dart2js: CPS translation of switches with continue to their labels.

pkg/compiler/lib/src/cps_ir/cps_ir_nodes_sexpr.dart

 // Copyright (c) 2014, 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 dart2js.ir_nodes_sexpr;
 
 import '../constants/values.dart';
 import '../util/util.dart';
 import 'cps_ir_nodes.dart';
 import '../universe/call_structure.dart' show
@@ skipping 12 matching lines @@
   String newContinuationName(Continuation node) => namer.nameContinuation(node);
   Decorator decorator;
 
   SExpressionStringifier([this.decorator]) {
     if (this.decorator == null) {
       this.decorator = (node, String s) => s;
     }
   }
 
   String access(Reference<Definition> r) {
+    if (r == null) return '**** NULL ****';
     return decorator(r, namer.getName(r.definition));
   }
 
   String optionalAccess(Reference<Definition> reference) {
     return reference == null ? '()' : '(${access(reference)})';
   }
 
   String visitParameter(Parameter node) {
     return namer.nameParameter(node);
   }
 
   String visitMutableVariable(MutableVariable node) {
     return namer.nameMutableVariable(node);
   }
 
   /// Main entry point for creating a [String] from a [Node].  All recursive
   /// calls must go through this method.
   String visit(Node node) {
-    if (node == null) return '**** NULL ****';
+    if (node == null) {
+      return node is Expression

[asgerf, 2016/01/19 22:45:24]

Dead code, null is not an expression.

[Kevin Millikin (Google), 2016/01/25 12:46:37]

Done.

+          ? '$indentation**** NULL ****'
+          : '**** NULL ****';
+    }
     String s = node.accept(this);
     return decorator(node, s);
   }
 
   String formatThisParameter(Parameter thisParameter) {
     return thisParameter == null ? '()' : '(${visit(thisParameter)})';
   }
 
   String visitFunctionDefinition(FunctionDefinition node) {
     String name = node.element.name;
@@ skipping 123 matching lines @@
     if (!node.target.name.isEmpty) {
       name = '${name}.${node.target.name}';
     }
     String args = formatArguments(node.selector.callStructure, node.arguments);
     return '(InvokeConstructor $name $args)';
   }
 
   String visitInvokeContinuation(InvokeContinuation node) {
     String name = access(node.continuation);
     if (node.isRecursive) name = 'rec $name';
-    String args = node.arguments.map(access).join(' ');
+    String args = node.arguments == null
+        ? '**** NULL ****'
+        : node.arguments.map(access).join(' ');
     String escaping = node.isEscapingTry ? ' escape' : '';
     return '$indentation(InvokeContinuation $name ($args)$escaping)';
   }
 
   String visitThrow(Throw node) {
     String value = access(node.value);
     return '$indentation(Throw $value)';
   }
 
   String visitRethrow(Rethrow node) {
@@ skipping 312 matching lines @@
   void setReturnContinuation(Continuation node) {
     assert(!_names.containsKey(node) || _names[node] == 'return');
     _names[node] = 'return';
   }
 
   String getName(Node node) {
     if (!_names.containsKey(node)) return 'MISSING_NAME';
     return _names[node];
   }
 }