Global inherits from %ObjectPrototype%

[bmeck]

This mandate is not in ES spec. It would be a mandate solely for frozen-realms and may cause oddities if the parent realm does not inherit from %ObjectPrototype%. Also keeps strange behaviors around like new constructor().

previous discussion at: https://esdiscuss.org/topic/proposal-revisions-draft-proposed-standard-ses-becomes-draft-proposed-frozen-realm-api#content-1

[erights]

The frozen realm omits all host objects and so is not considered a host-specific kind of realm. We should prefer more deterministic specs to less deterministic specs. Thus, we should specify what the frozen global inherits from, i.e., what the value of the frozen realm's global's [[Prototype]] is. If we do not specify that it is the frozen realm's %ObjectPrototype%, what value should we specify? What are the other plausible candidates?

The only plausible one that comes to mind is null. Would that be better? It would avoid the new constructor() weirdness. However, unless we add toString as a standard global property/variable, the global would not be stringable. Is there anything else normally on %ObjectPrototype% that we should add directly to the frozen global if we do have it inherit from null?

[caridy]

FYI, in the current spec text for this repo, neither spawned realms, and immutableRoot realms have a way to control the realm's [[GlobalObject]] internal slot, it will always be a newly created object of the newly created realm's %ObjectPrototype% intrinsic.

Although, when creating new realms via new Realm() you will have the ability to pass a target and a handler to create a proxy object that will be used as a [[GlobalObject]] of the new realm. More details here: https://rawgit.com/caridy/proposal-realms/master/index.html#sec-realm

[erights]

What needs to be said to ensure that the platform-created global is initialized only with things from the ES spec, and not with, e.g., any host-provided properties.

I think we need to state explicitly that https://tc39.github.io/ecma262/#sec-setdefaultglobalbindings must not add any properties other than "each property of the Global Object specified in clause 18,". Proposing that this be changed unconditionally in the language at 8.2.4 is best. If for some reason we can't get that, then we need to make sure that frozen realms engage a variant that does have this guarantee. Likewise with the initial state of all the objects that are magically created by the realm initialization mechanism.