Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Refactor EnvironmentRecordTrait functions #1569

Merged
merged 1 commit into from
Sep 15, 2021
Merged

Refactor EnvironmentRecordTrait functions #1569

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
4 changes: 2 additions & 2 deletions boa/src/builtins/function/mod.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -159,7 +159,7 @@ impl Function {
// Create binding
local_env
// Function parameters can share names in JavaScript...
.create_mutable_binding(param.name().to_owned(), false, true, context)
.create_mutable_binding(param.name(), false, true, context)
.expect("Failed to create binding for rest param");

// Set Binding to value
Expand All @@ -178,7 +178,7 @@ impl Function {
) {
// Create binding
local_env
.create_mutable_binding(param.name().to_owned(), false, true, context)
.create_mutable_binding(param.name(), false, true, context)
.expect("Failed to create binding");

// Set Binding to value
Expand Down
151 changes: 125 additions & 26 deletions boa/src/environment/declarative_environment_record.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -49,61 +49,97 @@ impl DeclarativeEnvironmentRecord {
}

impl EnvironmentRecordTrait for DeclarativeEnvironmentRecord {
fn has_binding(&self, name: &str) -> bool {
self.env_rec.borrow().contains_key(name)
/// `9.1.1.1.1 HasBinding ( N )`
///
/// More information:
/// - [ECMAScript reference][spec]
///
/// [spec]: https://tc39.es/ecma262/#sec-declarative-environment-records-hasbinding-n
fn has_binding(&self, name: &str, _context: &mut Context) -> JsResult<bool> {
// 1. If envRec has a binding for the name that is the value of N, return true.
// 2. Return false.
Ok(self.env_rec.borrow().contains_key(name))
}

/// `9.1.1.1.2 CreateMutableBinding ( N, D )`
///
/// More information:
/// - [ECMAScript reference][spec]
///
/// [spec]: https://tc39.es/ecma262/#sec-declarative-environment-records-createmutablebinding-n-d
fn create_mutable_binding(
&self,
name: String,
name: &str,
deletion: bool,
allow_name_reuse: bool,
_context: &mut Context,
) -> JsResult<()> {
// 1. Assert: envRec does not already have a binding for N.
if !allow_name_reuse {
assert!(
!self.env_rec.borrow().contains_key(name.as_str()),
!self.env_rec.borrow().contains_key(name),
"Identifier {} has already been declared",
name
);
}

// 2. Create a mutable binding in envRec for N and record that it is uninitialized.
// If D is true, record that the newly created binding may be deleted by a subsequent DeleteBinding call.
self.env_rec.borrow_mut().insert(
name.into_boxed_str(),
name.into(),
DeclarativeEnvironmentRecordBinding {
value: None,
can_delete: deletion,
mutable: true,
strict: false,
},
);

// 3. Return NormalCompletion(empty).
Ok(())
}

/// `9.1.1.1.3 CreateImmutableBinding ( N, S )`
///
/// More information:
/// - [ECMAScript reference][spec]
///
/// [spec]: https://tc39.es/ecma262/#sec-declarative-environment-records-createimmutablebinding-n-s
fn create_immutable_binding(
&self,
name: String,
name: &str,
strict: bool,
_context: &mut Context,
) -> JsResult<()> {
// 1. Assert: envRec does not already have a binding for N.
assert!(
!self.env_rec.borrow().contains_key(name.as_str()),
!self.env_rec.borrow().contains_key(name),
"Identifier {} has already been declared",
name
);

// 2. Create an immutable binding in envRec for N and record that it is uninitialized.
// If S is true, record that the newly created binding is a strict binding.
self.env_rec.borrow_mut().insert(
name.into_boxed_str(),
name.into(),
DeclarativeEnvironmentRecordBinding {
value: None,
can_delete: true,
mutable: false,
strict,
},
);

// 3. Return NormalCompletion(empty).
Ok(())
}

/// `9.1.1.1.4 InitializeBinding ( N, V )`
///
/// More information:
/// - [ECMAScript reference][spec]
///
/// [spec]: https://tc39.es/ecma262/#sec-declarative-environment-records-initializebinding-n-v
fn initialize_binding(
&self,
name: &str,
Expand All @@ -112,13 +148,25 @@ impl EnvironmentRecordTrait for DeclarativeEnvironmentRecord {
) -> JsResult<()> {
if let Some(ref mut record) = self.env_rec.borrow_mut().get_mut(name) {
if record.value.is_none() {
// 2. Set the bound value for N in envRec to V.
// 3. Record that the binding for N in envRec has been initialized.
record.value = Some(value);

// 4. Return NormalCompletion(empty).
return Ok(());
}
}

// 1. Assert: envRec must have an uninitialized binding for N.
panic!("record must have binding for {}", name);
}

