[gn] Allow building a snapshot with unwinding information.

[gn] Allow building a snapshot with unwinding information.

Add a new "v8_perf_prof_unwinding_info" option to gn that translates to building
the snapshot with "--perf-prof-unwinding-info". It allows unwinding TF generated
code from the snapshot.

Additionally, add a warning if one uses the option along with a snapshot which
was not build with unwinding information.

Running tests in this configuration revealed an issue in the checks performed
when accessing the stub cache. We would assume that the `Code::Flags` bitfield
only contains the `Kind` and `ExtraICState` fields, when there is also a
`HasUnwindingInfo` field which can now be set for stubs.


BUG=

Review-Url: https://codereview.chromium.org/2887783002
Cr-Commit-Position: refs/heads/master@{#45477}
Committed: https://chromium.googlesource.com/v8/v8/+/73ab0f4b9fd31542eb6a72949092b9874a31761d

[Pierre Langlois, 2017-05-17 12:48:19]

pierre.langlois@arm.com changed reviewers:
+ jarin@chromium.org

[Pierre Langlois, 2017-05-22 13:45:04]

Description was changed from

==========
[gn] Allow building a snapshot with unwinding information.

Add a new "v8_perf_prof_unwinding_info" option to gn that translates to building
the snapshot with "--perf-prof-unwinding-info". It allows unwinding TF generated
code from the snapshot.

Additionally, add a warning if one uses the option along with a snapshot which
was not build with unwinding information.

BUG=
==========

to

==========
[gn] Allow building a snapshot with unwinding information.

Add a new "v8_perf_prof_unwinding_info" option to gn that translates to building
the snapshot with "--perf-prof-unwinding-info". It allows unwinding TF generated
code from the snapshot.

Additionally, add a warning if one uses the option along with a snapshot which
was not build with unwinding information.

Running tests in this configuration revealed an issue in the checks performed
when accessing the stub cache. We would assume that the `Code::Flags` bitfield
only contains the `Kind` and `ExtraICState` fields, when there is also a
`HasUnwindingInfo` field which can now be set for stubs.


BUG=
==========

[Pierre Langlois, 2017-05-22 13:45:04]

pierre.langlois@arm.com changed reviewers:
+ bmeurer@chromium.org

[Pierre Langlois, 2017-05-22 14:21:03]

Hello,

Any thought on this patch? It helps figuring out where things like "LoadIC" come
from when looking at a perf profile.

Thanks!
Pierre

[Benedikt Meurer, 2017-05-23 04:16:44]

LGTM from my side.

[Jarin, 2017-05-23 08:01:40]

lgtm, thank you! I am sorry for the delay.

[Pierre Langlois, 2017-05-23 08:26:02]

The CQ bit was checked by pierre.langlois@arm.com

[commit-bot: I haz the power, 2017-05-23 08:26:12]

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, 2017-05-23 09:47:29]

CQ is committing da patch.

Bot data: {"patchset_id": 20001, "attempt_start_ts": 1495527962547330,
"parent_rev": "8e0daf78daccd2f25a494dc3c0da9a25c4aadd52", "commit_rev":
"73ab0f4b9fd31542eb6a72949092b9874a31761d"}

[commit-bot: I haz the power, 2017-05-23 09:47:42]

Description was changed from

==========
[gn] Allow building a snapshot with unwinding information.

Add a new "v8_perf_prof_unwinding_info" option to gn that translates to building
the snapshot with "--perf-prof-unwinding-info". It allows unwinding TF generated
code from the snapshot.

Additionally, add a warning if one uses the option along with a snapshot which
was not build with unwinding information.

Running tests in this configuration revealed an issue in the checks performed
when accessing the stub cache. We would assume that the `Code::Flags` bitfield
only contains the `Kind` and `ExtraICState` fields, when there is also a
`HasUnwindingInfo` field which can now be set for stubs.


BUG=
==========

to

==========
[gn] Allow building a snapshot with unwinding information.

Add a new "v8_perf_prof_unwinding_info" option to gn that translates to building
the snapshot with "--perf-prof-unwinding-info". It allows unwinding TF generated
code from the snapshot.

Additionally, add a warning if one uses the option along with a snapshot which
was not build with unwinding information.

Running tests in this configuration revealed an issue in the checks performed
when accessing the stub cache. We would assume that the `Code::Flags` bitfield
only contains the `Kind` and `ExtraICState` fields, when there is also a
`HasUnwindingInfo` field which can now be set for stubs.


BUG=

Review-Url: https://codereview.chromium.org/2887783002
Cr-Commit-Position: refs/heads/master@{#45477}
Committed:
https://chromium.googlesource.com/v8/v8/+/73ab0f4b9fd31542eb6a72949092b9874a3...
==========

[commit-bot: I haz the power, 2017-05-23 09:47:43]

Committed patchset #2 (id:20001) as
https://chromium.googlesource.com/v8/v8/+/73ab0f4b9fd31542eb6a72949092b9874a3...