Require that heap collections are used over traceable elements.

Require that heap collections are used over traceable elements.

While it is fully supported, having Blink GC heap collection objects
with elements not themselves being heap objects nor containing
references to such, is unnecessary. And arguably a sign that the code
is unintentionally using a heap collection.

Thus, add static_assert()s which prevent heap collections containing
no traceable references.

R=haraken
BUG=585328
Committed: https://crrev.com/334dbe1a064d529de2be7ef984fefc575c3d1d3a
Cr-Commit-Position: refs/heads/master@{#389435}

[sof, 2016-04-22 09:51:11]

sigbjornf@opera.com changed reviewers:
+ oilpan-reviews@chromium.org

[sof, 2016-04-22 09:51:12]

Just tabling this one for discussion & consideration -- I think we need to
clarify how heap collections ought to be used in Blink.

[haraken, 2016-04-22 18:10:28]

LGTM

Limiting on-heap collections to only traceable elements sounds like a reasonable
rule.

[sof, 2016-04-23 08:10:41]

On 2016/04/22 18:10:28, haraken wrote:
> LGTM
> 
> Limiting on-heap collections to only traceable elements sounds like a
reasonable
> rule.

Static asserts like this naturally brings the question of if they should instead
be used to automatically infer what Allocator to use & thereby allow the
retirement of the Heap* collection types. (There could well be details that
would prevent this from working out, but it seems within the realm of the
possible.)

Worth an idle thought or two.

[sof, 2016-04-25 06:48:33]

The CQ bit was checked by sigbjornf@opera.com to run a CQ dry run

[commit-bot: I haz the power, 2016-04-25 06:48:46]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1912093002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1912093002/1

[commit-bot: I haz the power, 2016-04-25 08:18:27]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-04-25 08:18:28]

Dry run: This issue passed the CQ dry run.

[sof, 2016-04-25 09:08:05]

Description was changed from

==========
Require that heap collections are used over traceable elements.

While it is fully supported, having Blink GC heap collection objects
with elements not themselves being heap objects nor containing
references to such, is unnecessary. And arguably a sign that the code
is unintentionally using a heap collection.

Thus, add static_assert()s which prevent heap collections containing
no traceable references.

R=
BUG=
==========

to

==========
Require that heap collections are used over traceable elements.

While it is fully supported, having Blink GC heap collection objects
with elements not themselves being heap objects nor containing
references to such, is unnecessary. And arguably a sign that the code
is unintentionally using a heap collection.

Thus, add static_assert()s which prevent heap collections containing
no traceable references.

R=haraken
BUG=585328
==========

[sof, 2016-04-25 09:08:09]

The CQ bit was checked by sigbjornf@opera.com

[commit-bot: I haz the power, 2016-04-25 09:08:23]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1912093002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1912093002/1

[commit-bot: I haz the power, 2016-04-25 09:12:28]

Description was changed from

==========
Require that heap collections are used over traceable elements.

While it is fully supported, having Blink GC heap collection objects
with elements not themselves being heap objects nor containing
references to such, is unnecessary. And arguably a sign that the code
is unintentionally using a heap collection.

Thus, add static_assert()s which prevent heap collections containing
no traceable references.

R=haraken
BUG=585328
==========

to

==========
Require that heap collections are used over traceable elements.

While it is fully supported, having Blink GC heap collection objects
with elements not themselves being heap objects nor containing
references to such, is unnecessary. And arguably a sign that the code
is unintentionally using a heap collection.

Thus, add static_assert()s which prevent heap collections containing
no traceable references.

R=haraken
BUG=585328
==========

[commit-bot: I haz the power, 2016-04-25 09:12:29]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-04-25 09:13:39]

Description was changed from

==========
Require that heap collections are used over traceable elements.

While it is fully supported, having Blink GC heap collection objects
with elements not themselves being heap objects nor containing
references to such, is unnecessary. And arguably a sign that the code
is unintentionally using a heap collection.

Thus, add static_assert()s which prevent heap collections containing
no traceable references.

R=haraken
BUG=585328
==========

to

==========
Require that heap collections are used over traceable elements.

While it is fully supported, having Blink GC heap collection objects
with elements not themselves being heap objects nor containing
references to such, is unnecessary. And arguably a sign that the code
is unintentionally using a heap collection.

Thus, add static_assert()s which prevent heap collections containing
no traceable references.

R=haraken
BUG=585328

Committed: https://crrev.com/334dbe1a064d529de2be7ef984fefc575c3d1d3a
Cr-Commit-Position: refs/heads/master@{#389435}
==========

[commit-bot: I haz the power, 2016-04-25 09:13:40]

Patchset 1 (id:??) landed as
https://crrev.com/334dbe1a064d529de2be7ef984fefc575c3d1d3a
Cr-Commit-Position: refs/heads/master@{#389435}