/// `9.1.1.1.5 SetMutableBinding ( N, V, S )`
///
/// More information:
/// - [ECMAScript reference][spec]
///
/// [spec]: https://tc39.es/ecma262/#sec-declarative-environment-records-setmutablebinding-n-v-s
#[allow(clippy::else_if_without_else)]
fn set_mutable_binding(
&self,
Expand All @@ -127,49 +175,70 @@ impl EnvironmentRecordTrait for DeclarativeEnvironmentRecord {
mut strict: bool,
context: &mut Context,
) -> JsResult<()> {
// 1. If envRec does not have a binding for N, then
if self.env_rec.borrow().get(name).is_none() {
// a. If S is true, throw a ReferenceError exception.
if strict {
return Err(context.construct_reference_error(format!("{} not found", name)));
}

self.create_mutable_binding(name.to_owned(), true, false, context)?;
// b. Perform envRec.CreateMutableBinding(N, true).
self.create_mutable_binding(name, true, false, context)?;
// c. Perform envRec.InitializeBinding(N, V).
self.initialize_binding(name, value, context)?;

// d. Return NormalCompletion(empty).
return Ok(());
}

let (record_strict, record_has_no_value, record_mutable) = {
let (binding_strict, binding_value_is_none, binding_mutable) = {
let env_rec = self.env_rec.borrow();
let record = env_rec.get(name).unwrap();
(record.strict, record.value.is_none(), record.mutable)
let binding = env_rec.get(name).unwrap();
(binding.strict, binding.value.is_none(), binding.mutable)
};
if record_strict {
strict = true

// 2. If the binding for N in envRec is a strict binding, set S to true.
if binding_strict {
strict = true;
}
if record_has_no_value {

// 3. If the binding for N in envRec has not yet been initialized, throw a ReferenceError exception.
if binding_value_is_none {
return Err(
context.construct_reference_error(format!("{} has not been initialized", name))
);
}
if record_mutable {
// 4. Else if the binding for N in envRec is a mutable binding, change its bound value to V.
} else if binding_mutable {
let mut env_rec = self.env_rec.borrow_mut();
let record = env_rec.get_mut(name).unwrap();
record.value = Some(value);
let binding = env_rec.get_mut(name).unwrap();
binding.value = Some(value);
// 5. Else,
// a. Assert: This is an attempt to change the value of an immutable binding.
// b. If S is true, throw a TypeError exception.
} else if strict {
return Err(context.construct_reference_error(format!(
"Cannot mutate an immutable binding {}",
name
)));
return Err(context
.construct_type_error(format!("Cannot mutate an immutable binding {}", name)));
}

// 6. Return NormalCompletion(empty).
Ok(())
}

/// `9.1.1.1.6 GetBindingValue ( N, S )`
///
/// More information:
/// - [ECMAScript reference][spec]
///
/// [spec]: https://tc39.es/ecma262/#sec-declarative-environment-records-getbindingvalue-n-s
fn get_binding_value(
&self,
name: &str,
_strict: bool,
context: &mut Context,
) -> JsResult<JsValue> {
// 1. Assert: envRec has a binding for N.
// 2. If the binding for N in envRec is an uninitialized binding, throw a ReferenceError exception.
// 3. Return the value currently bound to N in envRec.
if let Some(binding) = self.env_rec.borrow().get(name) {
if let Some(ref val) = binding.value {
Ok(val.clone())
Expand All @@ -181,32 +250,62 @@ impl EnvironmentRecordTrait for DeclarativeEnvironmentRecord {
}
}

fn delete_binding(&self, name: &str) -> bool {
/// `9.1.1.1.7 DeleteBinding ( N )`
///
/// More information:
/// - [ECMAScript reference][spec]
///
/// [spec]: https://tc39.es/ecma262/#sec-declarative-environment-records-deletebinding-n
fn delete_binding(&self, name: &str, _context: &mut Context) -> JsResult<bool> {
// 1. Assert: envRec has a binding for the name that is the value of N.
// 2. If the binding for N in envRec cannot be deleted, return false.
// 3. Remove the binding for N from envRec.
// 4. Return true.
match self.env_rec.borrow().get(name) {
Some(binding) => {
if binding.can_delete {
self.env_rec.borrow_mut().remove(name);
true
Ok(true)
} else {
false
Ok(false)
}
}
None => panic!("env_rec has no binding for {}", name),
}
}

/// `9.1.1.1.8 HasThisBinding ( )`
///
/// More information:
/// - [ECMAScript reference][spec]
///
/// [spec]: https://tc39.es/ecma262/#sec-declarative-environment-records-hasthisbinding
fn has_this_binding(&self) -> bool {
// 1. Return false.
false
}

fn get_this_binding(&self, _context: &mut Context) -> JsResult<JsValue> {
Ok(JsValue::undefined())
}

