script_bindings/
wrap.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/. */
4use std::ffi::c_void;
5use std::ptr;
6
7use js::JSCLASS_IS_GLOBAL;
8use js::context::JSContext;
9use js::gc::{HandleObject, MutableHandleObject};
10use js::glue::SetProxyReservedSlot;
11use js::jsapi::{JS_SetReservedSlot, JSAutoRealm, JSClass, JSObject};
12use js::jsval::{PrivateValue, UndefinedValue};
13use js::rust::wrappers2::{
14    JS_CopyOwnPropertiesAndPrivateFields, JS_InitializePropertiesFromCompatibleNativeObject,
15    JS_NewObjectWithGivenProto, JS_WrapObject, NewProxyObject,
16};
17use js::rust::{Handle, get_context_realm, get_object_class, get_object_realm};
18
19use crate::codegen::PrototypeList;
20use crate::conversions::DOM_OBJECT_SLOT;
21use crate::import::module::JS_GetReservedSlot;
22use crate::proxyhandler::ensure_expando_object;
23use crate::root::{DomRoot, MaybeUnreflectedDom, Root};
24use crate::utils::DOM_PROTO_UNFORGEABLE_HOLDER_SLOT;
25use crate::weakref::DOM_WEAK_SLOT;
26use crate::{DomObject, DomTypes, MutDomObject};
27
28type ProtoObjectFn = fn(&mut js::context::JSContext, HandleObject, MutableHandleObject);
29
30/// TODO: unforgeable is missing
31pub(crate) struct WrapConfig {
32    pub(crate) is_maybe_cross_origin_object: bool,
33    pub(crate) is_proxy: bool,
34    pub(crate) weak_referenceable: bool,
35    pub(crate) proxy_handler: Option<*const c_void>,
36    pub(crate) prototype_id: PrototypeList::ID,
37    pub(crate) class: Option<&'static JSClass>,
38    // this function has to be more general because we do not have the correct type for globalscope.
39    pub(crate) proto_object_fn: ProtoObjectFn,
40    pub(crate) is_global: bool,
41    pub(crate) has_legacy_unforgeable_members: bool,
42}
43
44#[cfg_attr(crown, allow(crown::unrooted_must_root))]
45pub(crate) unsafe fn wrap<T: MutDomObject, D: DomTypes>(
46    cx: &mut JSContext,
47    scope: &D::GlobalScope,
48    given_proto: Option<js::rust::Handle<*mut JSObject>>,
49    object: Box<T>,
50    config: WrapConfig,
51) -> DomRoot<T> {
52    unsafe {
53        let raw = Root::new(MaybeUnreflectedDom::from_box(object));
54
55        let scope = scope.reflector().get_jsobject();
56        assert!(!scope.get().is_null());
57        assert!(((*get_object_class(scope.get())).flags & JSCLASS_IS_GLOBAL) != 0);
58        let _ac = JSAutoRealm::new(cx.raw_cx(), scope.get());
59
60        rooted!(&in(cx) let mut canonical_proto = ptr::null_mut::<JSObject>());
61        (config.proto_object_fn)(cx, scope, canonical_proto.handle_mut());
62        assert!(!canonical_proto.is_null());
63
64        rooted!(&in(cx) let mut obj = ptr::null_mut::<JSObject>());
65        if config.is_proxy {
66            let handler: *const libc::c_void = config.proxy_handler.unwrap();
67
68            if config.is_maybe_cross_origin_object {
69                obj.set(NewProxyObject(
70                    cx,
71                    handler,
72                    Handle::undefined(),
73                    ptr::null_mut(),
74                    ptr::null(),
75                    true,
76                ));
77            } else {
78                obj.set(NewProxyObject(
79                    cx,
80                    handler,
81                    Handle::undefined(),
82                    canonical_proto.get(),
83                    ptr::null(),
84                    false,
85                ));
86            };
87
88            assert!(!obj.is_null());
89            SetProxyReservedSlot(
90                obj.get(),
91                0,
92                &PrivateValue(raw.as_ptr() as *const libc::c_void),
93            );
94        } else {
95            rooted!(&in(cx) let mut proto = ptr::null_mut::<JSObject>());
96            if let Some(given) = given_proto {
97                proto.set(*given);
98                if get_context_realm(cx.raw_cx()) != get_object_realm(*given) {
99                    assert!(JS_WrapObject(cx, proto.handle_mut()));
100                }
101            } else {
102                proto.set(*canonical_proto);
103            }
104            obj.set(JS_NewObjectWithGivenProto(
105                cx,
106                config.class.unwrap(),
107                proto.handle(),
108            ));
109            assert!(!obj.is_null());
110            JS_SetReservedSlot(
111                obj.get(),
112                DOM_OBJECT_SLOT,
113                &PrivateValue(raw.as_ptr() as *const libc::c_void),
114            );
115        };
116
117        if config.weak_referenceable {
118            let val = PrivateValue(ptr::null());
119            JS_SetReservedSlot(obj.get(), DOM_WEAK_SLOT, &val);
120        }
121
122        let root = raw.reflect_with(obj.get());
123        root.reflector().set_proto_id(config.prototype_id as u16);
124
125        // From here on we copy the legacy unforgeable properties to instance which was originally in a different function.
126        if config.has_legacy_unforgeable_members {
127            rooted!(&in(cx) let mut expando = ptr::null_mut::<JSObject>());
128            if config.is_proxy {
129                ensure_expando_object(cx.raw_cx(), obj.handle().into(), expando.handle_mut());
130            }
131
132            let copy_fn = if config.is_global {
133                JS_CopyOwnPropertiesAndPrivateFields
134            } else {
135                JS_InitializePropertiesFromCompatibleNativeObject
136            };
137
138            let mut slot = UndefinedValue();
139            JS_GetReservedSlot(
140                canonical_proto.get(),
141                DOM_PROTO_UNFORGEABLE_HOLDER_SLOT,
142                &mut slot,
143            );
144            rooted!(&in(cx) let mut unforgeable_holder = ptr::null_mut::<JSObject>());
145            unforgeable_holder.handle_mut().set(slot.to_object());
146            if config.is_proxy {
147                assert!(copy_fn(cx, expando.handle(), unforgeable_holder.handle()));
148            } else {
149                assert!(copy_fn(cx, obj.handle(), unforgeable_holder.handle()));
150            }
151        }
152
153        DomRoot::from_ref(&*root)
154    }
155}
script_bindings/wrap.rs

script_bindings/
wrap.rs
