gecko-dev/dom/bindings/CallbackFunction.h
Boris Zbarsky f771d7e529 Bug 1477923. Make WebIDL callbacks store a global in addition to the object that's used as a callback. r=mccr8
We want to be able to enter the Realm we were in when the callback was created
before calling it, but if the callback stores a cross-compartment wrapper we
don't really have a good way to find that Realm.  So we store it explicitly by
storing a global when the callback is created.

The changes to the constructor signatures to use JSObject* instead of
JS::Handle<JSObject*> are so we can avoid having to root the global for these
calls.  These changes make two of the constructors ambiguous when nullptr is
being passed for the first arg; this patch adds casts to disambiguate.
2018-08-03 17:11:39 -04:00

80 lines
2.4 KiB
C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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 http://mozilla.org/MPL/2.0/. */
/**
* A common base class for representing WebIDL callback function types in C++.
*
* This class implements common functionality like lifetime
* management, initialization with the callable, and setup of the call
* environment. Subclasses corresponding to particular callback
* function types should provide a Call() method that actually does
* the call.
*/
#ifndef mozilla_dom_CallbackFunction_h
#define mozilla_dom_CallbackFunction_h
#include "mozilla/dom/CallbackObject.h"
namespace mozilla {
namespace dom {
class CallbackFunction : public CallbackObject
{
public:
// See CallbackObject for an explanation of the arguments.
explicit CallbackFunction(JSContext* aCx, JS::Handle<JSObject*> aCallable,
JS::Handle<JSObject*> aCallableGlobal,
nsIGlobalObject* aIncumbentGlobal)
: CallbackObject(aCx, aCallable, aCallableGlobal, aIncumbentGlobal)
{
}
// See CallbackObject for an explanation of the arguments.
explicit CallbackFunction(JSObject* aCallable,
JSObject* aCallableGlobal,
JSObject* aAsyncStack,
nsIGlobalObject* aIncumbentGlobal)
: CallbackObject(aCallable, aCallableGlobal, aAsyncStack, aIncumbentGlobal)
{
}
JS::Handle<JSObject*> CallableOrNull() const
{
return CallbackOrNull();
}
JS::Handle<JSObject*> CallablePreserveColor() const
{
return CallbackPreserveColor();
}
bool HasGrayCallable() const
{
// Play it safe in case this gets called after unlink.
return mCallback && JS::ObjectIsMarkedGray(mCallback);
}
protected:
explicit CallbackFunction(CallbackFunction* aCallbackFunction)
: CallbackObject(aCallbackFunction)
{
}
// See CallbackObject for an explanation of the arguments.
CallbackFunction(JSObject* aCallable,
JSObject* aCallableGlobal,
const FastCallbackConstructor&)
: CallbackObject(aCallable, aCallableGlobal, FastCallbackConstructor())
{
}
};
} // namespace dom
} // namespace mozilla
#endif // mozilla_dom_CallbackFunction_h