/// `9.1.1.1.9 HasSuperBinding ( )`
///
/// More information:
/// - [ECMAScript reference][spec]
///
/// [spec]: https://tc39.es/ecma262/#sec-declarative-environment-records-hassuperbinding
fn has_super_binding(&self) -> bool {
// 1. Return false.
false
}

/// `9.1.1.1.10 WithBaseObject ( )`
///
/// More information:
/// - [ECMAScript reference][spec]
///
/// [spec]: https://tc39.es/ecma262/#sec-declarative-environment-records-withbaseobject
fn with_base_object(&self) -> Option<JsObject> {
None
}
Expand Down
26 changes: 13 additions & 13 deletions boa/src/environment/environment_record_trait.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -24,7 +24,7 @@ use std::fmt::Debug;
pub trait EnvironmentRecordTrait: Debug + Trace + Finalize {
/// Determine if an Environment Record has a binding for the String value N.
/// Return true if it does and false if it does not.
fn has_binding(&self, name: &str) -> bool;
fn has_binding(&self, name: &str, context: &mut Context) -> JsResult<bool>;

/// Create a new but uninitialized mutable binding in an Environment Record. The String value N is the text of the bound name.
/// If the Boolean argument deletion is true the binding may be subsequently deleted.
Expand All @@ -35,7 +35,7 @@ pub trait EnvironmentRecordTrait: Debug + Trace + Finalize {
/// paraments with the same name.
fn create_mutable_binding(
&self,
name: String,
name: &str,
deletion: bool,
allow_name_reuse: bool,
context: &mut Context,
Expand All @@ -47,7 +47,7 @@ pub trait EnvironmentRecordTrait: Debug + Trace + Finalize {
/// regardless of the strict mode setting of operations that reference that binding.
fn create_immutable_binding(
&self,
name: String,
name: &str,
strict: bool,
context: &mut Context,
) -> JsResult<()>;
Expand Down Expand Up @@ -85,7 +85,7 @@ pub trait EnvironmentRecordTrait: Debug + Trace + Finalize {
/// The String value name is the text of the bound name.
/// If a binding for name exists, remove the binding and return true.
/// If the binding exists but cannot be removed return false. If the binding does not exist return true.
fn delete_binding(&self, name: &str) -> bool;
fn delete_binding(&self, name: &str, context: &mut Context) -> JsResult<bool>;

/// Determine if an Environment Record establishes a this binding.
/// Return true if it does and false if it does not.
Expand Down Expand Up @@ -129,7 +129,7 @@ pub trait EnvironmentRecordTrait: Debug + Trace + Finalize {
/// Create mutable binding while handling outer environments
fn recursive_create_mutable_binding(
&self,
name: String,
name: &str,
deletion: bool,
scope: VariableScope,
context: &mut Context,
Expand All @@ -146,7 +146,7 @@ pub trait EnvironmentRecordTrait: Debug + Trace + Finalize {
/// Create immutable binding while handling outer environments
fn recursive_create_immutable_binding(
&self,
name: String,
name: &str,
deletion: bool,
scope: VariableScope,
context: &mut Context,
Expand All @@ -168,7 +168,7 @@ pub trait EnvironmentRecordTrait: Debug + Trace + Finalize {
strict: bool,
context: &mut Context,
) -> JsResult<()> {
if self.has_binding(name) {
if self.has_binding(name, context)? {
self.set_mutable_binding(name, value, strict, context)
} else {
self.get_outer_environment_ref()
Expand All @@ -184,7 +184,7 @@ pub trait EnvironmentRecordTrait: Debug + Trace + Finalize {
value: JsValue,
context: &mut Context,
) -> JsResult<()> {
if self.has_binding(name) {
if self.has_binding(name, context)? {
self.initialize_binding(name, value, context)
} else {
self.get_outer_environment_ref()
Expand All @@ -194,17 +194,17 @@ pub trait EnvironmentRecordTrait: Debug + Trace + Finalize {
}

/// Check if a binding exists in current or any outer environment
fn recursive_has_binding(&self, name: &str) -> bool {
self.has_binding(name)
fn recursive_has_binding(&self, name: &str, context: &mut Context) -> JsResult<bool> {
Ok(self.has_binding(name, context)?
|| match self.get_outer_environment_ref() {
Some(outer) => outer.recursive_has_binding(name),
Some(outer) => outer.recursive_has_binding(name, context)?,
None => false,
}
})
}

/// Retrieve binding from current or any outer environment
fn recursive_get_binding_value(&self, name: &str, context: &mut Context) -> JsResult<JsValue> {
if self.has_binding(name) {
if self.has_binding(name, context)? {
self.get_binding_value(name, false, context)
} else {
match self.get_outer_environment_ref() {
Expand Down
Loading