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Quellcode-Bibliothek builder.rs
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Spracherkennung für: .rs vermutete Sprache: Unknown {[0] [0] [0]} [Methode: Schwerpunktbildung, einfache Gewichte, sechs Dimensionen]
//! Data collection.
//!
//! `ScopeBuilder` is the entry point of this module.
//!
//! Each AST node that will hold bindings (global, block, function, etc.) has a
//! corresponding scope builder type defined in this module:
//! * `GlobalScopeBuilder`
//! * `BlockScopeBuilder`
//! * `FunctionExpressionScopeBuilder`
//! * `FunctionParametersScopeBuilder`
//! * `FunctionBodyScopeBuilder`
//!
//! They follow the pattern:
//! * They are created and pushed to the `ScopeBuilderStack` when the
//! algorithm enters a scope.
//! * They collect the information necessary to build a `ScopeData` object
//! (which will eventually become a `js::ScopeCreationData` on the
//! C++ side).
//! * They stay on the scope builder stack until the algorithm leaves that
//! scope.
//! * Then they are converted by `into_scope_data()`.
//!
//! Fields in the builder types mostly correspond to local variables in spec
//! algorithms. For example, `GlobalScopeBuilder` has fields named
//! `functions_to_initialize`, `declared_function_names`, and
//! `declared_var_names` which correspond to the
//! [GlobalDeclarationInstantiation][1] algorithm's local variables
//! *functionsToInitialize*, *declaredFunctionNames*, and *declaredVarNames*.
//!
//! This module performs some steps of those algorithms -- the parts that can
//! be done at compile time. The results are passed along to the emitter and
//! ultimately the JS runtime.
//!
//! # Syntax-only mode
//!
//! When doing syntax-only parsing, we collect minimal information, that does
//! not include `ScopeData`, but `ScriptStencil` for functions.
//!
//! [1]: https://tc39.es/ecma262/#sec-globaldeclarationinstantiation
use crate::data::FunctionDeclarationPropertyMap;
use crate::free_name_tracker::FreeNameTracker;
use ast::associated_data::AssociatedData;
use ast::source_atom_set::{CommonSourceAtomSetIndices, SourceAtomSetIndex};
use ast::source_location_accessor::SourceLocationAccessor;
use ast::type_id::NodeTypeIdAccessor;
use indexmap::set::IndexSet;
use std::collections::hash_map::Keys;
use std::collections::{HashMap, HashSet};
use stencil::function::{FunctionFlags, FunctionSyntaxKind};
use stencil::scope::{
BindingName, FunctionScopeData, GlobalScopeData, LexicalScopeData, ScopeData, ScopeDa taList,
ScopeDataMap, ScopeIndex, VarScopeData,
};
use stencil::script::{ScriptStencil, ScriptStencilIndex, ScriptStencilList, SourceExtent};
/// The kind of items inside the result of VarScopedDeclarations.
///
/// This enum isn't actually used, but just for simplifying comment in
/// ScopeKind.
#[derive(Debug, Clone, PartialEq)]
enum VarScopedDeclarationsItemKind {
/// Static Semantics: VarScopedDeclarations
/// https://tc39.es/ecma262/#sec-variable-statement-static-semantics-varscopeddeclarations
///
/// VariableDeclarationList : VariableDeclaration
///
/// 1. Return a new List containing VariableDeclaration.
///
/// VariableDeclarationList : VariableDeclarationList, VariableDeclaration
///
/// 1. Let declarations be VarScopedDeclarations of VariableDeclarationList.
/// 2. Append VariableDeclaration to declarations.
/// 3. Return declarations.
#[allow(dead_code)]
VariableDeclaration,
/// Static Semantics: VarScopedDeclarations
/// https://tc39.es/ecma262/#sec-for-in-and-for-of-statements-static-semantics-varscopeddeclarations
///
/// IterationStatement :
/// for ( var ForBinding in Expression ) Statement
/// for ( var ForBinding of AssignmentExpression ) Statement
/// for await ( var ForBinding of AssignmentExpression ) Statement
///
/// 1. Let declarations be a List containing ForBinding.
/// 2. Append to declarations the elements of the VarScopedDeclarations of
/// Statement.
/// 3. Return declarations.
#[allow(dead_code)]
ForBinding,
/// Static Semantics: VarScopedDeclarations
/// https://tc39.es/ecma262/#sec-function-definitions-static-semantics-varscopeddeclarations
///
/// FunctionStatementList : StatementList
///
/// 1. Return the TopLevelVarScopedDeclarations of StatementList.
/// Static Semantics: VarScopedDeclarations
/// https://tc39.es/ecma262/#sec-scripts-static-semantics-varscopeddeclarations
///
/// ScriptBody : StatementList
///
/// 1. Return TopLevelVarScopedDeclarations of StatementList.
/// Static Semantics: TopLevelVarScopedDeclarations
/// https://tc39.es/ecma262/#sec-block-static-semantics-toplevelvarscopeddeclarations
///
/// StatementListItem : Declaration
///
/// 1. If Declaration is Declaration : HoistableDeclaration, then
/// a. Let declaration be DeclarationPart of HoistableDeclaration.
/// b. Return « declaration ».
/// 2. Return a new empty List.
/// Static Semantics: DeclarationPart
/// https://tc39.es/ecma262/#sec-static-semantics-declarationpart
///
/// HoistableDeclaration : FunctionDeclaration
///
/// 1. Return FunctionDeclaration.
#[allow(dead_code)]
FunctionDeclaration,
/// HoistableDeclaration : GeneratorDeclaration
///
/// 1. Return GeneratorDeclaration.
#[allow(dead_code)]
GeneratorDeclaration,
/// HoistableDeclaration : AsyncFunctionDeclaration
///
/// 1. Return AsyncFunctionDeclaration.
#[allow(dead_code)]
AsyncFunctionDeclaration,
/// HoistableDeclaration : AsyncGeneratorDeclaration
///
/// 1. Return AsyncGeneratorDeclaration.
#[allow(dead_code)]
AsyncGeneratorDeclaration,
/// Static Semantics: TopLevelVarScopedDeclarations
/// https://tc39.es/ecma262/#sec-labelled-statements-static-semantics-toplevelvarscopeddeclarations
///
/// LabelledItem : FunctionDeclaration
///
/// 1. Return a new List containing FunctionDeclaration.
/* FunctionDeclaration */
/// Annex B Initializers in ForIn Statement Heads
/// https://tc39.es/ecma262/#sec-initializers-in-forin-statement-heads
///
/// IterationStatement :
/// for ( var BindingIdentifier Initializer in Expression ) Statement
///
/// 1. Let declarations be a List containing BindingIdentifier.
/// 2. Append to declarations the elements of the VarScopedDeclarations of
/// Statement.
/// 3. Return declarations.
#[allow(dead_code)]
BindingIdentifier,
}
/// The kind of items inside the result of LexicallyScopedDeclarations.
