Fix super() construction with default parameters (#3339)

- Remove unused `PushDeclarativeEnvironment` opcode

boa_engine/src/bytecompiler/declarations.rs

@@ -1030,8 +1030,8 @@ impl ByteCompiler<'_, '_> {
             //          visibility of declarations in the function body.
             // b. Let varEnv be NewDeclarativeEnvironment(env).
             // c. Set the VariableEnvironment of calleeContext to varEnv.
-            self.push_compile_environment(true);
+            self.push_compile_environment(false);
-            env_label = Some(self.emit_opcode_with_operand(Opcode::PushFunctionEnvironment));
+            env_label = Some(self.emit_opcode_with_operand(Opcode::PushDeclarativeEnvironment));
 
             // d. Let instantiatedVarNames be a new empty List.
             let mut instantiated_var_names = Vec::new();

boa_engine/src/environments/compile.rs

@@ -291,9 +291,4 @@ impl CompileTimeEnvironment {
     pub(crate) fn outer(&self) -> Option<Rc<Self>> {
         self.outer.clone()
     }
-
-    /// Gets the environment index of this environment.
-    pub(crate) const fn environment_index(&self) -> u32 {
-        self.environment_index
-    }
 }

boa_engine/src/environments/runtime/mod.rs

@@ -309,61 +309,6 @@ impl EnvironmentStack {
         )));
     }
 
-    /// Push a function environment that inherits it's internal slots from the outer function
-    /// environment.
-    ///
-    /// # Panics
-    ///
-    /// Panics if no environment exists on the stack.
-    #[track_caller]
-    pub(crate) fn push_function_inherit(
-        &mut self,
-        compile_environment: Rc<CompileTimeEnvironment>,
-    ) {
-        let num_bindings = compile_environment.num_bindings();
-
-        debug_assert!(
-            self.stack.len() as u32 == compile_environment.environment_index(),
-            "tried to push an invalid compile environment"
-        );
-
-        let (poisoned, with, slots) = {
-            let with = self
-                .stack
-                .last()
-                .expect("can only be called inside a function")
-                .as_declarative()
-                .is_none();
-
-            let (environment, slots) = self
-                .stack
-                .iter()
-                .rev()
-                .find_map(|env| {
-                    if let Some(env) = env.as_declarative() {
-                        if let DeclarativeEnvironmentKind::Function(fun) = env.kind() {
-                            return Some((env, fun.slots().clone()));
-                        }
-                    }
-                    None
-                })
-                .expect("can only be called inside a function");
-            (environment.poisoned(), with || environment.with(), slots)
-        };
-
-        self.stack.push(Environment::Declarative(Gc::new(
-            DeclarativeEnvironment::new(
-                DeclarativeEnvironmentKind::Function(FunctionEnvironment::new(
-                    num_bindings,
-                    poisoned,
-                    with,
-                    slots,
-                )),
-                compile_environment,
-            ),
-        )));
-    }
-
     /// Push a module environment on the environments stack.
     ///
     /// # Panics

boa_engine/src/vm/code_block.rs

@@ -361,9 +361,6 @@ impl CodeBlock {
             | Instruction::ConcatToString { value_count: value } => value.value().to_string(),
             Instruction::PushDeclarativeEnvironment {
                 compile_environments_index,
-            }
-            | Instruction::PushFunctionEnvironment {
-                compile_environments_index,
             } => compile_environments_index.to_string(),
             Instruction::CopyDataProperties {
                 excluded_key_count: value1,
@@ -643,7 +640,8 @@ impl CodeBlock {
             | Instruction::Reserved53
             | Instruction::Reserved54
             | Instruction::Reserved55
-            | Instruction::Reserved56 => unreachable!("Reserved opcodes are unrechable"),
+            | Instruction::Reserved56
+            | Instruction::Reserved57 => unreachable!("Reserved opcodes are unrechable"),
         }
     }
 }

boa_engine/src/vm/flowgraph/mod.rs

@@ -226,8 +226,7 @@ impl CodeBlock {
                     graph.add_node(previous_pc, NodeShape::None, label.into(), Color::None);
                     graph.add_edge(previous_pc, pc, None, Color::None, EdgeStyle::Line);
                 }
-                Instruction::PushDeclarativeEnvironment { .. }
+                Instruction::PushDeclarativeEnvironment { .. } => {
-                | Instruction::PushFunctionEnvironment { .. } => {
                     let random = rand::random();
 
                     graph.add_node(
@@ -522,7 +521,8 @@ impl CodeBlock {
                 | Instruction::Reserved53
                 | Instruction::Reserved54
                 | Instruction::Reserved55
-                | Instruction::Reserved56 => unreachable!("Reserved opcodes are unrechable"),
+                | Instruction::Reserved56
+                | Instruction::Reserved57 => unreachable!("Reserved opcodes are unrechable"),
             }
         }
 

boa_engine/src/vm/opcode/mod.rs

@@ -1757,13 +1757,6 @@ generate_opcodes! {
     /// Stack: object **=>**
     PushObjectEnvironment,
 
-    /// Push a function environment.
-    ///
-    /// Operands: compile_environments_index: `u32`
-    ///
-    /// Stack: **=>**
-    PushFunctionEnvironment { compile_environments_index: u32 },
-
     /// Pop the current environment.
     ///
     /// Operands:
@@ -2183,6 +2176,8 @@ generate_opcodes! {
     Reserved55 => Reserved,
     /// Reserved [`Opcode`].
     Reserved56 => Reserved,
+    /// Reserved [`Opcode`].
+    Reserved57 => Reserved,
 }
 
 /// Specific opcodes for bindings.

boa_engine/src/vm/opcode/push/environment.rs

@@ -26,30 +26,6 @@ impl Operation for PushDeclarativeEnvironment {
     }
 }
 
-/// `PushFunctionEnvironment` implements the Opcode Operation for `Opcode::PushFunctionEnvironment`
-///
-/// Operation:
-///  - Push a function environment.
-#[derive(Debug, Clone, Copy)]
-pub(crate) struct PushFunctionEnvironment;
-
-impl Operation for PushFunctionEnvironment {
-    const NAME: &'static str = "PushFunctionEnvironment";
-    const INSTRUCTION: &'static str = "INST - PushFunctionEnvironment";
-
-    fn execute(context: &mut Context<'_>) -> JsResult<CompletionType> {
-        let compile_environments_index = context.vm.read::<u32>();
-        let compile_environment = context.vm.frame().code_block.compile_environments
-            [compile_environments_index as usize]
-            .clone();
-        context
-            .vm
-            .environments
-            .push_function_inherit(compile_environment);
-        Ok(CompletionType::Normal)
-    }
-}
-
 /// `PushObjectEnvironment` implements the Opcode Operation for `Opcode::PushObjectEnvironment`
 ///
 /// Operation:

boa_engine/src/vm/tests.rs

@@ -366,3 +366,24 @@ fn truncate_environments_on_non_caught_native_error() {
         TestAction::assert_native_error(source, JsNativeErrorKind::Reference, "a is not defined"),
     ]);
 }
+
+#[test]
+fn super_construction_with_paramater_expression() {
+    run_test_actions([
+        TestAction::run(indoc! {r#"
+            class Person {
+                constructor(name) {
+                    this.name = name;
+                }
+            }
+
+            class Student extends Person {
+                constructor(name = 'unknown') {
+                    super(name);
+                }
+            }
+        "#}),
+        TestAction::assert_eq("new Student().name", js_string!("unknown")),
+        TestAction::assert_eq("new Student('Jack').name", js_string!("Jack")),
+    ]);
+}