Store active runnable and active function in `CallFrame` (#3197)

* Move acrive runnable to CallFrame

* Move active function to CallFrame

* Add some code doc

* Fix doc link

* Apply review

boa_engine/src/builtins/array/mod.rs

@@ -174,9 +174,7 @@ impl BuiltInConstructor for Array {
         // If NewTarget is undefined, let newTarget be the active function object; else let newTarget be NewTarget.
         let new_target = &if new_target.is_undefined() {
             context
-                .vm
-                .active_function
-                .clone()
+                .active_function_object()
                 .unwrap_or_else(|| context.intrinsics().constructors().array().constructor())
                 .into()
         } else {

boa_engine/src/builtins/async_function/mod.rs

@@ -66,7 +66,7 @@ impl BuiltInConstructor for AsyncFunction {
         args: &[JsValue],
         context: &mut Context<'_>,
     ) -> JsResult<JsValue> {
-        let active_function = context.vm.active_function.clone().unwrap_or_else(|| {
+        let active_function = context.active_function_object().unwrap_or_else(|| {
             context
                 .intrinsics()
                 .constructors()

boa_engine/src/builtins/async_generator_function/mod.rs

@@ -71,7 +71,7 @@ impl BuiltInConstructor for AsyncGeneratorFunction {
         args: &[JsValue],
         context: &mut Context<'_>,
     ) -> JsResult<JsValue> {
-        let active_function = context.vm.active_function.clone().unwrap_or_else(|| {
+        let active_function = context.active_function_object().unwrap_or_else(|| {
             context
                 .intrinsics()
                 .constructors()

boa_engine/src/builtins/error/aggregate.rs

@@ -63,9 +63,7 @@ impl BuiltInConstructor for AggregateError {
         // 1. If NewTarget is undefined, let newTarget be the active function object; else let newTarget be NewTarget.
         let new_target = &if new_target.is_undefined() {
             context
-                .vm
-                .active_function
-                .clone()
+                .active_function_object()
                 .unwrap_or_else(|| {
                     context
                         .intrinsics()

boa_engine/src/builtins/error/eval.rs

@@ -65,9 +65,7 @@ impl BuiltInConstructor for EvalError {
         // 1. If NewTarget is undefined, let newTarget be the active function object; else let newTarget be NewTarget.
         let new_target = &if new_target.is_undefined() {
             context
-                .vm
-                .active_function
-                .clone()
+                .active_function_object()
                 .unwrap_or_else(|| {
                     context
                         .intrinsics()

boa_engine/src/builtins/error/mod.rs

@@ -165,9 +165,7 @@ impl BuiltInConstructor for Error {
         // 1. If NewTarget is undefined, let newTarget be the active function object; else let newTarget be NewTarget.
         let new_target = &if new_target.is_undefined() {
             context
-                .vm
-                .active_function
-                .clone()
+                .active_function_object()
                 .unwrap_or_else(|| context.intrinsics().constructors().error().constructor())
                 .into()
         } else {

boa_engine/src/builtins/error/range.rs

@@ -63,9 +63,7 @@ impl BuiltInConstructor for RangeError {
         // 1. If NewTarget is undefined, let newTarget be the active function object; else let newTarget be NewTarget.
         let new_target = &if new_target.is_undefined() {
             context
-                .vm
-                .active_function
-                .clone()
+                .active_function_object()
                 .unwrap_or_else(|| {
                     context
                         .intrinsics()

boa_engine/src/builtins/error/reference.rs

@@ -62,9 +62,7 @@ impl BuiltInConstructor for ReferenceError {
         // 1. If NewTarget is undefined, let newTarget be the active function object; else let newTarget be NewTarget.
         let new_target = &if new_target.is_undefined() {
             context
-                .vm
-                .active_function
-                .clone()
+                .active_function_object()
                 .unwrap_or_else(|| {
                     context
                         .intrinsics()

boa_engine/src/builtins/error/syntax.rs

@@ -65,9 +65,7 @@ impl BuiltInConstructor for SyntaxError {
         // 1. If NewTarget is undefined, let newTarget be the active function object; else let newTarget be NewTarget.
         let new_target = &if new_target.is_undefined() {
             context
-                .vm
-                .active_function
-                .clone()
+                .active_function_object()
                 .unwrap_or_else(|| {
                     context
                         .intrinsics()

