Fix bug where generators got closed prematurely.

Fix bug where generators got closed prematurely.

In a generator function, the parser rewrites a return statement into a "final"
yield.  A final yield used to close the generator, which was incorrect because
the return may occur inside a try-finally clause and so the generator may not
yet terminate.

BUG=

Committed: https://crrev.com/2a0e4225dddc9c39eb2d0cd36d2b7249120c78ab
Cr-Commit-Position: refs/heads/master@{#33537}

[neis, 2016-01-25 12:01:22]

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

[commit-bot: I haz the power, 2016-01-25 12:01:33]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1634553002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1634553002/1

[neis, 2016-01-25 12:28:22]

Description was changed from

==========
Fix bug where generators got closed prematurely.

In a generator function, the parser rewrites a return statement into a "final"
yield.  A final yield used to close the generator, which was incorrect because
the return may occur inside a try-finally clause and so the generator may not
yet terminate.

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

to

==========
Fix bug where generators got closed prematurely.

In a generator function, the parser rewrites a return statement into a "final"
yield.  A final yield used to close the generator, which was incorrect because
the return may occur inside a try-finally clause and so the generator may not
yet terminate.

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

[neis, 2016-01-25 12:28:22]

neis@chromium.org changed reviewers:
+ mstarzinger@chromium.org

[neis, 2016-01-25 12:28:43]

PTAL

[commit-bot: I haz the power, 2016-01-25 12:37:44]

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

[commit-bot: I haz the power, 2016-01-25 12:37:45]

Dry run: This issue passed the CQ dry run.

[Michael Starzinger, 2016-01-25 12:56:05]

LGTM, just nits and suggestions.

https://codereview.chromium.org/1634553002/diff/1/src/parsing/parser.cc
File src/parsing/parser.cc (right):

https://codereview.chromium.org/1634553002/diff/1/src/parsing/parser.cc#newco...
src/parsing/parser.cc:4658: // try { InitialYield; ...body...; FinalYield }
nit: On top of the pseudo-code, can we add a description of why we do this
desugaring here in prose? That will help people understand the reasoning behind
this.

https://codereview.chromium.org/1634553002/diff/1/test/mjsunit/es6/generators...
File test/mjsunit/es6/generators-states.js (right):

https://codereview.chromium.org/1634553002/diff/1/test/mjsunit/es6/generators...
test/mjsunit/es6/generators-states.js:71: // return that doesn't close
nit: Please capitalize and punctuate comment.

https://codereview.chromium.org/1634553002/diff/1/test/mjsunit/es6/generators...
test/mjsunit/es6/generators-states.js:81: let g = function*() { try {return 42}
finally {x.throw(666)} };
As discussed offline, can we add another test case of the following structure on
top of the existings ones here, just to make this clearer:

let x;
let g = function*() {
  try { return 42 } finally {
    try { x.throw(666) } catch(e) {}
  }
}

x = g();
assertEquals({value: 42, done: true}, x.next());

[neis, 2016-01-25 13:11:48]

All done.

[neis, 2016-01-25 13:11:51]

The CQ bit was checked by neis@chromium.org

[neis, 2016-01-25 13:11:51]

The patchset sent to the CQ was uploaded after l-g-t-m from
mstarzinger@chromium.org
Link to the patchset: https://codereview.chromium.org/1634553002/#ps20001
(title: "Address comments.")

[commit-bot: I haz the power, 2016-01-25 13:11:55]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1634553002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1634553002/20001

[commit-bot: I haz the power, 2016-01-25 13:15:36]

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

[commit-bot: I haz the power, 2016-01-25 13:15:36]

Try jobs failed on following builders:
  v8_presubmit on tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_presubmit/builds/10096)

[neis, 2016-01-25 13:18:03]

neis@chromium.org changed reviewers:
+ rossberg@chromium.org

[neis, 2016-01-25 13:18:30]

On 2016/01/25 13:15:36, commit-bot: I haz the power wrote:
> Try jobs failed on following builders:
>   v8_presubmit on tryserver.v8 (JOB_FAILED,
> http://build.chromium.org/p/tryserver.v8/builders/v8_presubmit/builds/10096)

Owner needed.  Andreas, please have a quick look.

[rossberg, 2016-01-26 18:45:10]

lgtm

[neis, 2016-01-27 07:53:31]

The CQ bit was checked by neis@chromium.org

[commit-bot: I haz the power, 2016-01-27 07:53:42]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1634553002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1634553002/20001

[commit-bot: I haz the power, 2016-01-27 08:12:35]

Description was changed from

==========
Fix bug where generators got closed prematurely.

In a generator function, the parser rewrites a return statement into a "final"
yield.  A final yield used to close the generator, which was incorrect because
the return may occur inside a try-finally clause and so the generator may not
yet terminate.

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

to

==========
Fix bug where generators got closed prematurely.

In a generator function, the parser rewrites a return statement into a "final"
yield.  A final yield used to close the generator, which was incorrect because
the return may occur inside a try-finally clause and so the generator may not
yet terminate.

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

[commit-bot: I haz the power, 2016-01-27 08:12:35]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2016-01-27 08:13:35]

Description was changed from

==========
Fix bug where generators got closed prematurely.

In a generator function, the parser rewrites a return statement into a "final"
yield.  A final yield used to close the generator, which was incorrect because
the return may occur inside a try-finally clause and so the generator may not
yet terminate.

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

to

==========
Fix bug where generators got closed prematurely.

In a generator function, the parser rewrites a return statement into a "final"
yield.  A final yield used to close the generator, which was incorrect because
the return may occur inside a try-finally clause and so the generator may not
yet terminate.

BUG=

Committed: https://crrev.com/2a0e4225dddc9c39eb2d0cd36d2b7249120c78ab
Cr-Commit-Position: refs/heads/master@{#33537}
==========

[commit-bot: I haz the power, 2016-01-27 08:13:35]

Patchset 2 (id:??) landed as
https://crrev.com/2a0e4225dddc9c39eb2d0cd36d2b7249120c78ab
Cr-Commit-Position: refs/heads/master@{#33537}