Add NativeEnqueuer to work with the Enqueuer.

sdk/lib/_internal/compiler/implementation/resolution/members.dart

Index: sdk/lib/_internal/compiler/implementation/resolution/members.dart
diff --git a/sdk/lib/_internal/compiler/implementation/resolution/members.dart b/sdk/lib/_internal/compiler/implementation/resolution/members.dart
index 1ebc7109cef5b0c72cf723b88ccd8b9772ae05cf..e163855c3c3816116672e0bef7e028cf1e41a016 100644
--- a/sdk/lib/_internal/compiler/implementation/resolution/members.dart
+++ b/sdk/lib/_internal/compiler/implementation/resolution/members.dart
@@ -1735,6 +1735,13 @@ class ResolverVisitor extends CommonResolverVisitor<Element> {
       } else if (!selector.applies(target, compiler)) {
         warnArgumentMismatch(node, target);
       }
+
+      if (selector.name == const SourceString('JS')) {

[ngeoffray, 2012/11/08 08:18:01]

Note that the equality check must be done on the element.

[sra1, 2012/11/15 00:09:10]

Which element?

+        var argNodes = node.arguments;
+        if (!argNodes.isEmpty) {
+          resolveJsTypeParameter(argNodes.head, node);
+        }
+      }
     }
 
     // TODO(ngeoffray): Warn if target is null and the send is
@@ -1751,6 +1758,72 @@ class ResolverVisitor extends CommonResolverVisitor<Element> {
             [target.name]);
   }
 
+  void resolveJsTypeParameter(Node node, Node expression) {

[ngeoffray, 2012/11/08 08:18:01]

I would move this method to the native enqueuer.

[sra1, 2012/11/12 20:28:03]

Done.  I've moved everything except the lookup of a string in the scope.

+    // Resolve 'JS' type; mark as an instantiated native type.
+    //
+    // The type is currently a string.  We make an attempt at parsing the
+    // string.
+    //
+    // We will need the JS form to support union types and possible some other
+    // hints.  We could get the parser to resolve complex types like List<int>
+    // by using expressions that name classes, and a union by using a list
+    // literal.
+    //
+    //  JS(int, '#.foo', this);
+    //
+    //  JS([List<int>, bool], '...');   // Union of types.
+    //
+    //  JS([], '1');   // Type not expressable but harmless.
+    //
+    //  JS(['existing', Object], ...);  // Object, but not a fresh native one.
+
+    LiteralString typeStringLiteral = node.asLiteralString();
+    if (typeStringLiteral != null) {
+      String typeString = typeStringLiteral.dartString.slowToString();
+      if (! const {'': 1, 'var':1, 'void':1,
+                        //'bool':1, 'num':1, 'int':1, 'String':1
+                    }.containsKey(typeString)) {
+        Element element = resolveJSTypeString(typeString, node);
+        if (element != null) {
+          element.ensureResolved(compiler);
+          DartType type = element.computeType(compiler);
+          world.nativeEnqueuer.registerJSDartType(type, expression);

[ngeoffray, 2012/11/08 08:18:01]

Could this just be (native)enqueuer.registerInstantiatedClass ?

[sra1, 2012/11/12 20:28:03]

No, the matching is much more complex (subtypes, and I will want to add special
rules for some things.)

+        }
+      }
+      // Is there some way to decorate `node` with the type? With a union?
+    }
+  }
+
+  ClassElement resolveJSTypeString(String typeString, Node node) {
+    String typeName;
+    if (typeString.startsWith('new:')) {
+      typeName = typeString.substring(4);
+    } else {
+      typeName = typeString;
+    }
+    Element element = scope.lookup(new SourceString(typeName));
+    if (element == null) {
+      if (typeName == 'dynamic') return compiler.dynamicClass;
+      int index = typeName.indexOf('<');
+      if (index > 1) {
+        element = scope.lookup(new SourceString(typeName.substring(0, index)));
+      }
+      if (element == null) {
+        compiler.cancel(
+            "Type of JS expression '$typeName' not found",
+            node: node);
+        return;
+      }
+    }
+    if (element is! ClassElement) {
+      compiler.cancel(
+          "Type of JS expression '$typeName' not a class",
+          node: node);
+    } else {
+      return element;
+    }
+  }
+
   visitSendSet(SendSet node) {
     Element target = resolveSend(node);
     Element setter = target;