980558 - Enable extraWarnings on safe JS context

Status: RESOLVED WONTFIX

(Core :: XPConnect, defect)

Description

[Bill McCloskey [inactive unless it's an emergency] (:billm)]

Attachment: extra-warnings

We use the safe JS context to run content scripts. We're not getting extraWarnings for these scripts. These warnings are often very useful since they tell you when you've used a property that doesn't exist (one of the most common JS errors in my experience).

Setting this option generates a few extra warnings at startup about "function does not always return a value", but it's not too severe. I'll file additional bugs to fix the return value stuff.

Comment 1

[Bobby Holley (:bholley)]

Comment on attachment 8387111 [details] [diff] [review]
extra-warnings

r+ for now, but the semantics here will need to change when this flag moves from the JSContext to the JSRuntime (with a per-compartment override) in bug  940305. So I'm not promising to maintain the behavior here, but I don't want to get in your way in the mean time.

Comment 2

[Bill McCloskey [inactive unless it's an emergency] (:billm)]

https://hg.mozilla.org/integration/mozilla-inbound/rev/263b6c86c1be

Comment 3

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

Backed out in http://hg.mozilla.org/integration/mozilla-inbound/rev/d8015367ac9b for build bustage: https://tbpl.mozilla.org/php/getParsedLog.php?id=35762956&tree=Mozilla-Inbound

Comment 4

[Bill McCloskey [inactive unless it's an emergency] (:billm)]

Thanks Wes. Somehow an extra + character snuck in there when I fixed a conflict.
https://hg.mozilla.org/integration/mozilla-inbound/rev/fd36c14f0153

Comment 5

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/mozilla-central/rev/fd36c14f0153

Comment 6

[Bobby Holley (:bholley)]

Bill backed this out:
https://hg.mozilla.org/integration/mozilla-inbound/rev/7fec954d58b6

Comment 7

[Bill McCloskey [inactive unless it's an emergency] (:billm)]

Hopefully we'll end up with some better system for setting this flag only for chrome code.

Comment 8

[Bobby Holley (:bholley)]

(In reply to Bill McCloskey (:billm) from comment #7)
> Hopefully we'll end up with some better system for setting this flag only
> for chrome code.

I implemented such a system in my patch for bug 940305. It's just waiting on Kyle's review.