avm2: Make `Executable` zero-alloc

core/src/avm2/function.rs

@@ -6,7 +6,7 @@ use crate::avm2::object::{ClassObject, Object};
 use crate::avm2::scope::ScopeChain;
 use crate::avm2::value::Value;
 use crate::avm2::Error;
-use gc_arena::{Collect, Gc, MutationContext};
+use gc_arena::{Collect, Gc};
 use std::fmt;
 
 /// Represents code written in AVM2 bytecode that can be executed by some
@@ -59,10 +59,10 @@ pub struct NativeExecutable<'gc> {
 #[collect(no_drop)]
 pub enum Executable<'gc> {
     /// Code defined in Ruffle's binary.
-    Native(Gc<'gc, NativeExecutable<'gc>>),
+    Native(NativeExecutable<'gc>),
 
     /// Code defined in a loaded ABC file.
-    Action(Gc<'gc, BytecodeExecutable<'gc>>),
+    Action(BytecodeExecutable<'gc>),
 }
 
 impl<'gc> Executable<'gc> {
@@ -72,27 +72,20 @@ impl<'gc> Executable<'gc> {
         scope: ScopeChain<'gc>,
         receiver: Option<Object<'gc>>,
         superclass: Option<ClassObject<'gc>>,
-        mc: MutationContext<'gc, '_>,
     ) -> Self {
         match method {
-            Method::Native(method) => Self::Native(Gc::allocate(
-                mc,
-                NativeExecutable {
-                    method,
-                    scope,
-                    bound_receiver: receiver,
-                    bound_superclass: superclass,
-                },
-            )),
-            Method::Bytecode(method) => Self::Action(Gc::allocate(
-                mc,
-                BytecodeExecutable {
-                    method,
-                    scope,
-                    receiver,
-                    bound_superclass: superclass,
-                },
-            )),
+            Method::Native(method) => Self::Native(NativeExecutable {
+                method,
+                scope,
+                bound_receiver: receiver,
+                bound_superclass: superclass,
+            }),
+            Method::Bytecode(method) => Self::Action(BytecodeExecutable {
+                method,
+                scope,
+                receiver,
+                bound_superclass: superclass,
+            }),
         }
     }
 

core/src/avm2/globals/vector.rs

@@ -873,8 +873,8 @@ pub fn sort<'gc>(
             let (compare_fnc, options) = if fn_or_options
                 .coerce_to_object(activation)
                 .ok()
-                .and_then(|o| o.as_executable())
-                .is_some()
+                .map(|o| o.as_executable().is_some())
+                .unwrap_or(false)
             {
                 (
                     Some(fn_or_options.coerce_to_object(activation)?),

core/src/avm2/object.rs

@@ -401,14 +401,7 @@ pub trait TObject<'gc>: 'gc + Collect + Debug + Into<Object<'gc>> + Clone + Copy
                 if !method.needs_arguments_object() {
                     let scope = class.instance_scope();
 
-                    return Executable::from_method(
-                        method,
-                        scope,
-                        None,
-                        Some(superclass),
-                        activation.context.gc_context,
-                    )
-                    .exec(
+                    return Executable::from_method(method, scope, None, Some(superclass)).exec(
                         Some(self.into()),
                         arguments,
                         activation,
@@ -424,14 +417,7 @@ pub trait TObject<'gc>: 'gc + Collect + Debug + Into<Object<'gc>> + Clone + Copy
                 if !method.needs_arguments_object() {
                     let scope = class.class_scope();
 
-                    return Executable::from_method(
-                        method,
-                        scope,
-                        None,
-                        Some(class),
-                        activation.context.gc_context,
-                    )
-                    .exec(
+                    return Executable::from_method(method, scope, None, Some(class)).exec(
                         Some(self.into()),
                         arguments,
                         activation,
@@ -1257,7 +1243,7 @@ pub trait TObject<'gc>: 'gc + Collect + Debug + Into<Object<'gc>> + Clone + Copy
     }
 
     /// Get this object's `Executable`, if it has one.
-    fn as_executable(&self) -> Option<Executable<'gc>> {
+    fn as_executable(&self) -> Option<Ref<Executable<'gc>>> {
         None
     }
 

core/src/avm2/object/class_object.rs

@@ -452,13 +452,8 @@ impl<'gc> ClassObject<'gc> {
         activation: &mut Activation<'_, 'gc, '_>,
     ) -> Result<Value<'gc>, Error> {
         let scope = self.0.read().instance_scope;
-        let constructor = Executable::from_method(
-            self.0.read().constructor.clone(),
-            scope,
-            None,
-            Some(self),
-            activation.context.gc_context,
-        );
+        let constructor =
+            Executable::from_method(self.0.read().constructor.clone(), scope, None, Some(self));
 
         constructor.exec(receiver, arguments, activation, self.into())
     }
@@ -480,7 +475,6 @@ impl<'gc> ClassObject<'gc> {
             scope,
             None,
             Some(self),
-            activation.context.gc_context,
         );
 
         constructor.exec(receiver, arguments, activation, self.into())

core/src/avm2/object/function_object.rs

@@ -24,7 +24,7 @@ pub struct FunctionObjectData<'gc> {
     base: ScriptObjectData<'gc>,
 
     /// Executable code
-    exec: Option<Executable<'gc>>,
+    exec: Executable<'gc>,
 }
 
 impl<'gc> FunctionObject<'gc> {
@@ -66,13 +66,7 @@ impl<'gc> FunctionObject<'gc> {
         subclass_object: Option<ClassObject<'gc>>,
     ) -> Object<'gc> {
         let fn_proto = activation.avm2().prototypes().function;
-        let exec = Some(Executable::from_method(
-            method,
-            scope,
-            receiver,
-            subclass_object,
-            activation.context.gc_context,
-        ));
+        let exec = Executable::from_method(method, scope, receiver, subclass_object);
 
         FunctionObject(GcCell::allocate(
             activation.context.gc_context,
@@ -110,8 +104,8 @@ impl<'gc> TObject<'gc> for FunctionObject<'gc> {
         Ok(Value::Object(Object::from(*self)))
     }
 
-    fn as_executable(&self) -> Option<Executable<'gc>> {
-        self.0.read().exec.clone()
+    fn as_executable(&self) -> Option<Ref<Executable<'gc>>> {
+        Some(Ref::map(self.0.read(), |r| &r.exec))
     }
 
     fn call(
@@ -120,11 +114,10 @@ impl<'gc> TObject<'gc> for FunctionObject<'gc> {
         arguments: &[Value<'gc>],
         activation: &mut Activation<'_, 'gc, '_>,
     ) -> Result<Value<'gc>, Error> {
-        if let Some(exec) = &self.0.read().exec {
-            exec.exec(receiver, arguments, activation, self.into())
-        } else {
-            Err("Not a callable function!".into())
-        }
+        self.0
+            .read()
+            .exec
+            .exec(receiver, arguments, activation, self.into())
     }
 
     fn construct(
@@ -151,10 +144,11 @@ impl<'gc> TObject<'gc> for FunctionObject<'gc> {
     fn derive(&self, activation: &mut Activation<'_, 'gc, '_>) -> Result<Object<'gc>, Error> {
         let this: Object<'gc> = Object::FunctionObject(*self);
         let base = ScriptObjectData::base_new(Some(this), None);
+        let exec = self.0.read().exec.clone();
 
         Ok(FunctionObject(GcCell::allocate(
             activation.context.gc_context,
-            FunctionObjectData { base, exec: None },
+            FunctionObjectData { base, exec },
         ))
         .into())
     }