Record dependencies and invalidate results.

pkg/analyzer/lib/src/task/driver.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.
 
 library analyzer.src.task.driver;
 
 import 'dart:async';
 import 'dart:collection';
 
 import 'package:analyzer/src/context/cache.dart';
@@ skipping 192 matching lines @@
       CacheEntry targetEntry = context.getCacheEntry(item.target);
       targetEntry.setErrorState(item.exception, item.descriptor.results);
       return null;
     }
     // Otherwise, perform the task.
     AnalysisTask task = item.buildTask();
     _onTaskStartedController.add(task);
     task.perform();
     CacheEntry entry = context.getCacheEntry(task.target);
     if (task.caughtException == null) {
+      List<TargetedResult> dependedOn = item.inputTargetedResults.toList();
       Map<ResultDescriptor, dynamic> outputs = task.outputs;
       for (ResultDescriptor result in task.descriptor.results) {
         // TODO(brianwilkerson) We could check here that a value was produced
         // and throw an exception if not (unless we want to allow null values).
-        entry.setValue(result, outputs[result]);
+        entry.setValue(result, outputs[result], dependedOn);
       }
     } else {
       entry.setErrorState(task.caughtException, item.descriptor.results);
     }
     _onTaskCompletedController.add(task);
     return task;
   }
 
   /**
    * Reset the state of the driver in response to a change in the state of one
@@ skipping 51 matching lines @@
   final TaskDescriptor descriptor;
 
   /**
    * An iterator used to iterate over the descriptors of the inputs to the task,
    * or `null` if all of the inputs have been collected and the task can be
    * created.
    */
   TaskInputBuilder builder;
 
   /**
+   * The [TargetedResult]s outputs of this task depends on.
+   */
+  final HashSet<TargetedResult> inputTargetedResults =
+      new HashSet<TargetedResult>();
+
+  /**
    * The inputs to the task that have been computed.
    */
   Map<String, dynamic> inputs;
 
   /**
    * The exception that was found while trying to populate the inputs. If this
    * field is non-`null`, then the task cannot be performed and all of the
    * results that this task would have computed need to be marked as being in
    * ERROR with this exception.
    */
@@ skipping 38 matching lines @@
    * If all of the inputs have been gathered, return `null` to indicate that the
    * client should build and perform the task. A value of `null` will also be
    * returned if some of the inputs cannot be computed and the task cannot be
    * performed. Callers can differentiate between these cases by checking the
    * [exception] field. If the field is `null`, then the task can be performed;
    * if the field is non-`null` then the task cannot be performed and all of the
    * tasks' results should be marked as being in ERROR.
    */
   WorkItem gatherInputs(TaskManager taskManager) {
     while (builder != null) {
-      //
-      // TODO(brianwilkerson) Capture information about which inputs were used
-      // to compute the results. This information can later be used to compute
-      // which results depend on a given result, and hence which results need to
-      // be invalidated when one result is invalidated.
-      //
       AnalysisTarget inputTarget = builder.currentTarget;
       ResultDescriptor inputResult = builder.currentResult;
+      inputTargetedResults.add(new TargetedResult(inputTarget, inputResult));
       CacheEntry inputEntry = context.getCacheEntry(inputTarget);
       CacheState inputState = inputEntry.getState(inputResult);
       if (inputState == CacheState.ERROR) {
         exception = inputEntry.exception;
         return null;
       } else if (inputState == CacheState.IN_PROCESS) {
         //
         // TODO(brianwilkerson) Implement this case.
         //
         // One possibility would be to return a WorkItem that would perform a
@@ skipping 94 matching lines @@
     TaskDescriptor descriptor = currentItem.descriptor;
     AnalysisTarget target = currentItem.target;
     for (WorkItem item in pendingItems) {
       if (item.descriptor == descriptor && item.target == target) {
         return true;
       }
     }
     return false;
   }
 }