Let parser handle factory modifiers.

pkg/front_end/lib/src/fasta/kernel/verifier.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.verifier;
 
 import 'package:kernel/ast.dart' show
+    Class,
     ExpressionStatement,
-    Program;
+    Field,
+    Library,
+    Procedure,
+    Program,
+    TreeNode;
 
 import 'package:kernel/verifier.dart' show
+    VerificationError,
     VerifyingVisitor;
 
+import '../errors.dart' show
+    printUnexpected;
+
 import 'redirecting_factory_body.dart' show
     RedirectingFactoryBody;
 
 void verifyProgram(Program program, {bool isOutline: false}) {
-  program.accept(new FastaVerifyingVisitor(isOutline));
+  FastaVerifyingVisitor verifier = new FastaVerifyingVisitor(isOutline);
+  program.accept(verifier);
+  if (verifier.errors.isNotEmpty) {
+    throw verifier.errors.first;
+  }
 }
 
 class FastaVerifyingVisitor extends VerifyingVisitor {
+  final List<VerificationError> errors = <VerificationError>[];
+
+  String fileUri;
+
   FastaVerifyingVisitor(bool isOutline) {
     this.isOutline = isOutline;
   }
 
   @override
+  problem(TreeNode node, String details) {

[Johnni Winther, 2017/02/28 13:36:39]

No use of this yet?

[ahe, 2017/02/28 13:46:25]

It's used a lot in the superclass. Too much, I think. It's kinda accusing me of
generating bad code ;-)

+    VerificationError error = new VerificationError(context, node, details);
+    printUnexpected(Uri.parse(fileUri), node.fileOffset, "$error");
+    errors.add(error);
+  }
+
+  @override
   visitExpressionStatement(ExpressionStatement node) {
     // Bypass verification of the [StaticGet] in [RedirectingFactoryBody] as
     // this is a static get without a getter.
     if (node is! RedirectingFactoryBody) {
       super.visitExpressionStatement(node);
     }
   }
+
+  visitLibrary(Library node) {
+    fileUri = node.fileUri;
+    super.visitLibrary(node);
+  }
+
+  visitClass(Class node) {
+    fileUri = node.fileUri;
+    super.visitClass(node);
+  }
+
+  visitField(Field node) {
+    fileUri = node.fileUri;
+    super.visitField(node);
+  }
+
+  visitProcedure(Procedure node) {
+    fileUri = node.fileUri;
+    super.visitProcedure(node);
+  }
 }