Bug 150453

Summary:

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

Product:

WebKit

Reporter:

Saam Barati <saam>

Component:

JavaScriptCore

Assignee:

Saam Barati <saam>

Status:

RESOLVED FIXED

Severity:

Normal

CC:

benjamin, commit-queue, fpizlo, ggaren, gskachkov, keith_miller, mark.lam, msaboff, oliver, sukolsak, ysuzuki

Priority:

Version:

WebKit Nightly Build

Hardware:

Unspecified

OS:

Unspecified

Attachments:

Description	Flags
Patch	none

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.