boa_engine/src/builtins/error/type.rs

@@ -73,9 +73,7 @@ impl BuiltInConstructor for TypeError {
         // 1. If NewTarget is undefined, let newTarget be the active function object; else let newTarget be NewTarget.
         let new_target = &if new_target.is_undefined() {
             context
-                .vm
-                .active_function
-                .clone()
+                .active_function_object()
                 .unwrap_or_else(|| {
                     context
                         .intrinsics()

boa_engine/src/builtins/error/uri.rs

@@ -64,9 +64,7 @@ impl BuiltInConstructor for UriError {
         // 1. If NewTarget is undefined, let newTarget be the active function object; else let newTarget be NewTarget.
         let new_target = &if new_target.is_undefined() {
             context
-                .vm
-                .active_function
-                .clone()
+                .active_function_object()
                 .unwrap_or_else(|| {
                     context
                         .intrinsics()

boa_engine/src/builtins/eval/mod.rs

@@ -256,7 +256,7 @@ impl Eval {
         let env_fp = context.vm.environments.len() as u32;
         context
             .vm
-            .push_frame(CallFrame::new(code_block).with_env_fp(env_fp));
+            .push_frame(CallFrame::new(code_block, None, None).with_env_fp(env_fp));
         context.realm().resize_global_env();
 
         let record = context.run();

boa_engine/src/builtins/function/mod.rs

@@ -532,9 +532,7 @@ impl BuiltInConstructor for BuiltInFunctionObject {
         context: &mut Context<'_>,
     ) -> JsResult<JsValue> {
         let active_function = context
-            .vm
-            .active_function
-            .clone()
+            .active_function_object()
             .unwrap_or_else(|| context.intrinsics().constructors().function().constructor());
         Self::create_dynamic_function(active_function, new_target, args, false, false, context)
             .map(Into::into)

boa_engine/src/builtins/generator/mod.rs

@@ -60,7 +60,6 @@ unsafe impl Trace for GeneratorState {
 pub(crate) struct GeneratorContext {
     pub(crate) environments: EnvironmentStack,
     pub(crate) stack: Vec<JsValue>,
-    pub(crate) active_function: Option<JsObject>,
     pub(crate) call_frame: Option<CallFrame>,
     pub(crate) realm: Realm,
 }
@@ -70,14 +69,12 @@ impl GeneratorContext {
     pub(crate) fn new(
         environments: EnvironmentStack,
         stack: Vec<JsValue>,
-        active_function: Option<JsObject>,
         call_frame: CallFrame,
         realm: Realm,
     ) -> Self {
         Self {
             environments,
             stack,
-            active_function,
             call_frame: Some(call_frame),
             realm,
         }
@@ -90,7 +87,6 @@ impl GeneratorContext {
             environments: context.vm.environments.clone(),
             call_frame: Some(context.vm.frame().clone()),
             stack: context.vm.stack[fp..].to_vec(),
-            active_function: context.vm.active_function.clone(),
             realm: context.realm().clone(),
         };
 
@@ -108,7 +104,6 @@ impl GeneratorContext {
     ) -> CompletionRecord {
         std::mem::swap(&mut context.vm.environments, &mut self.environments);
         std::mem::swap(&mut context.vm.stack, &mut self.stack);
-        std::mem::swap(&mut context.vm.active_function, &mut self.active_function);
         context.swap_realm(&mut self.realm);
         context
             .vm
@@ -125,7 +120,6 @@ impl GeneratorContext {
 
         std::mem::swap(&mut context.vm.environments, &mut self.environments);
         std::mem::swap(&mut context.vm.stack, &mut self.stack);
-        std::mem::swap(&mut context.vm.active_function, &mut self.active_function);
         context.swap_realm(&mut self.realm);
         self.call_frame = context.vm.pop_frame();
         assert!(self.call_frame.is_some());

