Merge the work on Generic Types Reification from 'dart-lang/reify' repo

pkg/kernel/bin/reified_dart.dart

+#!/usr/bin/env dart
+// 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.
+
+import 'dart:io';
+
+import 'package:args/args.dart' as args;
+import 'package:path/path.dart' as path;
+
+args.ArgParser parser = new args.ArgParser(allowTrailingOptions: true)
+  ..addOption("sdk",
+      abbr: "s",
+      help: "Path to the Dart SDK. By default it will be searched at the path\n"
+          "'../../../out/ReleaseX64/patched_sdk' relative to the directory\n"
+          "of 'reified_dart'.",
+      defaultsTo: null)
+  ..addOption("dartk",
+      abbr: "k",
+      help: "Path to 'dartk' executable. By default it will be searched for\n"
+          "in the same directory as 'reified_dart'.",
+      defaultsTo: null)
+  ..addOption("dill-output",
+      abbr: "d",
+      help: "Path to intermediate reified .dill file. If not specified,\n"
+          "the intermediate file is created in a temporary location\n"
+          "and is removed after program execution.",
+      defaultsTo: null);
+
+String getUsage() => """
+Usage: reified_dart [options] FILE
+
+Reifies generic types in FILE and runs the transformed program.
+
+Examples:
+    reified_dart foo.dart
+    reified_dart --sdk=/path/to/sdk foo.dart
+    reified_dart --sdk=/path/to/sdk --dartk=/path/to/dartk foo.dart
+
+Options:
+${parser.usage}
+""";
+
+void fail(String message) {
+  stderr.writeln(message);
+  exit(1);
+}
+
+args.ArgResults options;
+
+void checkIsDirectory(String path, {String option, String description}) {
+  description = (description == null ? "" : "$description\n");
+  var stat = new File(path).statSync();

[karlklose, 2017/02/17 12:35:19]

How about 'type' or 'kind' instead of 'stat'? You could also switch on the
return value of 'statSync' directly.

[Dmitry Stefantsov, 2017/02/17 13:10:34]

Done.

+  switch (stat.type) {
+    case FileSystemEntityType.DIRECTORY:
+    case FileSystemEntityType.LINK:
+      return;
+    case FileSystemEntityType.NOT_FOUND:
+      throw fail('$description$option not found: $path');
+    default:
+      fail('$description$option is not a directory: $path');
+  }
+}
+
+void checkIsFile(String path, {String option, String description}) {
+  description = (description == null ? "" : "$description\n");
+  var stat = new File(path).statSync();
+  switch (stat.type) {
+    case FileSystemEntityType.DIRECTORY:
+      throw fail('$description$option is a directory: $path');
+
+    case FileSystemEntityType.NOT_FOUND:
+      throw fail('$description$option not found: $path');
+  }
+}
+
+String defaultSdk() {
+  String currentFile = Platform.script.toFilePath();
+
+  // Respect different path separators.
+  String relativePath = "../../../out/ReleaseX64/patched_sdk";
+  List<String> components = relativePath.split("/");
+  relativePath = "";
+  for (String component in components) {
+    relativePath = path.join(relativePath, component);
+  }
+
+  String currentDir = path.dirname(currentFile);
+  String sdkPath = path.join(currentDir, relativePath);
+  sdkPath = path.normalize(sdkPath);

[karlklose, 2017/02/17 12:35:19]

Add call to 'normalize' to previous line?

[Dmitry Stefantsov, 2017/02/17 13:10:34]

Done.

+
+  return sdkPath;
+}
+
+String defaultDartk() {
+  String currentFile = Platform.script.toFilePath();
+  String dartkPath = path.join(path.dirname(currentFile), "dartk.dart");
+  return dartkPath;
+}
+
+main(List<String> arguments) async {
+  if (arguments.length == 0) {
+    fail(getUsage());
+  }
+
+  try {
+    options = parser.parse(arguments);
+  } on FormatException catch (e) {
+    fail(e.message);
+  }
+
+  if (options.rest.length != 1) {
+    fail("Exactly one FILE should be given.");
+  }
+
+  String inputFilename = options.rest.single;
+  checkIsFile(inputFilename, option: "Input file");
+
+  String sdkPath = options["sdk"];
+  if (sdkPath == null) {

[karlklose, 2017/02/17 12:35:19]

Consider moving this whole logic into getDefaultSdk (and also getDefaultDartk
below).

[Dmitry Stefantsov, 2017/02/17 13:10:34]

Done.

+    sdkPath = defaultSdk();
+    checkIsDirectory(sdkPath,
+        option: "Path to Dart SDK",
+        description: "The --sdk option wasn't specified, "
+            "so default location was checked.");
+  } else {
+    checkIsDirectory(sdkPath, option: "Path to Dart SDK");
+  }
+
+  String dartkPath = options["dartk"];
+  if (dartkPath == null) {
+    dartkPath = defaultDartk();
+    checkIsFile(dartkPath,
+        option: "Path to 'dartk'",
+        description: "The --dartk option wasn't specified, "
+            "so default location was checked.");
+  } else {
+    checkIsFile(dartkPath, option: "Path to 'dartk'");
+  }
+
+  String dillOutput = options["dill-output"];
+  File tempFile = null;
+  if (dillOutput == null) {
+    Directory tmp = await Directory.systemTemp.createTemp();
+    Uri uri = tmp.uri.resolve("generated.dill");
+    dillOutput = uri.toFilePath();
+    tempFile = new File.fromUri(uri);
+  }
+
+  ProcessResult result = Process.runSync(dartkPath, [

[karlklose, 2017/02/17 12:35:19]

Since main is already async you could also use 'await Process.run' (also below)

[Dmitry Stefantsov, 2017/02/17 13:10:34]

Done.

+    "--sdk=$sdkPath",
+    "--target=vmreify",
+    "--link",
+    "--out=$dillOutput",
+    inputFilename,
+  ]);
+  if (result.exitCode != 0) {
+    tempFile?.parent?.delete(recursive: true);
+    stderr.write(result.stderr);

[karlklose, 2017/02/17 12:35:19]

Maybe print something like 'execution failed with exit code ${result.exitCode}'?

[Dmitry Stefantsov, 2017/02/17 13:10:34]

Done.

+    exit(result.exitCode);
+  }
+
+  result = Process.runSync("/usr/bin/env", [
+    "dart",
+    dillOutput,
+    inputFilename,
+  ]);
+  if (result.exitCode != 0) {

[karlklose, 2017/02/17 12:35:19]

I would print result.stdOut even with failures.

This can share code with l. 174-176, for example,
  stdout.write(result.stdout);
  stderr.write(result.stderr);
  tmpFile?.parent?.delete(recursive: true); // You could also leave the file
there, the OS should remove it.
  if (result.exitCode != 0) {
    print('Execution failed with exit code ${result.exitCode}');
  }

[Dmitry Stefantsov, 2017/02/17 13:10:34]

Done.

+    tempFile?.parent?.delete(recursive: true);
+    stderr.write(result.stderr);
+    exit(result.exitCode);
+  }
+
+  stdout.write(result.stdout);
+  stderr.write(result.stderr);
+  tempFile?.parent?.delete(recursive: true);
+}