Re-apply: Inside a generative constructor, "this" is created at the very end. So we have to use the…

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

Index: sdk/lib/_internal/compiler/implementation/world.dart
===================================================================
--- sdk/lib/_internal/compiler/implementation/world.dart	(revision 19293)
+++ sdk/lib/_internal/compiler/implementation/world.dart	(working copy)
@@ -51,7 +51,11 @@
       }
     }
 
-    compiler.resolverWorld.instantiatedClasses.forEach(addSubtypes);
+    // Use the [:seenClasses:] set to include non-instantiated
+    // classes: if the superclass of these classes require RTI, then
+    // they also need RTI, so that a constructor passes the type
+    // variables to the super constructor.
+    compiler.enqueuer.resolution.seenClasses.forEach(addSubtypes);

[karlklose, 2013/03/01 12:15:22]

Could we create constraints to track this dependency instead of adding all the
classes?

[ngeoffray, 2013/03/01 12:39:27]

We could put a rti dependency. This would require to find classes seen but not
instantiated and check if any of its supertype needs rti (if we don't want to
add bogus rti dependencies in the rtiDependencies map).

Looks simpler though to just poulate them in the subtypes tree. I don't think it
affects negatively the generated code or the compiler. Maybe since you're
asking, you thought about a case where it would matter?

[karlklose, 2013/03/01 13:23:39]

No, I don't have a case in mind.

 
     // Find the classes that need runtime type information. Such
     // classes are:
@@ -64,6 +68,7 @@
       if (classesNeedingRti.contains(cls)) return;
       classesNeedingRti.add(cls);
 
+      // TODO(ngeoffray): This should use subclasses, not subtypes.

[karlklose, 2013/03/01 12:15:22]

I find this use of subtypes confusing, because they are really classes and not
types. It is also inconsistent with the pair superclass/supertype, where the
latter is indeed a type.

[ngeoffray, 2013/03/01 12:39:27]

Yes, this is mostly for historic reasons. I don't think we had proper DartType
when we started to have the subtypes set.

       Set<ClassElement> classes = subtypes[cls];
       if (classes != null) {
         classes.forEach((ClassElement sub) {