Generate hints for imports.

pkg/analyzer/lib/src/task/dart.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.dart;
 
 import 'dart:collection';
 import 'dart:math' as math;
 
 import 'package:analyzer/src/generated/ast.dart';
@@ skipping 263 matching lines @@
     new ResultDescriptor<List<AnalysisError>>(
         'SCAN_ERRORS', AnalysisError.NO_ERRORS, contributesTo: DART_ERRORS);
 
 /**
  * The [TypeProvider] of the context.
  */
 final ResultDescriptor<TypeProvider> TYPE_PROVIDER =
     new ResultDescriptor<TypeProvider>('TYPE_PROVIDER', null);
 
 /**
- * The used local [Element]s of a [LibraryUnitTarget].
+ * The [UsedImportedElements] of a [LibraryUnitTarget].
+ */
+final ResultDescriptor<UsedImportedElements> USED_IMPORTED_ELEMENTS =
+    new ResultDescriptor<UsedImportedElements>('USED_IMPORTED_ELEMENTS', null);
+
+/**
+ * The [UsedLocalElements] of a [LibraryUnitTarget].
  */
 final ResultDescriptor<UsedLocalElements> USED_LOCAL_ELEMENTS =
     new ResultDescriptor<UsedLocalElements>('USED_LOCAL_ELEMENTS', null);
 
 /**
  * The errors produced while verifying a compilation unit.
  *
  * The list will be empty if there were no errors, but will not be `null`.
  *
  * The result is only available for targets representing a Dart compilation unit.
@@ skipping 1357 matching lines @@
       element = definedNames[setterName];
       if (element != null) {
         newNames[setterName] = element;
       }
     }
     return newNames;
   }
 }
 
 /**
+ * A task that builds [USED_IMPORTED_ELEMENTS] for a unit.
+ */
+class GatherUsedImportedElementsTask extends SourceBasedAnalysisTask {
+  /**
+   * The name of the [RESOLVED_UNIT] input.
+   */
+  static const String UNIT_INPUT = 'UNIT_INPUT';
+
+  /**
+   * The task descriptor describing this kind of task.
+   */
+  static final TaskDescriptor DESCRIPTOR = new TaskDescriptor(
+      'GatherUsedImportedElementsTask', createTask, buildInputs,
+      <ResultDescriptor>[USED_IMPORTED_ELEMENTS]);
+
+  GatherUsedImportedElementsTask(
+      InternalAnalysisContext context, AnalysisTarget target)
+      : super(context, target);
+
+  @override
+  TaskDescriptor get descriptor => DESCRIPTOR;
+
+  @override
+  void internalPerform() {
+    CompilationUnit unit = getRequiredInput(UNIT_INPUT);
+    CompilationUnitElement unitElement = unit.element;
+    LibraryElement libraryElement = unitElement.library;
+    //
+    // Prepare used imported elements.
+    //
+    GatherUsedImportedElementsVisitor visitor =
+        new GatherUsedImportedElementsVisitor(libraryElement);
+    unit.accept(visitor);
+    //
+    // Record outputs.
+    //
+    outputs[USED_IMPORTED_ELEMENTS] = visitor.usedElements;
+  }
+
+  /**
+   * Return a map from the names of the inputs of this kind of task to the task
+   * input descriptors describing those inputs for a task with the
+   * given [target].
+   */
+  static Map<String, TaskInput> buildInputs(LibraryUnitTarget target) {
+    return <String, TaskInput>{UNIT_INPUT: RESOLVED_UNIT.of(target)};
+  }
+
+  /**
+   * Create a [GatherUsedImportedElementsTask] based on the given [target] in
+   * the given [context].
+   */
+  static GatherUsedImportedElementsTask createTask(
+      AnalysisContext context, LibraryUnitTarget target) {
+    return new GatherUsedImportedElementsTask(context, target);
+  }
+}
+
+/**
  * A task that builds [USED_LOCAL_ELEMENTS] for a unit.
  */
 class GatherUsedLocalElementsTask extends SourceBasedAnalysisTask {
   /**
    * The name of the [RESOLVED_UNIT] input.
    */
   static const String UNIT_INPUT = 'UNIT_INPUT';
 
   /**
    * The task descriptor describing this kind of task.
    */
   static final TaskDescriptor DESCRIPTOR = new TaskDescriptor(
-      'GatherUsedElementsTask', createTask, buildInputs,
+      'GatherUsedLocalElementsTask', createTask, buildInputs,
       <ResultDescriptor>[USED_LOCAL_ELEMENTS]);
 
   GatherUsedLocalElementsTask(
       InternalAnalysisContext context, AnalysisTarget target)
       : super(context, target);
 
   @override
   TaskDescriptor get descriptor => DESCRIPTOR;
 
   @override
   void internalPerform() {
     CompilationUnit unit = getRequiredInput(UNIT_INPUT);
     CompilationUnitElement unitElement = unit.element;
     LibraryElement libraryElement = unitElement.library;
     //
-    // Prepare visited elements.
+    // Prepare used local elements.
     //
     GatherUsedLocalElementsVisitor visitor =
         new GatherUsedLocalElementsVisitor(libraryElement);
     unit.accept(visitor);
     //
     // Record outputs.
     //
     outputs[USED_LOCAL_ELEMENTS] = visitor.usedElements;
   }
 