///
/// This enum isn't actually used, but just for simplifying comment in
/// ScopeKind.
#[derive(Debug, Clone, PartialEq)]
enum LexicallyScopedDeclarations {
/// Static Semantics: LexicallyScopedDeclarations
/// https://tc39.es/ecma262/#sec-block-static-semantics-lexicallyscopeddeclarations
///
/// StatementListItem : Declaration
///
/// 1. Return a new List containing DeclarationPart of Declaration.
/// Static Semantics: DeclarationPart
/// https://tc39.es/ecma262/#sec-static-semantics-declarationpart
///
/// HoistableDeclaration : FunctionDeclaration
///
/// 1. Return FunctionDeclaration.
#[allow(dead_code)]
FunctionDeclaration,
/// HoistableDeclaration : GeneratorDeclaration
///
/// 1. Return GeneratorDeclaration.
#[allow(dead_code)]
GeneratorDeclaration,
/// HoistableDeclaration : AsyncFunctionDeclaration
///
/// 1. Return AsyncFunctionDeclaration.
#[allow(dead_code)]
AsyncFunctionDeclaration,
/// HoistableDeclaration : AsyncGeneratorDeclaration
///
/// 1. Return AsyncGeneratorDeclaration.
#[allow(dead_code)]
AsyncGeneratorDeclaration,
/// Declaration : ClassDeclaration
///
/// 1. Return ClassDeclaration.
#[allow(dead_code)]
ClassDeclaration,
/// Declaration : LexicalDeclaration
///
/// 1. Return LexicalDeclaration.
#[allow(dead_code)]
LexicalDeclarationWithLet,
#[allow(dead_code)]
LexicalDeclarationWithConst,
/// Static Semantics: LexicallyScopedDeclarations
/// https://tc39.es/ecma262/#sec-labelled-statements-static-semantics-lexicallyscopeddeclarations
///
/// LabelledItem : FunctionDeclaration
///
/// 1. Return a new List containing FunctionDeclaration.
/* FunctionDeclaration */
/// Static Semantics: LexicallyScopedDeclarations
/// https://tc39.es/ecma262/#sec-function-definitions-static-semantics-lexicallyscopeddeclarations
///
/// FunctionStatementList : StatementList
///
/// 1. Return the TopLevelLexicallyScopedDeclarations of StatementList.
/// Static Semantics: LexicallyScopedDeclarations
/// https://tc39.es/ecma262/#sec-scripts-static-semantics-lexicallyscopeddeclarations
///
/// ScriptBody : StatementList
///
/// 1. Return TopLevelLexicallyScopedDeclarations of StatementList.
/// Static Semantics: TopLevelLexicallyScopedDeclarations
/// https://tc39.es/ecma262/#sec-block-static-semantics-toplevellexicallyscopeddeclarations
///
/// StatementListItem : Declaration
///
/// 1. If Declaration is Declaration : HoistableDeclaration, then
/// a. Return « ».
/// 2. Return a new List containing Declaration.
/// Static Semantics: LexicallyScopedDeclarations
/// https://tc39.es/ecma262/#sec-exports-static-semantics-lexicallyscopeddeclarations
///
/// ExportDeclaration : export Declaration
///
/// 1. Return a new List containing DeclarationPart of Declaration.
/// ExportDeclaration : export default HoistableDeclaration
///
/// 1. Return a new List containing DeclarationPart of HoistableDeclaration.
/// ExportDeclaration : export default ClassDeclaration
///
/// 1. Return a new List containing ClassDeclaration.
/* ClassDeclaration */
/// ExportDeclaration : export default AssignmentExpression ;
///
/// 1. Return a new List containing this ExportDeclaration.
#[allow(dead_code)]
ExportDeclarationWithAssignmentExpression,
}
/// Items on the ScopeBuilder.scope_stack.
/// Specifies the kind of BindingIdentifier.
///
/// This includes only BindingIdentifier that appears inside list or recursive
/// structure.
///
/// BindingIdentifier that appears only once for a structure
/// (e.g. Function.name) should be handled immediately, without using
/// ScopeBuilder.scope_stack.
#[derive(Debug, Clone, PartialEq)]
enum ScopeKind {
/// VarScopedDeclarationsItemKind::VariableDeclaration
/// VarScopedDeclarationsItemKind::ForBinding
/// VarScopedDeclarationsItemKind::BindingIdentifier
Var,
/// LexicallyScopedDeclarations::LexicalDeclarationWithLet
Let,
/// LexicallyScopedDeclarations::LexicalDeclarationWithConst
Const,
/// Pushed when entering function, to catch function name.
FunctionName,
/// Pushed when entering function parameter, to disable FunctionName's
/// effect.
/// Equivalent to the case there's no kind on the stack.
FunctionParametersAndBody,
FormalParameter,
#[allow(dead_code)]
CatchParameter,
/// LexicallyScopedDeclarations::ExportDeclarationWithAssignmentExpression
#[allow(dead_code)]
Export,
/// VarScopedDeclarationsItemKind::FunctionDeclaration
/// VarScopedDeclarationsItemKind::GeneratorDeclaration
/// VarScopedDeclarationsItemKind::AsyncFunctionDeclaration
/// VarScopedDeclarationsItemKind::AsyncGeneratorDeclaration
#[allow(dead_code)]
ScriptBodyStatementList,
#[allow(dead_code)]
FunctionStatementList,
/// LexicallyScopedDeclarations::FunctionDeclaration
/// LexicallyScopedDeclarations::GeneratorDeclaration
/// LexicallyScopedDeclarations::AsyncFunctionDeclaration
/// LexicallyScopedDeclarations::AsyncGeneratorDeclaration
/// LexicallyScopedDeclarations::ClassDeclaration
#[allow(dead_code)]
BlockStatementList,
}
/// Index into BaseScopeData.bindings.
#[derive(Debug, Clone, Copy, PartialEq)]
pub struct BindingIndex {
index: usize,
}
impl BindingIndex {
fn new(index: usize) -> Self {
Self { index }
}
pub fn next(&self) -> Self {
Self {
index: self.index + 1,
}
}
}
impl From<BindingIndex> for usize {
fn from(index: BindingIndex) -> usize {
index.index
}
}
#[derive(Debug)]
struct PossiblyAnnexBFunction {
#[allow(dead_code)]
name: SourceAtomSetIndex,
#[allow(dead_code)]
owner_scope_index: ScopeIndex,
#[allow(dead_code)]
binding_index: BindingIndex,
/// Index of the script in the list of `functions` in the
/// `FunctionScriptStencilBuilder`.
