From 6bf0a5cb5034a7e684dcc3500e841785237ce2dd Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 19:32:43 +0200 Subject: Adding upstream version 1:115.7.0. Signed-off-by: Daniel Baumann --- js/public/friend/WindowProxy.h | 105 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 105 insertions(+) create mode 100644 js/public/friend/WindowProxy.h (limited to 'js/public/friend/WindowProxy.h') diff --git a/js/public/friend/WindowProxy.h b/js/public/friend/WindowProxy.h new file mode 100644 index 0000000000..9023e9e96b --- /dev/null +++ b/js/public/friend/WindowProxy.h @@ -0,0 +1,105 @@ +/* -*- 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/. */ + +/* + * Window and WindowProxy. + * + * For silly obscure reasons embedders are better off not knowing, the web wants + * every global object to exist as two linked components: a Window component + * that stores global variables and appears in environment chains but can't be + * directly referred to by any script, and a WindowProxy component that + * intermediates access to its Window that *can* be directly referred to by + * script. (Thus the global |window| and |globalThis| properties, |this| in + * global code, the value of |(function() { return this; })()| in non-strict + * mode code, and similar values are WindowProxy objects, not Windows.) + * + * Maintaining an invariant of never exposing a Window to script requires + * substituting in its WindowProxy in a variety of apparently arbitrary (but + * actually *very* carefully and nervously selected) places throughout the + * engine and indeed the universe. + * + * This header defines functions that let embeddings convert from a WindowProxy + * to its Window and vice versa. + * + * If you're not embedding SpiderMonkey in a web browser, you can almost + * certainly ignore this header. + */ + +#ifndef js_friend_WindowProxy_h +#define js_friend_WindowProxy_h + +#include "jstypes.h" // JS_PUBLIC_API + +#include "js/Class.h" // JSCLASS_IS_GLOBAL +#include "js/Object.h" // JS::GetClass +#include "js/RootingAPI.h" // JS::Handle + +struct JS_PUBLIC_API JSContext; +class JS_PUBLIC_API JSObject; + +namespace js { + +/** + * Tell the JS engine which Class is used for WindowProxy objects. Used by the + * functions below. + */ +extern JS_PUBLIC_API void SetWindowProxyClass(JSContext* cx, + const JSClass* clasp); + +/** + * Associates a WindowProxy with a Window (global object). `windowProxy` must + * have the Class set by SetWindowProxyClass. + */ +extern JS_PUBLIC_API void SetWindowProxy(JSContext* cx, + JS::Handle global, + JS::Handle windowProxy); + +namespace detail { + +extern JS_PUBLIC_API bool IsWindowSlow(JSObject* obj); + +extern JS_PUBLIC_API JSObject* ToWindowProxyIfWindowSlow(JSObject* obj); + +} // namespace detail + +/** + * Returns true iff `obj` is a global object with an associated WindowProxy, + * see SetWindowProxy. + */ +inline bool IsWindow(JSObject* obj) { + if (JS::GetClass(obj)->flags & JSCLASS_IS_GLOBAL) { + return detail::IsWindowSlow(obj); + } + return false; +} + +/** + * Returns true iff `obj` has the WindowProxy Class (see SetWindowProxyClass). + */ +extern JS_PUBLIC_API bool IsWindowProxy(JSObject* obj); + +/** + * If `obj` is a Window, get its associated WindowProxy (or a CCW or dead + * wrapper if the page was navigated away from), else return `obj`. This + * function is infallible and never returns nullptr. + */ +MOZ_ALWAYS_INLINE JSObject* ToWindowProxyIfWindow(JSObject* obj) { + if (JS::GetClass(obj)->flags & JSCLASS_IS_GLOBAL) { + return detail::ToWindowProxyIfWindowSlow(obj); + } + return obj; +} + +/** + * If `obj` is a WindowProxy, get its associated Window (the compartment's + * global), else return `obj`. This function is infallible and never returns + * nullptr. + */ +extern JS_PUBLIC_API JSObject* ToWindowIfWindowProxy(JSObject* obj); + +} // namespace js + +#endif // js_friend_WindowProxy_h -- cgit v1.2.3