Adjusts dart2js backend to handle method type arguments.

pkg/compiler/lib/src/diagnostics/messages.dart

 // Copyright (c) 2011, 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.
 
 /**
  * The messages in this file should meet the following guide lines:
  *
  * 1. The message should be a complete sentence starting with an uppercase
  * letter, and ending with a period.
  *
@@ skipping 412 matching lines @@
   THIS_CALL_TO_FACTORY,
   THIS_IS_THE_DECLARATION,
   THIS_IS_THE_METHOD,
   THIS_IS_THE_PART_OF_TAG,
   THIS_PROPERTY,
   RETHROW_OUTSIDE_CATCH,
   TOP_LEVEL_VARIABLE_DECLARED_STATIC,
   TYPE_ARGUMENT_COUNT_MISMATCH,
   TYPE_VARIABLE_IN_CONSTANT,
   TYPE_VARIABLE_WITHIN_STATIC_MEMBER,
+  TYPE_VARIABLE_FROM_METHOD_NOT_REIFIED,
   TYPEDEF_FORMAL_WITH_DEFAULT,
   UNARY_OPERATOR_BAD_ARITY,
   UNBOUND_LABEL,
   UNIMPLEMENTED_EXPLICIT_GETTER,
   UNIMPLEMENTED_EXPLICIT_SETTER,
   UNIMPLEMENTED_GETTER,
   UNIMPLEMENTED_GETTER_ONE,
   UNIMPLEMENTED_IMPLICIT_GETTER,
   UNIMPLEMENTED_IMPLICIT_SETTER,
   UNIMPLEMENTED_METHOD,
@@ skipping 702 matching lines @@
 class C<T> {
   const C();
 
   m(T t) => const C<T>();
 }
 
 void main() => new C().m(null);
 """
           ]),
 
+      MessageKind.TYPE_VARIABLE_FROM_METHOD_NOT_REIFIED: const MessageTemplate(
+          MessageKind.TYPE_VARIABLE_FROM_METHOD_NOT_REIFIED,
+          "Method type variables are not reified.",
+          howToFix: "Try using the intended upper bound of the "
+              "type variable, or dynamic."

[Johnni Winther, 2016/05/23 12:50:41]

You can add an [options] argument to MessageTemplate to make the examples work.

And I think you need to add checks for and use fo this message template in
resolution/members.dart in handleIs, handleAs, and
handleTypeVariableTypeLiteralAccess

[eernst, 2016/05/23 14:30:24]

Marked as TODOs for the next CL.

+// GENERIC_METHODS: These examples can be commented in when the compiler
+// supports generic methods without an option:
+//
+//        examples: const [
+//            """
+// // Method type variables are not reified, so they cannot be returned.
+// Type f<T>() => T;
+//
+// main() => f<int>();
+// """,
+//            """
+// // Method type variables are not reified, so they cannot be tested dynamically.
+// bool f<T>(Object o) => o is T;
+//
+// main() => f<int>(42);
+// """,
+//            """
+// // Method type variables are not reified, so they cannot be tested dynamically.
+// bool f<T>(Object o) => o as T;
+//
+// main() => f<int>(42);
+// """
+//    ]
+      ),
+
       MessageKind.INVALID_TYPE_VARIABLE_BOUND: const MessageTemplate(
           MessageKind.INVALID_TYPE_VARIABLE_BOUND,
           "'#{typeArgument}' is not a subtype of bound '#{bound}' for "
           "type variable '#{typeVariable}' of type '#{thisType}'.",
           howToFix: "Try to change or remove the type argument.",
           examples: const [
             """
 class C<T extends num> {}
 
 // 'String' is not a valid instantiation of T with bound num.'.
@@ skipping 2552 matching lines @@
   static String convertToString(value) {
     if (value is ErrorToken) {
       // Shouldn't happen.
       return value.assertionMessage;
     } else if (value is Token) {
       value = value.value;
     }
     return '$value';
   }
 }