More miscellaneous script splitting changes (#36220)

* script: Move HasParent to script_bindings and update imports for InheritTypes. Signed-off-by: Josh Matthews <josh@joshmatthews.net> * script: Make principal creation generic over DOM interface. Signed-off-by: Josh Matthews <josh@joshmatthews.net> * script: Move a bunch of proxy-related code to script_bindings. Signed-off-by: Josh Matthews <josh@joshmatthews.net> * script: Make some proxy-related code generic over the DOM interface. Signed-off-by: Josh Matthews <josh@joshmatthews.net> * script: Move DomSlice to script_bindings. Signed-off-by: Josh Matthews <josh@joshmatthews.net> * script: Move some utility bindings code to script_bindings. Signed-off-by: Josh Matthews <josh@joshmatthews.net> * script: Make enumerating and resolving globals generic over the DOM interface. Signed-off-by: Josh Matthews <josh@joshmatthews.net> * script: Make realm helpers generic over the DOM interface. Signed-off-by: Josh Matthews <josh@joshmatthews.net> * script: Move implementations on concrete DOM types to concrete bindings. Signed-off-by: Josh Matthews <josh@joshmatthews.net> * script: Make additional codegen helpers generic over the DOM interface. Signed-off-by: Josh Matthews <josh@joshmatthews.net> * script: Make iterator creation generic over the DOM interface. Signed-off-by: Josh Matthews <josh@joshmatthews.net> * script: Make reporting an exception a generic operation. Signed-off-by: Josh Matthews <josh@joshmatthews.net> * script: Move AsCCharPtrPtr to script_bindings. Signed-off-by: Josh Matthews <josh@joshmatthews.net> * Formatting. Signed-off-by: Josh Matthews <josh@joshmatthews.net> * Address clippy warnings. Signed-off-by: Josh Matthews <josh@joshmatthews.net> --------- Signed-off-by: Josh Matthews <josh@joshmatthews.net>
2025-08-05 21:50:18 +01:00 · 2025-03-30 07:06:30 -04:00 · 2025-03-30 07:06:30 -04:00 · b445053a7c
commit b445053a7c
parent 971490084e
33 changed files with 806 additions and 628 deletions
--- a/components/script_bindings/proxyhandler.rs
+++ b/components/script_bindings/proxyhandler.rs
@ -0,0 +1,494 @@
+/* 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 https://mozilla.org/MPL/2.0/. */
+
+//! Utilities for the implementation of JSAPI proxy handlers.
+
+use std::ffi::CStr;
+use std::os::raw::c_char;
+use std::ptr;
+
+use js::glue::{GetProxyHandlerFamily, GetProxyPrivate, SetProxyPrivate};
+use js::jsapi::{
+    DOMProxyShadowsResult, GetStaticPrototype, GetWellKnownSymbol, Handle as RawHandle,
+    HandleId as RawHandleId, HandleObject as RawHandleObject, JS_AtomizeAndPinString,
+    JS_DefinePropertyById, JS_GetOwnPropertyDescriptorById, JSContext, JSErrNum, JSFunctionSpec,
+    JSObject, JSPropertySpec, MutableHandle as RawMutableHandle,
+    MutableHandleIdVector as RawMutableHandleIdVector,
+    MutableHandleObject as RawMutableHandleObject, ObjectOpResult, PropertyDescriptor,
+    SetDOMProxyInformation, SymbolCode, jsid,
+};
+use js::jsid::SymbolId;
+use js::jsval::{ObjectValue, UndefinedValue};
+use js::rust::wrappers::{
+    AppendToIdVector, JS_AlreadyHasOwnPropertyById, JS_NewObjectWithGivenProto,
+    RUST_INTERNED_STRING_TO_JSID, SetDataPropertyDescriptor,
+};
+use js::rust::{Handle, HandleObject, HandleValue, MutableHandle, MutableHandleObject};
+use js::{jsapi, rooted};
+
+use crate::conversions::{is_dom_proxy, jsid_to_string, jsstring_to_str};
+use crate::script_runtime::JSContext as SafeJSContext;
+use crate::str::DOMString;
+use crate::utils::delete_property_by_id;
+
+/// Determine if this id shadows any existing properties for this proxy.
+///
+/// # Safety
+/// `cx` must point to a valid, non-null JSContext.
+pub unsafe extern "C" fn shadow_check_callback(
+    cx: *mut JSContext,
+    object: RawHandleObject,
+    id: RawHandleId,
+) -> DOMProxyShadowsResult {
+    // TODO: support OverrideBuiltins when #12978 is fixed.