@@ skipping 21 matching lines @@
  */
 class GenerateHintsTask extends SourceBasedAnalysisTask {
   /**
    * The name of the [RESOLVED_UNIT] input.
    */
   static const String UNIT_INPUT = 'UNIT_INPUT';
 
   /**
    * The name of a list of [USED_LOCAL_ELEMENTS] for each library unit input.
    */
-  static const String USED_ELEMENTS_INPUT = 'USED_ELEMENTS_INPUT';
+  static const String USED_LOCAL_ELEMENTS_INPUT = 'USED_LOCAL_ELEMENTS';
+
+  /**
+   * The name of a list of [USED_IMPORTED_ELEMENTS] for each library unit input.
+   */
+  static const String USED_IMPORTED_ELEMENTS_INPUT = 'USED_IMPORTED_ELEMENTS';
 
   /**
    * The task descriptor describing this kind of task.
    */
   static final TaskDescriptor DESCRIPTOR = new TaskDescriptor(
       'GenerateHintsTask', createTask, buildInputs, <ResultDescriptor>[HINTS]);
 
   GenerateHintsTask(InternalAnalysisContext context, AnalysisTarget target)
       : super(context, target);
 
   @override
   TaskDescriptor get descriptor => DESCRIPTOR;
 
   @override
   void internalPerform() {
     RecordingErrorListener errorListener = new RecordingErrorListener();
     Source source = getRequiredSource();
     ErrorReporter errorReporter = new ErrorReporter(errorListener, source);
     //
     // Prepare inputs.
     //
     CompilationUnit unit = getRequiredInput(UNIT_INPUT);
-    List<UsedLocalElements> usedElementsList =
-        getRequiredInput(USED_ELEMENTS_INPUT);
+    List<UsedImportedElements> usedImportedElementsList =
+        getRequiredInput(USED_IMPORTED_ELEMENTS_INPUT);
+    List<UsedLocalElements> usedLocalElementsList =
+        getRequiredInput(USED_LOCAL_ELEMENTS_INPUT);
     CompilationUnitElement unitElement = unit.element;
     LibraryElement libraryElement = unitElement.library;
     //
     // Generate errors.
     //
-    // TODO(scheglov) move collecting used imports into a separate task
-//      unit.accept(_importsVerifier);
-    // Dead code analysis.
     unit.accept(new DeadCodeVerifier(errorReporter));
-    // Unused elements.
+    // Verify imports.
+    {
+      ImportsVerifier verifier = new ImportsVerifier();
+      verifier.addImports(unit);
+      usedImportedElementsList.forEach(verifier.removeUsedElements);
+      verifier.generateDuplicateImportHints(errorReporter);
+      verifier.generateUnusedImportHints(errorReporter);
+    }
+    // Unused local elements.
     {
       UsedLocalElements usedElements =
-          new UsedLocalElements.merge(usedElementsList);
+          new UsedLocalElements.merge(usedLocalElementsList);
       UnusedLocalElementsVerifier visitor =
           new UnusedLocalElementsVerifier(errorListener, usedElements);
       unitElement.accept(visitor);
     }
     // Dart2js analysis.
     if (context.analysisOptions.dart2jsHint) {
       unit.accept(new Dart2JSVerifier(errorReporter));
     }
     // Dart best practices.
     InheritanceManager inheritanceManager =
@@ skipping 11 matching lines @@
 
   /**
    * Return a map from the names of the inputs of this kind of task to the task
    * input descriptors describing those inputs for a task with the
    * given [target].
    */
   static Map<String, TaskInput> buildInputs(LibraryUnitTarget target) {
     Source libSource = target.library;
     return <String, TaskInput>{
       UNIT_INPUT: RESOLVED_UNIT.of(target),
-      USED_ELEMENTS_INPUT: UNITS.of(libSource).toList((unit) {
+      USED_LOCAL_ELEMENTS_INPUT: UNITS.of(libSource).toList((unit) {
         LibraryUnitTarget target = new LibraryUnitTarget(libSource, unit);
         return USED_LOCAL_ELEMENTS.of(target);
+      }),
+      USED_IMPORTED_ELEMENTS_INPUT: UNITS.of(libSource).toList((unit) {
+        LibraryUnitTarget target = new LibraryUnitTarget(libSource, unit);
+        return USED_IMPORTED_ELEMENTS.of(target);
       })
     };
   }
 
   /**
    * Create a [GenerateHintsTask] based on the given [target] in
    * the given [context].
    */
   static GenerateHintsTask createTask(
       AnalysisContext context, AnalysisTarget target) {
@@ skipping 710 matching lines @@
   @override
   bool moveNext() {
     if (_newSources.isEmpty) {
       return false;
     }
     currentTarget = _newSources.first;
     _newSources.remove(currentTarget);
     return true;
   }
 }