abi-optimize This enum

Author: y21

crates/dash_node_impl/src/events.rs

@@ -6,13 +6,12 @@ use dash_middle::interner::Symbol;
 use dash_proc_macro::Trace;
 use dash_rt::state::State;
 use dash_rt::typemap::Key;
-use dash_vm::frame::This;
 use dash_vm::gc::ObjectId;
 use dash_vm::localscope::LocalScope;
 use dash_vm::value::function::args::CallArgs;
 use dash_vm::value::function::native::{CallContext, register_native_fn};
 use dash_vm::value::function::{Function, FunctionKind};
-use dash_vm::value::object::{Object, OrdObject, PropertyValue};
+use dash_vm::value::object::{Object, OrdObject, PropertyValue, This};
 use dash_vm::value::ops::conversions::ValueConversion;
 use dash_vm::value::propertykey::{PropertyKey, ToPropertyKey};
 use dash_vm::value::root_ext::RootErrExt;
@@ -161,7 +160,7 @@ fn emit(cx: CallContext) -> Result<Value, Value> {
         if let Some(handlers) = this.handlers.borrow().get(&name.sym()) {
             for handler in handlers {
                 handler
-                    .apply(This::Bound(cx.this), CallArgs::from(args), sc)
+                    .apply(This::bound(cx.this), CallArgs::from(args), sc)
                     .root_err(sc)?;
                 did_emit = true;
             }

crates/dash_node_impl/src/lib.rs

@@ -13,12 +13,11 @@ use dash_rt::format_value;
 use dash_rt::runtime::Runtime;
 use dash_rt::state::State;
 use dash_vm::eval::EvalError;
-use dash_vm::frame::This;
 use dash_vm::gc::ObjectId;
 use dash_vm::localscope::LocalScope;
 use dash_vm::value::array::Array;
 use dash_vm::value::function::args::CallArgs;
-use dash_vm::value::object::{OrdObject, Object, PropertyValue};
+use dash_vm::value::object::{Object, OrdObject, PropertyValue, This};
 use dash_vm::value::propertykey::ToPropertyKey;
 use dash_vm::value::{Root, Unpack, Unrooted, Value, ValueKind};
 use dash_vm::{Vm, delegate, extract, throw};
@@ -244,7 +243,7 @@ fn execute_node_module(
     let dirname = Value::string(scope.intern(dir_path.to_str().expect("invalid utf-8 path")).into());
     let filename = Value::string(scope.intern(file_path.to_str().expect("invalid utf-8 path")).into());
     fun.apply(
-        This::Default,
+        This::default(),
         [exports, module, require, dirname, filename].into(),
         scope,
     )

crates/dash_node_impl/src/util.rs

@@ -1,10 +1,9 @@
 use dash_middle::interner::sym;
-use dash_vm::frame::This;
 use dash_vm::localscope::LocalScope;
 use dash_vm::throw;
 use dash_vm::value::function::args::CallArgs;
 use dash_vm::value::function::native::{CallContext, register_native_fn};
-use dash_vm::value::object::{OrdObject, Object, PropertyDataDescriptor, PropertyValue, PropertyValueKind};
+use dash_vm::value::object::{Object, OrdObject, PropertyDataDescriptor, PropertyValue, PropertyValueKind, This};
 use dash_vm::value::propertykey::ToPropertyKey;
 use dash_vm::value::{Root, Typeof, Value, ValueContext};
 
@@ -49,7 +48,7 @@ fn inherits(cx: CallContext) -> Result<Value, Value> {
     }
 
     let super_inst = super_ctor
-        .construct(This::Default, CallArgs::empty(), cx.scope)
+        .construct(This::default(), CallArgs::empty(), cx.scope)
         .root(cx.scope)?;
 
     super_inst.set_property(

crates/dash_rt/src/inspect.rs

@@ -2,7 +2,6 @@ use std::fmt::Write;
 
 use dash_middle::interner::{Symbol, sym};
 
-use dash_vm::frame::This;
 use dash_vm::localscope::LocalScope;
 use dash_vm::util::intern_f64;
 use dash_vm::value::array::{Array, ArrayIterator};
@@ -12,7 +11,7 @@ use dash_vm::value::propertykey::{PropertyKey, ToPropertyKey};
 use dash_vm::value::typedarray::TypedArray;
 use dash_vm::value::{Typeof, Unpack, ValueKind};
 
