Use SummarySdkAnalysisContext if the SDK has the analysis_summary file.

pkg/analyzer/lib/src/generated/sdk_io.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_io;
 
 import 'dart:io';
 
 import 'package:analyzer/src/context/context.dart';
 import 'package:analyzer/src/generated/ast.dart';
 import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/generated/error.dart';
 import 'package:analyzer/src/generated/java_core.dart';
 import 'package:analyzer/src/generated/java_engine.dart';
 import 'package:analyzer/src/generated/java_engine_io.dart';
 import 'package:analyzer/src/generated/java_io.dart';
 import 'package:analyzer/src/generated/parser.dart';
 import 'package:analyzer/src/generated/scanner.dart';
 import 'package:analyzer/src/generated/sdk.dart';
 import 'package:analyzer/src/generated/source_io.dart';
+import 'package:analyzer/src/summary/format.dart' show SdkBundle;
+import 'package:analyzer/src/summary/summary_sdk.dart';
+import 'package:path/path.dart' as pathos;
 
 /**
  * A Dart SDK installed in a specified directory. Typical Dart SDK layout is
  * something like...
  *
  *     dart-sdk/
  *        bin/
  *           dart[.exe]  <-- VM
  *        lib/
  *           core/
@@ skipping 203 matching lines @@
    * should be used when it is available
    */
   DirectoryBasedDartSdk(JavaFile sdkDirectory, [bool useDart2jsPaths = false]) {
     this._sdkDirectory = sdkDirectory.getAbsoluteFile();
     _libraryMap = initialLibraryMap(useDart2jsPaths);
   }
 
   @override
   AnalysisContext get context {
     if (_analysisContext == null) {
-      _analysisContext = new SdkAnalysisContext();
+      SdkBundle sdkBundle = _getSummarySdkBundle();
+      if (sdkBundle != null) {
+        _analysisContext = new SummarySdkAnalysisContext(sdkBundle);
+      } else {
+        _analysisContext = new SdkAnalysisContext();
+      }
       SourceFactory factory = new SourceFactory([new DartUriResolver(this)]);
       _analysisContext.sourceFactory = factory;
       List<String> uris = this.uris;
       ChangeSet changeSet = new ChangeSet();
       for (String uri in uris) {
         changeSet.addedSource(factory.forUri(uri));
       }
       _analysisContext.applyChanges(changeSet);
     }
     return _analysisContext;
@@ skipping 271 matching lines @@
         file = file.getParentFile();
         file = new JavaFile.relative(file, relativePath);
       }
       return new FileBasedSource(file, parseUriWithException(dartUri));
     } on URISyntaxException {
       return null;
     }
   }
 
   /**
+   * Return the [SdkBundle] for this SDK, if it exists, or `null` otherwise.
+   */
+  SdkBundle _getSummarySdkBundle() {
+    String rootPath = directory.getAbsolutePath();
+    String path = pathos.join(rootPath, 'lib', '_internal', 'analysis_summary');
+    try {
+      File file = new File(path);
+      if (file.existsSync()) {
+        List<int> bytes = file.readAsBytesSync();
+        return new SdkBundle.fromBuffer(bytes);
+      }
+    } catch (exception, stackTrace) {
+      AnalysisEngine.instance.logger.logError(
+          'Failed to load SDK analysis summary from $path',
+          new CaughtException(exception, stackTrace));
+    }
+    return null;
+  }
+
+  /**
    * Return the given [file] if it exists and is executable, or `null` if it
    * does not exist or is not executable.
    */
   JavaFile _verifyExecutable(JavaFile file) =>
       file.isExecutable() ? file : null;
 }
 
 /**
  * An object used to read and parse the libraries file
  * (dart-sdk/lib/_internal/sdk_library_metadata/lib/libraries.dart) for information
@@ skipping 50 matching lines @@
     SdkLibrariesReader_LibraryBuilder libraryBuilder =
         new SdkLibrariesReader_LibraryBuilder(_useDart2jsPaths);
     // If any syntactic errors were found then don't try to visit the AST
     // structure.
     if (!errorListener.errorReported) {
       unit.accept(libraryBuilder);
     }
     return libraryBuilder.librariesMap;
   }
 }