avm2: Implement Op::Typeof and dummy XML/XMLList

Author: CUB3D

core/src/avm2/activation.rs

@@ -673,6 +673,7 @@ impl<'a, 'gc, 'gc_context> Activation<'a, 'gc, 'gc_context> {
                 } => self.op_debug(method, is_local_register, register_name, register),
                 Op::DebugFile { file_name } => self.op_debug_file(method, file_name),
                 Op::DebugLine { line_num } => self.op_debug_line(line_num),
+                Op::TypeOf => self.op_type_of(),
                 _ => self.unknown_op(op),
             };
 
@@ -2253,6 +2254,50 @@ impl<'a, 'gc, 'gc_context> Activation<'a, 'gc, 'gc_context> {
         Ok(FrameControl::Continue)
     }
 
+    fn op_type_of(&mut self) -> Result<FrameControl<'gc>, Error> {
+        let value = self.context.avm2.pop();
+
+        let type_name = match value {
+            Value::Undefined => "undefined",
+            Value::Null => "object",
+            Value::Bool(_) => "boolean",
+            Value::Number(_) | Value::Integer(_) | Value::Unsigned(_) => "number",
+            Value::Object(o) => {
+                // Subclasses always have a typeof = "object", must be a subclass if the prototype chain is > 2, or not a subclass if <=2
+                let is_not_subclass = matches!(
+                    o.proto().and_then(|p| p.proto()).and_then(|p| p.proto()),
+                    None
+                );
+
+                match o {
+                    Object::FunctionObject(_) => {
+                        if is_not_subclass {
+                            "function"
+                        } else {
+                            "object"
+                        }
+                    }
+                    Object::XmlObject(_) => {
+                        if is_not_subclass {
+                            "xml"
+                        } else {
+                            "object"
+                        }
+                    }
+                    _ => "object",
+                }
+            }
+            Value::String(_) => "string",
+        };
+
+        self.context.avm2.push(Value::String(AvmString::new(
+            self.context.gc_context,
+            type_name,
+        )));
+
+        Ok(FrameControl::Continue)
+    }
+
     #[allow(unused_variables)]
     #[cfg(avm_debug)]
     fn op_debug(

core/src/avm2/globals.rs

@@ -7,7 +7,7 @@ use crate::avm2::method::NativeMethod;
 use crate::avm2::names::{Namespace, QName};
 use crate::avm2::object::{
     implicit_deriver, ArrayObject, DomainObject, FunctionObject, NamespaceObject, Object,
-    PrimitiveObject, ScriptObject, StageObject, TObject,
+    PrimitiveObject, ScriptObject, StageObject, TObject, XmlObject,
 };
 use crate::avm2::scope::Scope;
 use crate::avm2::script::Script;
@@ -29,6 +29,8 @@ mod number;
 mod object;
 mod string;
 mod r#uint;
+mod xml;
+mod xml_list;
 
 const NS_RUFFLE_INTERNAL: &str = "https://ruffle.rs/AS3/impl/";
 
@@ -96,6 +98,8 @@ pub struct SystemPrototypes<'gc> {
     pub application_domain: Object<'gc>,
     pub event: Object<'gc>,
     pub video: Object<'gc>,
+    pub xml: Object<'gc>,
+    pub xml_list: Object<'gc>,
 }
 
 impl<'gc> SystemPrototypes<'gc> {
@@ -130,6 +134,8 @@ impl<'gc> SystemPrototypes<'gc> {
             application_domain: empty,
             event: empty,
             video: empty,
+            xml: empty,
+            xml_list: empty,
         }
     }
 }
@@ -274,6 +280,15 @@ fn array_deriver<'gc>(
     ArrayObject::derive(base_proto, activation.context.gc_context, class, scope)
 }
 
+fn xml_deriver<'gc>(
+    base_proto: Object<'gc>,
+    activation: &mut Activation<'_, 'gc, '_>,
+    class: GcCell<'gc, Class<'gc>>,
+    scope: Option<GcCell<'gc, Scope<'gc>>>,
+) -> Result<Object<'gc>, Error> {
+    XmlObject::derive(base_proto, activation.context.gc_context, class, scope)
+}
+
 fn stage_deriver<'gc>(
     base_proto: Object<'gc>,
     activation: &mut Activation<'_, 'gc, '_>,
@@ -443,6 +458,34 @@ pub fn load_player_globals<'gc>(
         script,
     )?;
 
