Timing hooks to profile linters (#24548).

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/token.dart';
@@ skipping 2795 matching lines @@
     Source source = getRequiredSource();
     ErrorReporter errorReporter = new ErrorReporter(errorListener, source);
     //
     // Prepare inputs.
     //
     CompilationUnit unit = getRequiredInput(RESOLVED_UNIT_INPUT);
 
     //
     // Generate lints.
     //
+    List<AstVisitor> visitors = <AstVisitor>[];
+
     List<Linter> linters = getLints(context);
-    linters.forEach((l) => l.reporter = errorReporter);
-    Iterable<AstVisitor> visitors = linters.map((l) => l.getVisitor()).toList();
-    unit.accept(new DelegatingAstVisitor(visitors.where((v) => v != null)));
+    for (Linter linter in linters) {
+      AstVisitor visitor = linter.getVisitor();
+      if (visitor != null) {
+        linter.reporter = errorReporter;
+        visitors
+            .add(new TimedAstVisitor(visitor, lintRegistry.getTimer(linter)));
+      }
+    }
+
+    DelegatingAstVisitor dv = new DelegatingAstVisitor(visitors);
+    unit.accept(dv);
 
     //
     // Record outputs.
     //
     outputs[LINTS] = errorListener.errors;
   }
 
   /**
    * 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
@@ skipping 2507 matching lines @@
 
   @override
   bool moveNext() {
     if (_newSources.isEmpty) {
       return false;
     }
     currentTarget = _newSources.removeLast();
     return true;
   }
 }