+
+    rooted!(in(cx) let mut expando = ptr::null_mut::<JSObject>());
+    get_expando_object(object, expando.handle_mut());
+    if !expando.get().is_null() {
+        let mut has_own = false;
+        let raw_id = Handle::from_raw(id);
+
+        if !JS_AlreadyHasOwnPropertyById(cx, expando.handle(), raw_id, &mut has_own) {
+            return DOMProxyShadowsResult::ShadowCheckFailed;
+        }
+
+        if has_own {
+            return DOMProxyShadowsResult::ShadowsViaDirectExpando;
+        }
+    }
+
+    // Our expando, if any, didn't shadow, so we're not shadowing at all.
+    DOMProxyShadowsResult::DoesntShadow
+}
+
+/// Initialize the infrastructure for DOM proxy objects.
+pub fn init() {
+    unsafe {
+        SetDOMProxyInformation(
+            GetProxyHandlerFamily(),
+            Some(shadow_check_callback),
+            ptr::null(),
+        );
+    }
+}
+
+/// Defines an expando on the given `proxy`.
+///
+/// # Safety
+/// `cx` must point to a valid, non-null JSContext.
+/// `result` must point to a valid, non-null ObjectOpResult.
+pub unsafe extern "C" fn define_property(
+    cx: *mut JSContext,
+    proxy: RawHandleObject,
+    id: RawHandleId,
+    desc: RawHandle<PropertyDescriptor>,
+    result: *mut ObjectOpResult,
+) -> bool {
+    rooted!(in(cx) let mut expando = ptr::null_mut::<JSObject>());
+    ensure_expando_object(cx, proxy, expando.handle_mut());
+    JS_DefinePropertyById(cx, expando.handle().into(), id, desc, result)
+}
+
+/// Deletes an expando off the given `proxy`.
+///
+/// # Safety
+/// `cx` must point to a valid, non-null JSContext.
+/// `bp` must point to a valid, non-null ObjectOpResult.
+pub unsafe extern "C" fn delete(
+    cx: *mut JSContext,
+    proxy: RawHandleObject,
+    id: RawHandleId,
+    bp: *mut ObjectOpResult,
+) -> bool {
+    rooted!(in(cx) let mut expando = ptr::null_mut::<JSObject>());
+    get_expando_object(proxy, expando.handle_mut());
+    if expando.is_null() {
+        (*bp).code_ = 0 /* OkCode */;
+        return true;
+    }
+
+    delete_property_by_id(cx, expando.handle(), Handle::from_raw(id), bp)
+}
+
+/// Controls whether the Extensible bit can be changed
+///
+/// # Safety
+/// `result` must point to a valid, non-null ObjectOpResult.
+pub unsafe extern "C" fn prevent_extensions(
+    _cx: *mut JSContext,
+    _proxy: RawHandleObject,
+    result: *mut ObjectOpResult,
+) -> bool {
+    (*result).code_ = JSErrNum::JSMSG_CANT_PREVENT_EXTENSIONS as ::libc::uintptr_t;
+    true
+}
+
+/// Reports whether the object is Extensible
+///
+/// # Safety
+/// `succeeded` must point to a valid, non-null bool.
+pub unsafe extern "C" fn is_extensible(
+    _cx: *mut JSContext,
+    _proxy: RawHandleObject,
+    succeeded: *mut bool,
+) -> bool {
+    *succeeded = true;
+    true
+}
+
+/// If `proxy` (underneath any functionally-transparent wrapper proxies) has as
+/// its `[[GetPrototypeOf]]` trap the ordinary `[[GetPrototypeOf]]` behavior
+/// defined for ordinary objects, set `*is_ordinary` to true and store `obj`'s
+/// prototype in `proto`.  Otherwise set `*isOrdinary` to false. In case of
+/// error, both outparams have unspecified value.
+///
+/// This implementation always handles the case of the ordinary
+/// `[[GetPrototypeOf]]` behavior. An alternative implementation will be
+/// necessary for maybe-cross-origin objects.
+///
+/// # Safety
+/// `is_ordinary` must point to a valid, non-null bool.
+pub unsafe extern "C" fn get_prototype_if_ordinary(
+    _: *mut JSContext,
+    proxy: RawHandleObject,
+    is_ordinary: *mut bool,
+    proto: RawMutableHandleObject,
+) -> bool {
+    *is_ordinary = true;
+    proto.set(GetStaticPrototype(proxy.get()));
+    true
+}
+
+/// Get the expando object, or null if there is none.
