';
 import 'dart:convert';
+import 'dart:ffi';
 import 'dart:io';
 
 import '../framework/devices.dart';
@@ -173,12 +174,14 @@ class WindowsRunOutputTest extends DesktopRunOutputTest {
     }
   );
 
+  final String arch = Abi.current() == Abi.windowsX64 ? 'x64': 'arm64';
+
   static final RegExp _buildOutput = RegExp(
     r'Building Windows application\.\.\.\s*\d+(\.\d+)?(ms|s)',
     multiLine: true,
   );
   static final RegExp _builtOutput = RegExp(
-    r'Built build\\windows\\x64\\runner\\(Debug|Release)\\\w+\.exe( \(\d+(\.\d+)?MB\))?\.',
+    r'Built build\\windows\\(x64|arm64)\\runner\\(Debug|Release)\\\w+\.exe( \(\d+(\.\d+)?MB\))?\.',
   );
 
   @override
@@ -205,7 +208,7 @@ class WindowsRunOutputTest extends DesktopRunOutputTest {
 
         return true;
       },
-      'Built build\\windows\\x64\\runner\\$buildMode\\app.exe',
+      'Built build\\windows\\$arch\\runner\\$buildMode\\app.exe',
     );
   }
 }

packages/flutter_tools/bin/tool_backend.dart

@@ -76,7 +76,7 @@ or
     else
       'flutter',
   ]);
-  final String bundlePlatform = targetPlatform.startsWith('windows') ? 'windows' : targetPlatform;
+  final String bundlePlatform = targetPlatform;
   final String target = '${buildMode}_bundle_${bundlePlatform}_assets';
   final Process assembleProcess = await Process.start(
     flutterExecutable,

packages/flutter_tools/lib/src/android/android_device.dart

@@ -234,6 +234,7 @@ class AndroidDevice extends Device {
       case TargetPlatform.tester:
       case TargetPlatform.web_javascript:
       case TargetPlatform.windows_x64:
+      case TargetPlatform.windows_arm64:
         throw UnsupportedError('Invalid target platform for Android');
     }
   }
@@ -570,6 +571,7 @@ class AndroidDevice extends Device {
       case TargetPlatform.linux_x64:
       case TargetPlatform.tester:
       case TargetPlatform.web_javascript:
+      case TargetPlatform.windows_arm64:
       case TargetPlatform.windows_x64:
         _logger.printError('Android platforms are only supported.');
         return LaunchResult.failed();

packages/flutter_tools/lib/src/artifacts.dart

@@ -144,6 +144,7 @@ TargetPlatform? _mapTargetPlatform(TargetPlatform? targetPlatform) {
     case TargetPlatform.linux_x64:
     case TargetPlatform.linux_arm64:
     case TargetPlatform.windows_x64:
+    case TargetPlatform.windows_arm64:
     case TargetPlatform.fuchsia_arm64:
     case TargetPlatform.fuchsia_x64:
     case TargetPlatform.tester:
@@ -526,6 +527,7 @@ class CachedArtifacts implements Artifacts {
       case TargetPlatform.linux_x64:
       case TargetPlatform.linux_arm64:
       case TargetPlatform.windows_x64:
+      case TargetPlatform.windows_arm64:
         return _getDesktopArtifactPath(artifact, platform, mode);
       case TargetPlatform.fuchsia_arm64:
       case TargetPlatform.fuchsia_x64:
@@ -743,8 +745,9 @@ class CachedArtifacts implements Artifacts {
         final String engineArtifactsPath = _cache.getArtifactDirectory('engine').path;
         return _fileSystem.path.join(engineArtifactsPath, platformDirName, _artifactToFileName(artifact, _platform, mode));
       case Artifact.windowsCppClientWrapper:
+        final String platformDirName = _enginePlatformDirectoryName(platform);
         final String engineArtifactsPath = _cache.getArtifactDirectory('engine').path;
-        return _fileSystem.path.join(engineArtifactsPath, 'windows-x64', _artifactToFileName(artifact, _platform, mode));
+        return _fileSystem.path.join(engineArtifactsPath, platformDirName, _artifactToFileName(artifact, _platform, mode));
       case Artifact.skyEnginePath:
         final Directory dartPackageDirectory = _cache.getCacheDir('pkg');
         return _fileSystem.path.join(dartPackageDirectory.path,  _artifactToFileName(artifact, _platform));
@@ -775,6 +778,7 @@ class CachedArtifacts implements Artifacts {
       case TargetPlatform.linux_arm64:
       case TargetPlatform.darwin:
       case TargetPlatform.windows_x64:
+      case TargetPlatform.windows_arm64:
         // TODO(zanderso): remove once debug desktop artifacts are uploaded
         // under a separate directory from the host artifacts.
         // https://github.com/flutter/flutter/issues/38935
@@ -813,10 +817,11 @@ TargetPlatform _currentHostPlatform(Platform platform, OperatingSystemUtils oper
   }
   if (platform.isLinux) {
     return operatingSystemUtils.hostPlatform == HostPlatform.linux_x64 ?
-             TargetPlatform.linux_x64 : TargetPlatform.linux_arm64;
+        TargetPlatform.linux_x64 : TargetPlatform.linux_arm64;
   }
   if (platform.isWindows) {
-    return TargetPlatform.windows_x64;
+    return operatingSystemUtils.hostPlatform == HostPlatform.windows_arm64 ?
+        TargetPlatform.windows_arm64 : TargetPlatform.windows_x64;
   }
   throw UnimplementedError('Host OS not supported.');
 }
@@ -1089,6 +1094,8 @@ class CachedLocalEngineArtifacts implements Artifacts {
         return 'linux-x64';
       case TargetPlatform.windows_x64:
         return 'windows-x64';
+      case TargetPlatform.windows_arm64:
+        return 'windows-arm64';
       case TargetPlatform.ios:
       case TargetPlatform.android:
       case TargetPlatform.android_arm:
@@ -1290,6 +1297,8 @@ class CachedLocalWebSdkArtifacts implements Artifacts {
         return 'linux-x64';
       case TargetPlatform.windows_x64:
         return 'windows-x64';
+      case TargetPlatform.windows_arm64:
+        return 'windows-arm64';
       case TargetPlatform.ios:
       case TargetPlatform.android:
       case TargetPlatform.android_arm:

