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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at https://mozilla.org/MPL/2.0/. */
use js::context::JSContext;
use script_bindings::reflector::DomGlobalGeneric;
use script_bindings::root::DomRoot;
use crate::DomTypeHolder;
use crate::dom::types::GlobalScope;
use crate::realms::enter_auto_realm;
pub(crate) trait DomGlobal {
/// Returns the [relevant global] in the same realm as the callee object.
/// Will enter the realm of the global to ensure the global is only
/// accessed from the correct realm.
///
/// [relevant global]: https://html.spec.whatwg.org/multipage/#concept-relevant-global
fn global(&self) -> DomRoot<GlobalScope>;
}
impl<T: DomGlobalGeneric<DomTypeHolder>> DomGlobal for T {
#[expect(unsafe_code)]
fn global(&self) -> DomRoot<GlobalScope> {
// SAFETY: We only use this `cx` to enter a realm. That does not
// incur a GC and hence is safe to perform. We do not want to
// pass a `cx` as parameter to this function, as this used in
// loads of places. At the same time, it also isn't necessary in
// nearly all cases to enter realm, since we are already in the
// correct realm.
//
// However, there are cases where it is difficult to ensure that
// we are in the correct realm. Hence we always enter a realm here
// even if that is unnecessary at times.
let cx = unsafe { JSContext::get_from_thread() };
let cx = &mut cx.expect("JS runtime has shut down");
let _realm = enter_auto_realm(cx, self);
<Self as DomGlobalGeneric<DomTypeHolder>>::global_from_reflector(self)
}
}