+pub fn get_expando_object(obj: RawHandleObject, mut expando: MutableHandleObject) {
+    unsafe {
+        assert!(is_dom_proxy(obj.get()));
+        let val = &mut UndefinedValue();
+        GetProxyPrivate(obj.get(), val);
+        expando.set(if val.is_undefined() {
+            ptr::null_mut()
+        } else {
+            val.to_object()
+        });
+    }
+}
+
+/// Get the expando object, or create it if it doesn't exist yet.
+/// Fails on JSAPI failure.
+///
+/// # Safety
+/// `cx` must point to a valid, non-null JSContext.
+pub unsafe fn ensure_expando_object(
+    cx: *mut JSContext,
+    obj: RawHandleObject,
+    mut expando: MutableHandleObject,
+) {
+    assert!(is_dom_proxy(obj.get()));
+    get_expando_object(obj, expando.reborrow());
+    if expando.is_null() {
+        expando.set(JS_NewObjectWithGivenProto(
+            cx,
+            ptr::null_mut(),
+            HandleObject::null(),
+        ));
+        assert!(!expando.is_null());
+
+        SetProxyPrivate(obj.get(), &ObjectValue(expando.get()));
+    }
+}
+
+/// Set the property descriptor's object to `obj` and set it to enumerable,
+/// and writable if `readonly` is true.
+pub fn set_property_descriptor(
+    desc: MutableHandle<PropertyDescriptor>,
+    value: HandleValue,
+    attrs: u32,
+    is_none: &mut bool,
+) {
+    unsafe {
+        SetDataPropertyDescriptor(desc, value, attrs);
+    }
+    *is_none = false;
+}
+
+pub fn id_to_source(cx: SafeJSContext, id: RawHandleId) -> Option<DOMString> {
+    unsafe {
+        rooted!(in(*cx) let mut value = UndefinedValue());
+        rooted!(in(*cx) let mut jsstr = ptr::null_mut::<jsapi::JSString>());
+        jsapi::JS_IdToValue(*cx, id.get(), value.handle_mut().into())
+            .then(|| {
+                jsstr.set(jsapi::JS_ValueToSource(*cx, value.handle().into()));
+                jsstr.get()
+            })
+            .and_then(ptr::NonNull::new)
+            .map(|jsstr| jsstring_to_str(*cx, jsstr))
+    }
+}
+
+/// Property and method specs that correspond to the elements of
+/// [`CrossOriginProperties(O)`].
+///
+/// [`CrossOriginProperties(O)`]: https://html.spec.whatwg.org/multipage/#crossoriginproperties-(-o-)
+pub struct CrossOriginProperties {
+    pub attributes: &'static [JSPropertySpec],
+    pub methods: &'static [JSFunctionSpec],
+}
+
+impl CrossOriginProperties {
+    /// Enumerate the property keys defined by `self`.
+    fn keys(&self) -> impl Iterator<Item = *const c_char> + '_ {
+        // Safety: All cross-origin property keys are strings, not symbols
+        self.attributes
+            .iter()
+            .map(|spec| unsafe { spec.name.string_ })
+            .chain(self.methods.iter().map(|spec| unsafe { spec.name.string_ }))
+            .filter(|ptr| !ptr.is_null())
+    }
+}
+
+/// Implementation of [`CrossOriginOwnPropertyKeys`].
+///
+/// [`CrossOriginOwnPropertyKeys`]: https://html.spec.whatwg.org/multipage/#crossoriginownpropertykeys-(-o-)
+pub fn cross_origin_own_property_keys(
+    cx: SafeJSContext,
+    _proxy: RawHandleObject,
+    cross_origin_properties: &'static CrossOriginProperties,
+    props: RawMutableHandleIdVector,
+) -> bool {
+    // > 2. For each `e` of `! CrossOriginProperties(O)`, append
+    // >    `e.[[Property]]` to `keys`.
+    for key in cross_origin_properties.keys() {
+        unsafe {
+            rooted!(in(*cx) let rooted = JS_AtomizeAndPinString(*cx, key));
+            rooted!(in(*cx) let mut rooted_jsid: jsid);
+            RUST_INTERNED_STRING_TO_JSID(*cx, rooted.handle().get(), rooted_jsid.handle_mut());
+            AppendToIdVector(props, rooted_jsid.handle());
+        }
+    }
+
+    // > 3. Return the concatenation of `keys` and `« "then", @@toStringTag,
+    // > @@hasInstance, @@isConcatSpreadable »`.
+    append_cross_origin_allowlisted_prop_keys(cx, props);
+
+    true
+}
+
+/// # Safety
+/// `is_ordinary` must point to a valid, non-null bool.
