dart2js send stats, includes:

pkg/compiler/lib/src/stats/analysis_result.dart

+// Copyright (c) 2015, 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 to get results from a static analysis of the source program.
+library compiler.src.stats.analysis_result;
+
+import '../tree/tree.dart' show Node;
+import '../universe/selector.dart' show Selector;
+
+/// A three-value logic bool (yes, no, maybe). We say that `yes` and `maybe` are
+/// "truthy", while `no` and `maybe` are "falsy".
+// TODO(sigmund): is it worth using an enum? or switch to true/false/null?
+enum Boolish { yes, no, maybe }
+
+/// Specifies results of some kind of static analysis on a source program.
+abstract class AnalysisResult {
+  /// Information computed about a specific [receiver].
+  ReceiverInfo infoForReceiver(Node receiver);
+
+  /// Information computed about a specific [selector] applied to a specific
+  /// [receiver].
+  SelectorInfo infoForSelector(Node receiver, Selector selector);
+}
+
+/// Analysis information about a receiver of a send.
+abstract class ReceiverInfo {
+  /// Receiver node for which this information is computed.
+  Node get receiver;
+
+  /// Return whether [receiver] resolves to a value that implements no such
+  /// method. The answer is `yes` if all values that [receiver] could evaluate
+  /// to at runtime contain it, or `no` if none of them does. Maybe if it
+  /// depends on some context or we can't determine this information precisely.
+  Boolish get hasNoSuchMethod;
+
+  /// When [hasNoSuchMethod] is yes, the precise number of possible noSuchMethod
+  /// handlers for this receiver.
+  int get possibleNsmTargets;
+
+  /// Return whether [receiver] may ever be null.
+  Boolish get isNull;
+}
+
+/// Information about a specific selector applied to a specific receiver.
+abstract class SelectorInfo {
+  /// Receiver node of the [selector].
+  Node get receiver;
+
+  /// Specific selector on [receiver] for which this information is computed.
+  Selector get selector;
+
+  /// Whether a member matching [selector] exists in [receiver].
+  Boolish get exists;
+
+  /// Whether [receiver] needs an interceptor to implement [selector].
+  Boolish get usesInterceptor;
+
+  /// Possible total number of methods that could be the target of the selector.
+  /// This needs to be combined with [isAccurate] to correctly understand the
+  /// value. Some invariants:
+  ///
+  ///   * If [exists] is `no`, the value here should be 0, regardless of
+  ///   accuracy.
+  ///   * If [exists] is `yes`, the value is always considered 1 or more.
+  ///     If [isAccurate] is false, we treat it as there may be many possible
+  ///     targets.
+  ///   * If [exists] is `maybe`, the value is considered 0 or more.
+  int get possibleTargets;
+
+  /// Whether the information about [possibleTargets] is accurate.
+  bool get isAccurate;
+}