script_index: ScriptStencilIndex,
}
#[derive(Debug)]
struct PossiblyAnnexBFunctionList {
functions: HashMap<SourceAtomSetIndex, Vec<PossiblyAnnexBFunction>>,
}
impl PossiblyAnnexBFunctionList {
fn new() -> Self {
Self {
functions: HashMap::new(),
}
}
fn push(
&mut self,
name: SourceAtomSetIndex,
owner_scope_index: ScopeIndex,
binding_index: BindingIndex,
script_index: ScriptStencilIndex,
) {
if let Some(functions) = self.functions.get_mut(&name) {
functions.push(PossiblyAnnexBFunction {
name,
owner_scope_index,
binding_index,
script_index,
});
return;
}
let mut functions = Vec::with_capacity(1);
functions.push(PossiblyAnnexBFunction {
name,
owner_scope_index,
binding_index,
script_index,
});
self.functions.insert(name, functions);
}
fn remove_if_exists(&mut self, name: SourceAtomSetIndex) {
self.functions.remove(&name);
}
fn mark_annex_b(&self, function_declaration_properties: &mut FunctionDeclarationPropertyMap) {
for functions in &mut self.functions.values() {
for fun in functions {
function_declaration_properties.mark_annex_b(fun.script_index);
}
}
}
fn names(&self) -> Keys<SourceAtomSetIndex, Vec<PossiblyAnnexBFunction>> {
self.functions.keys()
}
fn clear(&mut self) {
self.functions.clear();
}
}
/// Common fields across all *ScopeBuilder.
#[derive(Debug)]
struct BaseScopeBuilder {
name_tracker: FreeNameTracker,
/// Bindings in this scope can be accessed dynamically by:
/// * direct `eval`
/// * `with` statement
/// * `delete name` statement
bindings_accessed_dynamically: bool,
}
impl BaseScopeBuilder {
fn new() -> Self {
Self {
name_tracker: FreeNameTracker::new(),
bindings_accessed_dynamically: false,
}
}
fn propagate_common(&mut self, inner: &BaseScopeBuilder) {
// When construct such as `eval`, `with` and `delete` access
// name dynamically in inner scopes, we have to propagate this
// flag to the outer scope such that we prevent optimizations.
self.bindings_accessed_dynamically |= inner.bindings_accessed_dynamically;
}
fn propagate_from_inner_non_script(&mut self, inner: &BaseScopeBuilder) {
self.propagate_common(inner);
self.name_tracker
.propagate_from_inner_non_script(&inner.name_tracker);
}
fn propagate_from_inner_script(&mut self, inner: &BaseScopeBuilder) {
self.propagate_common(inner);
self.name_tracker
.propagate_from_inner_script(&inner.name_tracker);
}
fn declare_var(&mut self, name: SourceAtomSetIndex) {
self.name_tracker.note_def(name);
}
fn declare_let(&mut self, name: SourceAtomSetIndex) {
self.name_tracker.note_def(name);
}
fn declare_const(&mut self, name: SourceAtomSetIndex) {
self.name_tracker.note_def(name);
}
fn declare_function(&mut self, name: SourceAtomSetIndex) {
self.name_tracker.note_def(name);
}
fn set_function_name(&mut self, name: SourceAtomSetIndex) {
self.name_tracker.note_def(name);
}
fn declare_param(&mut self, name: SourceAtomSetIndex) {
self.name_tracker.note_def(name);
}
}
/// Variables declared/used in GlobalDeclarationInstantiation.
#[derive(Debug)]
struct GlobalScopeBuilder {
base: BaseScopeBuilder,
/// Runtime Semantics: GlobalDeclarationInstantiation ( script, env )
/// https://tc39.es/ecma262/#sec-globaldeclarationinstantiation
///
/// Step 8. Let functionsToInitialize be a new empty List.
functions_to_initialize: Vec<ScriptStencilIndex>,
/// Step 9. Let declaredFunctionNames be a new empty List.
declared_function_names: IndexSet<SourceAtomSetIndex>,
/// Step 11. Let declaredVarNames be a new empty List.
/// NOTE: This is slightly different than the spec that this can contain
/// names in declaredFunctionNames.
/// The duplication should be filtered before the use.
declared_var_names: IndexSet<SourceAtomSetIndex>,
/// Step 15. Let lexDeclarations be the LexicallyScopedDeclarations of
/// script.
let_names: Vec<SourceAtomSetIndex>,
const_names: Vec<SourceAtomSetIndex>,
scope_index: ScopeIndex,
}
impl GlobalScopeBuilder {
fn new(scope_index: ScopeIndex) -> Self {
Self {
base: BaseScopeBuilder::new(),
functions_to_initialize: Vec::new(),
declared_function_names: IndexSet::new(),
declared_var_names: IndexSet::new(),
let_names: Vec::new(),
const_names: Vec::new(),
scope_index,
}
}
fn declare_var(&mut self, name: SourceAtomSetIndex) {
// Runtime Semantics: GlobalDeclarationInstantiation ( script, env )
// https://tc39.es/ecma262/#sec-globaldeclarationinstantiation
//
// Step 7. Let varDeclarations be the VarScopedDeclarations of script.
//
// Step 12. For each d in varDeclarations, do
// Step 12.a. If d is a VariableDeclaration, a ForBinding, or a
// BindingIdentifier, then
// Step 12.a.i. For each String vn in the BoundNames of d, do
// (implicit)
// Step 12.a.i.i If vn is not an element of declaredFunctionNames, then
// (done in remove_function_names_from_var_names)
// Step 12.a.i.1.a. Let vnDefinable be ? envRec.CanDeclareGlobalVar(vn).
// Step 12.a.i.1.b. If vnDefinable is false, throw a TypeError
// exception.
// (done in runtime)
// Step 12.a.i.1.c. If vn is not an element of declaredVarNames, then
// Step 12.a.i.1.a.i. Append vn to declaredVarNames.
self.declared_var_names.insert(name);
self.base.declare_var(name);
}
fn declare_let(&mut self, name: SourceAtomSetIndex) {
// Runtime Semantics: GlobalDeclarationInstantiation ( script, env )
// https://tc39.es/ecma262/#sec-globaldeclarationinstantiation
//
// Step 15. Let lexDeclarations be the LexicallyScopedDeclarations of
// script.
self.let_names.push(name);
self.base.declare_let(name);
}
fn declare_const(&mut self, name: SourceAtomSetIndex) {
// Runtime Semantics: GlobalDeclarationInstantiation ( script, env )
// https://tc39.es/ecma262/#sec-globaldeclarationinstantiation
//
// Step 15. Let lexDeclarations be the LexicallyScopedDeclarations of
// script.
self.const_names.push(name);
self.base.declare_const(name);
}
fn declare_function(&mut self, name: SourceAtomSetIndex, fun_index: ScriptStencilIndex) {
// Runtime Semantics: GlobalDeclarationInstantiation ( script, env )
// https://tc39.es/ecma262/#sec-globaldeclarationinstantiation
//
// Step 10. For each d in varDeclarations, in reverse list order, do
// Step 10.a. If d is neither a VariableDeclaration nor a ForBinding
// nor a BindingIdentifier, then
// (implicit)
// Step 10.a.i. Assert: d is either a FunctionDeclaration,
// a GeneratorDeclaration, an AsyncFunctionDeclaration,
// or an AsyncGeneratorDeclaration.
