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::conversions::ToJSValConvertible;
11use js::glue::{IsWrapper, JSPrincipalsCallbacks, UnwrapObjectDynamic, UnwrapObjectStatic};
12use js::jsapi::{
13    CallArgs, DOMCallbacks, HandleObject as RawHandleObject, JS_FreezeObject, JSContext, JSObject,
14};
15use js::realm::CurrentRealm;
16use js::rust::{HandleObject, MutableHandleValue, get_object_class, is_dom_class};
17use script_bindings::interfaces::{DomHelpers, Interface};
18use script_bindings::settings_stack::StackEntry;
19
20use crate::DomTypes;
21use crate::dom::bindings::codegen::{InterfaceObjectMap, PrototypeList};
22use crate::dom::bindings::constructor::call_html_constructor;
23use crate::dom::bindings::conversions::DerivedFrom;
24use crate::dom::bindings::error::{Error, report_pending_exception, throw_dom_exception};
25use crate::dom::bindings::principals::PRINCIPALS_CALLBACKS;
26use crate::dom::bindings::proxyhandler::is_platform_object_same_origin;
27use crate::dom::bindings::reflector::{DomObject, DomObjectWrap, reflect_dom_object};
28use crate::dom::bindings::root::DomRoot;
29use crate::dom::bindings::settings_stack;
30use crate::dom::globalscope::GlobalScope;
31use crate::dom::windowproxy::WindowProxyHandler;
32use crate::realms::InRealm;
33use crate::script_runtime::{CanGc, JSContext as SafeJSContext};
34use crate::script_thread::ScriptThread;
35
36#[derive(JSTraceable, MallocSizeOf)]
37/// Static data associated with a global object.
38pub(crate) struct GlobalStaticData {
39    #[ignore_malloc_size_of = "WindowProxyHandler does not properly implement it anyway"]
40    /// The WindowProxy proxy handler for this global.
41    pub(crate) windowproxy_handler: &'static WindowProxyHandler,
42}
43
44impl GlobalStaticData {
45    /// Creates a new GlobalStaticData.
46    pub(crate) fn new() -> GlobalStaticData {
47        GlobalStaticData {
48            windowproxy_handler: WindowProxyHandler::proxy_handler(),
49        }
50    }
51}
52
53pub(crate) use script_bindings::utils::*;
54
55/// Returns a JSVal representing the frozen JavaScript array
56pub(crate) fn to_frozen_array<T: ToJSValConvertible>(
57    convertibles: &[T],
58    cx: SafeJSContext,
59    mut rval: MutableHandleValue,
60    can_gc: CanGc,
61) {
62    script_bindings::conversions::SafeToJSValConvertible::safe_to_jsval(
63        convertibles,
64        cx,
65        rval.reborrow(),
66        can_gc,
67    );
68
69    rooted!(in(*cx) let obj = rval.to_object());
70    unsafe { JS_FreezeObject(*cx, RawHandleObject::from(obj.handle())) };
71}
72
73/// Returns wether `obj` is a platform object using dynamic unwrap
74/// <https://heycam.github.io/webidl/#dfn-platform-object>
75#[expect(dead_code)]
76pub(crate) fn is_platform_object_dynamic(obj: *mut JSObject, cx: *mut JSContext) -> bool {
77    is_platform_object(obj, &|o| unsafe {
78        UnwrapObjectDynamic(o, cx, /* stopAtWindowProxy = */ false)
79    })
80}
81
82/// Returns wether `obj` is a platform object using static unwrap
83/// <https://heycam.github.io/webidl/#dfn-platform-object>
84pub(crate) fn is_platform_object_static(obj: *mut JSObject) -> bool {
85    is_platform_object(obj, &|o| unsafe { UnwrapObjectStatic(o) })
86}
87
88fn is_platform_object(
89    obj: *mut JSObject,
90    unwrap_obj: &dyn Fn(*mut JSObject) -> *mut JSObject,
91) -> bool {
92    unsafe {
93        // Fast-path the common case
94        let mut clasp = get_object_class(obj);
95        if is_dom_class(&*clasp) {
96            return true;
97        }
98        // Now for simplicity check for security wrappers before anything else
99        if IsWrapper(obj) {
100            let unwrapped_obj = unwrap_obj(obj);
101            if unwrapped_obj.is_null() {
102                return false;
103            }
104            clasp = get_object_class(obj);
105        }
106        // TODO also check if JS_IsArrayBufferObject
107        is_dom_class(&*clasp)
108    }
109}
110
111unsafe extern "C" fn instance_class_has_proto_at_depth(
112    clasp: *const js::jsapi::JSClass,
113    proto_id: u32,
114    depth: u32,
115) -> bool {
116    let domclass: *const DOMJSClass = clasp as *const _;
117    let domclass = unsafe { &*domclass };
118    domclass.dom_class.interface_chain[depth as usize] as u32 == proto_id
119}
120
121/// <https://searchfox.org/mozilla-central/rev/c18faaae88b30182e487fa3341bc7d923e22f23a/xpcom/base/CycleCollectedJSRuntime.cpp#792>
122unsafe extern "C" fn instance_class_is_error(clasp: *const js::jsapi::JSClass) -> bool {
123    if !is_dom_class(unsafe { &*clasp }) {
124        return false;
125    }
126    let domclass: *const DOMJSClass = clasp as *const _;
127    let domclass = unsafe { &*domclass };
128    let root_interface = domclass.dom_class.interface_chain[0] as u32;
129    // TODO: support checking bare Exception prototype as well.
