[debug] introduce precise binary code coverage.

[debug] introduce precise binary code coverage.

With precise binary code coverage, the reported count is either 0 or 1.
We only report 1 the first time we collect coverage data after the
function has been executed.

Since we do not care about the accurate execution count, we can optimize
the function once it has been executed once.

Also change best effort coverage to be implicitly binary.

R=caseq@chromium.org, jgruber@chromium.org, pfeldman@chromium.org
BUG=v8:5808
Review-Url: https://codereview.chromium.org/2766573003
Cr-Commit-Position: refs/heads/master@{#44074}
Committed: https://chromium.googlesource.com/v8/v8/+/d71ef941edca6ff99850a71ac146d9bbae5e61b7

[Yang, 2017-03-21 14:14:08]

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

[commit-bot: I haz the power, 2017-03-21 14:14:10]

Dry run: 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, 2017-03-21 14:39:05]

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

[commit-bot: I haz the power, 2017-03-21 14:39:06]

Dry run: This issue passed the CQ dry run.

[jgruber, 2017-03-21 16:54:35]

lgtm

https://codereview.chromium.org/2766573003/diff/1/src/debug/debug-coverage.cc
File src/debug/debug-coverage.cc (left):

https://codereview.chromium.org/2766573003/diff/1/src/debug/debug-coverage.cc...
src/debug/debug-coverage.cc:68: // Feedback vectors are already listed to
prevent losing them to GC.
Nit: These comments were pretty useful. I also prefer the old
switch(code_coverage_mode) structure of this function.

https://codereview.chromium.org/2766573003/diff/1/src/debug/debug-coverage.cc
File src/debug/debug-coverage.cc (right):

https://codereview.chromium.org/2766573003/diff/1/src/debug/debug-coverage.cc...
src/debug/debug-coverage.cc:89: if (reset_count)
vector->clear_invocation_count();
If counts are reset iff collecting precise coverage, maybe we can remove the
reset_count parameter.

[Yang, 2017-03-22 06:46:00]

Addressed comments.

Pavel, I need your review for the protocol change.

https://codereview.chromium.org/2766573003/diff/1/src/debug/debug-coverage.cc
File src/debug/debug-coverage.cc (right):

https://codereview.chromium.org/2766573003/diff/1/src/debug/debug-coverage.cc...
src/debug/debug-coverage.cc:89: if (reset_count)
vector->clear_invocation_count();
On 2017/03/21 16:54:34, jgruber wrote:
> If counts are reset iff collecting precise coverage, maybe we can remove the
> reset_count parameter.

One use case I expect is that precise coverage has been enabled, but we collect
best effort coverage. In that case we have the ArrayList, but do not want to
reset the invocation counts.

But if we are in best effort mode, we definitely should not reset the invocation
count.

[pfeldman, 2017-03-22 17:29:57]

https://codereview.chromium.org/2766573003/diff/20001/src/inspector/js_protoc...
File src/inspector/js_protocol.json (right):

https://codereview.chromium.org/2766573003/diff/20001/src/inspector/js_protoc...
src/inspector/js_protocol.json:906: { "name": "binary", "type": "boolean",
"optional": true, "description": "Collect binary information of 'covered' or
'not covered' instead of accurate call counts." }
I thought opt-in callCount would work better since the method itself mentions
"coverage". I.e. binary is the default.

[Yang, 2017-03-23 06:45:04]

Description was changed from

==========
[debug] introduce precise binary code coverage.

With precise binary code coverage, the reported count is either 0 or 1.
We only report 1 the first time we collect coverage data after the
function has been executed.

Since we do not care about the accurate execution count, we can optimize
the function once it has been executed once.

R=caseq@chromium.org, jgruber@chromium.org, pfeldman@chromium.org
BUG=v8:5808
==========

to

==========
[debug] introduce precise binary code coverage.

With precise binary code coverage, the reported count is either 0 or 1.
We only report 1 the first time we collect coverage data after the
function has been executed.

Since we do not care about the accurate execution count, we can optimize
the function once it has been executed once.

