Implement line and column numbers.

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 2413488ea7a3f6f6db6f4cff02130b882f52c465..3c1ebed2c1ed0cdd93bede0072828d6058b7d094 100644
--- a/pkg/front_end/lib/src/fasta/compiler_command_line.dart
+++ b/pkg/front_end/lib/src/fasta/compiler_command_line.dart
@@ -11,11 +11,15 @@ import 'command_line.dart' show
     CommandLine,
     argumentError;
 
+import 'compiler_context.dart' show
+    CompilerContext;
+
 const Map<String, dynamic> optionSpecification = const <String, dynamic>{
   "-o": Uri,
   "--output": Uri,
   "--platform": Uri,
   "--packages": Uri,
+  "--fatal": ",",
 };
 
 class CompilerCommandLine extends CommandLine {
@@ -65,6 +69,26 @@ class CompilerCommandLine extends CommandLine {
         ? null
         : options["--platform"] ?? Uri.base.resolve("platform.dill");
   }
+
+  Set<String> get fatal {
+    return new Set<String>.from(options["--fatal"] ?? <String>[]);
+  }
+
+  bool get areErrorsFatal => fatal.contains("errors");
+
+  bool get areWarningsFatal => fatal.contains("warnings");
+
+  bool get areNitsFatal => fatal.contains("nits");
+
+  static dynamic withGlobalOptions(String programName, List<String> arguments,
+      dynamic f(CompilerContext context)) {
+    return CompilerContext.withGlobalOptions(
+        new CompilerCommandLine(programName, arguments), f);
+  }
+
+  static CompilerCommandLine forRootContext() {
+    return new CompilerCommandLine("", [""]);
+  }
 }
 
 String computeUsage(String programName, bool verbose) {
@@ -140,4 +164,11 @@ Supported options:
 
   --compile-sdk
     Compile the SDK from scratch instead of reading it from 'platform.dill'.
+
+  --fatal=errors

[karlklose, 2017/02/20 08:06:19]

Why not three different flags? Does 'fatal=warnings' imply 'fatal=errors'? If
no, it feels a bit strange to have a '--option=value' pair repeated for the same
option. If yes, please add documentation stating that.

[ahe, 2017/02/20 08:47:02]

I couldn't find a way to describe it nicely before, but I've updated the
documentation.

+  --fatal=warnings
+  --fatal=nits
+    Makes messages of the given kinds fatal, that is, immediately stop the
+    compiler with a non-zero exit-code. In --verbose mode, also display an
+    internal stack trace from the compiler.
 """;