130    root_interface == PrototypeList::ID::DOMException as u32
131}
132
133pub(crate) const DOM_CALLBACKS: DOMCallbacks = DOMCallbacks {
134    instanceClassMatchesProto: Some(instance_class_has_proto_at_depth),
135    instanceClassIsError: Some(instance_class_is_error),
136};
137
138/// Eagerly define all relevant WebIDL interface constructors on the
139/// provided global object.
140pub(crate) fn define_all_exposed_interfaces(cx: &mut CurrentRealm, global: &GlobalScope) {
141    for (_, interface) in &InterfaceObjectMap::MAP {
142        (interface.define)(cx, global.reflector().get_jsobject());
143    }
144}
145
146impl DomHelpers<crate::DomTypeHolder> for crate::DomTypeHolder {
147    fn throw_dom_exception(
148        cx: SafeJSContext,
149        global: &<crate::DomTypeHolder as DomTypes>::GlobalScope,
150        result: Error,
151        can_gc: CanGc,
152    ) {
153        throw_dom_exception(cx, global, result, can_gc)
154    }
155
156    fn call_html_constructor<
157        T: DerivedFrom<<crate::DomTypeHolder as DomTypes>::Element> + DomObject,
158    >(
159        cx: &mut js::context::JSContext,
160        args: &CallArgs,
161        global: &<crate::DomTypeHolder as DomTypes>::GlobalScope,
162        proto_id: PrototypeList::ID,
163        creator: unsafe fn(SafeJSContext, HandleObject, *mut ProtoOrIfaceArray),
164    ) -> bool {
165        call_html_constructor::<T>(cx, args, global, proto_id, creator)
166    }
167
168    fn settings_stack() -> &'static LocalKey<RefCell<Vec<StackEntry<crate::DomTypeHolder>>>> {
169        &settings_stack::STACK
170    }
171
172    fn principals_callbacks() -> &'static JSPrincipalsCallbacks {
173        &PRINCIPALS_CALLBACKS
174    }
175
176    fn is_platform_object_same_origin(cx: &CurrentRealm, obj: RawHandleObject) -> bool {
177        unsafe { is_platform_object_same_origin(cx, obj) }
178    }
179
180    fn interface_map() -> &'static phf::Map<&'static [u8], Interface> {
181        &InterfaceObjectMap::MAP
182    }
183
184    fn push_new_element_queue() {
185        ScriptThread::custom_element_reaction_stack().push_new_element_queue()
186    }
187    fn pop_current_element_queue(can_gc: CanGc) {
188        ScriptThread::custom_element_reaction_stack().pop_current_element_queue(can_gc)
189    }
190
191    fn reflect_dom_object<T, U>(obj: Box<T>, global: &U, can_gc: CanGc) -> DomRoot<T>
192    where
193        T: DomObject + DomObjectWrap<crate::DomTypeHolder>,
194        U: DerivedFrom<GlobalScope>,
195    {
196        reflect_dom_object(obj, global, can_gc)
197    }
198
199    fn report_pending_exception(
200        cx: SafeJSContext,
201        dispatch_event: bool,
202        realm: InRealm,
203        can_gc: CanGc,
204    ) {
205        report_pending_exception(cx, dispatch_event, realm, can_gc)
206    }
207}
script/dom/bindings/utils.rs

script/dom/bindings/
utils.rs