+    activation
+        .context
+        .avm2
+        .system_prototypes
+        .as_mut()
+        .unwrap()
+        .xml = class(
+        activation,
+        xml::create_class(mc),
+        xml_deriver,
+        domain,
+        script,
+    )?;
+
+    activation
+        .context
+        .avm2
+        .system_prototypes
+        .as_mut()
+        .unwrap()
+        .xml_list = class(
+        activation,
+        xml_list::create_class(mc),
+        xml_deriver,
+        domain,
+        script,
+    )?;
+
     // package `flash.system`
     activation
         .context

core/src/avm2/globals/xml.rs

@@ -0,0 +1,38 @@
+//! XML builtin and prototype
+
+use crate::avm2::activation::Activation;
+use crate::avm2::class::Class;
+use crate::avm2::method::Method;
+use crate::avm2::names::{Namespace, QName};
+use crate::avm2::object::Object;
+use crate::avm2::value::Value;
+use crate::avm2::Error;
+use gc_arena::{GcCell, MutationContext};
+
+/// Implements `XML`'s instance initializer.
+pub fn instance_init<'gc>(
+    _activation: &mut Activation<'_, 'gc, '_>,
+    _this: Option<Object<'gc>>,
+    _args: &[Value<'gc>],
+) -> Result<Value<'gc>, Error> {
+    Ok(Value::Undefined)
+}
+
+/// Implements `XML`'s class initializer
+pub fn class_init<'gc>(
+    _activation: &mut Activation<'_, 'gc, '_>,
+    _this: Option<Object<'gc>>,
+    _args: &[Value<'gc>],
+) -> Result<Value<'gc>, Error> {
+    Ok(Value::Undefined)
+}
+
+pub fn create_class<'gc>(mc: MutationContext<'gc, '_>) -> GcCell<'gc, Class<'gc>> {
+    Class::new(
+        QName::new(Namespace::public(), "XML"),
+        Some(QName::new(Namespace::public(), "Object").into()),
+        Method::from_builtin(instance_init),
+        Method::from_builtin(class_init),
+        mc,
+    )
+}

core/src/avm2/globals/xml_list.rs

@@ -0,0 +1,38 @@
+//! XMLList builtin and prototype
+
+use crate::avm2::activation::Activation;
+use crate::avm2::class::Class;
+use crate::avm2::method::Method;
+use crate::avm2::names::{Namespace, QName};
+use crate::avm2::object::Object;
+use crate::avm2::value::Value;
+use crate::avm2::Error;
+use gc_arena::{GcCell, MutationContext};
+
+/// Implements `XMLList`'s instance initializer.
+pub fn instance_init<'gc>(
+    _activation: &mut Activation<'_, 'gc, '_>,
+    _this: Option<Object<'gc>>,
+    _args: &[Value<'gc>],
+) -> Result<Value<'gc>, Error> {
+    Ok(Value::Undefined)
+}
+
+/// Implements `XMLList`'s class initializer
+pub fn class_init<'gc>(
+    _activation: &mut Activation<'_, 'gc, '_>,
+    _this: Option<Object<'gc>>,
+    _args: &[Value<'gc>],
+) -> Result<Value<'gc>, Error> {
+    Ok(Value::Undefined)
+}
+
+pub fn create_class<'gc>(mc: MutationContext<'gc, '_>) -> GcCell<'gc, Class<'gc>> {
+    Class::new(
+        QName::new(Namespace::public(), "XMLList"),
+        Some(QName::new(Namespace::public(), "Object").into()),
+        Method::from_builtin(instance_init),
+        Method::from_builtin(class_init),
+        mc,
+    )
+}

core/src/avm2/object.rs

@@ -28,6 +28,7 @@ mod namespace_object;
 mod primitive_object;
 mod script_object;
 mod stage_object;
+mod xml_object;
 
 pub use crate::avm2::object::array_object::ArrayObject;
 pub use crate::avm2::object::dispatch_object::DispatchObject;
@@ -38,6 +39,7 @@ pub use crate::avm2::object::namespace_object::NamespaceObject;
 pub use crate::avm2::object::primitive_object::PrimitiveObject;
 pub use crate::avm2::object::script_object::ScriptObject;
 pub use crate::avm2::object::stage_object::StageObject;
+pub use crate::avm2::object::xml_object::XmlObject;
 
