[heap] Filter out non-heap values when tracing wrappers

[heap] Filter out non-heap values when tracing wrappers

We used to rely on the fact that all values kept alive through wrapper
tracing were materialized as heap objects. Smis break this invariant and
need to be filter out.

BUG=chromium:716031
Review-Url: https://codereview.chromium.org/2852463003
Cr-Commit-Position: refs/heads/master@{#44946}
Committed: https://chromium.googlesource.com/v8/v8/+/1f3a95f1f7a11ba7a97901ea6046c251ef77bed4

[Hannes Payer (out of office), 2017-04-27 14:46:18]

hpayer@chromium.org changed reviewers:
+ hpayer@chromium.org

[Hannes Payer (out of office), 2017-04-27 14:46:18]

https://codereview.chromium.org/2852463003/diff/1/src/heap/heap.cc
File src/heap/heap.cc (right):

https://codereview.chromium.org/2852463003/diff/1/src/heap/heap.cc#newcode5676
src/heap/heap.cc:5676: if (!(*object)->IsHeapObject()) return;
Do you still want to keep the nullptr check? Or can it never be null?

[Michael Lippautz, 2017-04-27 14:47:50]

https://codereview.chromium.org/2852463003/diff/1/src/heap/heap.cc
File src/heap/heap.cc (right):

https://codereview.chromium.org/2852463003/diff/1/src/heap/heap.cc#newcode5676
src/heap/heap.cc:5676: if (!(*object)->IsHeapObject()) return;
On 2017/04/27 14:46:18, Hannes Payer wrote:
> Do you still want to keep the nullptr check? Or can it never be null?

If it is a heap object it cannot be null, as this would be represented as an
empty handle on the embedder side.

If we get a tagged null pointer we will crash in the DCHECK, which is what we
want to see.

[Hannes Payer (out of office), 2017-04-27 15:00:41]

lgtm

[Michael Lippautz, 2017-04-27 15:01:30]

The CQ bit was checked by mlippautz@chromium.org

[commit-bot: I haz the power, 2017-04-27 15:01:35]

CQ is trying da patch.

Follow status at:
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-04-27 15:33:05]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1493305290110770, "parent_rev":
"a16c3c910548e37eb62bb467fea706a21f6a2d46", "commit_rev":
"1f3a95f1f7a11ba7a97901ea6046c251ef77bed4"}

[commit-bot: I haz the power, 2017-04-27 15:33:12]

Description was changed from

==========
[heap] Filter out non-heap values when tracing wrappers

We used to rely on the fact that all values kept alive through wrapper
tracing were materialized as heap objects. Smis break this invariant and
need to be filter out.

BUG=chromium:716031
==========

to

==========
[heap] Filter out non-heap values when tracing wrappers

We used to rely on the fact that all values kept alive through wrapper
tracing were materialized as heap objects. Smis break this invariant and
need to be filter out.

BUG=chromium:716031

Review-Url: https://codereview.chromium.org/2852463003
Cr-Commit-Position: refs/heads/master@{#44946}
Committed:
https://chromium.googlesource.com/v8/v8/+/1f3a95f1f7a11ba7a97901ea6046c251ef7...
==========

[commit-bot: I haz the power, 2017-04-27 15:33:13]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/v8/v8/+/1f3a95f1f7a11ba7a97901ea6046c251ef7...