Use different SDKs based on option settings

pkg/analysis_server/lib/src/server/driver.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 driver;
 
 import 'dart:async';
 import 'dart:io';
 import 'dart:math';
 
@@ skipping 357 matching lines @@
     analysisServerOptions.enableIncrementalResolutionValidation =
         results[INCREMENTAL_RESOLUTION_VALIDATION];
     analysisServerOptions.noErrorNotification = results[NO_ERROR_NOTIFICATION];
     analysisServerOptions.noIndex = results[NO_INDEX];
     analysisServerOptions.useAnalysisHighlight2 =
         results[USE_ANALISYS_HIGHLIGHT2];
     analysisServerOptions.fileReadMode = results[FILE_READ_MODE];
 
     _initIncrementalLogger(results[INCREMENTAL_RESOLUTION_LOG]);
 
-    DartSdk defaultSdk;
+    JavaFile defaultSdkDirectory;
     if (results[SDK_OPTION] != null) {
-      defaultSdk = new DirectoryBasedDartSdk(new JavaFile(results[SDK_OPTION]));
+      defaultSdkDirectory = new JavaFile(results[SDK_OPTION]);
     } else {
-      // No path to the SDK provided; use DirectoryBasedDartSdk.defaultSdk,
-      // which will make a guess.
-      defaultSdk = DirectoryBasedDartSdk.defaultSdk;
+      // No path to the SDK was provided.
+      // Use DirectoryBasedDartSdk.defaultSdkDirectory, which will make a guess.
+      defaultSdkDirectory = DirectoryBasedDartSdk.defaultSdkDirectory;
     }
+    SdkCreator defaultSdkCreator =
+        () => new DirectoryBasedDartSdk(defaultSdkDirectory);
+    // TODO(brianwilkerson) It would be nice to avoid creating an SDK that
+    // cannot be re-used, but the SDK is needed to create a package map provider
+    // in the case where we need to run `pub` in order to get the package map.
+    DirectoryBasedDartSdk defaultSdk = defaultSdkCreator();
     //
     // Initialize the instrumentation service.
     //
     String logFilePath = results[INSTRUMENTATION_LOG_FILE];
     if (logFilePath != null) {
       _rollLogFiles(logFilePath, 5);
       FileInstrumentationServer fileBasedServer =
           new FileInstrumentationServer(logFilePath);
       instrumentationServer = instrumentationServer != null
           ? new MulticastInstrumentationServer(
@@ skipping 17 matching lines @@
     plugins.add(linterPlugin);
     plugins.add(linterServerPlugin);
     plugins.add(dartCompletionPlugin);
     plugins.addAll(_userDefinedPlugins);
 
     ExtensionManager manager = new ExtensionManager();
     manager.processPlugins(plugins);
     //
     // Create the sockets and start listening for requests.
     //
-    socketServer = new SocketServer(analysisServerOptions, defaultSdk, service,
-        serverPlugin, packageResolverProvider, embeddedUriResolverProvider);
+    socketServer = new SocketServer(
+        analysisServerOptions,
+        defaultSdkCreator,
+        defaultSdk,
+        service,
+        serverPlugin,
+        packageResolverProvider,
+        embeddedUriResolverProvider);
     httpServer = new HttpAnalysisServer(socketServer);
     stdioServer = new StdioAnalysisServer(socketServer);
     socketServer.userDefinedPlugins = _userDefinedPlugins;
 
     if (serve_http) {
       httpServer.serveHttp(port);
     }
 
     _captureExceptions(service, () {
       stdioServer.serveStdio().then((_) async {
@@ skipping 151 matching lines @@
    */
   static void _rollLogFiles(String path, int numOld) {
     for (int i = numOld - 1; i >= 0; i--) {
       try {
         String oldPath = i == 0 ? path : '$path.$i';
         new File(oldPath).renameSync('$path.${i+1}');
       } catch (e) {}
     }
   }
 }