script/dom/bindings/
utils.rs

1/* This Source Code Form is subject to the terms of the Mozilla Public
2 * License, v. 2.0. If a copy of the MPL was not distributed with this
3 * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
4
5//! Various utilities to glue JavaScript and the DOM implementation together.
6
7use std::cell::RefCell;
8use std::thread::LocalKey;
9
10use js::context::JSContext;
11use js::glue::{IsWrapper, JSPrincipalsCallbacks, UnwrapObjectStatic};
12use js::jsapi::{CallArgs, DOMCallbacks, JSObject};
13use js::realm::CurrentRealm;
14use js::rust::{HandleObject, get_object_class, is_dom_class};
15use script_bindings::interfaces::{DomHelpers, Interface};
16use script_bindings::reflector::{DomObject, DomObjectWrap, reflect_dom_object_with_cx};
17use script_bindings::settings_stack::StackEntry;
18
19use crate::DomTypes;
20use crate::dom::bindings::codegen::{InterfaceObjectMap, PrototypeList};
21use crate::dom::bindings::constructor::call_html_constructor;
22use crate::dom::bindings::conversions::DerivedFrom;
23use crate::dom::bindings::error::{Error, report_pending_exception, throw_dom_exception};
24use crate::dom::bindings::principals::PRINCIPALS_CALLBACKS;
25use crate::dom::bindings::root::DomRoot;
26use crate::dom::bindings::settings_stack;
27use crate::dom::globalscope::GlobalScope;
28use crate::dom::windowproxy::WindowProxyHandler;
29use crate::script_thread::ScriptThread;
30
31#[derive(JSTraceable, MallocSizeOf)]
32/// Static data associated with a global object.
33pub(crate) struct GlobalStaticData {
34    #[ignore_malloc_size_of = "WindowProxyHandler does not properly implement it anyway"]
35    /// The WindowProxy proxy handler for this global.
36    pub(crate) windowproxy_handler: &'static WindowProxyHandler,
37}
38
39impl GlobalStaticData {
40    /// Creates a new GlobalStaticData.
41    pub(crate) fn new() -> GlobalStaticData {
42        GlobalStaticData {
43            windowproxy_handler: WindowProxyHandler::proxy_handler(),
44        }
45    }
46}
47
48pub(crate) use script_bindings::utils::*;
49
50/// Returns wether `obj` is a platform object using static unwrap
51/// <https://heycam.github.io/webidl/#dfn-platform-object>
52pub(crate) fn is_platform_object_static(obj: *mut JSObject) -> bool {
53    is_platform_object(obj, &|o| unsafe { UnwrapObjectStatic(o) })
54}
55
56fn is_platform_object(
57    obj: *mut JSObject,
58    unwrap_obj: &dyn Fn(*mut JSObject) -> *mut JSObject,
59) -> bool {
60    unsafe {
61        // Fast-path the common case
62        let mut clasp = get_object_class(obj);
63        if is_dom_class(&*clasp) {
64            return true;
65        }
66        // Now for simplicity check for security wrappers before anything else
67        if IsWrapper(obj) {
68            let unwrapped_obj = unwrap_obj(obj);
69            if unwrapped_obj.is_null() {
70                return false;
71            }
72            clasp = get_object_class(obj);
73        }
74        // TODO also check if JS_IsArrayBufferObject
75        is_dom_class(&*clasp)
76    }
77}
78
79unsafe extern "C" fn instance_class_has_proto_at_depth(
80    clasp: *const js::jsapi::JSClass,
81    proto_id: u32,
82    depth: u32,
83) -> bool {
84    let domclass: *const DOMJSClass = clasp as *const _;
85    let domclass = unsafe { &*domclass };
86    domclass.dom_class.interface_chain[depth as usize] as u32 == proto_id
87}
88
89/// <https://searchfox.org/mozilla-central/rev/c18faaae88b30182e487fa3341bc7d923e22f23a/xpcom/base/CycleCollectedJSRuntime.cpp#792>
90unsafe extern "C" fn instance_class_is_error(clasp: *const js::jsapi::JSClass) -> bool {
91    if !is_dom_class(unsafe { &*clasp }) {
92        return false;
93    }
94    let domclass: *const DOMJSClass = clasp as *const _;
95    let domclass = unsafe { &*domclass };
96    let root_interface = domclass.dom_class.interface_chain[0] as u32;
97    // TODO: support checking bare Exception prototype as well.
98    root_interface == PrototypeList::ID::DOMException as u32
99}
100
101pub(crate) const DOM_CALLBACKS: DOMCallbacks = DOMCallbacks {
102    instanceClassMatchesProto: Some(instance_class_has_proto_at_depth),
103    instanceClassIsError: Some(instance_class_is_error),
104};
105
106/// Eagerly define all relevant WebIDL interface constructors on the
107/// provided global object.
108pub(crate) fn define_all_exposed_interfaces(cx: &mut CurrentRealm, global: &GlobalScope) {
109    for (_, interface) in &InterfaceObjectMap::MAP {
110        (interface.define)(cx, global.reflector().get_jsobject());
111    }
112}
113
114impl DomHelpers<crate::DomTypeHolder> for crate::DomTypeHolder {
115    fn throw_dom_exception(
116        cx: &mut JSContext,
117        global: &<crate::DomTypeHolder as DomTypes>::GlobalScope,
118        result: Error,
119    ) {
120        throw_dom_exception(cx, global, result)
121    }
122
123    fn call_html_constructor<
124        T: DerivedFrom<<crate::DomTypeHolder as DomTypes>::Element> + DomObject,
125    >(
126        cx: &mut JSContext,
127        args: &CallArgs,
128        global: &<crate::DomTypeHolder as DomTypes>::GlobalScope,
129        proto_id: PrototypeList::ID,
130        creator: unsafe fn(&mut JSContext, HandleObject, *mut ProtoOrIfaceArray),
131    ) -> bool {
132        call_html_constructor::<T>(cx, args, global, proto_id, creator)
133    }
134
135    fn settings_stack() -> &'static LocalKey<RefCell<Vec<StackEntry<crate::DomTypeHolder>>>> {
136        &settings_stack::STACK
137    }
138
139    fn principals_callbacks() -> &'static JSPrincipalsCallbacks {
140        &PRINCIPALS_CALLBACKS
141    }
142
143    fn interface_map() -> &'static phf::Map<&'static [u8], Interface> {
144        &InterfaceObjectMap::MAP
145    }
146
147    fn push_new_element_queue() {
148        ScriptThread::custom_element_reaction_stack().push_new_element_queue()
149    }
150    fn pop_current_element_queue(cx: &mut JSContext) {
151        ScriptThread::custom_element_reaction_stack().pop_current_element_queue(cx)
152    }
153
154    fn reflect_dom_object_with_cx<T, U>(cx: &mut JSContext, obj: Box<T>, global: &U) -> DomRoot<T>
155    where
156        T: DomObject + DomObjectWrap<crate::DomTypeHolder>,
157        U: DerivedFrom<GlobalScope>,
158    {
159        reflect_dom_object_with_cx(obj, global, cx)
160    }
161
162    fn report_pending_exception(cx: &mut CurrentRealm) {
163        report_pending_exception(cx)
164    }
165}
script/dom/bindings/utils.rs

script/dom/bindings/
utils.rs
