Allow self-referencing closures.

frog/leg/ssa/builder.dart

Index: frog/leg/ssa/builder.dart
diff --git a/frog/leg/ssa/builder.dart b/frog/leg/ssa/builder.dart
index 359e7cd95a50864237fe4af110e85a182d552111..93e5b14216420ed33d3230cb8513db7be0fc0c0f 100644
--- a/frog/leg/ssa/builder.dart
+++ b/frog/leg/ssa/builder.dart
@@ -216,11 +216,10 @@ class LocalsHandler {
         new ClosureTranslator(builder.compiler, builder.elements);
     closureData = translator.translate(node);
 
-    if (closureData.thisElement !== null &&
-        isAccessedDirectly(closureData.thisElement)) {
+    if (closureData.thisElement !== null && !closureData.isClosure()) {
       HInstruction thisInstruction = new HThis();
-      updateLocal(closureData.thisElement, thisInstruction);
       builder.add(thisInstruction);
+      updateLocal(closureData.thisElement, thisInstruction);
     }
 
     FunctionParameters params = function.computeParameters(builder.compiler);
@@ -240,6 +239,12 @@ class LocalsHandler {
     closureData.freeVariableMapping.forEach((Element from, Element to) {
       redirectElement(from, to);
     });
+    // Inside closure redirect references to itself to [:this:].
+    if (closureData.isClosure()) {
+      HInstruction thisInstruction = new HThis();
+      builder.add(thisInstruction);
+      updateLocal(closureData.closureElement, thisInstruction);

[ngeoffray, 2012/02/13 10:13:38]

Could you share some code with line 219? It looks like only the element to
update is different.

[floitsch, 2012/02/13 12:03:42]

Refactored together.

+    }
   }
 
   /**
@@ -1403,8 +1408,7 @@ class SsaBuilder implements Visitor {
       visit(node.selector);
       closureTarget = pop();
     } else {
-      assert(element.kind === ElementKind.VARIABLE ||
-             element.kind === ElementKind.PARAMETER);
+      assert(Elements.isLocal(element));
       closureTarget = localsHandler.readLocal(element);
     }
     var inputs = <HInstruction>[];