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 48fa3b3179a952a017a6840514296f8084cb26f4..b7caa38702e7906331ae6508c3c07955e25589e5 100644
--- a/sdk/lib/_internal/compiler/implementation/closure.dart
+++ b/sdk/lib/_internal/compiler/implementation/closure.dart
@@ -390,11 +390,20 @@ 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) {
@@ -417,13 +426,28 @@ 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
+      // therefore the closure needs a this-element.
+      // TODO(karlklose,johnniwinther): if the type is null, the annotation is
+      // from a parameter; in checked mode, we need to resolve all types.

[ngeoffray, 2013/05/13 09:10:59]

So for foo(T a), we don't resolve the "T" ?

[karlklose, 2013/05/14 13:49:41]

I updated the comment to be more precise.

[ngeoffray, 2013/05/15 08:45:32]

Thank you. I still find it a bit obscure: what is the result, why is it being
thrown away?

Also an example of which cases we're missing would be helpful.

+      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);
@@ -435,9 +459,9 @@ 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;
@@ -461,6 +485,12 @@ class ClosureTranslator extends Visitor {
     if (Elements.isLocal(element)) {
       mutatedVariables.add(element);
     }
+    if (element != null && element is VariableElement) {

[ngeoffray, 2013/05/13 09:10:59]

Should that be Elements.isLocal(element) ?

[karlklose, 2013/05/14 13:49:41]

Done.

[karlklose, 2013/05/14 13:49:41]

Done.

+      VariableElement variable = element;
+      if (variable.variables.type.containsTypeVariables) {

[ngeoffray, 2013/05/13 09:10:59]

Change to element.computeType(compiler).containsTypeVariables ?

[karlklose, 2013/05/14 13:49:41]

Done.

+        registerNeedsThis();
+      }
+    }
     super.visitSendSet(node);
   }
 
@@ -497,7 +527,9 @@ 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();
+        }
       }
     }
 
@@ -666,6 +698,12 @@ class ClosureTranslator extends Visitor {
         });
       }
 
+      // Compute the function type and check for type variables in return or
+      // parameter types.
+      if (element.computeType(compiler).containsTypeVariables) {
+        registerNeedsThis();
+      }
+
       visitChildren();
     });