boa_engine/src/builtins/generator_function/mod.rs

@@ -76,7 +76,7 @@ impl BuiltInConstructor for GeneratorFunction {
         args: &[JsValue],
         context: &mut Context<'_>,
     ) -> JsResult<JsValue> {
-        let active_function = context.vm.active_function.clone().unwrap_or_else(|| {
+        let active_function = context.active_function_object().unwrap_or_else(|| {
             context
                 .intrinsics()
                 .constructors()

boa_engine/src/builtins/intl/collator/mod.rs

@@ -216,9 +216,7 @@ impl BuiltInConstructor for Collator {
         // 1. If NewTarget is undefined, let newTarget be the active function object, else let newTarget be NewTarget.
         let new_target = &if new_target.is_undefined() {
             context
-                .vm
-                .active_function
-                .clone()
+                .active_function_object()
                 .unwrap_or_else(|| context.intrinsics().constructors().collator().constructor())
                 .into()
         } else {

boa_engine/src/builtins/intl/date_time_format.rs

@@ -99,9 +99,7 @@ impl BuiltInConstructor for DateTimeFormat {
         // 1. If NewTarget is undefined, let newTarget be the active function object, else let newTarget be NewTarget.
         let new_target = &if new_target.is_undefined() {
             context
-                .vm
-                .active_function
-                .clone()
+                .active_function_object()
                 .unwrap_or_else(|| {
                     context
                         .intrinsics()

boa_engine/src/builtins/json/mod.rs

@@ -131,7 +131,7 @@ impl Json {
         let env_fp = context.vm.environments.len() as u32;
         context
             .vm
-            .push_frame(CallFrame::new(code_block).with_env_fp(env_fp));
+            .push_frame(CallFrame::new(code_block, None, None).with_env_fp(env_fp));
         context.realm().resize_global_env();
         let record = context.run();
         context.vm.pop_frame();

boa_engine/src/builtins/object/mod.rs

@@ -131,9 +131,7 @@ impl BuiltInConstructor for Object {
         if !new_target.is_undefined()
             && new_target
                 != &context
-                    .vm
-                    .active_function
-                    .clone()
+                    .active_function_object()
                     .unwrap_or_else(|| context.intrinsics().constructors().object().constructor())
                     .into()
         {

boa_engine/src/builtins/regexp/mod.rs

@@ -172,9 +172,7 @@ impl BuiltInConstructor for RegExp {
         if new_target.is_undefined() {
             // a. Let newTarget be the active function object.
             let new_target = context
-                .vm
-                .active_function
-                .clone()
+                .active_function_object()
                 .map_or(JsValue::undefined(), JsValue::new);
 
             // b. If patternIsRegExp is true and flags is undefined, then

boa_engine/src/context/mod.rs

@@ -27,7 +27,7 @@ use crate::{
     property::{Attribute, PropertyDescriptor, PropertyKey},
     realm::Realm,
     script::Script,
-    vm::{CallFrame, Vm},
+    vm::{ActiveRunnable, CallFrame, Vm},
     JsResult, JsValue, Source,
 };
 use boa_ast::{expression::Identifier, StatementList};
@@ -706,6 +706,41 @@ impl Context<'_> {
     pub(crate) const fn is_strict(&self) -> bool {
         self.strict
     }
+
+    /// `9.4.1 GetActiveScriptOrModule ( )`
+    ///
+    /// More information:
+    ///  - [ECMAScript reference][spec]
+    ///
+    /// [spec]: https://tc39.es/ecma262/#sec-getactivescriptormodule
+    pub(crate) fn get_active_script_or_module(&self) -> Option<ActiveRunnable> {
+        // 1. If the execution context stack is empty, return null.
+        // 2. Let ec be the topmost execution context on the execution context stack whose ScriptOrModule component is not null.
+        // 3. If no such execution context exists, return null. Otherwise, return ec's ScriptOrModule.
+        self.vm
+            .frames
+            .iter()
+            .rev()
+            .find_map(|frame| frame.active_runnable.clone())
+    }
+
+    /// Get `active function object`
+    ///
+    /// More information:
+    ///  - [ECMAScript reference][spec]
+    ///
+    /// [spec]: https://tc39.es/ecma262/#active-function-object
+    pub(crate) fn active_function_object(&self) -> Option<JsObject> {
+        if self.vm.native_active_function.is_some() {
+            return self.vm.native_active_function.clone();
+        }
+
+        if let Some(frame) = self.vm.frames.last() {
+            return frame.active_function.clone();
+        }
+
+        None
+    }
 }
 
