Analyzer: add ignore_for_file comment that ignores a type of problem for the whole file; add tests.

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 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/standard_resolution_map.dart';
@@ skipping 2987 matching lines @@
    * Create a [GenerateLintsTask] based on the given [target] in
    * the given [context].
    */
   static GenerateLintsTask createTask(
       AnalysisContext context, AnalysisTarget target) {
     return new GenerateLintsTask(context, target);
   }
 }
 
 /**
- * Information about analysis `//ignore:` comments within a source file.
+ * Information about analysis `//ignore:` and `//ignore_for_file` comments
+ * within a source file.
  */
 class IgnoreInfo {
   /**
    *  Instance shared by all cases without matches.
    */
   static final IgnoreInfo _EMPTY_INFO = new IgnoreInfo();
 
   /**
    * A regular expression for matching 'ignore' comments.  Produces matches
    * containing 2 groups.  For example:
    *
    *     * ['//ignore: error_code', 'error_code']
    *
    * Resulting codes may be in a list ('error_code_1,error_code2').
    */
   static final RegExp _IGNORE_MATCHER =
       new RegExp(r'//[ ]*ignore:(.*)$', multiLine: true);
 
+  /**
+   * A regular expression for matching 'ignore_for_file' comments.  Produces
+   * matches containing 2 groups.  For example:
+   *
+   *     * ['//ignore_for_file: error_code', 'error_code']
+   *
+   * Resulting codes may be in a list ('error_code_1,error_code2').
+   */
+  static final RegExp _IGNORE_FOR_FILE_MATCHER =
+      new RegExp(r'//[ ]*ignore_for_file:(.*)$', multiLine: true);
+
   final Map<int, List<String>> _ignoreMap = new HashMap<int, List<String>>();
 
+  final Set<String> _ignoreForFileSet = new HashSet<String>();
+
   /**
    * Whether this info object defines any ignores.
    */
-  bool get hasIgnores => ignores.isNotEmpty;
+  bool get hasIgnores => ignores.isNotEmpty || _ignoreForFileSet.isNotEmpty;
 
   /**
    * Map of line numbers to associated ignored error codes.
    */
   Map<int, Iterable<String>> get ignores => _ignoreMap;
 
   /**
+   * Iterable of error codes ignored for the whole file.
+   */
+  Iterable<String> get ignoreForFiles => _ignoreForFileSet;
+
+  /**
    * Ignore this [errorCode] at [line].
    */
   void add(int line, String errorCode) {
     _ignoreMap.putIfAbsent(line, () => new List<String>()).add(errorCode);
   }
 
   /**
    * Ignore these [errorCodes] at [line].
    */
   void addAll(int line, Iterable<String> errorCodes) {
     _ignoreMap.putIfAbsent(line, () => new List<String>()).addAll(errorCodes);
   }
 
   /**
+   * Ignore these [errorCodes] in the whole file.
+   */
+  void addAllForFile(Iterable<String> errorCodes) {
+    _ignoreForFileSet.addAll(errorCodes);
+  }
+
+  /**
    * Test whether this [errorCode] is ignored at the given [line].
    */
   bool ignoredAt(String errorCode, int line) =>
+      _ignoreForFileSet.contains(errorCode) ||
       _ignoreMap[line]?.contains(errorCode) == true;
 
   /**
    * Calculate ignores for the given [content] with line [info].
    */
   static IgnoreInfo calculateIgnores(String content, LineInfo info) {
     Iterable<Match> matches = _IGNORE_MATCHER.allMatches(content);
-    if (matches.isEmpty) {
+    Iterable<Match> fileMatches = _IGNORE_FOR_FILE_MATCHER.allMatches(content);
+    if (matches.isEmpty && fileMatches.isEmpty) {
       return _EMPTY_INFO;
     }
 
     IgnoreInfo ignoreInfo = new IgnoreInfo();
     for (Match match in matches) {
       // See _IGNORE_MATCHER for format --- note the possibility of error lists.
       Iterable<String> codes = match
           .group(1)
           .split(',')
           .map((String code) => code.trim().toLowerCase());
       ignoreInfo.addAll(info.getLocation(match.start).lineNumber, codes);
     }
+    for (Match match in fileMatches) {
+      Iterable<String> codes = match
+          .group(1)
+          .split(',')
+          .map((String code) => code.trim().toLowerCase());
+      ignoreInfo.addAllForFile(codes);
+    }
     return ignoreInfo;
   }
 }
 
 /**
  * A task that ensures that all of the inferable instance members in a
  * compilation unit have had their type inferred.
  */
 class InferInstanceMembersInUnitTask extends SourceBasedAnalysisTask {
   /**
@@ skipping 2749 matching lines @@
 
   @override
   bool moveNext() {
     if (_newSources.isEmpty) {
       return false;
     }
     currentTarget = _newSources.removeLast();
     return true;
   }
 }