Handle missing context when getting frame details

Handle missing context when getting frame details

This bug was triggered by a very specific combination:

* A context-allocated variable at script scope.
* OSR optimization.
* A scheduled breakpoint, which triggers at stack checks.

Stack checks differ from other possible breakpoint locations in that
the context (among other things) may be in a register and not on the
stack, making it impossible to recover during deoptimization. The
frame_inspector then returns undefined when asked for the context.

In GetFrameDetails, handle this case by omitting all context-allocated
variables.

BUG=v8:5279
Committed: https://crrev.com/d25280801118b0a999b87acd6cf8f87a277b666d
Cr-Commit-Position: refs/heads/master@{#38611}

[jgruber, 2016-08-12 09:42:41]

The CQ bit was checked by jgruber@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-08-12 09:42:45]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[jgruber, 2016-08-12 09:43:36]

jgruber@chromium.org changed reviewers:
+ yangguo@chromium.org

[commit-bot: I haz the power, 2016-08-12 09:57:57]

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

[commit-bot: I haz the power, 2016-08-12 09:57:57]

Dry run: Try jobs failed on following builders:
  v8_mac_rel_ng on master.tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_mac_rel_ng/builds/6905)
  v8_mac_rel_ng_triggered on master.tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_mac_rel_ng_triggered/bui...)

[Yang, 2016-08-12 10:25:38]

lgtm

[jgruber, 2016-08-12 10:48:57]

The CQ bit was checked by jgruber@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-08-12 10:49:05]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[jgruber, 2016-08-12 10:49:58]

Description was changed from

==========
Handle missing context when getting frame details

This bug was triggered by a very specific combination:

* A context-allocated variable at script scope.
* OSR optimization.
* A scheduled breakpoint, which triggers at stack checks.

Stack checks differ from other possible breakpoint locations in that
the context (among other things) may be in a register and not on the
stack, making it impossible to recover during deoptimization. The
frame_inspector then returns undefined instead of the context.

In GetFrameDetails, handle this case by omitting all context-allocated
variables.

BUG=v8:5279
==========

to

==========
Handle missing context when getting frame details

This bug was triggered by a very specific combination:

* A context-allocated variable at script scope.
* OSR optimization.
* A scheduled breakpoint, which triggers at stack checks.

Stack checks differ from other possible breakpoint locations in that
the context (among other things) may be in a register and not on the
stack, making it impossible to recover during deoptimization. The
frame_inspector then returns undefined when asked for the context.

In GetFrameDetails, handle this case by omitting all context-allocated
variables.

BUG=v8:5279
==========

[commit-bot: I haz the power, 2016-08-12 11:11:47]

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

[commit-bot: I haz the power, 2016-08-12 11:11:47]

Dry run: This issue passed the CQ dry run.

[jgruber, 2016-08-12 11:17:54]

The CQ bit was checked by jgruber@chromium.org

[jgruber, 2016-08-12 11:17:54]

The patchset sent to the CQ was uploaded after l-g-t-m from yangguo@chromium.org
Link to the patchset: https://codereview.chromium.org/2245603002/#ps20001
(title: "Correctly set local_count")

[commit-bot: I haz the power, 2016-08-12 11:17:57]

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, 2016-08-12 11:20:03]

Description was changed from

==========
Handle missing context when getting frame details

This bug was triggered by a very specific combination:

* A context-allocated variable at script scope.
* OSR optimization.
* A scheduled breakpoint, which triggers at stack checks.

Stack checks differ from other possible breakpoint locations in that
the context (among other things) may be in a register and not on the
stack, making it impossible to recover during deoptimization. The
frame_inspector then returns undefined when asked for the context.

In GetFrameDetails, handle this case by omitting all context-allocated
variables.

BUG=v8:5279
==========

to

==========
Handle missing context when getting frame details

This bug was triggered by a very specific combination:

* A context-allocated variable at script scope.
* OSR optimization.
* A scheduled breakpoint, which triggers at stack checks.

Stack checks differ from other possible breakpoint locations in that
the context (among other things) may be in a register and not on the
stack, making it impossible to recover during deoptimization. The
frame_inspector then returns undefined when asked for the context.

In GetFrameDetails, handle this case by omitting all context-allocated
variables.

BUG=v8:5279
==========

[commit-bot: I haz the power, 2016-08-12 11:20:04]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2016-08-12 11:20:24]

Description was changed from

==========
Handle missing context when getting frame details

This bug was triggered by a very specific combination:

* A context-allocated variable at script scope.
* OSR optimization.
* A scheduled breakpoint, which triggers at stack checks.

Stack checks differ from other possible breakpoint locations in that
the context (among other things) may be in a register and not on the
stack, making it impossible to recover during deoptimization. The
frame_inspector then returns undefined when asked for the context.

In GetFrameDetails, handle this case by omitting all context-allocated
variables.

BUG=v8:5279
==========

to

==========
Handle missing context when getting frame details

This bug was triggered by a very specific combination:

* A context-allocated variable at script scope.
* OSR optimization.
* A scheduled breakpoint, which triggers at stack checks.

Stack checks differ from other possible breakpoint locations in that
the context (among other things) may be in a register and not on the
stack, making it impossible to recover during deoptimization. The
frame_inspector then returns undefined when asked for the context.

In GetFrameDetails, handle this case by omitting all context-allocated
variables.

BUG=v8:5279

Committed: https://crrev.com/d25280801118b0a999b87acd6cf8f87a277b666d
Cr-Commit-Position: refs/heads/master@{#38611}
==========

[commit-bot: I haz the power, 2016-08-12 11:20:27]

Patchset 2 (id:??) landed as
https://crrev.com/d25280801118b0a999b87acd6cf8f87a277b666d
Cr-Commit-Position: refs/heads/master@{#38611}