Avoid reading RawObject::class_ directly in the runtime.

Avoid reading RawObject::class_ directly in the runtime.

Instead rely on tags_ and perform lookups through isolate's class table where appropriately.

R=iposva@google.com

Committed: https://code.google.com/p/dart/source/detail?r=8244

[Vyacheslav Egorov (Google), 2012-05-30 16:17:02]

Please take a look. 

This is expected to be the last CL before class_ can be removed.

(changes in the scavenger forwarding address encoding and FreeListElement layout
will be done in the same CL as class_ removal for simplicity)

[Vyacheslav Egorov (Google), 2012-05-31 08:50:33]

ping

[Ivan Posva, 2012-05-31 13:06:24]

https://chromiumcodereview.appspot.com/10444091/diff/1/runtime/vm/raw_object.cc
File runtime/vm/raw_object.cc (left):

https://chromiumcodereview.appspot.com/10444091/diff/1/runtime/vm/raw_object....
runtime/vm/raw_object.cc:281: case kFreeListElement: {
You do not handle kFreeListElements here, but I do not see a corresponding
change to set the FreeBit in this CL.

[Vyacheslav Egorov (Google), 2012-05-31 13:21:48]

https://chromiumcodereview.appspot.com/10444091/diff/1/runtime/vm/raw_object.cc
File runtime/vm/raw_object.cc (left):

https://chromiumcodereview.appspot.com/10444091/diff/1/runtime/vm/raw_object....
runtime/vm/raw_object.cc:281: case kFreeListElement: {
On 2012/05/31 13:06:24, Ivan Posva wrote:
> You do not handle kFreeListElements here, but I do not see a corresponding
> change to set the FreeBit in this CL.

But free bit is always set for FreeListElement is not it?

Take a look at FreeListElement::set_next

[Ivan Posva, 2012-06-01 16:31:06]

LGTM with comment.

-Ivan

https://chromiumcodereview.appspot.com/10444091/diff/1/runtime/vm/raw_object.h
File runtime/vm/raw_object.h (right):

https://chromiumcodereview.appspot.com/10444091/diff/1/runtime/vm/raw_object....
runtime/vm/raw_object.h:338: ASSERT(!FreeBit::decode(tags));
Please mark this with a TODO that we need to revisit this once we give the free
list elements a different layout.