 impl<'host> Context<'host> {

boa_engine/src/job.rs

@@ -22,7 +22,6 @@ use std::{any::Any, cell::RefCell, collections::VecDeque, fmt::Debug, future::Fu
 use crate::{
     object::{JsFunction, NativeObject},
     realm::Realm,
-    vm::ActiveRunnable,
     Context, JsResult, JsValue,
 };
 use boa_gc::{Finalize, Trace};
@@ -69,7 +68,6 @@ pub struct NativeJob {
     #[allow(clippy::type_complexity)]
     f: Box<dyn FnOnce(&mut Context<'_>) -> JsResult<JsValue>>,
     realm: Option<Realm>,
-    active_runnable: Option<ActiveRunnable>,
 }
 
 impl Debug for NativeJob {
@@ -87,19 +85,17 @@ impl NativeJob {
         Self {
             f: Box::new(f),
             realm: None,
-            active_runnable: None,
         }
     }
 
     /// Creates a new `NativeJob` from a closure and an execution realm.
-    pub fn with_realm<F>(f: F, realm: Realm, context: &mut Context<'_>) -> Self
+    pub fn with_realm<F>(f: F, realm: Realm, _context: &mut Context<'_>) -> Self
     where
         F: FnOnce(&mut Context<'_>) -> JsResult<JsValue> + 'static,
     {
         Self {
             f: Box::new(f),
             realm: Some(realm),
-            active_runnable: context.vm.active_runnable.clone(),
         }
     }
 
@@ -115,7 +111,7 @@ impl NativeJob {
     ///
     /// If the native job has an execution realm defined, this sets the running execution
     /// context to the realm's before calling the inner closure, and resets it after execution.
-    pub fn call(mut self, context: &mut Context<'_>) -> JsResult<JsValue> {
+    pub fn call(self, context: &mut Context<'_>) -> JsResult<JsValue> {
         // If realm is not null, each time job is invoked the implementation must perform
         // implementation-defined steps such that execution is prepared to evaluate ECMAScript
         // code at the time of job's invocation.
@@ -126,12 +122,9 @@ impl NativeJob {
             // invoked. If realm is not null, each time job is invoked the implementation must
             // perform implementation-defined steps such that scriptOrModule is the active script or
             // module at the time of job's invocation.
-            std::mem::swap(&mut context.vm.active_runnable, &mut self.active_runnable);
-
             let result = (self.f)(context);
 
             context.enter_realm(old_realm);
-            std::mem::swap(&mut context.vm.active_runnable, &mut self.active_runnable);
 
             result
         } else {

boa_engine/src/module/source.rs

@@ -1607,20 +1607,19 @@ impl SourceTextModule {
         let mut envs = EnvironmentStack::new(global_env);
         envs.push_module(module_compile_env);
 
+        // 9. Set the Function of moduleContext to null.
         // 12. Set the ScriptOrModule of moduleContext to module.
-        let active_runnable = context
-            .vm
-            .active_runnable
-            .replace(ActiveRunnable::Module(parent.clone()));
+        let call_frame = CallFrame::new(
+            codeblock.clone(),
+            Some(ActiveRunnable::Module(parent.clone())),
+            None,
+        );
+        context.vm.push_frame(call_frame);
 
         // 13. Set the VariableEnvironment of moduleContext to module.[[Environment]].
         // 14. Set the LexicalEnvironment of moduleContext to module.[[Environment]].
         // 15. Set the PrivateEnvironment of moduleContext to null.
         std::mem::swap(&mut context.vm.environments, &mut envs);
-        let stack = std::mem::take(&mut context.vm.stack);
-
-        // 9. Set the Function of moduleContext to null.
-        let active_function = context.vm.active_function.take();
 
         // 10. Assert: module.[[Realm]] is not undefined.
         // 11. Set the Realm of moduleContext to module.[[Realm]].
@@ -1682,10 +1681,11 @@ impl SourceTextModule {
         }
 
