Fix prototypes of interface objects (fixes #2665)

Callback interface objects' (i.e. NodeFilter's) prototype is now Object instead of
Function and non-callback interface objects' their proper ancestor, starting with
the Function prototype.

The function do_create_interface_objects is removed in favour of 4 functions:
create_callback_interface_object, create_interface_prototype_object,
create_noncallback_interface_object and create_named_constructors.

While this increases the amount of codegen'd code, this greatly improves the
readability of the code involved in this part of DOM, instead of having one function
doing 4 different things. We can always find a more adequate abstraction later.

NativeProperties and everything related to the interface objects have been removed
from the utils module.

Author: nox

components/script/dom/bindings/codegen/CodegenRust.py

@@ -0,0 +1,184 @@
+/* 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 http://mozilla.org/MPL/2.0/. */
+
+//! Machinery to initialise interface prototype objects and interface objects.
+
+use dom::bindings::codegen::PrototypeList;
+use dom::bindings::conversions::get_dom_class;
+use dom::bindings::utils::{ConstantSpec, NonNullJSNative, define_constants};
+use js::jsapi::{HandleObject, HandleValue, JSClass, JSContext, JSFunctionSpec};
+use js::jsapi::{JSPropertySpec, JS_DefineProperty1, JS_DefineProperty2};
+use js::jsapi::{JS_DefineProperty4, JS_GetFunctionObject, JS_GetPrototype};
+use js::jsapi::{JS_InternString, JS_LinkConstructorAndPrototype, JS_NewFunction};
+use js::jsapi::{JS_NewObject, JS_NewObjectWithUniqueType, MutableHandleObject};
+use js::jsapi::{RootedObject, RootedString};
+use js::rust::{define_methods, define_properties};
+use js::{JSFUN_CONSTRUCTOR, JSPROP_PERMANENT, JSPROP_READONLY};
+use libc;
+use std::ptr;
+
+/// Create and define the interface object of a callback interface.
+pub unsafe fn create_callback_interface_object(cx: *mut JSContext,
+                                               receiver: HandleObject,
+                                               constants: &'static [ConstantSpec],
+                                               name: &'static [u8]) {
+    assert!(!constants.is_empty());
+    let obj = RootedObject::new(cx, JS_NewObject(cx, ptr::null()));
+    assert!(!obj.ptr.is_null());
+    define_constants(cx, obj.handle(), constants);
+    define_name(cx, obj.handle(), name);
+    define_global_object(cx, receiver, name, obj.handle());
+}
+
+/// Create the interface prototype object of a non-callback interface.
+pub unsafe fn create_interface_prototype_object(
+        cx: *mut JSContext,
+        proto: HandleObject,
+        class: &'static JSClass,
+        regular_methods: Option<&'static [JSFunctionSpec]>,
+        regular_properties: Option<&'static [JSPropertySpec]>,
+        constants: &'static [ConstantSpec],
+        rval: MutableHandleObject) {
+    create_object(cx, proto, class, regular_methods, regular_properties, constants, rval);
+}
+
+/// Create and define the interface object of a non-callback interface.
+pub unsafe fn create_noncallback_interface_object(
+        cx: *mut JSContext,
+        receiver: HandleObject,
+        proto: HandleObject,
+        class: &'static JSClass,
+        static_methods: Option<&'static [JSFunctionSpec]>,
+        static_properties: Option<&'static [JSPropertySpec]>,
+        constants: &'static [ConstantSpec],
+        interface_prototype_object: HandleObject,
+        name: &'static [u8],
+        length: u32,
+        rval: MutableHandleObject) {
+    create_object(cx, proto, class, static_methods, static_properties, constants, rval);
+    assert!(JS_LinkConstructorAndPrototype(cx, rval.handle(), interface_prototype_object));
+    define_name(cx, rval.handle(), name);
+    define_length(cx, rval.handle(), length);
+    define_global_object(cx, receiver, name, rval.handle());
+}
+
+/// Create and define the named constructors of a non-callback interface.
+pub unsafe fn create_named_constructors(
+        cx: *mut JSContext,
+        receiver: HandleObject,
+        named_constructors: &[(NonNullJSNative, &'static [u8], u32)],
+        interface_prototype_object: HandleObject) {
