Support general handling of type variables by substituting types into the current context.

sdk/lib/_internal/compiler/implementation/helpers/trace.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.
 
 part of dart2js.helpers;
 
 /**
  * Helper method for printing stack traces for debugging.
  *
  * [message] is printed as the header of the stack trace.
  *
  * If [condition] is provided, the stack trace is only printed if [condition]
  * returns [:true:] on the stack trace text. This can be used to filter the
  * printed stack traces based on their content. For instance only print stack
  * traces that contain specific paths.
  */
-void trace(String message, [bool condition(String stackTrace)]) {
+void trace(String message, {bool condition(String stackTrace), int limit}) {
   try {
     throw '';
   } catch (e, s) {
     String stackTrace = prettifyStackTrace(
-        s, rangeStart: 1, filePrefix: stackTraceFilePrefix);
+        s, rangeStart: 1, rangeEnd: limit, filePrefix: stackTraceFilePrefix);
     if (condition != null) {
       if (!condition(stackTrace)) return;
     }
     print('$message\n$stackTrace');
   }
 }
 
-void traceAndReport(Compiler compiler, Spannable node,
-                    String message, [bool condition(String stackTrace)]) {
+void traceAndReport(Compiler compiler, Spannable node, String message,
+                    {bool condition(String stackTrace), int limit}) {
 
-  trace(message, (String stackTrace) {
+  trace(message, condition: (String stackTrace) {
     bool result = condition != null ? condition(stackTrace) : true;
     if (result) {
       reportHere(compiler, node, message);
     }
     return result;
   });
 }
 
 /// Helper class for the processing of stack traces in [prettifyStackTrace].
 class _StackTraceLine {
@@ skipping 134 matching lines @@
   }
   for (int index = text.length ; index < intendedLength ; index ++) {
     int dotsIndex = index % dotsLength;
     sb.write(dots.substring(dotsIndex, dotsIndex + 1));
   }
   if (padLeft) {
     sb.write(text);
   }
   return sb.toString();
 }