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

script_bindings/
wrap.rs