         // 25. Remove moduleContext from the execution context stack.
+        context
+            .vm
+            .pop_frame()
+            .expect("There should be a call frame");
         std::mem::swap(&mut context.vm.environments, &mut envs);
-        context.vm.stack = stack;
-        context.vm.active_function = active_function;
-        context.vm.active_runnable = active_runnable;
         context.swap_realm(&mut realm);
 
         debug_assert!(envs.current().as_declarative().is_some());
@@ -1733,22 +1733,18 @@ impl SourceTextModule {
             _ => unreachable!("`execute` should only be called for evaluating modules."),
         };
 
+        // 2. Set the Function of moduleContext to null.
+        // 4. Set the ScriptOrModule of moduleContext to module.
         let env_fp = environments.len() as u32;
-        let mut callframe = CallFrame::new(codeblock).with_env_fp(env_fp);
+        let mut callframe =
+            CallFrame::new(codeblock, Some(ActiveRunnable::Module(self.parent())), None)
+                .with_env_fp(env_fp);
         callframe.promise_capability = capability;
 
-        // 4. Set the ScriptOrModule of moduleContext to module.
-        let active_runnable = context
-            .vm
-            .active_runnable
-            .replace(ActiveRunnable::Module(self.parent()));
-
         // 5. Assert: module has been linked and declarations in its module environment have been instantiated.
         // 6. Set the VariableEnvironment of moduleContext to module.[[Environment]].
         // 7. Set the LexicalEnvironment of moduleContext to module.[[Environment]].
         std::mem::swap(&mut context.vm.environments, &mut environments);
-        // 2. Set the Function of moduleContext to null.
-        let function = context.vm.active_function.take();
         // 3. Set the Realm of moduleContext to module.[[Realm]].
         context.swap_realm(&mut realm);
         // 8. Suspend the running execution context.
@@ -1766,8 +1762,6 @@ impl SourceTextModule {
         let result = context.run();
 
         std::mem::swap(&mut context.vm.environments, &mut environments);
-        context.vm.active_function = function;
-        context.vm.active_runnable = active_runnable;
         context.swap_realm(&mut realm);
         context.vm.pop_frame();
 

boa_engine/src/script.rs

@@ -138,15 +138,11 @@ impl Script {
         let codeblock = self.codeblock(context)?;
 
         let old_realm = context.enter_realm(self.inner.realm.clone());
-        let active_function = context.vm.active_function.take();
-        let old_active = context
-            .vm
-            .active_runnable
-            .replace(ActiveRunnable::Script(self.clone()));
         let env_fp = context.vm.environments.len() as u32;
-        context
-            .vm
-            .push_frame(CallFrame::new(codeblock).with_env_fp(env_fp));
+        context.vm.push_frame(
+            CallFrame::new(codeblock, Some(ActiveRunnable::Script(self.clone())), None)
+                .with_env_fp(env_fp),
+        );
 
         // TODO: Here should be https://tc39.es/ecma262/#sec-globaldeclarationinstantiation
 
@@ -154,8 +150,6 @@ impl Script {
         let record = context.run();
         context.vm.pop_frame();
 
-        context.vm.active_function = active_function;
-        context.vm.active_runnable = old_active;
         context.enter_realm(old_realm);
 
         context.clear_kept_objects();

boa_engine/src/vm/call_frame/mod.rs

@@ -12,6 +12,8 @@ use crate::{
 use boa_gc::{Finalize, Gc, Trace};
 use thin_vec::ThinVec;
 
+use super::ActiveRunnable;
+
 /// A `CallFrame` holds the state of a function call.
 #[derive(Clone, Debug, Finalize, Trace)]
 pub struct CallFrame {
@@ -36,6 +38,11 @@ pub struct CallFrame {
 
     /// How many iterations a loop has done.
     pub(crate) loop_iteration_count: u64,
+
+    /// \[\[ScriptOrModule\]\]
+    pub(crate) active_runnable: Option<ActiveRunnable>,
+
+    pub(crate) active_function: Option<JsObject>,
 }
 
