Merge SetObjectNames extra pass into the main pass.

Merge SetObjectNames extra pass into the main pass.

Because heap snapshotting is now performed in a single pass
it is safe to make calls to GetConstructorName and further to
LocalLookupRealNamedProperty right within that main pass.

Committed: https://code.google.com/p/v8/source/detail?r=11535

[mnaganov (inactive), 2012-05-10 09:15:39]

lgtm

[yurys, 2012-05-10 12:13:52]

https://chromiumcodereview.appspot.com/10332087/diff/1/src/profile-generator.cc
File src/profile-generator.cc (right):

https://chromiumcodereview.appspot.com/10332087/diff/1/src/profile-generator....
src/profile-generator.cc:1681: const char* tag = objects_tags_.GetTag(object);
How can we be sure that the object has already been tagged at this point?

https://chromiumcodereview.appspot.com/10332087/diff/1/src/profile-generator....
src/profile-generator.cc:3087: debug_heap->Verify();
We can remove this second verification.

[mnaganov (inactive), 2012-05-10 12:15:56]

https://chromiumcodereview.appspot.com/10332087/diff/1/src/profile-generator.cc
File src/profile-generator.cc (right):

https://chromiumcodereview.appspot.com/10332087/diff/1/src/profile-generator....
src/profile-generator.cc:1681: const char* tag = objects_tags_.GetTag(object);
On 2012/05/10 12:13:52, Yury Semikhatsky wrote:
> How can we be sure that the object has already been tagged at this point?

Global objects tagging is always done before snapshot taking, because it can
modify the heap state. Perhaps, add a comment about this?

[yurys, 2012-05-10 12:23:31]

https://chromiumcodereview.appspot.com/10332087/diff/1/src/profile-generator.cc
File src/profile-generator.cc (right):

https://chromiumcodereview.appspot.com/10332087/diff/1/src/profile-generator....
src/profile-generator.cc:1681: const char* tag = objects_tags_.GetTag(object);
On 2012/05/10 12:15:56, Mikhail Naganov (Chromium) wrote:
> On 2012/05/10 12:13:52, Yury Semikhatsky wrote:
> > How can we be sure that the object has already been tagged at this point?
> 
> Global objects tagging is always done before snapshot taking, because it can
> modify the heap state. Perhaps, add a comment about this?
I think a comment would be helpful here. Also what about non-global objects, do
we care about their tags?

[alexeif, 2012-05-10 13:40:24]

https://chromiumcodereview.appspot.com/10332087/diff/1/src/profile-generator.cc
File src/profile-generator.cc (right):

https://chromiumcodereview.appspot.com/10332087/diff/1/src/profile-generator....
src/profile-generator.cc:1681: const char* tag = objects_tags_.GetTag(object);
On 2012/05/10 12:23:31, Yury Semikhatsky wrote:
> On 2012/05/10 12:15:56, Mikhail Naganov (Chromium) wrote:
> > On 2012/05/10 12:13:52, Yury Semikhatsky wrote:
> > > How can we be sure that the object has already been tagged at this point?
> > 
> > Global objects tagging is always done before snapshot taking, because it can
> > modify the heap state. Perhaps, add a comment about this?
> I think a comment would be helpful here. Also what about non-global objects,
do
> we care about their tags?
Yep, looks like non-global objects, i.e. arrays those names are setup near line
1713 may miss their tags. This happens if the array is processed before its
retainer. It needs to be fixed. Btw it is not related to this patch, which is
about setting JSGlobalObject tags only.