Implement correct scoping rules for variables.

sdk/lib/_internal/compiler/implementation/scanner/listener.dart

Index: sdk/lib/_internal/compiler/implementation/scanner/listener.dart
diff --git a/sdk/lib/_internal/compiler/implementation/scanner/listener.dart b/sdk/lib/_internal/compiler/implementation/scanner/listener.dart
index dc912fb6dc637361375f5330459e94aaddb676c0..7eefb79a8798e7599dca94dc2736d097d01875bd 100644
--- a/sdk/lib/_internal/compiler/implementation/scanner/listener.dart
+++ b/sdk/lib/_internal/compiler/implementation/scanner/listener.dart
@@ -1072,12 +1072,24 @@ class ElementListener extends Listener {
   }
 
   NodeList makeNodeList(int count, Token beginToken, Token endToken,
-                        String delimiter) {
+                        String delimiter,
+                        {List<VariableDefinitions> declarations}) {

[ahe, 2013/09/26 07:48:07]

Please don't use named arguments. They add call overhead, but in this case,
declarations don't belong here in the first place. A node list is a list of
nodes. That's it.

     Link<Node> poppedNodes = const Link<Node>();
     for (; count > 0; --count) {
       // This effectively reverses the order of nodes so they end up
       // in correct (source) order.
-      poppedNodes = poppedNodes.prepend(popNode());
+      Node node = popNode();
+      poppedNodes = poppedNodes.prepend(node);
+      if (declarations != null) {
+        Node potentialDeclaration = node;
+        if (node.asLabeledStatement() != null) {
+          LabeledStatement labelled = potentialDeclaration;
+          potentialDeclaration = labelled.statement;
+        }
+        if (potentialDeclaration.asVariableDefinitions() != null) {
+          declarations.add(potentialDeclaration);
+        }
+      }
     }
     SourceString sourceDelimiter =
         (delimiter == null) ? null : new SourceString(delimiter);
@@ -1454,7 +1466,10 @@ class NodeListener extends ElementListener {
     if (count == 0 && beginToken == null) {
       pushNode(new EmptyStatement(endToken));
     } else {
-      pushNode(new Block(makeNodeList(count, beginToken, endToken, null)));
+      List<VariableDefinitions> declarations = <VariableDefinitions>[];

[ahe, 2013/09/26 07:48:07]

This is what we have a link builder for. Please use that to avoid allocating
growable lists in the parser.

+      pushNode(new Block(makeNodeList(count, beginToken, endToken, null,
+                                      declarations: declarations),
+                         new Link<VariableDefinitions>.fromList(declarations)));
     }
   }
 
@@ -1529,7 +1544,10 @@ class NodeListener extends ElementListener {
   }
 
   void endBlock(int count, Token beginToken, Token endToken) {
-    pushNode(new Block(makeNodeList(count, beginToken, endToken, null)));
+    List<VariableDefinitions> declarations = <VariableDefinitions>[];
+    pushNode(new Block(makeNodeList(count, beginToken, endToken, null,
+                                    declarations: declarations),
+                       new Link<VariableDefinitions>.fromList(declarations)));
   }
 
   void endThrowExpression(Token throwToken, Token endToken) {
@@ -1730,11 +1748,13 @@ class NodeListener extends ElementListener {
   void handleSwitchCase(int labelCount, int caseCount,
                         Token defaultKeyword, int statementCount,
                         Token firstToken, Token endToken) {
-    NodeList statements = makeNodeList(statementCount, null, null, null);
+    List<VariableDefinitions> declarations = <VariableDefinitions>[];
+    NodeList statements = makeNodeList(statementCount, null, null, null,
+        declarations: declarations);
     NodeList labelsAndCases =
         makeNodeList(labelCount + caseCount, null, null, null);
     pushNode(new SwitchCase(labelsAndCases, defaultKeyword, statements,
-                            firstToken));
+        firstToken, new Link<VariableDefinitions>.fromList(declarations)));
   }
 
   void handleBreakStatement(bool hasTarget,