// Step 10.a.ii. NOTE: If there are multiple function declarations for
// the same name, the last declaration is used.
// Step 10.a.iii. Let fn be the sole element of the BoundNames of d.
// Step 10.a.iv. If fn is not an element of declaredFunctionNames, then
//
// NOTE: Instead of iterating in reverse list oder, we iterate in
// normal order and overwrite existing item.
// Steps 10.a.iv.1. Let fnDefinable be
// ? envRec.CanDeclareGlobalFunction(fn).
// Steps 10.a.iv.2. If fnDefinable is false, throw a TypeError
// exception.
// (done in runtime)
// Step 10.a.iv.3. Append fn to declaredFunctionNames.
self.declared_function_names.insert(name.clone());
// Step 10.a.iv.4. Insert d as the first element of
// functionsToInitialize.
self.functions_to_initialize.push(fun_index);
self.base.declare_function(name);
}
fn remove_function_names_from_var_names(&mut self) {
// Runtime Semantics: GlobalDeclarationInstantiation ( script, env )
// https://tc39.es/ecma262/#sec-globaldeclarationinstantiation
//
// Step 12.a.i.i If vn is not an element of declaredFunctionNames, then
//
// To avoid doing 2-pass, we note all var names, and filter function
// names out after visiting all of them.
for n in &self.declared_function_names {
self.declared_var_names.remove(n);
}
}
fn perform_annex_b(
&mut self,
function_declaration_properties: &mut FunctionDeclarationPropertyMap,
possibly_annex_b_functions: &mut PossiblyAnnexBFunctionList,
) {
// Annex B
// Changes to GlobalDeclarationInstantiation
// https://tc39.es/ecma262/#sec-web-compat-globaldeclarationinstantiation
//
// Step 1. Let strict be IsStrict of script.
//
// FIXME: Once directives are supported, reflect it here.
let strict = false;
// Step 2. If strict is false, then
if strict {
return;
}
// Step 2.a. Let declaredFunctionOrVarNames be a new empty List.
// Step 2.b. Append to declaredFunctionOrVarNames the elements of
// declaredFunctionNames.
// Step 2.c. Append to declaredFunctionOrVarNames the elements of
// declaredVarNames.
//
// NOTE: Use `self.declared_var_names` to avoid duplication against
// `declaredVarNames`.
// And duplication against `declaredFunctionNames` will be
// removed in `remove_function_names_from_var_names`.
// Step 2.d. For each FunctionDeclaration f that is directly contained
// in the StatementList of a Block, CaseClause, or
// DefaultClause Contained within script, do
//
// NOTE: `possibly_annex_b_functions` contains all of them.
// Step 2.d.i. Let F be StringValue of the BindingIdentifier of f.
// Step 2.d.ii. If replacing the FunctionDeclaration f with a
// VariableStatement that has F as a BindingIdentifier
// would not produce any Early Errors for script, then
//
// NOTE: Early Errors happen if any of top-level lexical has
// the same name. Filter out those functions here.
for n in &self.let_names {
possibly_annex_b_functions.remove_if_exists(*n);
}
for n in &self.const_names {
possibly_annex_b_functions.remove_if_exists(*n);
}
// Step 2.d.ii.1. If env.HasLexicalDeclaration(F) is false, then
// Step 2.d.ii.1.a. Let fnDefinable be ? env.CanDeclareGlobalVar(F).
// Step 2.d.ii.1.b. If fnDefinable is true, then
//
// FIXME: Are these steps performed by any implementation?
// https://github.com/tc39/ecma262/issues/2019
// Step 2.d.ii.1.b.i. NOTE: A var binding for F is only instantiated
// here if it is neither a VarDeclaredName nor
// the name of another FunctionDeclaration.
// Step 2.d.ii.1.b.ii. If declaredFunctionOrVarNames does not
// contain F, then
// Step 2.d.ii.1.b.ii.1. Perform
// ?env.CreateGlobalVarBinding(F, false).
// Step 2.d.ii.1.b.ii.2. Append F to declaredFunctionOrVarNames.
for n in possibly_annex_b_functions.names() {
self.declare_var(*n);
}
// Step 2.d.ii.1.b.iii. When the FunctionDeclaration f is evaluated,
// perform the following steps in place of the
// FunctionDeclaration Evaluation algorithm
// provided in
// https://tc39.es/ecma262/#sec-function-definitions-runtime-semantics-evaluation :
// Step 2.d.ii.1.b.iii.1. Let genv be the running execution
// context's VariableEnvironment.
// Step 2.d.ii.1.b.iii.2. Let benv be the running execution
// context's LexicalEnvironment.
// Step 2.d.ii.1.b.iii.3. Let fobj be
// ! benv.GetBindingValue(F, false).
// Step 2.d.ii.1.b.iii.4. Perform
// ? genv.SetMutableBinding(F, fobj, false).
// Step 2.d.ii.1.b.iii.5. Return NormalCompletion(empty).
possibly_annex_b_functions.mark_annex_b(function_declaration_properties);
}
fn into_scope_data(
mut self,
function_declaration_properties: &mut FunctionDeclarationPropertyMap,
possibly_annex_b_functions: &mut PossiblyAnnexBFunctionList,
) -> ScopeData {
// Runtime Semantics: GlobalDeclarationInstantiation ( script, env )
// https://tc39.es/ecma262/#sec-globaldeclarationinstantiation
//
// NOTE: Steps are reordered to match the order of binding in runtime.
// Step 13. NOTE: Annex B adds additional steps at this point.
//
// NOTE: Reordered here to reflect the change to
// self.declared_var_names.
self.perform_annex_b(function_declaration_properties, possibly_annex_b_functions);
// Step 12.a.i.i If vn is not an element of declaredFunctionNames, then
self.remove_function_names_from_var_names();
let mut data = GlobalScopeData::new(
self.declared_var_names.len() + self.declared_function_names.len(),
self.let_names.len(),
self.const_names.len(),
self.functions_to_initialize,
);
// Step 18. For each String vn in declaredVarNames, in list order, do
for n in &self.declared_var_names {
// 18.a. Perform ? envRec.CreateGlobalVarBinding(vn, false).
let is_closed_over = self.base.name_tracker.is_closed_over_def(n);
data.base
.bindings
.push(BindingName::new(*n, is_closed_over))
}
// Step 17. For each Parse Node f in functionsToInitialize, do
for n in &self.declared_function_names {
// Step 17.a. Let fn be the sole element of the BoundNames of f.
// Step 17.b. Let fo be InstantiateFunctionObject of f with
// argument env.
