1107496 - Add PlainObject subclass

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Brian Hackett [Laid off!]]

Attachment: patch

There are a lot of subclasses of JSObject and NativeObject for the various kinds of objects that can be created, but there isn't one for the ordinary objects created using '{}' object literals, 'new Foo()', 'Object.create()', etc.  The clasp for these objects is stored on JSObject itself, which leads to lots of weird code like 'obj->is<JSObject>()', makes it hard to create these objects in an elegant way, is error prone (a class_ left out on a subclass will cause references to resolve to JSObject::class_, which is never what we want to happen), and leads to the code being underspecified (we have to use JSObject or NativeObject to refer to these objects).

The attached patch adds a PlainObject subclass to NativeObject to refer to these objects.  I don't know if there's a better name to use here, but PlainObject seemed nice to easily distinguish these from the JSObject/NativeObject superclasses.  This patch also cleans up some object creation APIs and replaces a lot of uses of NativeObject or JSObject with specific subclasses, and fixes a TypedObject bug where a couple functions ended up being named 'Object' due to the class resolving thing above.

Comment 1

[Luke Wagner [:luke]]

Comment on attachment 8532030 [details] [diff] [review]
patch

Review of attachment 8532030 [details] [diff] [review]:
-----------------------------------------------------------------

Nice

Comment 2

[Brian Hackett [Laid off!]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/64ec5c15d182

Comment 3

[Ryan VanderMeulen [:RyanVM]]

Backed out for SM(ggc) failures.
https://hg.mozilla.org/integration/mozilla-inbound/rev/3e1e87355f8f

https://treeherder.mozilla.org/logviewer.html#?job_id=4391254&repo=mozilla-inbound

Comment 4

[Brian Hackett [Laid off!]]

Hmm, the try run I did (acf43bc57a51) never even ran SM(ggc).

https://hg.mozilla.org/integration/mozilla-inbound/rev/516d97ff2d4d

Comment 5

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/mozilla-central/rev/516d97ff2d4d