VM: [Kernel] Add --embedder-entry-points-manifest to dartk/transform and pass it to the treeshaker

pkg/kernel/bin/util.dart

+// Copyright (c) 2016, 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:kernel/target/targets.dart';
+import 'package:kernel/transformations/treeshaker.dart';
+
+/// Parses all given [embedderEntryPointManifests] and returns the program roots
+/// specified in them.
+///
+/// A embedder manifest consists of lines of the following form:
+///
+///   <import-uri>,<class-name>,<member-name>
+///
+/// Where
+///
+///   <import-uri> : The uri of the library which contains the root.
+///   <class-name> : Is either the name of the class or '::' for the library.
+///   <member-name>: Can be of the forms:
+///
+///     - get:<name>
+///     - set:<name>
+///     - <field-name>
+///     - <procedure-name>
+///     - <constructor-name>
+///     - <klass>.<factory-constructor-name>
+///     - *external-instantiation*
+///
+List<ProgramRoot> parseProgramRoots(List<String> embedderEntryPointManifests) {
+  List<ProgramRoot> roots = <ProgramRoot>[];
+
+  for (var file in embedderEntryPointManifests) {
+    var lines = new File(file).readAsStringSync().trim().split('\n');
+    for (var line in lines) {
+      var parts = line.split(',');
+      assert(parts.length == 3);
+
+      var library = parts[0];
+      var klass = parts[1];
+      var member = parts[2];
+
+      // The vm represents the toplevel class as '::'.
+      if (klass == '::') klass = null;
+
+      ProgramRootKind kind = ProgramRootKind.Other;
+
+      if (member.startsWith('set:')) {
+        kind = ProgramRootKind.Setter;
+        member = member.substring('set:'.length);
+      } else if (member.startsWith('get:')) {
+        kind = ProgramRootKind.Getter;
+        member = member.substring('get:'.length);
+      } else if (member == "*external-instantiation*") {
+        kind = ProgramRootKind.ExternallyInstantiatedClass;
+        member = null;
+      } else if (member.startsWith('$klass.')) {
+        kind = ProgramRootKind.Constructor;
+        member = member.substring('$klass.'.length);
+      }
+
+      roots.add(new ProgramRoot(library, klass, member, kind));
+    }
+  }
+
+  return roots;
+}