Add substitution for classes that use type variables.

sdk/lib/_internal/compiler/implementation/ssa/builder.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of ssa;
 
 /**
  * A special element for the extra parameter taken by intercepted
  * methods. We need to override [Element.computeType] because our
  * optimizers may look at its declared type.
@@ skipping 3163 matching lines @@
       Element member = currentElement;
       if (member.enclosingElement.isClosure()) {
         ClosureClassElement closureClass = member.enclosingElement;
         member = closureClass.methodElement;
         member = member.getOutermostEnclosingMemberOrTopLevel();
       }
       if (member.isFactoryConstructor()) {
         // The type variable is stored in a parameter of the method.
         inputs.add(localsHandler.readLocal(type.element));
       } else if (member.isInstanceMember() ||
-          member.isGenerativeConstructor()) {
-        // The type variable is stored in [this].
+                 member.isGenerativeConstructor()) {
+        // The type variable is stored on the object.

[kasperl, 2013/02/12 12:14:10]

Extend the comment with an example of the kind of code this unfolds to?

[karlklose, 2013/02/12 13:22:30]

Done.

         int index = RuntimeTypeInformation.getTypeVariableIndex(type);
-        pushInvokeHelper2(backend.getGetRuntimeTypeArgument(),
-                          localsHandler.readThis(),
+        HInstruction thisObject = localsHandler.readThis();
+        String substituionNameString =

[kasperl, 2013/02/12 12:14:10]

substituion -> substitution

[karlklose, 2013/02/12 13:22:30]

Done.

+            backend.namer.substitutionName(member.getEnclosingClass());
+        HInstruction substitutionName = graph.addConstantString(
+            new LiteralDartString(substituionNameString), null, constantSystem);
+        HInstruction substitution = createForeign('#[#]', HType.UNKNOWN,
+            <HInstruction>[thisObject, substitutionName]);
+        add(substitution);
+        pushInvokeHelper3(backend.getGetRuntimeTypeArgument(),
+                          thisObject,
+                          substitution,
                           graph.addConstantInt(index, constantSystem),
                           HType.UNKNOWN);
         inputs.add(pop());
       } else {
         // TODO(ngeoffray): Match the VM behavior and throw an
         // exception at runtime.
         compiler.cancel('Unimplemented unresolved type variable',
                         node: currentNode);
       }
     }
@@ skipping 1850 matching lines @@
           new HSubGraphBlockInformation(elseBranch.graph));
 
     HBasicBlock conditionStartBlock = conditionBranch.block;
     conditionStartBlock.setBlockFlow(info, joinBlock);
     SubGraph conditionGraph = conditionBranch.graph;
     HIf branch = conditionGraph.end.last;
     assert(branch is HIf);
     branch.blockInformation = conditionStartBlock.blockFlow;
   }
 }