Enable full type-checks in checked mode.

sdk/lib/_internal/compiler/implementation/closure.dart

Index: sdk/lib/_internal/compiler/implementation/closure.dart
diff --git a/sdk/lib/_internal/compiler/implementation/closure.dart b/sdk/lib/_internal/compiler/implementation/closure.dart
index aa17a0079bdad5ed78f786bf586684ab1a367b41..f369e5adffb22cc8976740f7273fdc55ced16129 100644
--- a/sdk/lib/_internal/compiler/implementation/closure.dart
+++ b/sdk/lib/_internal/compiler/implementation/closure.dart
@@ -375,11 +375,20 @@ class ClosureTranslator extends Visitor {
     scopeVariables.add(element);
   }
 
+  void registerNeedsThis() {
+    if (closureData.thisElement != null) {
+      useLocal(closureData.thisElement);
+    }
+  }
+
   visit(Node node) => node.accept(this);
 
   visitNode(Node node) => node.visitChildren(this);
 
   visitVariableDefinitions(VariableDefinitions node) {
+    if (node.type != null) {
+      visit(node.type);
+    }
     for (Link<Node> link = node.definitions.nodes;
          !link.isEmpty;
          link = link.tail) {
@@ -402,13 +411,28 @@ class ClosureTranslator extends Visitor {
     }
   }
 
+  visitTypeAnnotation(TypeAnnotation node) {
+    if (compiler.enableTypeAssertions && currentElement.isInstanceMember()) {
+      DartType type = elements.getType(node);
+      // In checked mode, using a type variable in a type annotation may lead
+      // to a runtime type check that needs to access the type argument and
+      // therefor the closure needs a this-element.

[ngeoffray, 2013/04/15 10:59:14]

therefore

[karlklose, 2013/05/02 15:04:54]

Done.

+      // TODO(karlklose,johnniwinther): if the type is null, the annotation is
+      // from a parameter; in checked mode, we need to resolve all types.

[ngeoffray, 2013/04/15 10:59:14]

I don't understand this TODO. How can it be null?

[karlklose, 2013/05/02 15:04:54]

Maybe we do not store the result in the TreeElements when computing the
signature. Investigating...

+      if (type != null && type.containsTypeVariables) {
+        registerNeedsThis();
+      }
+    }
+    node.visitChildren(this);
+  }
+
   visitIdentifier(Identifier node) {
     if (node.isThis()) {
-      useLocal(closureData.thisElement);
+      registerNeedsThis();
     } else {
       Element element = elements[node];
       if (element != null && element.kind == ElementKind.TYPE_VARIABLE) {
-        useLocal(closureData.thisElement);
+        registerNeedsThis();
       }
     }
     node.visitChildren(this);
@@ -420,9 +444,9 @@ class ClosureTranslator extends Visitor {
       useLocal(element);
     } else if (node.receiver == null &&
                Elements.isInstanceSend(node, elements)) {
-      useLocal(closureData.thisElement);
+      registerNeedsThis();
     } else if (node.isSuperCall) {
-      useLocal(closureData.thisElement);
+      registerNeedsThis();
     } else if (node.isParameterCheck) {
       Element parameter = elements[node.receiver];
       FunctionElement enclosing = parameter.enclosingElement;
@@ -446,6 +470,12 @@ class ClosureTranslator extends Visitor {
     if (Elements.isLocal(element)) {
       mutatedVariables.add(element);
     }
+    if (element != null && element is VariableElement) {
+      VariableElement variable = element;
+      if (variable.variables.type.containsTypeVariables) {
+        registerNeedsThis();

[ngeoffray, 2013/04/15 10:59:14]

Not sure you need this:
- If element is a field, then "this" is already needed
- If element is a local, then its type annotation already said it needed "this".

[karlklose, 2013/05/02 15:04:54]

It is needed.

+      }
+    }
     super.visitSendSet(node);
   }
 
@@ -482,7 +512,9 @@ class ClosureTranslator extends Visitor {
       if (outermostElement.isConstructor() || outermostElement.isField()) {
         analyzeTypeVariables(type);
       } else if (outermostElement.isInstanceMember()) {
-        if (hasTypeVariable(type)) useLocal(closureData.thisElement);
+        if (hasTypeVariable(type)) {
+          registerNeedsThis();
+        }
       }
     }
 
@@ -651,6 +683,10 @@ class ClosureTranslator extends Visitor {
         });
       }
 
+      if (element.computeType(compiler).containsTypeVariables) {

[ngeoffray, 2013/04/15 10:59:14]

So that's the function type if the element? It matches both parameters and
return type right? Please add a comment.

[karlklose, 2013/05/02 15:04:54]

Done.

+        registerNeedsThis();
+      }
+
       visitChildren();
     });