+    let mut constructor = RootedObject::new(cx, ptr::null_mut());
+
+    for &(native, name, arity) in named_constructors {
+        assert!(*name.last().unwrap() == b'\0');
+
+        let fun = JS_NewFunction(cx,
+                                 Some(native),
+                                 arity,
+                                 JSFUN_CONSTRUCTOR,
+                                 name.as_ptr() as *const libc::c_char);
+        assert!(!fun.is_null());
+        constructor.ptr = JS_GetFunctionObject(fun);
+        assert!(!constructor.ptr.is_null());
+
+        assert!(JS_DefineProperty1(cx,
+                                   constructor.handle(),
+                                   b"prototype\0".as_ptr() as *const libc::c_char,
+                                   interface_prototype_object,
+                                   JSPROP_PERMANENT | JSPROP_READONLY,
+                                   None,
+                                   None));
+
+        define_global_object(cx, receiver, name, constructor.handle());
+    }
+}
+
+/// Return whether a value is an instance of a given prototype.
+/// http://heycam.github.io/webidl/#es-interface-hasinstance
+pub unsafe fn has_instance(
+        cx: *mut JSContext,
+        prototype: HandleObject,
+        value: HandleValue,
+        id: PrototypeList::ID,
+        index: usize)
+        -> bool {
+    if !value.is_object() {
+        // Step 1.
+        return false;
+    }
+    let mut value = RootedObject::new(cx, value.to_object());
+
+    // Steps 2-3 only concern callback interface objects.
+
+    if let Ok(dom_class) = get_dom_class(value.ptr) {
+        if dom_class.interface_chain[index] == id {
+            // Step 4.
+            return true;
+        }
+    }
+
+    while JS_GetPrototype(cx, value.handle(), value.handle_mut()) {
+        if value.ptr as *const _ == prototype.ptr {
+            // Step 5.3.
+            return true;
+        }
+    }
+    // Step 5.2.
+    false
+}
+
+unsafe fn create_object(
+        cx: *mut JSContext,
+        proto: HandleObject,
+        class: &'static JSClass,
+        methods: Option<&'static [JSFunctionSpec]>,
+        properties: Option<&'static [JSPropertySpec]>,
+        constants: &'static [ConstantSpec],
+        rval: MutableHandleObject) {
+    rval.set(JS_NewObjectWithUniqueType(cx, class, proto));
+    assert!(!rval.ptr.is_null());
+    if let Some(methods) = methods {
+        define_methods(cx, rval.handle(), methods).unwrap();
+    }
+    if let Some(properties) = properties {
+        define_properties(cx, rval.handle(), properties).unwrap();
+    }
+    define_constants(cx, rval.handle(), constants);
+}
+
+unsafe fn define_name(cx: *mut JSContext, obj: HandleObject, name: &'static [u8]) {
+    assert!(*name.last().unwrap() == b'\0');
+    let name =
+        RootedString::new(cx, JS_InternString(cx, name.as_ptr() as *const libc::c_char));
+    assert!(!name.ptr.is_null());
+    assert!(JS_DefineProperty2(cx,
+                               obj,
+                               b"name\0".as_ptr() as *const libc::c_char,
+                               name.handle(),
+                               JSPROP_READONLY,
+                               None, None));
+}
+
+unsafe fn define_length(cx: *mut JSContext, obj: HandleObject, length: u32) {
+    assert!(JS_DefineProperty4(cx,
+                               obj,
+                               b"length\0".as_ptr() as *const libc::c_char,
+                               length,
+                               JSPROP_READONLY,
+                               None, None));
+}
+
+unsafe fn define_global_object(
+        cx: *mut JSContext,
+        receiver: HandleObject,
+        name: &'static [u8],
+        obj: HandleObject) {
+    assert!(JS_DefineProperty1(cx,
+                               receiver,
+                               name.as_ptr() as *const libc::c_char,
+                               obj,
+                               0,
+                               None, None));
+}

components/script/dom/bindings/interface.rs

@@ -138,6 +138,7 @@ pub mod conversions;
 pub mod error;
 pub mod global;
 pub mod inheritance;
+pub mod interface;
 pub mod js;
 pub mod num;
 pub mod proxyhandler;