[es6] Define generator prototype as writable prop

[es6] Define generator prototype as writable prop

The April 14 2015 final draft of the ES6 specification states that the
`prototype` property of generator function instances should be writable.

BUG=v8:4140, v8:4140
LOG=N
R=arv@chromium.org

Committed: https://crrev.com/f7b5912276dbb13dbd6fade196ad37207a4cb730
Cr-Commit-Position: refs/heads/master@{#28641}

[mike3, 2015-05-22 21:00:32]

Hi Erik, could you please take a look?

[caitp (gmail), 2015-05-22 21:11:22]

caitpotter88@gmail.com changed reviewers:
+ caitpotter88@gmail.com

[caitp (gmail), 2015-05-22 21:11:23]

https://codereview.chromium.org/1153633003/diff/1/src/bootstrapper.cc
File src/bootstrapper.cc (right):

https://codereview.chromium.org/1153633003/diff/1/src/bootstrapper.cc#newcode...
src/bootstrapper.cc:2182: Handle<Map>
strict_function_map(strict_function_map_writable_prototype_);
Can you add a note here about the `{ [[Writable]]: true, [[Enumerable]]: false,
[[Configurable]]: false }.` and point to section 25.2.4.3 (similar to how draft
sections are pointed to in the standard lib sources)

Also note, this is sort of weird, but GeneratorFunction.prototype is
non-writable still (as mentioned in 25.2.2.2

[mike3, 2015-05-22 21:31:16]

On 2015/05/22 21:11:23, caitp wrote:
> src/bootstrapper.cc:2182: Handle<Map>
> strict_function_map(strict_function_map_writable_prototype_);
> Can you add a note here about the `{ [[Writable]]: true, [[Enumerable]]:
false,
> [[Configurable]]: false }.` and point to section 25.2.4.3 (similar to how
draft
> sections are pointed to in the standard lib sources)

Sure

> Also note, this is sort of weird, but GeneratorFunction.prototype is
> non-writable still (as mentioned in 25.2.2.2

Between Generator Functions, Generator Objects, intrinsics, prototypes, and
intrinsic prototypes, the spec gets pretty tough to follow at this point!

[arv (Not doing code reviews), 2015-05-26 16:01:03]

LGTM

It was not clear to me if Caitlin's comment was a side note or something that we
are not doing right?

[caitp (gmail), 2015-05-26 16:12:52]

On 2015/05/26 16:01:03, arv wrote:
> LGTM
> 
> It was not clear to me if Caitlin's comment was a side note or something that
we
> are not doing right?

It's a mix --- I think previously, instances of generator functions didn't have
a writable prototype, but it looks to me like only the base GeneratorFunction
"class" has a readonly prototype.

So, we probably need to add some code to make sure that works properly

[mike3, 2015-05-26 16:54:45]

On 2015/05/26 16:12:52, caitp wrote:
> So, we probably need to add some code to make sure that works properly

It sounds like you are thinking of a test for the GeneratorFunction object's
`prototype` property descriptor. Is that right? If so, should I include it in
this patch?

[caitp (gmail), 2015-05-26 16:56:37]

On 2015/05/26 16:54:45, mike3 wrote:
> On 2015/05/26 16:12:52, caitp wrote:
> > So, we probably need to add some code to make sure that works properly
> 
> It sounds like you are thinking of a test for the GeneratorFunction object's
> `prototype` property descriptor. Is that right? If so, should I include it in
> this patch?

Yes you should --- And, if it doesn't work, you should fix it, probably fixable
in bootstrapper.cc

[mike3, 2015-05-26 17:27:40]

On 2015/05/26 16:56:37, caitp wrote:
> On 2015/05/26 16:54:45, mike3 wrote:
> > On 2015/05/26 16:12:52, caitp wrote:
> > > So, we probably need to add some code to make sure that works properly
> > 
> > It sounds like you are thinking of a test for the GeneratorFunction object's
> > `prototype` property descriptor. Is that right? If so, should I include it
in
> > this patch?
> 
> Yes you should --- And, if it doesn't work, you should fix it, probably
fixable
> in bootstrapper.cc

Okay, the latest patch has some assertions for the GeneratorFunction intrinsic's
`prototype` property descriptor. Luckily, that was already correct, so no
additional
change to the source was necessary.

[caitp (gmail), 2015-05-26 17:29:58]

On 2015/05/26 17:27:40, mike3 wrote:
> On 2015/05/26 16:56:37, caitp wrote:
> > On 2015/05/26 16:54:45, mike3 wrote:
> > > On 2015/05/26 16:12:52, caitp wrote:
> > > > So, we probably need to add some code to make sure that works properly
> > > 
> > > It sounds like you are thinking of a test for the GeneratorFunction
object's
> > > `prototype` property descriptor. Is that right? If so, should I include it
> in
> > > this patch?
> > 
> > Yes you should --- And, if it doesn't work, you should fix it, probably
> fixable
> > in bootstrapper.cc
> 
> Okay, the latest patch has some assertions for the GeneratorFunction
intrinsic's
> `prototype` property descriptor. Luckily, that was already correct, so no
> additional
> change to the source was necessary.

Thanks, LGTM

[arv (Not doing code reviews), 2015-05-26 17:32:27]

LGTM

[mike3, 2015-05-26 18:02:07]

The CQ bit was checked by mike@mikepennisi.com

[commit-bot: I haz the power, 2015-05-26 18:02:17]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1153633003/40001

[commit-bot: I haz the power, 2015-05-26 18:31:41]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2015-05-26 18:32:00]

Patchset 3 (id:??) landed as
https://crrev.com/f7b5912276dbb13dbd6fade196ad37207a4cb730
Cr-Commit-Position: refs/heads/master@{#28641}

[mike3, 2015-05-26 18:35:16]

On 2015/05/26 18:32:00, I haz the power - commit-bot wrote:
> Patchset 3 (id:??) landed as
> https://crrev.com/f7b5912276dbb13dbd6fade196ad37207a4cb730
> Cr-Commit-Position: refs/heads/master@{#28641}

Thanks, Cait and Erik!

[arv (Not doing code reviews), 2015-05-26 18:36:06]

On 2015/05/26 18:35:16, mike3 wrote:

> Thanks, Cait and Erik!

Thank you for fixing this.