ES6: Add support for Map/Set forEach

ES6: Add support for Map/Set forEach

This implements MapIterator and SetIterator which matches
the same constructs in the ES6 spec. However, these 2
iterators are not exposed to user code yet. They are only
used internally to implement Map.prototype.forEach and
Set.prototype.forEach.

Each iterator has a reference to the OrderedHashTable where
it directly accesses the hash table's entries.

The OrderedHashTable has a reference to the newest iterator
and each iterator has a reference to the next and previous
iterator, effectively creating a double linked list.

When the OrderedHashTable is mutated (or replaced) all the
iterators are updated.

When the iterator iterates passed the end of the data table
it closes itself. Closed iterators no longer have a
reference to the OrderedHashTable and they are removed from
the double linked list. In the case of Map/Set forEach, we
manually call Close on the iterator in case an exception was
thrown so that the iterator never reached the end.

At this point the OrderedHashTable keeps all the non finished
iterators alive but since the only thing we currently expose
is forEach there are no unfinished iterators outside a forEach
call. Once we expose the iterators to user code we will need
to make the references from the OrderedHashTable to the
iterators weak and have some mechanism to close an iterator
when it is garbage collected.

BUG=1793, 2323
LOG=Y
TBR=mstarzinger@chromium.org

Committed: https://code.google.com/p/v8/source/detail?r=20823

[adamk, 2014-04-16 18:35:10]

https://codereview.chromium.org/240323003/diff/1/src/objects.cc
File src/objects.cc (right):

https://codereview.chromium.org/240323003/diff/1/src/objects.cc#newcode16493
src/objects.cc:16493: template class OrderedHashTable<OrderedHashMap,
JSMapIterator, 2>;
Based on the Windows build error, I think you need a template instantiation
here:

template int OrderedHashTable<OrderedHashMap, JSMapIterator,
2>::FindEntry(Object* key);

https://codereview.chromium.org/240323003/diff/1/src/objects.cc#newcode16683
src/objects.cc:16683: template class OrderedHashTableIterator<JSMapIterator,
OrderedHashMap>;
Based on the windows build errors, I think you need some more explicit template
instantiations here:

template Handle<JSObject> OrderedHashTableIterator<JSSetIterator,
OrderedHashSet>::Next(Handle<JSSetIterator> iterator);
template Handle<JSObject> OrderedHashTableIterator<JSMapIterator,
OrderedHashMap>::Next(Handle<JSMapIterator> iterator);

https://codereview.chromium.org/240323003/diff/1/src/objects.h
File src/objects.h (right):

https://codereview.chromium.org/240323003/diff/1/src/objects.h#newcode10139
src/objects.h:10139: #ifdef OBJECT_PRINT
There's a DECLARE_PRINTER() method that'll do this for you, why does that not
suffice for this case?

[arv (Not doing code reviews), 2014-04-16 18:49:48]

Moar template instantiations

[arv (Not doing code reviews), 2014-04-16 18:49:54]

https://codereview.chromium.org/240323003/diff/1/src/objects.cc
File src/objects.cc (right):

https://codereview.chromium.org/240323003/diff/1/src/objects.cc#newcode16493
src/objects.cc:16493: template class OrderedHashTable<OrderedHashMap,
JSMapIterator, 2>;
On 2014/04/16 18:35:11, adamk wrote:
> Based on the Windows build error, I think you need a template instantiation
> here:
> 
> template int OrderedHashTable<OrderedHashMap, JSMapIterator,
> 2>::FindEntry(Object* key);

Done.

https://codereview.chromium.org/240323003/diff/1/src/objects.cc#newcode16683
src/objects.cc:16683: template class OrderedHashTableIterator<JSMapIterator,
OrderedHashMap>;
On 2014/04/16 18:35:11, adamk wrote:
> Based on the windows build errors, I think you need some more explicit
template
> instantiations here:
> 
> template Handle<JSObject> OrderedHashTableIterator<JSSetIterator,
> OrderedHashSet>::Next(Handle<JSSetIterator> iterator);
> template Handle<JSObject> OrderedHashTableIterator<JSMapIterator,
> OrderedHashMap>::Next(Handle<JSMapIterator> iterator);

Done.

https://codereview.chromium.org/240323003/diff/1/src/objects.h
File src/objects.h (right):

https://codereview.chromium.org/240323003/diff/1/src/objects.h#newcode10139
src/objects.h:10139: #ifdef OBJECT_PRINT
On 2014/04/16 18:35:11, adamk wrote:
> There's a DECLARE_PRINTER() method that'll do this for you, why does that not
> suffice for this case?

This is only a helper function for the DECLARE_PRINTER in the subclasses.

[arv (Not doing code reviews), 2014-04-16 20:37:56]

Inline Create functions

[adamk, 2014-04-16 21:12:39]

Committed patchset #3 manually as r20823 (presubmit successful).

[arv (Not doing code reviews), 2014-04-16 21:47:02]

Explicit instantiate the functions instead

[Jakob Kummerow, 2014-04-22 14:50:40]

This hits unreachable code in types.cc:

out/ia32.debug/d8 --allow-natives-syntax --harmony -e "var s = new Set(); var it
= %SetCreateIterator(s, 2);"

[arv (Not doing code reviews), 2014-04-22 15:06:56]

On 2014/04/22 14:50:40, Jakob wrote:
> This hits unreachable code in types.cc:
> 
> out/ia32.debug/d8 --allow-natives-syntax --harmony -e "var s = new Set(); var
it
> = %SetCreateIterator(s, 2);"

Looking

[Jakob Kummerow, 2014-04-22 15:08:13]

Likely:

diff --git a/src/types.cc b/src/types.cc
index 394f772..13ab324 100644
--- a/src/types.cc
+++ b/src/types.cc
@@ -225,7 +225,9 @@ int TypeImpl<Config>::BitsetType::Lub(i::Map* map) {
     case JS_TYPED_ARRAY_TYPE:
     case JS_DATA_VIEW_TYPE:
     case JS_SET_TYPE:
+    case JS_SET_ITERATOR_TYPE:
     case JS_MAP_TYPE:
+    case JS_MAP_ITERATOR_TYPE:
     case JS_WEAK_MAP_TYPE:
     case JS_WEAK_SET_TYPE:
       if (map->is_undetectable()) return kUndetectable;

[arv (Not doing code reviews), 2014-04-22 15:23:10]

On 2014/04/22 15:06:56, arv wrote:
> On 2014/04/22 14:50:40, Jakob wrote:
> > This hits unreachable code in types.cc:
> > 
> > out/ia32.debug/d8 --allow-natives-syntax --harmony -e "var s = new Set();
var
> it
> > = %SetCreateIterator(s, 2);"
> 
> Looking

Fix at https://codereview.chromium.org/246993003/