Implement line and column numbers.

pkg/front_end/lib/src/fasta/kernel/kernel_class_builder.dart

 // Copyright (c) 2016, 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 fasta.kernel_class_builder;
 
 import 'package:kernel/ast.dart' show
     Class,
     DartType,
     ExpressionStatement,
     InterfaceType,
     Member,
     StringLiteral,
     Supertype,
     Throw;
 
 import '../errors.dart' show
     internalError;
 
+import '../messages.dart' show
+    warning;
+
 import 'kernel_builder.dart' show
     Builder,
     ClassBuilder,
     ConstructorReferenceBuilder,
     KernelProcedureBuilder,
     KernelTypeBuilder,
     LibraryBuilder,
     MetadataBuilder,
     ProcedureBuilder,
     TypeVariableBuilder,
@@ skipping 68 matching lines @@
               builder.redirectionTarget;
           if (redirectionTarget != null) {
             assert(builder.actualBody == null);
             Builder targetBuilder = redirectionTarget.target;
             if (targetBuilder is ProcedureBuilder) {
               Member target = targetBuilder.target;
               builder.body = new RedirectingFactoryBody(target);
             } else {
               // TODO(ahe): Throw NSM error. This requires access to core
               // types.
-              String message =
-                  "Missing constructor: ${redirectionTarget.fullNameForErrors}";
-              print(message);
+              String message = "Redirection constructor target not found: "
+                  "${redirectionTarget.fullNameForErrors}";
+              warning(library.fileUri, -1, message);
               builder.body = new ExpressionStatement(
                   new Throw(new StringLiteral(message)));
             }
           }
         }
       });
     }
     return count;
   }
 }