github.com/flutter/flutter changes required to use kernel

packages/flutter_tools/lib/src/commands/build_aot.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 'dart:io';
 
 import 'package:path/path.dart' as path;
 
 import '../base/common.dart';
 import '../base/logger.dart';
 import '../base/process.dart';
 import '../base/utils.dart';
 import '../build_info.dart';
 import '../dart/package_map.dart';
 import '../globals.dart';
 import '../resident_runner.dart';
+import '../toolchain.dart';
 import 'build.dart';
 
 // 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',
 ];
 
 class BuildAotCommand extends BuildSubCommand {
   BuildAotCommand() {
     usesTargetOption();
@@ skipping 17 matching lines @@
   @override
   Future<Null> runCommand() async {
     await super.runCommand();
     String targetPlatform = argResults['target-platform'];
     TargetPlatform platform = getTargetPlatformForName(targetPlatform);
     if (platform == null)
       throwToolExit('Unknown platform: $targetPlatform');
 
     String typeName = path.basename(tools.getEngineArtifactsDirectory(platform, getBuildMode()).path);
     Status status = logger.startProgress('Building AOT snapshot in ${getModeName(getBuildMode())} mode ($typeName)...');
-    String outputPath = await buildAotSnapshot(
-      findMainDartFile(targetFile),
+    String dartFile = findMainDartFile(targetFile);
+    String dillFile = await buildDilFile(dartFile);
+    String outputPath =  await buildAotSnapshot(
+      dillFile != null ? dillFile : dartFile,
       platform,
       getBuildMode(),
       outputPath: argResults['output-dir'],
       interpreter: argResults['interpreter']
     );
     status.stop();
 
     if (outputPath == null)
       throwToolExit(null);
 
     printStatus('Built to $outputPath${Platform.pathSeparator}.');
   }
 }
 
 String _getSdkExtensionPath(PackageMap packageMap, String package) {
   return path.dirname(packageMap.map[package].toFilePath());
 }
 
+
+Future<String> buildDilFile(String dartFile) async {
+  String engineSourcePath = ToolConfiguration.instance.engineSrcPath;
+  String engineBuildPath = ToolConfiguration.instance.engineBuildPath;
+  if (engineSourcePath == null) {
+    throw new Exception('Engine source path not found!');
+  }
+  if (engineBuildPath == null) {
+    throw new Exception('Engine build path path not found!');
+  }
+  String buildScript = path.join(
+      engineSourcePath, 'dart/pkg/kernel/bin/dartk.dart');
+  String transformScript = path.join(
+      engineSourcePath, 'dart/pkg/kernel/bin/transform.dart');
+  String patchedSdk = path.join(
+      engineBuildPath, 'patched_sdk');
+
+  PackageMap packageMap = new PackageMap(PackageMap.globalPackagesPath);
+  String packageMapError = packageMap.checkValid();
+  if (packageMapError != null) {
+    printError(packageMapError);
+    return null;
+  }
+
+  String skyEnginePkg = _getSdkExtensionPath(packageMap, 'sky_engine');
+  String uiPath = path.join(skyEnginePkg, 'dart_ui', 'ui.dart');
+  String jniPath = path.join(skyEnginePkg, 'dart_jni', 'jni.dart');
+  String vmServicePath = path.join(skyEnginePkg, 'sdk_ext', 'vmservice_io.dart');
+
+  String dillFile = dartFile.replaceAll('.dart', '.dill');
+  String transformedDillFile = dartFile.replaceAll('.dart', '.transformed.dill');
+  String inferredDillFile = dartFile.replaceAll('.dart', '.transformed.inferred.dill');
+  RunResult results = await runAsync(<String>[
+    'dart',
+    '-c',
+    buildScript,
+    dartFile,
+    '--target=flutter',
+    '--link',
+    '--sdk=$patchedSdk',
+    '-o',
+    dillFile,
+    '--url-mapping=dart:ui::$uiPath',
+    '--url-mapping=dart:jni::$jniPath',
+    '--url-mapping=dart:vmservice_sky::$vmServicePath',
+  ]);
+  if (results.exitCode != 0) {
+    printStatus(results.toString());
+    return null;
+  }
+  results = await runAsync(<String>[
+    transformScript,
+    '-o',
+    transformedDillFile,
+    dillFile,
+  ]);
+  if (results.exitCode != 0) {
+    printStatus(results.toString());
+    return null;
+  }
+
+        bool disableInference = false;
+  //bool disableInference = true;
+  if (disableInference) return transformedDillFile;
+
+  results = await runAsync(<String>[
+    transformScript,
+    '-t',
+    'infervalues',
+    '-o',
+    inferredDillFile,
+    transformedDillFile,
+  ]);
+  if (results.exitCode != 0) {
+    printStatus(results.toString());
+    return null;
+  }
+
+  return inferredDillFile;
+}
+
 /// Build an AOT snapshot. Return `null` (and log to `printError`) if the method
 /// fails.
 Future<String> buildAotSnapshot(
   String mainPath,
   TargetPlatform platform,
   BuildMode buildMode, {
   String outputPath,
   bool interpreter: false
 }) async {
   outputPath ??= getAotBuildDirectory();
@@ skipping 228 matching lines @@
       linkCommand.add(kVmIsolateSnapshotO);
       linkCommand.add(kIsolateSnapshotO);
     } else {
       linkCommand.add(assemblyO);
     }
     runCheckedSync(linkCommand);
   }
 
   return outputPath;
 }