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

@@ -347,6 +347,7 @@ class AOTSnapshotter {
       TargetPlatform.linux_x64,
       TargetPlatform.linux_arm64,
       TargetPlatform.windows_x64,
+      TargetPlatform.windows_arm64,
     ].contains(platform);
   }
 }

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

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+import 'dart:ffi' show Abi;
+
 import 'package:archive/archive.dart';
 import 'package:file/file.dart';
 import 'package:meta/meta.dart';
@@ -472,8 +474,17 @@ class _WindowsUtils extends OperatingSystemUtils {
     required super.processManager,
   }) : super._private();
 
+  HostPlatform? _hostPlatform;
+
   @override
-  HostPlatform hostPlatform = HostPlatform.windows_x64;
+  HostPlatform get hostPlatform {
+    if (_hostPlatform == null) {
+       final Abi abi = Abi.current();
+      _hostPlatform = (abi == Abi.windowsArm64) ? HostPlatform.windows_arm64 :
+                                                  HostPlatform.windows_x64;
+    }
+    return _hostPlatform!;
+  }
 
   @override
   void makeExecutable(File file) {}
@@ -607,15 +618,17 @@ enum HostPlatform {
   darwin_arm64,
   linux_x64,
   linux_arm64,
-  windows_x64;
+  windows_x64,
+  windows_arm64;
 
   String get platformName {
     return switch (this) {
       HostPlatform.darwin_x64 => 'x64',
       HostPlatform.darwin_arm64 => 'arm64',
       HostPlatform.linux_x64 => 'x64',
       HostPlatform.linux_arm64 => 'arm64',
-      HostPlatform.windows_x64 => 'x64'
+      HostPlatform.windows_x64 => 'x64',
+      HostPlatform.windows_arm64 => 'arm64',
     };
   }
 }
@@ -626,6 +639,7 @@ String getNameForHostPlatform(HostPlatform platform) {
     HostPlatform.darwin_arm64 => 'darwin-arm64',
     HostPlatform.linux_x64 => 'linux-x64',
     HostPlatform.linux_arm64 => 'linux-arm64',
-    HostPlatform.windows_x64 => 'windows-x64'
+    HostPlatform.windows_x64 => 'windows-x64',
+    HostPlatform.windows_arm64 => 'windows-arm64',
   };
 }

packages/flutter_tools/lib/src/build_info.dart

@@ -513,6 +513,7 @@ enum TargetPlatform {
   linux_x64,
   linux_arm64,
   windows_x64,
+  windows_arm64,
   fuchsia_arm64,
   fuchsia_x64,
   tester,
@@ -544,6 +545,7 @@ enum TargetPlatform {
       case TargetPlatform.tester:
       case TargetPlatform.web_javascript:
       case TargetPlatform.windows_x64:
+      case TargetPlatform.windows_arm64:
         throw UnsupportedError('Unexpected Fuchsia platform $this');
     }
   }
@@ -555,6 +557,7 @@ enum TargetPlatform {
       case TargetPlatform.windows_x64:
         return 'x64';
       case TargetPlatform.linux_arm64:
+      case TargetPlatform.windows_arm64:
         return 'arm64';
       case TargetPlatform.android:
       case TargetPlatform.android_arm:
@@ -713,6 +716,8 @@ String getNameForTargetPlatform(TargetPlatform platform, {DarwinArch? darwinArch
       return 'linux-arm64';
     case TargetPlatform.windows_x64:
       return 'windows-x64';
+    case TargetPlatform.windows_arm64:
+      return 'windows-arm64';
     case TargetPlatform.fuchsia_arm64:
       return 'fuchsia-arm64';
     case TargetPlatform.fuchsia_x64:
@@ -756,6 +761,8 @@ TargetPlatform getTargetPlatformForName(String platform) {
       return TargetPlatform.linux_arm64;
     case 'windows-x64':
       return TargetPlatform.windows_x64;
+    case 'windows-arm64':
+      return TargetPlatform.windows_arm64;
     case 'web-javascript':
       return TargetPlatform.web_javascript;
     case 'flutter-tester':