// Step 17.c. Perform
// ? envRec.CreateGlobalFunctionBinding(fn, fo, false).
let is_closed_over = self.base.name_tracker.is_closed_over_def(n);
data.base
.bindings
.push(BindingName::new_top_level_function(*n, is_closed_over));
}
// Step 15. Let lexDeclarations be the LexicallyScopedDeclarations of
// script.
// Step 16. For each element d in lexDeclarations, do
// Step 16.b. For each element dn of the BoundNames of d, do
for n in &self.let_names {
// Step 16.b.ii. Else,
// Step 16.b.ii.1. Perform ? envRec.CreateMutableBinding(dn, false).
let is_closed_over = self.base.name_tracker.is_closed_over_def(n);
data.base
.bindings
.push(BindingName::new(*n, is_closed_over))
}
for n in &self.const_names {
// Step 16.b.i. If IsConstantDeclaration of d is true, then
// Step 16.b.i.1. Perform ? envRec.CreateImmutableBinding(dn, true).
let is_closed_over = self.base.name_tracker.is_closed_over_def(n);
data.base
.bindings
.push(BindingName::new(*n, is_closed_over))
}
ScopeData::Global(data)
}
}
#[derive(Debug)]
struct FunctionNameAndStencilIndex {
name: SourceAtomSetIndex,
stencil: ScriptStencilIndex,
}
/// Variables declared/used in BlockDeclarationInstantiation
#[derive(Debug)]
struct BlockScopeBuilder {
base: BaseScopeBuilder,
/// Runtime Semantics: BlockDeclarationInstantiation ( code, env )
/// https://tc39.es/ecma262/#sec-blockdeclarationinstantiation
///
/// Step 3. Let declarations be the LexicallyScopedDeclarations of code.
let_names: Vec<SourceAtomSetIndex>,
const_names: Vec<SourceAtomSetIndex>,
/// Runtime Semantics: BlockDeclarationInstantiation ( code, env )
/// https://tc39.es/ecma262/#sec-blockdeclarationinstantiation
///
/// Step 4.b. If d is a FunctionDeclaration, a GeneratorDeclaration, an
/// AsyncFunctionDeclaration, or an AsyncGeneratorDeclaration,
/// then
functions: Vec<FunctionNameAndStencilIndex>,
/// Scope associated to this builder.
scope_index: ScopeIndex,
}
impl BlockScopeBuilder {
fn new(scope_index: ScopeIndex) -> Self {
Self {
base: BaseScopeBuilder::new(),
let_names: Vec::new(),
const_names: Vec::new(),
functions: Vec::new(),
scope_index,
}
}
fn declare_let(&mut self, name: SourceAtomSetIndex) {
// Runtime Semantics: BlockDeclarationInstantiation ( code, env )
// https://tc39.es/ecma262/#sec-blockdeclarationinstantiation
//
// Step 3. Let declarations be the LexicallyScopedDeclarations of code.
self.let_names.push(name);
self.base.declare_let(name);
}
fn declare_const(&mut self, name: SourceAtomSetIndex) {
// Runtime Semantics: BlockDeclarationInstantiation ( code, env )
// https://tc39.es/ecma262/#sec-blockdeclarationinstantiation
//
// Step 3. Let declarations be the LexicallyScopedDeclarations of code.
self.const_names.push(name);
self.base.declare_const(name);
}
fn declare_function(&mut self, name: SourceAtomSetIndex, fun_index: ScriptStencilIndex) {
// Runtime Semantics: BlockDeclarationInstantiation ( code, env )
// https://tc39.es/ecma262/#sec-blockdeclarationinstantiation
//
// Step 3. Let declarations be the LexicallyScopedDeclarations of code.
//
// Step 4.b. If d is a FunctionDeclaration, a GeneratorDeclaration, an
// AsyncFunctionDeclaration, or an AsyncGeneratorDeclaration,
// then
self.functions.push(FunctionNameAndStencilIndex {
name,
stencil: fun_index,
});
self.base.declare_function(name);
}
fn into_scope_data(
self,
enclosing: ScopeIndex,
possibly_annex_b_functions: &mut PossiblyAnnexBFunctionList,
) -> ScopeData {
let mut data = LexicalScopeData::new_block(
self.let_names.len() + self.functions.len(),
self.const_names.len(),
enclosing,
self.functions.iter().map(|n| n.stencil).collect(),
);
// Runtime Semantics: BlockDeclarationInstantiation ( code, env )
// https://tc39.es/ecma262/#sec-blockdeclarationinstantiation
//
// Step 1. Let envRec be env's EnvironmentRecord.
// Step 2. Assert: envRec is a declarative Environment Record.
// (implicit)
// Step 4. For each element d in declarations, do
// Step 4.a. For each element dn of the BoundNames of d, do
for n in &self.let_names {
// Step 4.a.ii. Else,
// Step 4.a.ii.1. Perform ! envRec.CreateMutableBinding(dn, false).
let is_closed_over = self.base.name_tracker.is_closed_over_def(n);
data.base
.bindings
.push(BindingName::new(*n, is_closed_over));
}
for n in &self.functions {
// Step 4.b. If d is a FunctionDeclaration, a GeneratorDeclaration,
// an AsyncFunctionDeclaration,
// or an AsyncGeneratorDeclaration, then
// Step 4.b.i. Let fn be the sole element of the BoundNames of d.
// Step 4.b.ii. Let fo be InstantiateFunctionObject of d with
// argument env.
// Step 4.b.iii. Perform envRec.InitializeBinding(fn, fo).
let is_closed_over = self.base.name_tracker.is_closed_over_def(&n.name);
let binding_index = BindingIndex::new(data.base.bindings.len());
data.base
.bindings
.push(BindingName::new(n.name, is_closed_over));
possibly_annex_b_functions.push(n.name, self.scope_index, binding_index, n.stencil);
}
for n in &self.const_names {
// Step 4.a.i. If IsConstantDeclaration of d is true, then
// Step 4.a.i.1. Perform ! envRec.CreateImmutableBinding(dn, true).
let is_closed_over = self.base.name_tracker.is_closed_over_def(n);
data.base
.bindings
.push(BindingName::new(*n, is_closed_over));
}
ScopeData::Lexical(data)
}
}
/// Scope for a FunctionExpression.
///
/// The FunctionExpression `(function f() { return f; })` introduces a lexical
/// scope with a single binding `f`, set to the function itself. We create this
/// scope builder whether the FunctionExpression has a name or not, for
/// consistency.