+pub unsafe extern "C" fn maybe_cross_origin_get_prototype_if_ordinary_rawcx(
+    _: *mut JSContext,
+    _proxy: RawHandleObject,
+    is_ordinary: *mut bool,
+    _proto: RawMutableHandleObject,
+) -> bool {
+    // We have a custom `[[GetPrototypeOf]]`, so return `false`
+    *is_ordinary = false;
+    true
+}
+
+/// Implementation of `[[SetPrototypeOf]]` for [`Location`] and [`WindowProxy`].
+///
+/// [`Location`]: https://html.spec.whatwg.org/multipage/#location-setprototypeof
+/// [`WindowProxy`]: https://html.spec.whatwg.org/multipage/#windowproxy-setprototypeof
+///
+/// # Safety
+/// `result` must point to a valid, non-null ObjectOpResult.
+pub unsafe extern "C" fn maybe_cross_origin_set_prototype_rawcx(
+    cx: *mut JSContext,
+    proxy: RawHandleObject,
+    proto: RawHandleObject,
+    result: *mut ObjectOpResult,
+) -> bool {
+    // > 1. Return `! SetImmutablePrototype(this, V)`.
+    //
+    // <https://tc39.es/ecma262/#sec-set-immutable-prototype>:
+    //
+    // > 1. Assert: Either `Type(V)` is Object or `Type(V)` is Null.
+    //
+    // > 2. Let current be `? O.[[GetPrototypeOf]]()`.
+    rooted!(in(cx) let mut current = ptr::null_mut::<JSObject>());
+    if !jsapi::GetObjectProto(cx, proxy, current.handle_mut().into()) {
+        return false;
+    }
+
+    // > 3. If `SameValue(V, current)` is true, return true.
+    if proto.get() == current.get() {
+        (*result).code_ = 0 /* OkCode */;
+        return true;
+    }
+
+    // > 4. Return false.
+    (*result).code_ = JSErrNum::JSMSG_CANT_SET_PROTO as usize;
+    true
+}
+
+pub fn get_getter_object(d: &PropertyDescriptor, out: RawMutableHandleObject) {
+    if d.hasGetter_() {
+        out.set(d.getter_);
+    }
+}
+
+pub fn get_setter_object(d: &PropertyDescriptor, out: RawMutableHandleObject) {
+    if d.hasSetter_() {
+        out.set(d.setter_);
+    }
+}
+
+/// <https://tc39.es/ecma262/#sec-isaccessordescriptor>
+pub fn is_accessor_descriptor(d: &PropertyDescriptor) -> bool {
+    d.hasSetter_() || d.hasGetter_()
+}
+
+/// <https://tc39.es/ecma262/#sec-isdatadescriptor>
+pub fn is_data_descriptor(d: &PropertyDescriptor) -> bool {
+    d.hasWritable_() || d.hasValue_()
+}
+
+/// Evaluate `CrossOriginGetOwnPropertyHelper(proxy, id) != null`.
+/// SpiderMonkey-specific.
+///
+/// `cx` and `proxy` are expected to be different-Realm here. `proxy` is a proxy
+/// for a maybe-cross-origin object.
+///
+/// # Safety
+/// `bp` must point to a valid, non-null bool.
+pub unsafe fn cross_origin_has_own(
+    cx: SafeJSContext,
+    _proxy: RawHandleObject,
+    cross_origin_properties: &'static CrossOriginProperties,
+    id: RawHandleId,
+    bp: *mut bool,
+) -> bool {
+    // TODO: Once we have the slot for the holder, it'd be more efficient to
+    //       use `ensure_cross_origin_property_holder`. We'll need `_proxy` to
+    //       do that.
+    *bp = jsid_to_string(*cx, Handle::from_raw(id)).is_some_and(|key| {
+        cross_origin_properties.keys().any(|defined_key| {
+            let defined_key = CStr::from_ptr(defined_key);
+            defined_key.to_bytes() == key.as_bytes()
+        })
+    });
+
+    true
+}
+
+/// Implementation of [`CrossOriginGetOwnPropertyHelper`].
+///
+/// `cx` and `proxy` are expected to be different-Realm here. `proxy` is a proxy
+/// for a maybe-cross-origin object.