 /// ---- `CallFrame` public API ----
@@ -51,7 +58,11 @@ impl CallFrame {
 /// ---- `CallFrame` creation methods ----
 impl CallFrame {
     /// Creates a new `CallFrame` with the provided `CodeBlock`.
-    pub(crate) fn new(code_block: Gc<CodeBlock>) -> Self {
+    pub(crate) fn new(
+        code_block: Gc<CodeBlock>,
+        active_runnable: Option<ActiveRunnable>,
+        active_function: Option<JsObject>,
+    ) -> Self {
         Self {
             code_block,
             pc: 0,
@@ -63,6 +74,8 @@ impl CallFrame {
             iterators: ThinVec::new(),
             binding_stack: Vec::new(),
             loop_iteration_count: 0,
+            active_runnable,
+            active_function,
         }
     }
 

boa_engine/src/vm/code_block.rs

@@ -758,7 +758,7 @@ pub(crate) fn create_function_object(
     let name: JsValue = code.name().clone().into();
     let length: JsValue = code.length.into();
 
-    let script_or_module = context.vm.active_runnable.clone();
+    let script_or_module = context.get_active_script_or_module();
 
     let function = if r#async {
         Function::new(
@@ -838,7 +838,7 @@ pub(crate) fn create_function_object_fast(
     let name: JsValue = code.name().clone().into();
     let length: JsValue = code.length.into();
 
-    let script_or_module = context.vm.active_runnable.clone();
+    let script_or_module = context.get_active_script_or_module();
 
     let function = if r#async {
         FunctionKind::Async {
@@ -943,7 +943,7 @@ pub(crate) fn create_generator_function_object(
         ObjectData::ordinary(),
     );
 
-    let script_or_module = context.vm.active_runnable.clone();
+    let script_or_module = context.get_active_script_or_module();
 
     let constructor = if r#async {
         let function = Function::new(
@@ -1007,87 +1007,89 @@ impl JsObject {
         context: &mut Context<'_>,
     ) -> JsResult<JsValue> {
         let old_realm = context.realm().clone();
-        let old_active_fn = context.vm.active_function.clone();
 
         let context = &mut context.guard(move |ctx| {
             ctx.enter_realm(old_realm);
-            ctx.vm.active_function = old_active_fn;
         });
 
         let this_function_object = self.clone();
-        let active_function = self.clone();
         let object = self.borrow();
         let function_object = object.as_function().expect("not a function");
         let realm = function_object.realm().clone();
 
         context.enter_realm(realm);
-        context.vm.active_function = Some(active_function);
-
-        let (code, mut environments, class_object, mut script_or_module) =
-            match function_object.kind() {
-                FunctionKind::Native {
-                    function,
-                    constructor,
-                } => {
-                    let function = function.clone();
-                    let constructor = *constructor;
-                    drop(object);
-
-                    return if constructor.is_some() {
-                        function.call(&JsValue::undefined(), args, context)
-                    } else {
-                        function.call(this, args, context)
-                    }
-                    .map_err(|err| err.inject_realm(context.realm().clone()));
-                }
-                FunctionKind::Ordinary {
-                    code,
-                    environments,
-                    class_object,
-                    script_or_module,
-                    ..
-                } => {
-                    let code = code.clone();
-                    if code.is_class_constructor() {
-                        return Err(JsNativeError::typ()
-                            .with_message("class constructor cannot be invoked without 'new'")
-                            .with_realm(context.realm().clone())
-                            .into());
-                    }
-                    (
-                        code,
-                        environments.clone(),
-                        class_object.clone(),
-                        script_or_module.clone(),
-                    )
-                }
-                FunctionKind::Async {
-                    code,
-                    environments,
-                    class_object,
-                    script_or_module,
-                    ..
+
+        let (code, mut environments, class_object, script_or_module) = match function_object.kind()
+        {
+            FunctionKind::Native {
+                function,
+                constructor,
+            } => {
+                let function = function.clone();
+                let constructor = *constructor;
+                drop(object);
+
+                context.vm.native_active_function = Some(this_function_object);
+
+                let result = if constructor.is_some() {
+                    function.call(&JsValue::undefined(), args, context)
+                } else {
+                    function.call(this, args, context)
                 }
-                | FunctionKind::Generator {
-                    code,
-                    environments,
-                    class_object,
-                    script_or_module,
-                    ..
+                .map_err(|err| err.inject_realm(context.realm().clone()));
+
+                context.vm.native_active_function = None;
+
+                return result;
+            }
+            FunctionKind::Ordinary {
+                code,
+                environments,
+                class_object,
+                script_or_module,
+                ..
+            } => {
+                let code = code.clone();
+                if code.is_class_constructor() {
+                    return Err(JsNativeError::typ()
+                        .with_message("class constructor cannot be invoked without 'new'")
+                        .with_realm(context.realm().clone())
+                        .into());
                 }
-                | FunctionKind::AsyncGenerator {
+                (
                     code,
-                    environments,
-                    class_object,
-                    script_or_module,
-                    ..
-                } => (
-                    code.clone(),
                     environments.clone(),
                     class_object.clone(),
                     script_or_module.clone(),
-                ),
-            };
+                )
+            }
+            FunctionKind::Async {
+                code,
+                environments,
+                class_object,
+                script_or_module,
+                ..
+            }
+            | FunctionKind::Generator {
+                code,
+                environments,
+                class_object,
+                script_or_module,
+                ..
+            }
+            | FunctionKind::AsyncGenerator {
+                code,
+                environments,
+                class_object,
+                script_or_module,
+                ..
+            } => (
+                code.clone(),
+                environments.clone(),
+                class_object.clone(),
+                script_or_module.clone(),
+            ),
+        };
 
