Use different SDKs based on option settings

pkg/analysis_server/lib/src/context_manager.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 context.directory.manager;
 
 import 'dart:async';
 import 'dart:collection';
 import 'dart:convert';
 import 'dart:core' hide Resource;
@@ skipping 288 matching lines @@
  * created, destroyed or updated, (b) inform the client when "pub list"
  * operations are in progress, and (c) determine which files should be
  * analyzed.
  *
  * TODO(paulberry): eliminate this interface, and instead have [ContextManager]
  * operations return data structures describing how context state should be
  * modified.
  */
 abstract class ContextManagerCallbacks {
   /**
-   * Create and return a new analysis context, allowing [disposition] to govern
-   * details of how the context is to be created.
+   * Return the default analysis options to be used when creating an analysis
+   * context.
    */
-  AnalysisContext addContext(Folder folder, FolderDisposition disposition);
+  AnalysisOptions get defaultAnalysisOptions;
+
+  /**
+   * Create and return a new analysis context rooted at the given [folder], with
+   * the given analysis [options], allowing [disposition] to govern details of
+   * how the context is to be created.
+   */
+  AnalysisContext addContext(
+      Folder folder, AnalysisOptions options, FolderDisposition disposition);
 
   /**
    * Called when the set of files associated with a context have changed (or
    * some of those files have been modified).  [changeSet] is the set of
    * changes that need to be applied to the context.
    */
   void applyChangesToContext(Folder contextFolder, ChangeSet changeSet);
 
   /**
    * Called when the ContextManager is about to start computing the package
@@ skipping 219 matching lines @@
         return true;
       }
     }
     // no
     return false;
   }
 
   /**
    * Process [options] for the given context [info].
    */
-  void processOptionsForContext(ContextInfo info, Folder folder,
+  void processOptionsForContext(ContextInfo info, Map<String, Object> options,
       {bool optionsRemoved: false}) {
-    Map<String, Object> options;
-    try {
-      options = analysisOptionsProvider.getOptions(folder);
-    } catch (_) {
-      // Parse errors are reported by GenerateOptionsErrorsTask.
-    }
-
     if (options == null && !optionsRemoved) {
       return;
     }
 
     // In case options files are removed, revert to defaults.
     if (optionsRemoved) {
       // Start with defaults.
       info.context.analysisOptions = new AnalysisOptionsImpl();
 
       // Apply inherited options.
@@ skipping 34 matching lines @@
       return;
     }
 
     // Set ignore patterns.
     YamlList exclude = analyzer[AnalyzerOptions.exclude];
     if (exclude != null) {
       setIgnorePatternsForContext(info, exclude);
     }
   }
 
+  /**
+   * Return the options from the analysis options file in the given [folder], or
+   * `null` if there is no file in the folder or if the contents of the file are
+   * not valid YAML.
+   */
+  Map<String, Object> readOptions(Folder folder) {
+    try {
+      return analysisOptionsProvider.getOptions(folder);
+    } catch (_) {
+      // Parse errors are reported by GenerateOptionsErrorsTask.
+    }
+    return null;
+  }
+
   @override
   void refresh(List<Resource> roots) {
     // Destroy old contexts
     List<ContextInfo> contextInfos = rootInfo.descendants.toList();
     if (roots == null) {
       contextInfos.forEach(_destroyContext);
     } else {
       roots.forEach((Resource resource) {
         contextInfos.forEach((ContextInfo contextInfo) {
           if (resource is Folder &&
@@ skipping 202 matching lines @@
         _addSourceFiles(changeSet, child, info);
       }
     }
   }
 
   void _checkForAnalysisOptionsUpdate(
       String path, ContextInfo info, ChangeType changeType) {
     if (AnalysisEngine.isAnalysisOptionsFileName(path, pathContext)) {
       var analysisContext = info.context;
       if (analysisContext is context.AnalysisContextImpl) {
-        processOptionsForContext(info, info.folder,
+        // TODO(brianwilkerson) This doesn't correctly update the source factory
+        // if the changes necessitate it (such as by changing the setting of the
+        // strong-mode option).
+        Map<String, Object> options = readOptions(info.folder);
+        processOptionsForContext(info, options,
             optionsRemoved: changeType == ChangeType.REMOVE);
         analysisContext.invalidateCachedResults();
         callbacks.applyChangesToContext(info.folder, new ChangeSet());
       }
     }
   }
 
   void _checkForPackagespecUpdate(
       String path, ContextInfo info, Folder folder) {
     // Check to see if this is the .packages file for this context and if so,
@@ skipping 120 matching lines @@
 
     FolderDisposition disposition;
     List<String> dependencies = <String>[];
 
     // Next resort to a package uri resolver.
     if (disposition == null) {
       disposition =
           _computeFolderDisposition(folder, dependencies.add, packagespecFile);
     }
 
+    Map<String, Object> optionMap = readOptions(info.folder);
+    AnalysisOptions options =
+        new AnalysisOptionsImpl.from(callbacks.defaultAnalysisOptions);
+    applyToAnalysisOptions(options, optionMap);
+
     info.setDependencies(dependencies);
-    info.context = callbacks.addContext(folder, disposition);
+    info.context = callbacks.addContext(folder, options, disposition);
     info.context.name = folder.path;
 
-    processOptionsForContext(info, folder);
+    processOptionsForContext(info, optionMap);
 
     return info;
   }
 
   /**
    * Potentially create a new context associated with the given [folder].
    *
    * If there are subfolders with 'pubspec.yaml' files, separate contexts are
    * created for them and excluded from the context associated with the
    * [folder].
@@ skipping 609 matching lines @@
       ResourceProvider resourceProvider) {
     if (packages != null) {
       // Construct package map for the SdkExtUriResolver.
       Map<String, List<Folder>> packageMap = buildPackageMap(resourceProvider);
       return <UriResolver>[new SdkExtUriResolver(packageMap)];
     } else {
       return const <UriResolver>[];
     }
   }
 }