#[derive(Debug)]
struct FunctionExpressionScopeBuilder {
base: BaseScopeBuilder,
function_expression_name: Option<SourceAtomSetIndex>,
scope_index: ScopeIndex,
}
impl FunctionExpressionScopeBuilder {
fn new(scope_index: ScopeIndex) -> Self {
Self {
base: BaseScopeBuilder::new(),
function_expression_name: None,
scope_index,
}
}
fn set_function_name(&mut self, name: SourceAtomSetIndex) {
self.function_expression_name = Some(name);
self.base.set_function_name(name);
}
fn into_scope_data(self, enclosing: ScopeIndex) -> ScopeData {
match &self.function_expression_name {
Some(name) => {
// Runtime Semantics: Evaluation
// https://tc39.es/ecma262/#sec-function-definitions-runtime-semantics-evaluation
//
// FunctionExpression :
// function BindingIdentifier ( FormalParameters )
// { FunctionBody }
//
// Step 1. Let scope be the running execution context's
// LexicalEnvironment.
// Step 2. Let funcEnv be NewDeclarativeEnvironment(scope).
// Step 3. Let envRec be funcEnv's EnvironmentRecord.
let mut data = LexicalScopeData::new_named_lambda(enclosing);
// Step 4. Let name be StringValue of BindingIdentifier .
// Step 5. Perform envRec.CreateImmutableBinding(name, false).
let is_closed_over = self.base.name_tracker.is_closed_over_def(name);
data.base
.bindings
.push(BindingName::new(*name, is_closed_over));
ScopeData::Lexical(data)
}
None => ScopeData::Alias(enclosing),
}
}
}
/// The value of [[ThisMode]] internal slot of function object.
/// https://tc39.es/ecma262/#sec-ecmascript-function-objects
///
/// Defines how this references are interpreted within the formal parameters
/// and code body of the function.
#[derive(Debug, Clone, PartialEq)]
enum ThisMode {
/// `this` refers to the `this` value of a lexically enclosing function.
Lexical,
/// `this` value is used exactly as provided by an invocation of the
/// function.
#[allow(dead_code)]
Strict,
/// `this` value of `undefined` is interpreted as a reference to the global
/// object.
Global,
}
/// The result of converting the builder of function parameters and body
/// into scope data.
struct FunctionScopeDataSet {
/// ScopeData::Function.
function: ScopeData,
/// Either ScopeData::Var or ScopeData::Alias.
extra_body_var: ScopeData,
/// Either ScopeData::Lexical or ScopeData::Alias.
lexical: ScopeData,
}
/// See FunctionParametersScopeBuilder.state.
#[derive(Debug)]
enum FunctionParametersState {
/// Entered FormalParameters.
Init,
/// Entered Parameter.
/// At this point, this parameter can be either non-destructuring or
/// destructuring.
/// If BindingIdentifier is found in this state, this parameter is
/// non-destructuring.
Parameter,
/// Entered BindingPattern inside Parameter.
/// This parameter is destructuring.
DestructuringParameter,
/// Entered rest parameter.
/// At this point, the rest parameter can be either non-destructuring or
/// destructuring.
/// If BindingIdentifier is found in this state, the rest parameter is
/// non-destructuring.
RestParameter,
/// Entered BindingPattern inside rest parameter.
/// The rest parameter is destructuring.
DestructuringRestParameter,
}
/// Function parameters in FormalParameters, and variables used in
/// FormalParameters
/// Shared part between full-parse and syntax-only parse.
#[derive(Debug)]
struct SharedFunctionParametersScopeBuilder {
base: BaseScopeBuilder,
/// FunctionDeclarationInstantiation ( func, argumentsList )
/// https://tc39.es/ecma262/#sec-functiondeclarationinstantiation
///
/// Step 3. Let strict be func.[[Strict]].
strict: bool,
/// Step 5. Let parameterNames be the BoundNames of formals.
parameter_names: HashSet<SourceAtomSetIndex>,
/// Step 7. Let simpleParameterList be IsSimpleParameterList of formals.
simple_parameter_list: bool,
/// Step 8. Let hasParameterExpressions be ContainsExpression of formals.
has_parameter_expressions: bool,
/// Step 17. Else if "arguments" is an element of parameterNames, then
parameter_has_arguments: bool,
}
impl SharedFunctionParametersScopeBuilder {
fn new(is_arrow: bool) -> Self {
let mut base = BaseScopeBuilder::new();
if !is_arrow {
// Arrow function closes over this/arguments from enclosing
// function.
base.name_tracker
.note_def(CommonSourceAtomSetIndices::this());
base.name_tracker
.note_def(CommonSourceAtomSetIndices::arguments());
}
Self {
base,
// FIMXE: Receive the enclosing strictness,
// and update on directive in body.
strict: false,
parameter_names: HashSet::new(),
simple_parameter_list: true,
has_parameter_expressions: false,
parameter_has_arguments: false,
}
}
fn perform_annex_b(
&self,
function_declaration_properties: &mut FunctionDeclarationPropertyMap,
possibly_annex_b_functions: &mut PossiblyAnnexBFunctionList,
body_scope_builder: &mut SharedFunctionBodyScopeBuilder,
) {
// Annex B
// Changes to FunctionDeclarationInstantiation
// https://tc39.es/ecma262/#sec-web-compat-functiondeclarationinstantiation
//
// Step 1. If strict is false, then
//
// FIXME: Once directives are supported, reflect it here.
let strict = false;
if strict {
return;
}
// Step 1.a. For each FunctionDeclaration f that is directly contained
// in the StatementList of a Block, CaseClause, or
// DefaultClause, do
//
// NOTE: `possibly_annex_b_functions` contains all of them.
// Step 1.a.i. Let F be StringValue of the BindingIdentifier of f.
// Step 1.a.ii. If replacing the FunctionDeclaration f with a
// VariableStatement that has F as a BindingIdentifier
// would not produce any Early Errors for func and F is
// not an element of parameterNames, then
//
// NOTE: Early Errors happen if any of top-level lexical has
// the same name. Filter out those functions here.
for n in &body_scope_builder.let_names {
possibly_annex_b_functions.remove_if_exists(*n);
}
for n in &body_scope_builder.const_names {
possibly_annex_b_functions.remove_if_exists(*n);
}
for n in &self.parameter_names {
possibly_annex_b_functions.remove_if_exists(*n);
}
// Step 1.a.ii.1. NOTE: A var binding for F is only instantiated here
// if it is neither a VarDeclaredName, the name of a
// formal parameter, or another FunctionDeclaration.
//
// NOTE: The binding is merged into the list of other var names.
// Step 1.a.ii.2. If initializedBindings does not contain F and F is
// not "arguments", then
possibly_annex_b_functions.remove_if_exists(CommonSourceAtomSetIndices::arguments());
// Step 1.a.ii.2.a. Perform ! varEnv.CreateMutableBinding(F, false).
// Step 1.a.ii.2.b. Perform varEnv.InitializeBinding(F, undefined).
// Step 1.a.ii.2.c. Append F to instantiatedVarNames.
for n in possibly_annex_b_functions.names() {
body_scope_builder.declare_var(*n);
}
// Step 1.a.ii.3. When the FunctionDeclaration f is evaluated, perform
// the following steps in place of the
// FunctionDeclaration Evaluation algorithm provided in
// https://tc39.es/ecma262/#sec-function-definitions-runtime-semantics-evaluation
// Step 1.a.ii.3.a. Let fenv be the running execution context's
// VariableEnvironment.
