150453 – We don't properly optimize TDZ checks when we declare a let variable without an initializer

Bug 150453 - We don't properly optimize TDZ checks when we declare a let variable without an initializer

Summary: We don't properly optimize TDZ checks when we declare a let variable without ...

Status:	RESOLVED FIXED

Alias:	None

Product:	WebKit
Classification:	Unclassified
Component:	JavaScriptCore (show other bugs)
Version:	WebKit Nightly Build
Hardware:	Unspecified Unspecified

Importance:	P2 Normal
Assignee:	Saam Barati

URL:
Keywords:

Depends on:
Blocks:

Attachments
Patch (1.36 KB, patch) 2016-03-29 12:45 PDT, Saam Barati	no flags	Details \| Formatted Diff \| Diff
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Description Saam Barati 2015-10-22 10:56:46 PDT

i.e:
```
let v;
return v;
```
has a TDZ check on the return value.

But, if we do:
```
let v = 20;
return v;
```
we optimize out the TDZ check.

Comment 1 Saam Barati 2016-03-26 11:53:24 PDT

This is probably a one line patch. I'm going to do it soon

Comment 2 Saam Barati 2016-03-29 12:45:57 PDT

Created attachment 275121 [details]
Patch

Comment 3 Mark Lam 2016-03-29 12:54:08 PDT

Comment on attachment 275121 [details]
Patch

r=me

Comment 4 WebKit Commit Bot 2016-03-29 15:11:23 PDT

Comment on attachment 275121 [details]
Patch

Clearing flags on attachment: 275121

Committed r198803: <http://trac.webkit.org/changeset/198803>

Comment 5 WebKit Commit Bot 2016-03-29 15:11:27 PDT

All reviewed patches have been landed.  Closing bug.