-use dash_vm::value::object::{Object, PropertyDataDescriptor, PropertyValueKind};
+use dash_vm::value::object::{Object, PropertyDataDescriptor, PropertyValueKind, This};
 use dash_vm::value::ops::conversions::ValueConversion;
 use dash_vm::value::primitive::Number;
 use dash_vm::value::root_ext::RootErrExt;
@@ -218,7 +217,7 @@ fn inspect_inner_into(
                                 if options.invoke_getters {
                                     colored(out, options, GREY, |s| *s += "(computed) ");
                                     inspect_inner_into(
-                                        property_value.get_or_apply(scope, This::Bound(value)).root(scope)?,
+                                        property_value.get_or_apply(scope, This::bound(value)).root(scope)?,
                                         scope,
                                         options,
                                         depth + 1,

crates/dash_rt_http/src/lib.rs

@@ -7,14 +7,13 @@ use dash_middle::util::{SharedOnce, ThreadSafeStorage};
 use dash_rt::event::EventMessage;
 use dash_rt::module::ModuleLoader;
 use dash_rt::state::State;
-use dash_vm::frame::This;
 use dash_vm::gc::persistent::Persistent;
 use dash_vm::gc::trace::{Trace, TraceCtxt};
 use dash_vm::js_std::receiver_t;
 use dash_vm::localscope::LocalScope;
 use dash_vm::value::function::native::CallContext;
 use dash_vm::value::function::{Function, FunctionKind};
-use dash_vm::value::object::{Object, OrdObject, PropertyValue};
+use dash_vm::value::object::{Object, OrdObject, PropertyValue, This};
 use dash_vm::value::ops::conversions::ValueConversion;
 use dash_vm::value::propertykey::ToPropertyKey;
 use dash_vm::value::root_ext::RootErrExt;
@@ -105,7 +104,7 @@ pub fn listen(cx: CallContext) -> Result<Value, Value> {
 
                     let ctx = Value::object(scope.register(ctx));
 
-                    if let Err(err) = cb.apply(This::Default, [ctx].into(), &mut scope).root_err(&mut scope) {
+                    if let Err(err) = cb.apply(This::default(), [ctx].into(), &mut scope).root_err(&mut scope) {
                         match err.to_js_string(&mut scope) {
                             Ok(err) => eprintln!("Unhandled exception in HTTP handler! {}", err.res(&scope)),
                             Err(..) => eprintln!("Unhandled exception in exception toString method in HTTP handler!"),

crates/dash_rt_net/src/listener/mod.rs

@@ -4,7 +4,6 @@ use dash_proc_macro::Trace;
 use dash_rt::event::EventMessage;
 use dash_rt::state::State;
 use dash_rt::wrap_async;
-use dash_vm::frame::This;
 use dash_vm::gc::ObjectId;
 use dash_vm::gc::trace::{Trace, TraceCtxt};
 use dash_vm::js_std::receiver_t;
@@ -13,7 +12,7 @@ use dash_vm::value::arraybuffer::ArrayBuffer;
 use dash_vm::value::function::args::CallArgs;
 use dash_vm::value::function::native::CallContext;
 use dash_vm::value::function::{Function, FunctionKind};
-use dash_vm::value::object::{Object, OrdObject, PropertyValue};
+use dash_vm::value::object::{Object, OrdObject, PropertyValue, This};
 use dash_vm::value::ops::conversions::ValueConversion;
 use dash_vm::value::promise::Promise;
 use dash_vm::value::propertykey::{PropertyKey, ToPropertyKey};

crates/dash_rt_timers/src/lib.rs

@@ -6,13 +6,12 @@ use dash_middle::util::ThreadSafeStorage;
 use dash_rt::event::EventMessage;
 use dash_rt::module::ModuleLoader;
 use dash_rt::state::State;
-use dash_vm::frame::This;
 use dash_vm::gc::persistent::Persistent;
 use dash_vm::localscope::LocalScope;
 use dash_vm::throw;
 use dash_vm::value::function::args::CallArgs;
 use dash_vm::value::function::native::{CallContext, register_native_fn};
-use dash_vm::value::object::{OrdObject, Object, PropertyValue};
+use dash_vm::value::object::{Object, OrdObject, PropertyValue, This};
 use dash_vm::value::ops::conversions::ValueConversion;
 use dash_vm::value::propertykey::ToPropertyKey;
 use dash_vm::value::string::JsString;
@@ -84,7 +83,7 @@ fn set_timeout(cx: CallContext) -> Result<Value, Value> {
             let mut sc = rt.vm_mut().scope();
             let callback = callback.get();
 
