Make closures in constructor initializers read type variables directly.

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 3258 matching lines @@
     HInstruction target = localsHandler.readThis();
     pushInvokeStatic(null,
                      backend.getGetRuntimeTypeArgument(),
                      [target,
                       substitutionName,
                       graph.addConstantInt(index, compiler)],
                       HType.UNKNOWN);
     return pop();
   }
 
+  // TODO(karlklose): this is needed to avoid a bug where the resolved type is
+  // not stored on a type annotation in the closure translator. Remove when

[ngeoffray, 2013/07/12 12:09:25]

Not sure I understand this comment. What does it mean to be stored on a type
annotation? Isn't it the resolver that does this? How come the closure
translator does something that we have to rely on here, instead of doing the
same?

[karlklose, 2013/07/12 12:22:54]

The wording isn't the best, I agree. With storing a type on an annotation i mean
having an entry in the types map in the tree elements. I did not mean to say
that the closure translator stores a type but that it finds an annotation for
which no types has been stored (in the resolver).

[ngeoffray, 2013/07/12 12:27:39]

So that's a bug in the resolver?

+  // fixed.
+  bool hasDirectLocal(Element element) {
+    return !localsHandler.isAccessedDirectly(element) ||
+        localsHandler.directLocals[element] != null;
+  }
+
   /**
    * Helper to create an instruction that gets the value of a type variable.
    */
   HInstruction addTypeVariableReference(TypeVariableType type) {
     Element member = currentElement;
     bool isClosure = member.enclosingElement.isClosure();
     if (isClosure) {
       ClosureClassElement closureClass = member.enclosingElement;
       member = closureClass.methodElement;
       member = member.getOutermostEnclosingMemberOrTopLevel();
     }
     bool isInConstructorContext = member.isConstructor() ||
-        member.isGenerativeConstructorBody() ||
-        member.isField();
+        member.isGenerativeConstructorBody();
     if (isClosure) {
-      if (member.isFactoryConstructor()) {
+      if (member.isFactoryConstructor() ||
+          (isInConstructorContext && hasDirectLocal(type.element))) {
         // The type variable is used from a closure in a factory constructor.
         // The value of the type argument is stored as a local on the closure
         // itself.
         return localsHandler.readLocal(type.element);
       } else if (member.isFunction() ||
           member.isGetter() ||
           member.isSetter() ||
-          member.isConstructor() ||
-          member.isGenerativeConstructorBody()) {
+          isInConstructorContext) {
         // The type variable is stored on the "enclosing object" and needs to be
         // accessed using the this-reference in the closure.
         return readTypeVariable(member.getEnclosingClass(), type.element);
       } else {
         assert(member.isField());
         // The type variable is stored in a parameter of the method.
         return localsHandler.readLocal(type.element);
       }
-    } else if (isInConstructorContext) {
+    } else if (isInConstructorContext || member.isField()) {
       // The type variable is stored in a parameter of the method.
       return localsHandler.readLocal(type.element);
     } else if (member.isInstanceMember()) {
       // The type variable is stored on the object.
       return readTypeVariable(member.getEnclosingClass(),
                               type.element);
     } else {
       // TODO(ngeoffray): Match the VM behavior and throw an
       // exception at runtime.
       compiler.cancel('Unimplemented unresolved type variable',
@@ skipping 2108 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;
   }
 }