         drop(object);
 
@@ -1185,12 +1187,10 @@ impl JsObject {
         let argument_count = args.len();
         let parameters_count = code.params.as_ref().len();
 
-        let frame = CallFrame::new(code)
+        let frame = CallFrame::new(code, script_or_module, Some(self.clone()))
             .with_argument_count(argument_count as u32)
             .with_env_fp(env_fp);
 
-        std::mem::swap(&mut context.vm.active_runnable, &mut script_or_module);
-
         context.vm.push_frame(frame);
 
         // Push function arguments to the stack.
@@ -1206,7 +1206,6 @@ impl JsObject {
 
         context.vm.pop_frame().expect("frame must exist");
         std::mem::swap(&mut environments, &mut context.vm.environments);
-        std::mem::swap(&mut context.vm.active_runnable, &mut script_or_module);
 
         result
     }
@@ -1218,20 +1217,16 @@ impl JsObject {
         context: &mut Context<'_>,
     ) -> JsResult<Self> {
         let old_realm = context.realm().clone();
-        let old_active_fn = context.vm.active_function.clone();
         let context = &mut context.guard(move |ctx| {
             ctx.enter_realm(old_realm);
-            ctx.vm.active_function = old_active_fn;
         });
 
         let this_function_object = self.clone();
-        let active_function = self.clone();
         let object = self.borrow();
         let function_object = object.as_function().expect("not a function");
         let realm = function_object.realm().clone();
 
         context.enter_realm(realm);
-        context.vm.active_function = Some(active_function);
 
         match function_object.kind() {
             FunctionKind::Native {
@@ -1243,7 +1238,9 @@ impl JsObject {
                 let constructor = *constructor;
                 drop(object);
 
-                function
+                context.vm.native_active_function = Some(this_function_object);
+
+                let result = function
                     .call(this_target, args, context)
                     .map_err(|err| err.inject_realm(context.realm().clone()))
                     .and_then(|v| match v {
@@ -1270,7 +1267,11 @@ impl JsObject {
                                 .into())
                             }
                         }
-                    })
+                    });
+
+                context.vm.native_active_function = None;
+
+                result
             }
             FunctionKind::Ordinary {
                 code,
@@ -1281,7 +1282,7 @@ impl JsObject {
             } => {
                 let code = code.clone();
                 let mut environments = environments.clone();
-                let mut script_or_module = script_or_module.clone();
+                let script_or_module = script_or_module.clone();
                 let constructor_kind = *constructor_kind;
                 drop(object);
 
@@ -1384,10 +1385,8 @@ impl JsObject {
 
                 let has_binding_identifier = code.has_binding_identifier();
 
