Move generated bindings to script_bindings (#36323)

This is the final step of #1799, where the majority of the generated
code for the JS bindings is now compiled as part of the script_bindings
build step. The remaining pieces in script must live there because they
refer to concrete DOM types; all code in script_bindings is generic over
the
[DomTypes](https://doc.servo.org/script/dom/bindings/codegen/DomTypes/trait.DomTypes.html)
trait.

My testing with incremental builds shows me a 12 second reduction in
build times on my 2024 M4 Macbook Pro when modifying code in the script
crate after these changes. Before this PR those changes took 20 seconds
to rebuild Servo, and now they take 8 seconds.

Testing: Existing WPT tests ensure no regressions.
Fixes: #1799

---------

Signed-off-by: Josh Matthews <josh@joshmatthews.net>

1 files changed, 16 insertions, 35 deletions

diff --git a/components/script/dom/bindings/constructor.rs b/components/script/dom/bindings/constructor.rs
index ae9305f0767..138dd4520d0 100644
--- a/components/script/dom/bindings/constructor.rs
+++ b/components/script/dom/bindings/constructor.rs
@@ -11,6 +11,7 @@ use js::glue::{UnwrapObjectDynamic, UnwrapObjectStatic};
 use js::jsapi::{CallArgs, CurrentGlobalOrNull, JSAutoRealm, JSObject};
 use js::rust::wrappers::{JS_SetPrototype, JS_WrapObject};
 use js::rust::{HandleObject, MutableHandleObject, MutableHandleValue};
+use script_bindings::interface::get_desired_proto;
 
 use super::utils::ProtoOrIfaceArray;
 use crate::dom::bindings::codegen::Bindings::WindowBinding::WindowMethods;
@@ -40,9 +41,8 @@ use crate::dom::bindings::codegen::Bindings::{
 };
 use crate::dom::bindings::codegen::PrototypeList;
 use crate::dom::bindings::conversions::DerivedFrom;
-use crate::dom::bindings::error::{Error, throw_constructor_without_new, throw_dom_exception};
+use crate::dom::bindings::error::{Error, throw_dom_exception};
 use crate::dom::bindings::inheritance::Castable;
-use crate::dom::bindings::interface::get_desired_proto;
 use crate::dom::bindings::reflector::DomObject;
 use crate::dom::bindings::root::DomRoot;
 use crate::dom::create::create_native_html_element;
@@ -55,7 +55,7 @@ use crate::script_runtime::{CanGc, JSContext, JSContext as SafeJSContext};
 use crate::script_thread::ScriptThread;
 
 /// <https://html.spec.whatwg.org/multipage/#htmlconstructor>
-unsafe fn html_constructor(
+fn html_constructor(
     cx: JSContext,
     global: &GlobalScope,
     call_args: &CallArgs,
@@ -75,7 +75,9 @@ unsafe fn html_constructor(
 
     // The new_target might be a cross-compartment wrapper. Get the underlying object
     // so we can do the spec's object-identity checks.
-    rooted!(in(*cx) let new_target_unwrapped = UnwrapObjectDynamic(call_args.new_target().to_object(), *cx, true));
+    rooted!(in(*cx) let new_target_unwrapped = unsafe {
+        UnwrapObjectDynamic(call_args.new_target().to_object(), *cx, true)
+    });
     if new_target_unwrapped.is_null() {
         throw_dom_exception(
             cx,
@@ -114,7 +116,7 @@ unsafe fn html_constructor(
     // Step 4. Let isValue be null.
     let mut is_value = None;
 
-    rooted!(in(*cx) let callee = UnwrapObjectStatic(call_args.callee()));
+    rooted!(in(*cx) let callee = unsafe { UnwrapObjectStatic(call_args.callee()) });
     if callee.is_null() {
         throw_dom_exception(cx, global, Error::Security, can_gc);
         return Err(());
@@ -123,7 +125,7 @@ unsafe fn html_constructor(
     {
         let _ac = JSAutoRealm::new(*cx, callee.get());
         rooted!(in(*cx) let mut constructor = ptr::null_mut::<JSObject>());
-        rooted!(in(*cx) let global_object = CurrentGlobalOrNull(*cx));
+        rooted!(in(*cx) let global_object = unsafe { CurrentGlobalOrNull(*cx) });
 
         // Step 5. If definition's local name is equal to definition's name
         // (i.e., definition is for an autonomous custom element):
@@ -233,13 +235,15 @@ unsafe fn html_constructor(
     };
 
     rooted!(in(*cx) let mut element = result.reflector().get_jsobject().get());
-    if !JS_WrapObject(*cx, element.handle_mut()) {
-        return Err(());
-    }
+    unsafe {
+        if !JS_WrapObject(*cx, element.handle_mut()) {
+            return Err(());
+        }
 
-    JS_SetPrototype(*cx, element.handle(), prototype.handle());
+        JS_SetPrototype(*cx, element.handle(), prototype.handle());
 
-    result.to_jsval(*cx, MutableHandleValue::from_raw(call_args.rval()));
+        result.to_jsval(*cx, MutableHandleValue::from_raw(call_args.rval()));
+    }
     Ok(())
 }
 
@@ -395,7 +399,7 @@ pub(crate) fn push_new_element_queue() {
     ScriptThread::push_new_element_queue();
 }
 
-pub(crate) unsafe fn call_html_constructor<T: DerivedFrom<Element> + DomObject>(
+pub(crate) fn call_html_constructor<T: DerivedFrom<Element> + DomObject>(
     cx: JSContext,
     args: &CallArgs,
     global: &GlobalScope,
@@ -418,26 +422,3 @@ pub(crate) unsafe fn call_html_constructor<T: DerivedFrom<Element> + DomObject>(
     )
     .is_ok()
 }
-
-pub(crate) unsafe fn call_default_constructor<D: crate::DomTypes>(
-    cx: JSContext,
-    args: &CallArgs,
-    global: &D::GlobalScope,
-    proto_id: PrototypeList::ID,
-    ctor_name: &str,
-    creator: unsafe fn(JSContext, HandleObject, *mut ProtoOrIfaceArray),
-    constructor: impl FnOnce(JSContext, &CallArgs, &D::GlobalScope, HandleObject) -> bool,
-) -> bool {
-    if !args.is_constructing() {
-        throw_constructor_without_new(cx, ctor_name);
-        return false;
-    }
-
-    rooted!(in(*cx) let mut desired_proto = ptr::null_mut::<JSObject>());
-    let proto_result = get_desired_proto(cx, args, proto_id, creator, desired_proto.handle_mut());
-    if proto_result.is_err() {
-        return false;
-    }
-
-    constructor(cx, args, global, desired_proto.handle())
-}