Throw if there is no compiler context available

pkg/front_end/lib/src/fasta/testing/kernel_chain.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.md file.
 
 // TODO(ahe): Copied from closure_conversion branch of kernel, remove this file
 // when closure_conversion is merged with master.
 
 library fasta.testing.kernel_chain;
 
 import 'dart:async' show Future;
 
 import 'dart:io' show Directory, File, IOSink;
 
 import 'dart:typed_data' show Uint8List;
 
 import 'package:kernel/kernel.dart' show loadProgramFromBinary;
 
 import 'package:kernel/target/targets.dart' show Target;
 
 import 'package:kernel/text/ast_to_text.dart' show Printer;
 
 import 'package:testing/testing.dart' show Result, StdioProcess, Step;
 
 import 'package:kernel/ast.dart' show Library, Program;
 
 import '../kernel/verifier.dart' show verifyProgram;
 
+import '../compiler_command_line.dart';
+
 import 'package:kernel/binary/ast_to_binary.dart' show BinaryPrinter;
 
 import 'package:kernel/binary/ast_from_binary.dart' show BinaryBuilder;
 
 import 'package:testing/testing.dart'
     show ChainContext, Result, StdioProcess, Step, TestDescription;
 
 import 'package:kernel/ast.dart' show Program;
 
 import 'package:front_end/front_end.dart';
@@ skipping 20 matching lines @@
 }
 
 class Verify extends Step<Program, Program, ChainContext> {
   final bool fullCompile;
 
   const Verify(this.fullCompile);
 
   String get name => "verify";
 
   Future<Result<Program>> run(Program program, ChainContext context) async {
-    var errors = verifyProgram(program, isOutline: !fullCompile);
-    if (errors.isEmpty) {
-      return pass(program);
-    } else {
-      return new Result<Program>(
-          null, context.expectationSet["VerificationError"], errors, null);
-    }
+    return await CompilerCommandLine.withGlobalOptions("", [""], (_) async {
+      var errors = verifyProgram(program, isOutline: !fullCompile);
+      if (errors.isEmpty) {
+        return pass(program);
+      } else {
+        return new Result<Program>(
+            null, context.expectationSet["VerificationError"], errors, null);
+      }
+    });
   }
 }
 
 class MatchExpectation extends Step<Program, Program, ChainContext> {
   final String suffix;
 
   // TODO(ahe): This is true by default which doesn't match well with the class
   // name.
   final bool updateExpectations;
 
@@ skipping 164 matching lines @@
 
 Future openWrite(Uri uri, f(IOSink sink)) async {
   IOSink sink = new File.fromUri(uri).openWrite();
   try {
     await f(sink);
   } finally {
     await sink.close();
   }
   print("Wrote $uri");
 }