-            if let Err(err) = callback.apply(This::Default, CallArgs::empty(), &mut sc) {
+            if let Err(err) = callback.apply(This::default(), CallArgs::empty(), &mut sc) {
                 eprintln!("Unhandled error in timer callback: {err:?}");
             }
 
@@ -111,7 +110,7 @@ fn set_immediate(cx: CallContext) -> Result<Value, Value> {
         let callback = callback.get();
         let mut sc = rt.vm_mut().scope();
 
-        if let Err(err) = callback.apply(This::Default, CallArgs::empty(), &mut sc) {
+        if let Err(err) = callback.apply(This::default(), CallArgs::empty(), &mut sc) {
             eprintln!("Unhandled error in timer callback: {err:?}");
         }
     })));

crates/dash_vm/src/dispatch.rs

@@ -571,7 +571,7 @@ mod handlers {
     use std::ops::{Add, ControlFlow, Div, Mul, Rem, Sub};
     use std::rc::Rc;
 
-    use crate::frame::{FrameState, This, TryBlock};
+    use crate::frame::{FrameState, TryBlock};
     use crate::throw;
     use crate::util::unlikely;
     use crate::value::array::table::ArrayTable;
@@ -582,7 +582,7 @@ mod handlers {
     use crate::value::function::generator::GeneratorFunction;
     use crate::value::function::user::UserFunction;
     use crate::value::function::{Function, FunctionKind, adjust_stack_from_flat_call, this_for_new_target};
-    use crate::value::object::{Object, OrdObject, PropertyValue, PropertyValueKind};
+    use crate::value::object::{Object, OrdObject, PropertyValue, PropertyValueKind, This, ThisKind};
     use crate::value::ops::conversions::ValueConversion;
     use crate::value::ops::equality;
     use crate::value::primitive::Number;
@@ -930,7 +930,7 @@ mod handlers {
 
         let value = match cx.global.clone().extract::<OrdObject>(&cx.scope) {
             Some(value) => match value.get_own_property_descriptor(name.to_key(&mut cx.scope), &mut cx.scope)? {
-                Some(value) => value.kind().get_or_apply(&mut cx, This::Default)?,
+                Some(value) => value.kind().get_or_apply(&mut cx, This::default())?,
                 None => {
                     let name = name.res(&cx.scope).to_owned();
                     throw!(&mut cx, ReferenceError, "{} is not defined", name)
@@ -1062,7 +1062,7 @@ mod handlers {
                         throw!(cx.scope, TypeError, "supertype constructor must be an object")
                     };
 
-                    This::BeforeSuper { super_constructor }
+                    This::before_super(super_constructor)
                 } else {
                     this_for_new_target(&mut cx.scope, callee)?
                 };
@@ -1076,7 +1076,7 @@ mod handlers {
                         throw!(cx.scope, TypeError, "supertype constructor must be an object")
                     };
 
-                    This::BeforeSuper { super_constructor }
+                    This::before_super(super_constructor)
                 } else {
                     let new_target = cx.active_frame().new_target().unwrap();
                     this_for_new_target(&mut cx.scope, new_target)?
@@ -1207,23 +1207,23 @@ mod handlers {
 
         let stack_len = cx.stack.len();
         let (callee, this) = if function_call_kind == FunctionCallKind::Super {
-            let callee = match cx.active_frame().this {
-                This::BeforeSuper { super_constructor } => Value::object(super_constructor),
+            let callee = match cx.active_frame().this.kind() {
+                ThisKind::BeforeSuper { super_constructor } => Value::object(super_constructor),
                 _ => throw!(
                     cx.scope,
                     TypeError,
                     "super() must be called exactly once in a subclass constructor"
                 ),
             };
-            (callee, This::Default)
+            (callee, This::default())
         } else if has_this {
             cx.stack[stack_len - argc - 2..].rotate_left(2);
             let (this, callee) = cx.pop_stack2_rooted();
-            (callee, This::Bound(this))
+            (callee, This::bound(this))
         } else {
             cx.stack[stack_len - argc - 1..].rotate_left(1);
             let callee = cx.pop_stack_rooted();
-            (callee, This::Default)
+            (callee, This::default())
         };
 
         if let Some(function) = callee.unpack().downcast_ref::<Function>(&cx.scope) {
@@ -2050,7 +2050,7 @@ mod handlers {
 
     pub fn bindthis(mut cx: DispatchContext<'_>) -> Result<Option<HandleResult>, Unrooted> {
         let value = cx.pop_stack_rooted();
-        cx.active_frame_mut().this = This::Bound(value);
+        cx.active_frame_mut().this = This::bound(value);
         Ok(None)
     }
 
