This removes the requirement of having a global object that actually
inherits from JS::GlobalObject, which is now a perfectly valid scenario.
With the upcoming removal of wrapper objects in LibWeb, the HTML::Window
object will inherit from DOM::EventTarget, which means it cannot also
inherit from JS::GlobalObject.
Intrinsics, i.e. mostly constructor and prototype objects, but also
things like empty and new object shape now live on a new heap-allocated
JS::Intrinsics object, thus completing the long journey of taking all
the magic away from the global object.
This represents the Realm's [[Intrinsics]] slot in the spec and matches
its existing [[GlobalObject]] / [[GlobalEnv]] slots in terms of
architecture.
In the majority of cases it should now be possibly to fully allocate a
regular object without the global object existing, and in fact that's
what we do now - the realm is allocated before the global object, and
the intrinsics between both :^)
The existing implementation of this AO lives in Interpreter::create(),
which makes it impossible to use without also constructing an
Interpreter.
This patch adds a new Realm::initialize_host_defined_realm() and takes
the global object and global this customization steps as Function
callback objects. This will be used by LibWeb to create realms during
Document construction.
This helps make the overall codebase consistent. `class_name()` in
`Kernel` is always `StringView`, but not elsewhere.
Additionally, this results in the `strlen` (which needs to be done
when printing or other operations) always being computed at
compile-time.
This is just another workaround, but it should be much more reliable
than Interpreter::realm(), especially when allocating NativeFunctions
and ECMAScriptFunctionObjects: we're guaranteed to have a GlobalObject
at that point, and it likely was set as the GlobalObject of a Realm and
can lead us back to it. We're however not guaranteed that the VM can
give us an Interpreter, which is why functions in LibWeb can be a bit
crashy at the moment.
We use a WeakPtr<Realm> to properly handle the unlikely case where the
Realm goes away after associating a GlobalObject to it.
We'll always need _something_ of this sort if we want to support
OrdinaryFunctionCreate and CreateBuiltinFunction without the explicit
realm argument while no JS is running, because they want to use the
current Realm Record (always in the first and as fallback in the second
case).