+///
+/// [`CrossOriginGetOwnPropertyHelper`]: https://html.spec.whatwg.org/multipage/#crossorigingetownpropertyhelper-(-o,-p-)
+pub fn cross_origin_get_own_property_helper(
+    cx: SafeJSContext,
+    proxy: RawHandleObject,
+    cross_origin_properties: &'static CrossOriginProperties,
+    id: RawHandleId,
+    desc: RawMutableHandle<PropertyDescriptor>,
+    is_none: &mut bool,
+) -> bool {
+    rooted!(in(*cx) let mut holder = ptr::null_mut::<JSObject>());
+
+    ensure_cross_origin_property_holder(
+        cx,
+        proxy,
+        cross_origin_properties,
+        holder.handle_mut().into(),
+    );
+
+    unsafe { JS_GetOwnPropertyDescriptorById(*cx, holder.handle().into(), id, desc, is_none) }
+}
+
+const ALLOWLISTED_SYMBOL_CODES: &[SymbolCode] = &[
+    SymbolCode::toStringTag,
+    SymbolCode::hasInstance,
+    SymbolCode::isConcatSpreadable,
+];
+
+pub fn is_cross_origin_allowlisted_prop(cx: SafeJSContext, id: RawHandleId) -> bool {
+    unsafe {
+        if jsid_to_string(*cx, Handle::from_raw(id)).is_some_and(|st| st == "then") {
+            return true;
+        }
+
+        rooted!(in(*cx) let mut allowed_id: jsid);
+        ALLOWLISTED_SYMBOL_CODES.iter().any(|&allowed_code| {
+            allowed_id.set(SymbolId(GetWellKnownSymbol(*cx, allowed_code)));
+            // `jsid`s containing `JS::Symbol *` can be compared by
+            // referential equality
+            allowed_id.get().asBits_ == id.asBits_
+        })
+    }
+}
+
+/// Append `« "then", @@toStringTag, @@hasInstance, @@isConcatSpreadable »` to
+/// `props`. This is used to implement [`CrossOriginOwnPropertyKeys`].
+///
+/// [`CrossOriginOwnPropertyKeys`]: https://html.spec.whatwg.org/multipage/#crossoriginownpropertykeys-(-o-)
+fn append_cross_origin_allowlisted_prop_keys(cx: SafeJSContext, props: RawMutableHandleIdVector) {
+    unsafe {
+        rooted!(in(*cx) let mut id: jsid);
+
+        let jsstring = JS_AtomizeAndPinString(*cx, c"then".as_ptr());
+        rooted!(in(*cx) let rooted = jsstring);
+        RUST_INTERNED_STRING_TO_JSID(*cx, rooted.handle().get(), id.handle_mut());
+        AppendToIdVector(props, id.handle());
+
+        for &allowed_code in ALLOWLISTED_SYMBOL_CODES.iter() {
+            id.set(SymbolId(GetWellKnownSymbol(*cx, allowed_code)));
+            AppendToIdVector(props, id.handle());
+        }
+    }
+}
+
+/// Get the holder for cross-origin properties for the current global of the
+/// `JSContext`, creating one and storing it in a slot of the proxy object if it
+/// doesn't exist yet.
+///
+/// This essentially creates a cache of [`CrossOriginGetOwnPropertyHelper`]'s
+/// results for all property keys.
+///
+/// `cx` and `proxy` are expected to be different-Realm here. `proxy` is a proxy
+/// for a maybe-cross-origin object. The `out_holder` return value will always
+/// be in the Realm of `cx`.
+///
+/// [`CrossOriginGetOwnPropertyHelper`]: https://html.spec.whatwg.org/multipage/#crossorigingetownpropertyhelper-(-o,-p-)
+fn ensure_cross_origin_property_holder(
+    cx: SafeJSContext,
+    _proxy: RawHandleObject,
+    cross_origin_properties: &'static CrossOriginProperties,
+    out_holder: RawMutableHandleObject,
+) -> bool {
+    // TODO: We don't have the slot to store the holder yet. For now,
+    //       the holder is constructed every time this function is called,
+    //       which is not only inefficient but also deviates from the
+    //       specification in a subtle yet observable way.
+
+    // Create a holder for the current Realm
+    unsafe {
+        out_holder.set(jsapi::JS_NewObjectWithGivenProto(
+            *cx,
+            ptr::null_mut(),
+            RawHandleObject::null(),
+        ));
+
+        if out_holder.get().is_null() ||
+            !jsapi::JS_DefineProperties(
+                *cx,
+                out_holder.handle(),
+                cross_origin_properties.attributes.as_ptr(),
+            ) ||
+            !jsapi::JS_DefineFunctions(
+                *cx,
+                out_holder.handle(),
+                cross_origin_properties.methods.as_ptr(),
+            )
+        {
+            return false;
+        }
+    }
+
+    // TODO: Store the holder in the slot that we don't have yet.
+
+    true
+}