// Step 1.a.ii.3.b. Let benv be the running execution context's
// LexicalEnvironment.
// Step 1.a.ii.3.c. Let fobj be ! benv.GetBindingValue(F, false).
// Step 1.a.ii.3.d. Perform ! fenv.SetMutableBinding(F, fobj, false).
// Step 1.a.ii.3.e. Return NormalCompletion(empty).
possibly_annex_b_functions.mark_annex_b(function_declaration_properties);
}
fn before_binding_pattern(&mut self) {
// Static Semantics: IsSimpleParameterList
// https://tc39.es/ecma262/#sec-destructuring-binding-patterns-static-semantics-issimpleparameterlist
//
// BindingElement : BindingPattern
//
// 1. Return false.
//
// BindingElement : BindingPattern Initializer
//
// 1. Return false.
self.simple_parameter_list = false;
}
fn before_rest_parameter(&mut self) {
// Static Semantics: IsSimpleParameterList
// https://tc39.es/ecma262/#sec-function-definitions-static-semantics-issimpleparameterlist
//
// FormalParameters : FunctionRestParameter
//
// 1. Return false.
//
// FormalParameters : FormalParameterList , FunctionRestParameter
//
// 1. Return false.
self.simple_parameter_list = false;
}
fn after_initializer(&mut self) {
// Static Semantics: IsSimpleParameterList
// https://tc39.es/ecma262/#sec-destructuring-binding-patterns-static-semantics-issimpleparameterlist
//
// BindingElement : BindingPattern Initializer
//
// 1. Return false.
//
// SingleNameBinding : BindingIdentifier Initializer
//
// 1. Return false.
self.simple_parameter_list = false;
// FunctionDeclarationInstantiation ( func, argumentsList )
// https://tc39.es/ecma262/#sec-functiondeclarationinstantiation
//
// Step 8. Let hasParameterExpressions be ContainsExpression of formals.
// Static Semantics: ContainsExpression
// https://tc39.es/ecma262/#sec-destructuring-binding-patterns-static-semantics-containsexpression
//
// BindingElement : BindingPattern Initializer
//
// 1. Return true.
//
// SingleNameBinding : BindingIdentifier Initializer
//
// 1. Return true.
self.has_parameter_expressions = true;
}
fn before_computed_property_name(&mut self) {
// FunctionDeclarationInstantiation ( func, argumentsList )
// https://tc39.es/ecma262/#sec-functiondeclarationinstantiation
//
// Step 8. Let hasParameterExpressions be ContainsExpression of formals.
// Static Semantics: ContainsExpression
// https://tc39.es/ecma262/#sec-destructuring-binding-patterns-static-semantics-containsexpression
//
// BindingProperty : PropertyName : BindingElement
//
// 1. Let has be IsComputedPropertyKey of PropertyName .
// 2. If has is true, return true.
// 3. Return ContainsExpression of BindingElement .
self.has_parameter_expressions = true;
}
fn declare_param(&mut self, name: SourceAtomSetIndex) {
// Step 17. Else if "arguments" is an element of parameterNames,
// then
if name == CommonSourceAtomSetIndices::arguments() {
self.parameter_has_arguments = true;
}
self.parameter_names.insert(name.clone());
self.base.declare_param(name);
}
fn is_parameter_closed_over(&self) -> bool {
for name in &self.parameter_names {
if self.base.name_tracker.is_closed_over_def(name) {
return true;
}
}
false
}
}
/// Function parameters in FormalParameters, and variables used in
/// FormalParameters
/// For full-parse.
#[derive(Debug)]
struct FunctionParametersScopeBuilder {
shared: SharedFunctionParametersScopeBuilder,
/// State of the analysis.
/// This is used to determine what kind of binding the parameter is.
state: FunctionParametersState,
/// List of positional parameter or None if destructuring.
/// This includes rest parameter.
positional_parameter_names: Vec<Option<SourceAtomSetIndex>>,
/// List of non-positional parameters (destructuring parameters).
non_positional_parameter_names: Vec<SourceAtomSetIndex>,
/// FunctionDeclarationInstantiation ( func, argumentsList )
/// https://tc39.es/ecma262/#sec-functiondeclarationinstantiation
///
/// Step 16. If func.[[ThisMode]] is lexical, then
this_mode: ThisMode,
/// Step 6. If parameterNames has any duplicate entries, let hasDuplicates
/// be true. Otherwise, let hasDuplicates be false.
has_duplicates: bool,
scope_index: ScopeIndex,
/// Index of the script in the list of `functions` in the
/// `FunctionScriptStencilBuilder`.
script_index: ScriptStencilIndex,
has_direct_eval: bool,
is_arrow: bool,
}
impl FunctionParametersScopeBuilder {
fn new(scope_index: ScopeIndex, is_arrow: bool, script_index: ScriptStencilIndex) -> Self {
Self {
shared: SharedFunctionParametersScopeBuilder::new(is_arrow),
state: FunctionParametersState::Init,
positional_parameter_names: Vec::new(),
non_positional_parameter_names: Vec::new(),
// FIXME: Receive correct value.
this_mode: ThisMode::Global,
has_duplicates: false,
scope_index,
script_index,
has_direct_eval: false,
is_arrow,
}
}
fn before_parameter(&mut self) {
match self.state {
FunctionParametersState::Init => {
self.state = FunctionParametersState::Parameter;
}
FunctionParametersState::Parameter => {
self.state = FunctionParametersState::Parameter;
}
FunctionParametersState::DestructuringParameter => {
self.state = FunctionParametersState::Parameter;
}
FunctionParametersState::RestParameter
| FunctionParametersState::DestructuringRestParameter => panic!("Invalid transition"),
}
}
fn before_binding_pattern(&mut self) {
self.shared.before_binding_pattern();
match self.state {
FunctionParametersState::Parameter => {
self.positional_parameter_names.push(None);
self.state = FunctionParametersState::DestructuringParameter;
}
FunctionParametersState::DestructuringParameter => {}
FunctionParametersState::RestParameter => {
self.positional_parameter_names.push(None);
self.state = FunctionParametersState::DestructuringRestParameter;
}
FunctionParametersState::DestructuringRestParameter => {}
FunctionParametersState::Init => panic!("Invalid transition"),
}
}
fn before_rest_parameter(&mut self) {
self.shared.before_rest_parameter();
match self.state {
FunctionParametersState::Init
| FunctionParametersState::Parameter
| FunctionParametersState::DestructuringParameter => {
self.state = FunctionParametersState::RestParameter;
}
FunctionParametersState::RestParameter
| FunctionParametersState::DestructuringRestParameter => panic!("Invalid transition"),
}
}
fn after_initializer(&mut self) {
self.shared.after_initializer();
}
fn before_computed_property_name(&mut self) {
self.shared.before_computed_property_name();
}
fn declare_param(&mut self, name: SourceAtomSetIndex) {
// FunctionDeclarationInstantiation ( func, argumentsList )
// https://tc39.es/ecma262/#sec-functiondeclarationinstantiation
//
// Step 5. Let parameterNames be the BoundNames of formals.
