Kill dead code (#38652)

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

@@ -18,7 +18,6 @@ import '../reporting/reporting.dart';
 
 import 'context.dart';
 import 'file_system.dart';
-import 'fingerprint.dart';
 import 'process.dart';
 
 GenSnapshot get genSnapshot => context.get<GenSnapshot>();
@@ -349,142 +348,3 @@ class AOTSnapshotter {
     return value;
   }
 }
-
-class JITSnapshotter {
-  /// Builds a JIT VM snapshot of the specified kernel. This snapshot includes
-  /// data as well as either machine code or DBC, depending on build configuration.
-  Future<int> build({
-    @required TargetPlatform platform,
-    @required BuildMode buildMode,
-    @required String mainPath,
-    @required String packagesPath,
-    @required String outputPath,
-    @required String compilationTraceFilePath,
-    List<String> extraGenSnapshotOptions = const <String>[],
-  }) async {
-    if (!_isValidJitPlatform(platform)) {
-      printError('${getNameForTargetPlatform(platform)} does not support JIT snapshotting.');
-      return 1;
-    }
-
-    final Directory outputDir = fs.directory(outputPath);
-    outputDir.createSync(recursive: true);
-
-    final String engineVmSnapshotData = artifacts.getArtifactPath(Artifact.vmSnapshotData, mode: buildMode);
-    final String engineIsolateSnapshotData = artifacts.getArtifactPath(Artifact.isolateSnapshotData, mode: buildMode);
-    final String isolateSnapshotData = fs.path.join(outputDir.path, 'isolate_snapshot_data');
-    final String isolateSnapshotInstructions = fs.path.join(outputDir.path, 'isolate_snapshot_instr');
-
-    final List<String> inputPaths = <String>[
-      mainPath, compilationTraceFilePath, engineVmSnapshotData, engineIsolateSnapshotData,
-    ];
-
-    final String depfilePath = fs.path.join(outputDir.path, 'snapshot.d');
-    final List<String> genSnapshotArgs = <String>[
-      '--deterministic',
-    ];
-    if (buildMode == BuildMode.debug) {
-      genSnapshotArgs.add('--enable_asserts');
-    }
-    if (extraGenSnapshotOptions != null && extraGenSnapshotOptions.isNotEmpty) {
-      printTrace('Extra gen_snapshot options: $extraGenSnapshotOptions');
-      genSnapshotArgs.addAll(extraGenSnapshotOptions);
-    }
-
-    final Set<String> outputPaths = <String>{
-      isolateSnapshotData,
-      isolateSnapshotInstructions,
-    };
-
-    // There are a couple special cases below where we create a snapshot
-    // with only the data section, which only contains interpreted code.
-    bool supportsAppJit = true;
-
-    if (platform == TargetPlatform.android_x64 &&
-        getCurrentHostPlatform() == HostPlatform.windows_x64) {
-      supportsAppJit = false;
-      printStatus('Android x64 dynamic build on Windows x64 will use purely interpreted '
-                  'code for now (see  https://github.com/flutter/flutter/issues/17489).');
-    }
-
-    if (platform == TargetPlatform.android_x86) {
-      supportsAppJit = false;
-      printStatus('Android x86 dynamic build will use purely interpreted code for now. '
-                  'To optimize performance, consider using --target-platform=android-x64.');
-    }
-
-    genSnapshotArgs.addAll(<String>[
-      '--snapshot_kind=${supportsAppJit ? 'app-jit' : 'app'}',
-      '--load_compilation_trace=$compilationTraceFilePath',
-      '--load_vm_snapshot_data=$engineVmSnapshotData',
-      '--load_isolate_snapshot_data=$engineIsolateSnapshotData',
-      '--isolate_snapshot_data=$isolateSnapshotData',
-    ]);
-
-    genSnapshotArgs.add('--isolate_snapshot_instructions=$isolateSnapshotInstructions');
-
-    if (platform == TargetPlatform.android_arm) {
-      // Use softfp for Android armv7 devices.
-      // TODO(cbracken): eliminate this when we fix https://github.com/flutter/flutter/issues/17489
-      genSnapshotArgs.add('--no-sim-use-hardfp');
-
-      // Not supported by the Pixel in 32-bit mode.
-      genSnapshotArgs.add('--no-use-integer-division');
-    }
-
-    genSnapshotArgs.add(mainPath);
-
-    // Verify that all required inputs exist.
-    final Iterable<String> missingInputs = inputPaths.where((String p) => !fs.isFileSync(p));
-    if (missingInputs.isNotEmpty) {
-      printError('Missing input files: $missingInputs from $inputPaths');
-      return 1;
-    }
-
-    // If inputs and outputs have not changed since last run, skip the build.
-    final Fingerprinter fingerprinter = Fingerprinter(
-      fingerprintPath: '$depfilePath.fingerprint',
-      paths: <String>[mainPath, ...inputPaths, ...outputPaths],
-      properties: <String, String>{
-        'buildMode': buildMode.toString(),
-        'targetPlatform': platform.toString(),
-        'entryPoint': mainPath,
-        'extraGenSnapshotOptions': extraGenSnapshotOptions.join(' '),
-      },
-      depfilePaths: <String>[],
-    );
-    // TODO(jonahwilliams): re-enable once this can be proved correct.
-    // if (await fingerprinter.doesFingerprintMatch()) {
-    //   printTrace('Skipping JIT snapshot build. Fingerprint match.');
-    //   return 0;
-    // }
-
-    final SnapshotType snapshotType = SnapshotType(platform, buildMode);
-    final int genSnapshotExitCode = await genSnapshot.run(
-      snapshotType: snapshotType,
-      additionalArgs: genSnapshotArgs,
-    );
-    if (genSnapshotExitCode != 0) {
-      printError('Dart snapshot generator failed with exit code $genSnapshotExitCode');
-      return genSnapshotExitCode;
-    }
-
-    // Write path to gen_snapshot, since snapshots have to be re-generated when we roll
-    // the Dart SDK.
-    final String genSnapshotPath = GenSnapshot.getSnapshotterPath(snapshotType);
-    await outputDir.childFile('gen_snapshot.d').writeAsString('gen_snapshot.d: $genSnapshotPath\n');
-
-    // Compute and record build fingerprint.
-    await fingerprinter.writeFingerprint();
-    return 0;
-  }
-
-  bool _isValidJitPlatform(TargetPlatform platform) {
-    return const <TargetPlatform>[
-      TargetPlatform.android_arm,
-      TargetPlatform.android_arm64,
-      TargetPlatform.android_x86,
-      TargetPlatform.android_x64,
-    ].contains(platform);
-  }
-}