preserve this binding in generator functions

fixes #93
y21 · Dec 28, 2024 · 3af6a7c · 3af6a7c
1 parent 5d023dd
commit 3af6a7c
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Showing 4 changed files with 16 additions and 12 deletions.
diff --git a/crates/dash_vm/src/eval.rs b/crates/dash_vm/src/eval.rs
@@ -2,15 +2,15 @@ use dash_compiler::FunctionCompiler;
 use dash_lexer::Lexer;
 use dash_middle::compiler::StaticImportKind;
 use dash_middle::interner::sym;
-use dash_optimizer::type_infer::name_res;
 use dash_optimizer::OptLevel;
+use dash_optimizer::type_infer::name_res;
 use dash_parser::Parser;
 
 use crate::frame::Frame;
 use crate::localscope::LocalScope;
 use crate::value::object::{NamedObject, Object, PropertyValue};
 use crate::value::{Root, Unrooted, Value};
-use crate::{throw, Vm};
+use crate::{Vm, throw};
 
 #[derive(Debug)]
 pub enum EvalError {

diff --git a/crates/dash_vm/src/js_std/generator.rs b/crates/dash_vm/src/js_std/generator.rs
@@ -1,7 +1,7 @@
 use std::mem;
 
 use crate::dispatch::HandleResult;
-use crate::frame::{Frame, This};
+use crate::frame::Frame;
 use crate::localscope::LocalScope;
 use crate::throw;
 use crate::value::function::generator::{GeneratorIterator, GeneratorState};
@@ -18,14 +18,15 @@ pub fn next(cx: CallContext) -> Result<Value, Value> {
     let generator = receiver_t::<GeneratorIterator>(cx.scope, &cx.this, "GeneratorIterator.prototype.next")?;
     let arg = cx.args.first().unwrap_or_undefined();
     let frame = {
-        let (ip, old_stack, arguments, try_blocks) = match &mut *generator.state().borrow_mut() {
+        let (ip, old_stack, arguments, try_blocks, this) = match &mut *generator.state().borrow_mut() {
             GeneratorState::Finished => return create_generator_value(cx.scope, true, None),
             GeneratorState::Running {
                 ip,
                 stack,
                 arguments,
                 try_blocks,
-            } => (*ip, mem::take(stack), arguments.take(), mem::take(try_blocks)),
+                this,
+            } => (*ip, mem::take(stack), arguments.take(), mem::take(try_blocks), *this),
         };
 
         let function = generator.function();
@@ -39,7 +40,7 @@ pub fn next(cx: CallContext) -> Result<Value, Value> {
         let current_sp = cx.scope.stack_size();
         cx.scope.try_extend_stack(old_stack).root_err(cx.scope)?;
 
-        let mut frame = Frame::from_function(This::Default, function, None, false, arguments);
+        let mut frame = Frame::from_function(this, function, None, false, arguments);
         frame.set_ip(ip);
         frame.set_sp(current_sp);
 
@@ -99,6 +100,7 @@ pub fn next(cx: CallContext) -> Result<Value, Value> {
                 stack,
                 arguments: frame.arguments,
                 try_blocks,
+                this: frame.this,
             });
 
             create_generator_value(cx.scope, false, Some(value))

diff --git a/crates/dash_vm/src/value/function/async.rs b/crates/dash_vm/src/value/function/async.rs
@@ -85,10 +85,7 @@ impl AsyncFunction {
                     Ok(promise)
                 }
             }
-            Err(value) => {
-                let promise = wrap_promise(scope, value);
-                Err(promise.into())
-            }
+            Err(value) => Err(value.into()),
         }
     }
 }

diff --git a/crates/dash_vm/src/value/function/generator.rs b/crates/dash_vm/src/value/function/generator.rs
@@ -28,7 +28,7 @@ impl GeneratorFunction {
         &self,
         scope: &mut LocalScope,
         callee: ObjectId,
-        _this: This,
+        this: This,
         args: Vec<Value>,
         _new_target: Option<ObjectId>,
     ) -> Result<Value, Unrooted> {
@@ -50,7 +50,7 @@ impl GeneratorFunction {
             scope.stack.drain(sp..).collect::<Vec<_>>()
         };
 
-        let iter = GeneratorIterator::new(callee, scope, args, arguments, Vec::new());
+        let iter = GeneratorIterator::new(callee, scope, args, arguments, Vec::new(), this);
         Ok(Value::object(scope.register(iter)))
     }
 }
@@ -63,6 +63,7 @@ pub enum GeneratorState {
         stack: Vec<Value>,
         try_blocks: Vec<TryBlock>,
         arguments: Option<ObjectId>,
+        this: This,
     },
 }
 
@@ -84,10 +85,12 @@ unsafe impl Trace for GeneratorState {
                 stack,
                 arguments,
                 try_blocks,
+                this,
             } => {
                 stack.trace(cx);
                 arguments.trace(cx);
                 try_blocks.trace(cx);
+                this.trace(cx);
             }
         }
     }
@@ -107,6 +110,7 @@ impl GeneratorIterator {
         stack: Vec<Value>,
         arguments: Option<ObjectId>,
         try_blocks: Vec<TryBlock>,
+        this: This,
     ) -> Self {
         Self {
             function,
@@ -116,6 +120,7 @@ impl GeneratorIterator {
                 stack,
                 arguments,
                 try_blocks,
+                this,
             }),
         }
     }