Dart2js option to dump info about compilation

sdk/lib/_internal/compiler/implementation/closure.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.
 
 library closureToClassMapper;
 
 import "elements/elements.dart";
 import "dart2jslib.dart";
 import "dart_types.dart";
 import "scanner/scannerlib.dart" show Token;
@@ skipping 57 matching lines @@
   }
 }
 
 // TODO(ahe): These classes continuously cause problems.  We need to
 // move these classes to elements/modelx.dart or see if we can find a
 // more general solution.
 class ClosureFieldElement extends ElementX implements VariableElement {
   /// The source variable this element refers to.
   final Element variableElement;
 
+  List<FunctionElement> nestedClosures = new List<FunctionElement>();

[ngeoffray, 2013/12/05 09:29:28]

What is this for a ClosureFieldElement? Please add a comment.

[sigurdm, 2013/12/05 11:35:03]

Actually nothing - I had misunderstood what a ClosureFieldElement is.

I added a class FieldElement subclass of VariableElement - so only fields and
functions have nestedClosures.

+
   ClosureFieldElement(String name,
                       this.variableElement,
                       ClassElement enclosing)
       : super(name, ElementKind.FIELD, enclosing);
 
   VariableListElement get variables {
     throw new SpannableAssertionFailure(
         variableElement, 'Should not access variables of ClosureFieldElement.');
   }
 
@@ skipping 605 matching lines @@
   }
 
   ClosureClassMap globalizeClosure(FunctionExpression node, Element element) {
     String closureName = computeClosureName(element);
     ClassElement globalizedElement = new ClosureClassElement(
         node, closureName, compiler, element, element.getCompilationUnit());
     FunctionElement callElement =
         new FunctionElementX.from(Compiler.CALL_OPERATOR_NAME,
                                   element,
                                   globalizedElement);
+    ClosureContainer enclosing = element.enclosingElement;
+    enclosing.nestedClosures.add(callElement);
     globalizedElement.addMember(callElement, compiler);
     // The nested function's 'this' is the same as the one for the outer
     // function. It could be [null] if we are inside a static method.
     Element thisElement = closureData.thisElement;
     return new ClosureClassMap(element, globalizedElement,
                                callElement, thisElement);
   }
 
   void visitInvokable(Element element, Expression node, void visitChildren()) {
     bool oldInsideClosure = insideClosure;
@@ skipping 97 matching lines @@
   }
 
   visitTryStatement(TryStatement node) {
     // TODO(ngeoffray): implement finer grain state.
     bool oldInTryStatement = inTryStatement;
     inTryStatement = true;
     node.visitChildren(this);
     inTryStatement = oldInTryStatement;
   }
 }