Also change best effort coverage to be implicitly binary.

R=caseq@chromium.org, jgruber@chromium.org, pfeldman@chromium.org
BUG=v8:5808
==========

[Yang, 2017-03-23 06:52:20]

On 2017/03/22 17:29:57, pfeldman wrote:
>
https://codereview.chromium.org/2766573003/diff/20001/src/inspector/js_protoc...
> File src/inspector/js_protocol.json (right):
> 
>
https://codereview.chromium.org/2766573003/diff/20001/src/inspector/js_protoc...
> src/inspector/js_protocol.json:906: { "name": "binary", "type": "boolean",
> "optional": true, "description": "Collect binary information of 'covered' or
> 'not covered' instead of accurate call counts." }
> I thought opt-in callCount would work better since the method itself mentions
> "coverage". I.e. binary is the default.

Done. And since binary is the default, I made best-effort coverage implicitly
binary too.

[Yang, 2017-03-23 07:39:42]

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

[commit-bot: I haz the power, 2017-03-23 07:39:49]

Dry run: 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, 2017-03-23 07:55:40]

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

[commit-bot: I haz the power, 2017-03-23 07:55:42]

Dry run: Try jobs failed on following builders:
  v8_linux64_gyp_rel_ng on master.tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_linux64_gyp_rel_ng/build...)
  v8_linux64_gyp_rel_ng_triggered on master.tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_linux64_gyp_rel_ng_trigg...)

[Yang, 2017-03-23 08:21:39]

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

[commit-bot: I haz the power, 2017-03-23 08:21:44]

Dry run: 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, 2017-03-23 08:45:07]

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

[commit-bot: I haz the power, 2017-03-23 08:45:08]

Dry run: This issue passed the CQ dry run.

[pfeldman, 2017-03-23 17:13:36]

lgtm

[Yang, 2017-03-23 17:21:36]

The CQ bit was checked by yangguo@chromium.org

[Yang, 2017-03-23 17:21:37]

The patchset sent to the CQ was uploaded after l-g-t-m from jgruber@chromium.org
Link to the patchset: https://codereview.chromium.org/2766573003/#ps80001
(title: "fix test")

[commit-bot: I haz the power, 2017-03-23 17:21:42]

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, 2017-03-23 17:23:18]

CQ is committing da patch.

Bot data: {"patchset_id": 80001, "attempt_start_ts": 1490289696999670,
"parent_rev": "20a803fd3c82fe6f644db4668f3b61f5e53b5958", "commit_rev":
"d71ef941edca6ff99850a71ac146d9bbae5e61b7"}

[commit-bot: I haz the power, 2017-03-23 17:23:25]

Description was changed from

==========
[debug] introduce precise binary code coverage.

With precise binary code coverage, the reported count is either 0 or 1.
We only report 1 the first time we collect coverage data after the
function has been executed.

Since we do not care about the accurate execution count, we can optimize
the function once it has been executed once.

Also change best effort coverage to be implicitly binary.

R=caseq@chromium.org, jgruber@chromium.org, pfeldman@chromium.org
BUG=v8:5808
==========

to

==========
[debug] introduce precise binary code coverage.

With precise binary code coverage, the reported count is either 0 or 1.
We only report 1 the first time we collect coverage data after the
function has been executed.

Since we do not care about the accurate execution count, we can optimize
the function once it has been executed once.

Also change best effort coverage to be implicitly binary.

R=caseq@chromium.org, jgruber@chromium.org, pfeldman@chromium.org
BUG=v8:5808

Review-Url: https://codereview.chromium.org/2766573003
Cr-Commit-Position: refs/heads/master@{#44074}
Committed:
https://chromium.googlesource.com/v8/v8/+/d71ef941edca6ff99850a71ac146d9bbae5...
==========

[commit-bot: I haz the power, 2017-03-23 17:23:26]

Committed patchset #5 (id:80001) as
https://chromium.googlesource.com/v8/v8/+/d71ef941edca6ff99850a71ac146d9bbae5...