Fix field-accesses for private fields that were "shadowed" by other private fields.

Fix field-accesses for private fields that were "shadowed" by other private fields.

Committed: https://code.google.com/p/dart/source/detail?r=10827

[floitsch, 2012-08-15 21:20:48]

The problem:
library1:
class A { var _x; }

new B()._x; // <==

library2:
class B extends A { var _x; }

At the marked line we would look up "_x" and find the one in B instead of the
one from library1. That's because we did the lookup without any library element.

[kasperl, 2012-08-16 12:47:57]

LGTM, but I think this could be improved using selectors.

https://chromiumcodereview.appspot.com/10827359/diff/1/lib/compiler/implement...
File lib/compiler/implementation/elements/elements.dart (right):

https://chromiumcodereview.appspot.com/10827359/diff/1/lib/compiler/implement...
lib/compiler/implementation/elements/elements.dart:1066: Element
lookupSuperMemberInLibrary(SourceString memberName,
Would it be possible to start using Selector for looking up stuff? The selector
has a name and a library...

https://chromiumcodereview.appspot.com/10827359/diff/1/lib/compiler/implement...
File lib/compiler/implementation/ssa/optimize.dart (right):

https://chromiumcodereview.appspot.com/10827359/diff/1/lib/compiler/implement...
lib/compiler/implementation/ssa/optimize.dart:558: Element
findConcreteFieldForDynamicAccess(HInstruction receiver,
Can you use a selector instead of the fieldName here? The HInvokeDynamicGetter
should know the selector so you should know the library from that.

https://chromiumcodereview.appspot.com/10827359/diff/1/lib/compiler/implement...
File lib/compiler/implementation/world.dart (right):

https://chromiumcodereview.appspot.com/10827359/diff/1/lib/compiler/implement...
lib/compiler/implementation/world.dart:38: MemberSet _memberSetFor(Type type,
Again it would seem like this could be rewritten with a selector instead of a
(library, member) pair.

[floitsch, 2012-08-16 16:15:55]

I think we can push the usage of selectors even further, but for now I'm
committing as is.
Feel free to add comments and I will address them in a future CL.

https://chromiumcodereview.appspot.com/10827359/diff/1/lib/compiler/implement...
File lib/compiler/implementation/elements/elements.dart (right):

https://chromiumcodereview.appspot.com/10827359/diff/1/lib/compiler/implement...
lib/compiler/implementation/elements/elements.dart:1066: Element
lookupSuperMemberInLibrary(SourceString memberName,
On 2012/08/16 12:47:57, kasperl wrote:
> Would it be possible to start using Selector for looking up stuff? The
selector
> has a name and a library...

Went a little bit into that direction. It's not complete but better than before.

https://chromiumcodereview.appspot.com/10827359/diff/1/lib/compiler/implement...
File lib/compiler/implementation/ssa/optimize.dart (right):

https://chromiumcodereview.appspot.com/10827359/diff/1/lib/compiler/implement...
lib/compiler/implementation/ssa/optimize.dart:558: Element
findConcreteFieldForDynamicAccess(HInstruction receiver,
On 2012/08/16 12:47:57, kasperl wrote:
> Can you use a selector instead of the fieldName here? The HInvokeDynamicGetter
> should know the selector so you should know the library from that.

Done.

https://chromiumcodereview.appspot.com/10827359/diff/1/lib/compiler/implement...
File lib/compiler/implementation/world.dart (right):

https://chromiumcodereview.appspot.com/10827359/diff/1/lib/compiler/implement...
lib/compiler/implementation/world.dart:38: MemberSet _memberSetFor(Type type,
On 2012/08/16 12:47:57, kasperl wrote:
> Again it would seem like this could be rewritten with a selector instead of a
> (library, member) pair.

Done.