Use AnalysisOptions.signature as a way to check compatibility.

pkg/analyzer/lib/src/generated/sdk.dart

 // Copyright (c) 2014, 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.
 
 library analyzer.src.generated.sdk;
 
 import 'dart:collection';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/visitor.dart';
 import 'package:analyzer/src/generated/engine.dart'
-    show AnalysisContext, AnalysisOptions, AnalysisOptionsImpl;
+    show AnalysisContext, AnalysisOptions;
 import 'package:analyzer/src/generated/source.dart' show Source;
 import 'package:analyzer/src/generated/utilities_general.dart';
 import 'package:analyzer/src/summary/idl.dart' show PackageBundle;
 
 /**
  * A Dart SDK installed in a specified location.
  */
 abstract class DartSdk {
   /**
    * The short name of the dart SDK 'async' library.
@@ skipping 183 matching lines @@
   /**
    * Initialize a newly created SDK description to describe an SDK based on the
    * files or directories at the given [paths] that is analyzed using the given
    * [options].
    */
   SdkDescription(this.paths, this.options);
 
   @override
   int get hashCode {
     int hashCode = 0;
-    for (int value in options.encodeCrossContextOptions()) {
+    for (int value in options.signature) {
       hashCode = JenkinsSmiHash.combine(hashCode, value);
     }
     for (String path in paths) {
       hashCode = JenkinsSmiHash.combine(hashCode, path.hashCode);
     }
     return JenkinsSmiHash.finish(hashCode);
   }
 
   @override
   bool operator ==(Object other) {
     if (other is SdkDescription) {
-      if (!AnalysisOptions.crossContextOptionsEqual(
-          options.encodeCrossContextOptions(),
-          other.options.encodeCrossContextOptions())) {
+      if (!AnalysisOptions.signaturesEqual(
+          options.signature, other.options.signature)) {
         return false;
       }
       int length = paths.length;
       if (other.paths.length != length) {
         return false;
       }
       for (int i = 0; i < length; i++) {
         if (other.paths[i] != paths[i]) {
           return false;
         }
@@ skipping 15 matching lines @@
       needsSeparator = true;
     }
 
     for (String path in paths) {
       add(path);
     }
     if (needsSeparator) {
       buffer.write(' ');
     }
     buffer.write('(');
-    buffer.write(AnalysisOptionsImpl
-        .decodeCrossContextOptions(options.encodeCrossContextOptions()));
+    buffer.write(options.signature);
     buffer.write(')');
     return buffer.toString();
   }
 }
 
 class SdkLibrariesReader_LibraryBuilder extends RecursiveAstVisitor<Object> {
   /**
    * The prefix added to the name of a library to form the URI used in code to
    * reference the library.
    */
@@ skipping 262 matching lines @@
     _platforms |= DART2JS_PLATFORM;
   }
 
   /**
    * Record that this library can be run on the VM.
    */
   void setVmLibrary() {
     _platforms |= VM_PLATFORM;
   }
 }