586053 - Function constructor misses opp'ty to (lazily create and then) share Function.prototype's emptyScope

Status: RESOLVED INCOMPLETE

(Core :: JavaScript Engine, defect)

Description

[Brendan Eich [:brendan]]

This is all under js_InitClass:

        fun = js_NewFunction(cx, NULL, constructor, nargs, 0, obj, atom);
        if (!fun)
            goto bad;

        AutoValueRooter tvr2(cx, ObjectValue(*fun));
        if (!DefineStandardSlot(cx, obj, key, atom, tvr2.value(), 0, named))
            goto bad;

For the case of the Function class, the js_NewFunction call and functions it calls will not find proto in the reserved (standard) slot of the global (obj here) and therefore it will make an empty scope for Function, the constructor object. Then when we define the toSource method, we'll lazily create and share Function.prototype.emptyScope.

Might be fixable by reordering the two paragraphs shown above, with rooting removed (we don't need that any longer).

/be

Comment 1

[Brendan Eich [:brendan]]

If we do what bug 584648 comment 5 wants, though, this bug is moot (I hope).

/be