981522 - Revert bug 942804 in Aurora

Status: RESOLVED FIXED

(Core :: JavaScript Engine: JIT, defect)

Description

[Andy Wingo [:wingo]]

Bug 942804 introduced Ion compilation for unaliased "let" bindings.  However this exposed bug 956166, a crasher, solved in bug 980263.  However, the bug managed to catch the Firefox 29 train.

I propose that we revert bug 942804 in aurora.

Comment 1

[Andy Wingo [:wingo]]

Attachment: Disable Ion-compilation of unalised let-bindings in Aurora

Comment 2

[Jan de Mooij [:jandem]]

Comment on attachment 8388381 [details] [diff] [review]
Disable Ion-compilation of unalised let-bindings in Aurora

Review of attachment 8388381 [details] [diff] [review]:
-----------------------------------------------------------------

Thanks!

Comment 3

[Andy Wingo [:wingo]]

Comment on attachment 8388381 [details] [diff] [review]
Disable Ion-compilation of unalised let-bindings in Aurora

[Approval Request Comment]
Bug caused by (feature/regressing bug #): Bug 942804
User impact if declined: Crashers in Ion (e,g. bug 956166)
Testing completed (on m-c, etc.): Ran test-case in bug 956166
Risk to taking this patch (and alternatives if risky): Very low; it just disables something in Ion.
String or IDL/UUID changes made by this patch: None.

Comment 4

[Andy Wingo [:wingo]]

https://hg.mozilla.org/releases/mozilla-aurora/rev/910ef9ba00d7