871995 - Fix rooting compilation failure in ObjectWrapperParent.cpp

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Steve Fink [:sfink] [:s:]]

js/ipc/ObjectWrapperParent.cpp fails to compile with the exact rooting enabled due to the patch from bug 871182: Rooted<AutoResolveFlag> is not a valid type. Sadly, this is only detected when you enable the rooting analysis, because only then does the template instantiation notice that it requires a root 'kind', which is really because you can't use any arbitrary T for Rooted<T>; you can only use T for which a couple of instantiations are defined (RootMethods<T>::RootKind or something like that is one; something that would actually trace your T is another.)

Comment 1

[Steve Fink [:sfink] [:s:]]

Attachment: Fix rooting compilation failure in ObjectWrapperParent.cpp

The solution is to have AutoResolveFlag change its mObj field from JSObject* to Rooted<JSObject*>. It's an Auto* class, which implies a stack lifetime, so it can contain Rooted fields.

This file is also |using namespace JS| but explicitly qualifying all kinds of stuff with JS::. I removed the ones that are unambiguous. Some, like JS::Class, I left qualified because I think it's helpful documentation. Perhaps it would better to qualify all of them and stop using the namespace? I don't know what the standards are for that, but I doubt it matters much.

Comment 2

[Till Schneidereit [:till]]

Comment on attachment 749268 [details] [diff] [review]
Fix rooting compilation failure in ObjectWrapperParent.cpp

Review of attachment 749268 [details] [diff] [review]:
-----------------------------------------------------------------

When I was thinking "how does this work", I should have taken that as a warning sign, perhaps.

::: js/ipc/ObjectWrapperParent.cpp
@@ +353,5 @@
>          return false;
>      *to = OBJECT_TO_JSVAL(obj);
>      return true;
>  }
>      

Not that I care too much to make you touch this file again, but there's some rogue whitespace here.

Comment 3

[Steve Fink [:sfink] [:s:]]

http://hg.mozilla.org/integration/mozilla-inbound/rev/01072a33f2ed

Comment 4

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/01072a33f2ed