 /// Represents an object that can be directly interacted with by the AVM2
 /// runtime.
@@ -53,7 +55,8 @@ pub use crate::avm2::object::stage_object::StageObject;
         StageObject(StageObject<'gc>),
         DomainObject(DomainObject<'gc>),
         EventObject(EventObject<'gc>),
-        DispatchObject(DispatchObject<'gc>)
+        DispatchObject(DispatchObject<'gc>),
+        XmlObject(XmlObject<'gc>),
     }
 )]
 pub trait TObject<'gc>: 'gc + Collect + Debug + Into<Object<'gc>> + Clone + Copy {

core/src/avm2/object/xml_object.rs

@@ -0,0 +1,82 @@
+//! Object representation for XML objects
+
+use crate::avm2::activation::Activation;
+use crate::avm2::class::Class;
+use crate::avm2::names::{Namespace, QName};
+use crate::avm2::object::script_object::{ScriptObjectClass, ScriptObjectData};
+use crate::avm2::object::{Object, ObjectPtr, TObject};
+use crate::avm2::scope::Scope;
+use crate::avm2::string::AvmString;
+use crate::avm2::traits::Trait;
+use crate::avm2::value::Value;
+use crate::avm2::Error;
+use crate::{impl_avm2_custom_object, impl_avm2_custom_object_properties};
+use gc_arena::{Collect, GcCell, MutationContext};
+
+#[derive(Clone, Collect, Debug, Copy)]
+#[collect(no_drop)]
+pub struct XmlObject<'gc>(GcCell<'gc, XmlObjectData<'gc>>);
+
+#[derive(Clone, Collect, Debug)]
+#[collect(no_drop)]
+pub struct XmlObjectData<'gc> {
+    /// Base script object
+    base: ScriptObjectData<'gc>,
+}
+
+impl<'gc> XmlObject<'gc> {
+    /// Instantiate an xml subclass.
+    pub fn derive(
+        base_proto: Object<'gc>,
+        mc: MutationContext<'gc, '_>,
+        class: GcCell<'gc, Class<'gc>>,
+        scope: Option<GcCell<'gc, Scope<'gc>>>,
+    ) -> Result<Object<'gc>, Error> {
+        let base = ScriptObjectData::base_new(
+            Some(base_proto),
+            ScriptObjectClass::InstancePrototype(class, scope),
+        );
+
+        Ok(XmlObject(GcCell::allocate(mc, XmlObjectData { base })).into())
+    }
+
+    pub fn empty_object(
+        mc: MutationContext<'gc, '_>,
+        base_proto: Option<Object<'gc>>,
+    ) -> Object<'gc> {
+        let base = ScriptObjectData::base_new(base_proto, ScriptObjectClass::NoClass);
+
+        XmlObject(GcCell::allocate(mc, XmlObjectData { base })).into()
+    }
+}
+
+impl<'gc> TObject<'gc> for XmlObject<'gc> {
+    impl_avm2_custom_object!(base);
+    impl_avm2_custom_object_properties!(base);
+
+    fn construct(
+        &self,
+        activation: &mut Activation<'_, 'gc, '_>,
+        _args: &[Value<'gc>],
+    ) -> Result<Object<'gc>, Error> {
+        let this: Object<'gc> = Object::XmlObject(*self);
+        Ok(Self::empty_object(
+            activation.context.gc_context,
+            Some(this),
+        ))
+    }
+
+    fn derive(
+        &self,
+        activation: &mut Activation<'_, 'gc, '_>,
+        class: GcCell<'gc, Class<'gc>>,
+        scope: Option<GcCell<'gc, Scope<'gc>>>,
+    ) -> Result<Object<'gc>, Error> {
+        let this: Object<'gc> = Object::XmlObject(*self);
+        Self::derive(this, activation.context.gc_context, class, scope)
+    }
+
+    fn value_of(&self, _mc: MutationContext<'gc, '_>) -> Result<Value<'gc>, Error> {
+        Ok(Value::Object(Object::from(*self)))
+    }
+}

core/tests/regression_tests.rs

@@ -519,6 +519,7 @@ swf_tests! {
     (as3_string_length, "avm2/string_length", 1),
     (as3_string_char_at, "avm2/string_char_at", 1),
     (as3_string_char_code_at, "avm2/string_char_code_at", 1),
+    (as3_typeof, "avm2/typeof", 1),
 }
 
 // TODO: These tests have some inaccuracies currently, so we use approx_eq to test that numeric values are close enough.