-                std::mem::swap(&mut context.vm.active_runnable, &mut script_or_module);
-
                 context.vm.push_frame(
-                    CallFrame::new(code)
+                    CallFrame::new(code, script_or_module, Some(self.clone()))
                         .with_argument_count(argument_count as u32)
                         .with_env_fp(environments_len as u32),
                 );
@@ -1403,7 +1402,6 @@ impl JsObject {
                 context.vm.pop_frame();
 
                 std::mem::swap(&mut environments, &mut context.vm.environments);
-                std::mem::swap(&mut context.vm.active_runnable, &mut script_or_module);
 
                 let environment = if has_binding_identifier {
                     environments.truncate(environments_len + 2);

boa_engine/src/vm/mod.rs

@@ -69,8 +69,10 @@ pub struct Vm {
     pub(crate) pending_exception: Option<JsError>,
     pub(crate) environments: EnvironmentStack,
     pub(crate) runtime_limits: RuntimeLimits,
-    pub(crate) active_function: Option<JsObject>,
-    pub(crate) active_runnable: Option<ActiveRunnable>,
+
+    /// This is used to assign a native (rust) function as the active function,
+    /// because we don't push a frame for them.
+    pub(crate) native_active_function: Option<JsObject>,
 
     #[cfg(feature = "trace")]
     pub(crate) trace: bool,
@@ -102,8 +104,7 @@ impl Vm {
             environments: EnvironmentStack::new(global),
             pending_exception: None,
             runtime_limits: RuntimeLimits::default(),
-            active_function: None,
-            active_runnable: None,
+            native_active_function: None,
             #[cfg(feature = "trace")]
             trace: false,
         }

boa_engine/src/vm/opcode/call/mod.rs

@@ -272,9 +272,7 @@ impl Operation for ImportCall {
         // 1. Let referrer be GetActiveScriptOrModule().
         // 2. If referrer is null, set referrer to the current Realm Record.
         let referrer = context
-            .vm
-            .active_runnable
-            .clone()
+            .get_active_script_or_module()
             .map_or_else(|| Referrer::Realm(context.realm().clone()), Into::into);
 
         // 3. Let argRef be ? Evaluation of AssignmentExpression.

boa_engine/src/vm/opcode/generator/mod.rs

@@ -38,8 +38,11 @@ impl Operation for Generator {
         let r#async = context.vm.read::<u8>() != 0;
 
         let code_block = context.vm.frame().code_block().clone();
+        let active_runnable = context.vm.frame().active_runnable.clone();
+        let active_function = context.vm.frame().active_function.clone();
         let pc = context.vm.frame().pc;
-        let mut dummy_call_frame = CallFrame::new(code_block);
+        let mut dummy_call_frame =
+            CallFrame::new(code_block, active_runnable, active_function.clone());
         dummy_call_frame.pc = pc;
         let mut call_frame = std::mem::replace(context.vm.frame_mut(), dummy_call_frame);
 
@@ -50,11 +53,8 @@ impl Operation for Generator {
 
         call_frame.fp = 0;
 
-        let this_function_object = context
-            .vm
-            .active_function
-            .clone()
-            .expect("active function should be set to the generator");
+        let this_function_object =
+            active_function.expect("active function should be set to the generator");
 
         let proto = this_function_object
             .get(PROTOTYPE, context)
@@ -83,7 +83,6 @@ impl Operation for Generator {
                 context: Some(GeneratorContext::new(
                     environments,
                     stack,
-                    context.vm.active_function.clone(),
                     call_frame,
                     context.realm().clone(),
                 )),
@@ -95,7 +94,6 @@ impl Operation for Generator {
                     context: GeneratorContext::new(
                         environments,
                         stack,
-                        context.vm.active_function.clone(),
                         call_frame,
                         context.realm().clone(),
                     ),

boa_engine/src/vm/opcode/meta/mod.rs

@@ -54,7 +54,7 @@ impl Operation for ImportMeta {
 
         // 1. Let module be GetActiveScriptOrModule().
 
-        let Some(ActiveRunnable::Module(module)) = context.vm.active_runnable.clone() else {
+        let Some(ActiveRunnable::Module(module)) = context.get_active_script_or_module() else {
             unreachable!("2. Assert: module is a Source Text Module Record.");
         };