Revert "Tweak public APIs and use them in patch_sdk, dart2js, and kernel-service."

pkg/front_end/lib/src/fasta/vm.dart

Index: pkg/front_end/lib/src/fasta/vm.dart
diff --git a/pkg/front_end/lib/src/fasta/vm.dart b/pkg/front_end/lib/src/fasta/vm.dart
new file mode 100644
index 0000000000000000000000000000000000000000..2da5da863b50ea880b9c269148ae24691840a280
--- /dev/null
+++ b/pkg/front_end/lib/src/fasta/vm.dart
@@ -0,0 +1,165 @@
+// Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+/// API for compiling Dart source code to .dill (Kernel IR) files.
+library front_end.vm;
+// TODO(ahe): Convert this file to use the API in `../../kernel_generator.dart`
+// and `../../compiler_options.dart`.
+
+import 'dart:async' show Future;
+
+import 'dart:io' show File, Platform;
+
+import 'dart:typed_data' show Uint8List;
+
+import 'package:front_end/file_system.dart';
+import 'package:front_end/physical_file_system.dart';
+
+import 'fasta.dart' as fasta;
+
+import 'package:kernel/target/targets.dart' show TargetFlags;
+import 'package:kernel/target/vm_fasta.dart' show VmFastaTarget;
+
+/// Compilation status codes.
+///
+/// Note: The [index] property of these constants must match
+/// `Dart_KernelCompilationStatus` in
+/// [dart_api.h](../../../../runtime/include/dart_api.h).
+enum Status {
+  /// Compilation was successful.
+  ok,
+
+  /// Compilation failed with a compile time error.
+  error,
+
+  /// Compiler crashed.
+  crash,
+}
+
+abstract class CompilationResult {
+  CompilationResult._();
+
+  factory CompilationResult.ok(Uint8List bytes) = _CompilationOk;
+
+  factory CompilationResult.errors(List<String> errors) = _CompilationError;
+
+  factory CompilationResult.error(String error) {
+    return new _CompilationError(<String>[error]);
+  }
+
+  factory CompilationResult.crash(Object exception, StackTrace stack) =
+      _CompilationCrash;
+
+  Status get status;
+
+  get payload;
+
+  List toResponse() => [status.index, payload];
+}
+
+Future<CompilationResult> parseScript(Uri script,
+    {bool verbose: false, bool strongMode: false}) async {
+  return parseScriptInFileSystem(script, PhysicalFileSystem.instance,
+      verbose: verbose, strongMode: strongMode);
+}
+
+Future<CompilationResult> parseScriptInFileSystem(
+    Uri script, FileSystem fileSystem,
+    {bool verbose: false, bool strongMode: false}) async {
+  final Uri packagesUri = (Platform.packageConfig != null)
+      ? Uri.parse(Platform.packageConfig)
+      : await _findPackagesFile(fileSystem, script);
+  if (packagesUri == null) {
+    throw "Could not find .packages";
+  }
+
+  final Uri patchedSdk = Uri.base
+      .resolveUri(new Uri.file(Platform.resolvedExecutable))
+      .resolveUri(new Uri.directory("patched_sdk"));
+
+  if (verbose) {
+    print("""DFE: Requesting compilation {
+  scriptUri: ${script}
+  packagesUri: ${packagesUri}
+  patchedSdk: ${patchedSdk}
+}""");
+  }
+
+  try {
+    return await fasta.parseScriptInFileSystem(script, fileSystem, packagesUri,
+        patchedSdk, new VmFastaTarget(new TargetFlags(strongMode: strongMode)),
+        verbose: verbose);
+  } catch (err, stack) {
+    return new CompilationResult.crash(err, stack);
+  }
+}
+
+class _CompilationOk extends CompilationResult {
+  final Uint8List bytes;
+
+  _CompilationOk(this.bytes) : super._();
+
+  @override
+  Status get status => Status.ok;
+
+  @override
+  get payload => bytes;
+
+  String toString() => "_CompilationOk(${bytes.length} bytes)";
+}
+
+abstract class _CompilationFail extends CompilationResult {
+  _CompilationFail() : super._();
+
+  String get errorString;
+
+  @override
+  get payload => errorString;
+}
+
+class _CompilationError extends _CompilationFail {
+  final List<String> errors;
+
+  _CompilationError(this.errors);
+
+  @override
+  Status get status => Status.error;
+
+  @override
+  String get errorString => errors.take(10).join('\n');
+
+  String toString() => "_CompilationError(${errorString})";
+}
+
+class _CompilationCrash extends _CompilationFail {
+  final Object exception;
+  final StackTrace stack;
+
+  _CompilationCrash(this.exception, this.stack);
+
+  @override
+  Status get status => Status.crash;
+
+  @override
+  String get errorString => "${exception}\n${stack}";
+
+  String toString() => "_CompilationCrash(${errorString})";
+}
+
+/// This duplicates functionality from the Loader which we can't easily
+/// access from here.
+Future<Uri> _findPackagesFile(FileSystem fileSystem, Uri base) async {
+  var dir = new File.fromUri(base).parent;
+  while (true) {
+    final packagesFile = dir.uri.resolve(".packages");
+    if (await fileSystem.entityForUri(packagesFile).exists()) {
+      return packagesFile;
+    }
+    if (dir.parent.path == dir.path) {
+      break;
+    }
+    dir = dir.parent;
+  }
+  return null;
+}