@@ -2085,7 +2085,7 @@ mod handlers {
         let iterable = value
             .get_property(symbol_iterator.to_key(&mut cx.scope), &mut cx.scope)?
             .root(&mut cx.scope);
-        let iterator = iterable.apply(This::Bound(value), CallArgs::empty(), &mut cx.scope)?;
+        let iterator = iterable.apply(This::bound(value), CallArgs::empty(), &mut cx.scope)?;
         cx.push_stack(iterator);
         Ok(None)
     }
@@ -2335,12 +2335,12 @@ mod handlers {
                     let fun = k
                         .get_property($v.to_key(&mut cx.scope), &mut cx.scope)?
                         .root(&mut cx.scope);
-                    let result = fun.apply(This::Default, args, &mut cx.scope)?;
+                    let result = fun.apply(This::default(), args, &mut cx.scope)?;
                     cx.push_stack(result);
                 } else {
                     // Fastpath: call builtin directly
                     // TODO: should we add to externals?
-                    let result = fun.apply(This::Default, args, &mut cx.scope)?;
+                    let result = fun.apply(This::default(), args, &mut cx.scope)?;
                     cx.push_stack(result);
                 }
             }};

crates/dash_vm/src/frame.rs

@@ -9,12 +9,10 @@ use dash_proc_macro::Trace;
 
 use crate::gc::ObjectId;
 use crate::gc::trace::{Trace, TraceCtxt};
-use crate::localscope::LocalScope;
-use crate::throw;
+use crate::value::object::This;
 use crate::value::string::JsString;
 use crate::value::{ExternalValue, Unrooted};
 
-use super::value::Value;
 use super::value::function::user::UserFunction;
 
 #[derive(Debug, Clone, Copy, Trace)]
@@ -97,41 +95,6 @@ unsafe impl Trace for LoopCounterMap {
     fn trace(&self, _: &mut TraceCtxt<'_>) {}
 }
 
-#[derive(Debug, Clone, Copy)]
-pub enum This {
-    /// No `this` binding. Evaluates to the global object in non-strict mode, or undefined in strict mode
-    Default,
-    /// Initial state of `this` in subclass constructors. Throws an error if attempted to evaluate as a value.
-    /// Gets changed to `Bound` by the call to super().
-    BeforeSuper { super_constructor: ObjectId },
-    /// Bound as a value.
-    Bound(Value),
-}
-
-impl This {
-    pub fn to_value(self, scope: &mut LocalScope<'_>) -> Result<Value, Value> {
-        match self {
-            // TODO: once we have strict mode, eval to undefined
-            This::Default => Ok(Value::object(scope.global)),
-            This::Bound(value) => Ok(value),
-            This::BeforeSuper { .. } => {
-                // panic!();
-                throw!(scope, Error, "`super()` must be called before accessing `this`")
-            }
-        }
-    }
-}
-
-unsafe impl Trace for This {
-    fn trace(&self, cx: &mut TraceCtxt<'_>) {
-        match *self {
-            This::Default => {}
-            This::BeforeSuper { super_constructor } => super_constructor.trace(cx),
-            This::Bound(value) => value.trace(cx),
-        }
-    }
-}
-
 #[derive(Debug, Clone, Trace)]
 pub struct Frame {
     pub function: Rc<Function>,
@@ -225,7 +188,7 @@ impl Frame {
         };
 
         Self {
-            this: This::Default,
+            this: This::default(),
             function: Rc::new(fun),
             externals: Vec::new().into(),
             ip: 0,

crates/dash_vm/src/gc/mod.rs

@@ -11,10 +11,9 @@ use smallvec::SmallVec;
 use trace::TraceCtxt;
 
 use crate::Vm;
-use crate::frame::This;
 use crate::localscope::LocalScope;
 use crate::value::function::args::CallArgs;
-use crate::value::object::PropertyValue;
+use crate::value::object::{PropertyValue, This};
 use crate::value::primitive::InternalSlots;
 use crate::value::propertykey::PropertyKey;
 use crate::value::{Typeof, Unrooted, Value};
@@ -119,6 +118,7 @@ pub struct AllocId<M> {
 }
 
 impl<M> AllocId<M> {
+    #[inline]
     pub(crate) fn from_raw(id_and_chunk: PackedInnerAllocId) -> Self {
         Self {
             id_and_chunk,