Report messages instead of just printing.

pkg/front_end/lib/src/fasta/compiler_command_line.dart

Index: pkg/front_end/lib/src/fasta/compiler_command_line.dart
diff --git a/pkg/front_end/lib/src/fasta/compiler_command_line.dart b/pkg/front_end/lib/src/fasta/compiler_command_line.dart
index 04a4b6c68ae8aee16f616cdd3aff285a5b3190ff..c4c4fd9d28bdef7c958c6fa1833a03e65be83929 100644
--- a/pkg/front_end/lib/src/fasta/compiler_command_line.dart
+++ b/pkg/front_end/lib/src/fasta/compiler_command_line.dart
@@ -6,20 +6,25 @@ library fasta.compiler_command_line;
 
 import 'dart:io' show exit;
 
+import 'package:kernel/target/targets.dart'
+    show Target, getTarget, TargetFlags, targets;
+
 import 'command_line.dart' show CommandLine, deprecated_argumentError;
 
 import 'compiler_context.dart' show CompilerContext;
 
-import 'package:kernel/target/targets.dart'
-    show Target, getTarget, TargetFlags, targets;
+import 'command_line_reporting.dart' as command_line_reporting;
 
 import 'fasta_codes.dart'
     show
+        LocatedMessage,
         Message,
         messageFastaUsageLong,
         messageFastaUsageShort,
         templateUnspecified;
 
+import 'severity.dart' show Severity;
+
 const Map<String, dynamic> optionSpecification = const <String, dynamic>{
   "--compile-sdk": Uri,
   "--fatal": ",",
@@ -128,6 +133,24 @@ class CompilerCommandLine extends CommandLine {
 
   Target get target => options["target"];
 
+  void Function(LocatedMessage, Severity) get report {
+    return options["report"] ?? command_line_reporting.report;
+  }
+
+  void Function(Message, Severity) get reportWithoutLocation {
+    return options["reportWithoutLocation"] ??
+        command_line_reporting.reportWithoutLocation;
+  }
+
+  String Function(LocatedMessage, Severity) get format {
+    return options["format"] ?? command_line_reporting.format;
+  }
+
+  String Function(Message, Severity) get formatWithoutLocation {
+    return options["formatWithoutLocation"] ??
+        command_line_reporting.formatWithoutLocation;
+  }
+
   static dynamic withGlobalOptions(String programName, List<String> arguments,
       dynamic f(CompilerContext context)) {
     return CompilerContext.withGlobalOptions(