match self.state {
FunctionParametersState::Init => panic!("Invalid state"),
FunctionParametersState::Parameter => {
self.positional_parameter_names.push(Some(name.clone()));
}
FunctionParametersState::DestructuringParameter => {
self.non_positional_parameter_names.push(name.clone());
}
FunctionParametersState::RestParameter => {
self.positional_parameter_names.push(Some(name.clone()));
}
FunctionParametersState::DestructuringRestParameter => {
self.non_positional_parameter_names.push(name.clone());
}
}
// Step 6. If parameterNames has any duplicate entries, let
// hasDuplicates be true. Otherwise, let hasDuplicates be
// false.
if self.shared.parameter_names.contains(&name) {
self.has_duplicates = true;
}
self.shared.declare_param(name);
}
fn into_scope_data_set(
self,
enclosing: ScopeIndex,
body_scope_builder: FunctionBodyScopeBuilder,
) -> FunctionScopeDataSet {
// FunctionDeclarationInstantiation ( func, argumentsList )
// https://tc39.es/ecma262/#sec-functiondeclarationinstantiation
//
// Step 15. Let argumentsObjectNeeded be true.
let mut arguments_object_needed = true;
// Step 16. If func.[[ThisMode]] is lexical, then
if self.this_mode == ThisMode::Lexical {
// Step 16.a. NOTE: Arrow functions never have an arguments objects.
// Step 16.b. Set argumentsObjectNeeded to false.
arguments_object_needed = false;
}
// Step 17. Else if "arguments" is an element of parameterNames,
// then
else if self.shared.parameter_has_arguments {
// Step 17.a. Set argumentsObjectNeeded to false.
arguments_object_needed = false;
}
// Step 18. Else if hasParameterExpressions is false, then
else if !self.shared.parameter_has_arguments {
// Step 18.a. If "arguments" is an element of functionNames or if
// "arguments" is
// an element of lexicalNames, then
if body_scope_builder.shared.function_or_lexical_has_arguments {
// Step 18.a.i. Set argumentsObjectNeeded to false.
arguments_object_needed = false;
}
}
// NOTE: In SpiderMonkey, single environment can have multiple
// binding kind.
// It's not necessary to create yet another environment here.
//
// Step 19. If strict is true or if hasParameterExpressions is false,
// then
if self.shared.strict || !self.shared.has_parameter_expressions {
// Step 19.a. NOTE: Only a single lexical environment is needed for
// the parameters and top-level vars.
// Step 19.b. Let env be the LexicalEnvironment of calleeContext.
// Step 19.c. Let envRec be env's EnvironmentRecord.
}
// Step 20. Else,
else {
// Step 20.a. NOTE: A separate Environment Record is needed to
// ensure that bindings created by direct eval calls in
// the formal parameter list are outside the environment
// where parameters are declared.
// Step 20.b. Let calleeEnv be the LexicalEnvironment of
// calleeContext.
// Step 20.c. Let env be NewDeclarativeEnvironment(calleeEnv).
// Step 20.d. Let envRec be env's EnvironmentRecord.
// Step 20.e. Assert: The VariableEnvironment of calleeContext is
// calleeEnv.
// Step 20.f. Set the LexicalEnvironment of calleeContext to env.
}
let has_extra_body_var_scope = self.shared.has_parameter_expressions;
// NOTE: Names in `body_scope_builder.var_names` is skipped if
// it's `arguments`, at step 27.c.i.
// The count here isn't the exact number of var bindings, but
// it's fine given FunctionScopeData::new doesn't require the
// exact number, but just maximum number.
let function_max_var_names_count = if has_extra_body_var_scope {
0
} else {
body_scope_builder.shared.var_names.len()
};
let mut function_scope_data = FunctionScopeData::new(
self.shared.has_parameter_expressions,
self.positional_parameter_names.len(),
self.non_positional_parameter_names.len(),
function_max_var_names_count,
enclosing,
self.script_index,
self.is_arrow,
);
// FunctionDeclarationInstantiation ( func, argumentsList )
// https://tc39.es/ecma262/#sec-functiondeclarationinstantiation
//
// Step 21. For each String paramName in parameterNames, do
// Step 21.a. Let alreadyDeclared be envRec.HasBinding(paramName).
// Step 21.b. NOTE: Early errors ensure that duplicate parameter names
// can only occur in non-strict functions that do not have
// parameter default values or rest parameters.
// Step 21.c. If alreadyDeclared is false, then
// Step 21.c.i. Perform ! envRec.CreateMutableBinding(paramName, false).
// Step 21.c.ii. If hasDuplicates is true, then
// Step 21.c.ii.1. Perform
// ! envRec.InitializeBinding(paramName, undefined).
//
// NOTE: The existence of duplication isn't encoded in scope data.
for maybe_name in &self.positional_parameter_names {
match maybe_name {
Some(n) => {
let is_closed_over = self.shared.base.name_tracker.is_closed_over_def(n)
|| (!has_extra_body_var_scope
&& body_scope_builder
.shared
.base
.name_tracker
.is_closed_over_def(n));
function_scope_data
.base
.bindings
.push(Some(BindingName::new(*n, is_closed_over)))
}
None => function_scope_data.base.bindings.push(None),
}
}
for n in &self.non_positional_parameter_names {
let is_closed_over = self.shared.base.name_tracker.is_closed_over_def(n)
|| (!has_extra_body_var_scope
&& body_scope_builder
.shared
.base
.name_tracker
.is_closed_over_def(n));
function_scope_data
.base
.bindings
.push(Some(BindingName::new(*n, is_closed_over)))
}
// Step 22. If argumentsObjectNeeded is true, then
// Steps 22.a-b. Create{Unm,M}appedArgumentsObject
// (done in emitter)
// Step 22.c. If strict is true, then
// Step 22.c.i. Perform
// ! envRec.CreateImmutableBinding("arguments", false).
// Step 22.d. Else,
// Step 22.d.i. Perform
// ! envRec.CreateMutableBinding("arguments", false).
// Step 22.e. Call envRec.InitializeBinding("arguments", ao).
//
// NOTE: In SpiderMonkey, whether immutable or not is not stored
// in scope data, but checked while parsing, including
// when parsing eval inside function.
// Step 22.f. Let parameterBindings be a new List of parameterNames
// with "arguments" appended.
//
// NOTE: Done in each consumer of parameterNames.
// Step 23. Else,
// Step 23.a. Let parameterBindings be parameterNames.
//
// NOTE: Done in each consumer of parameterNames.
// Steps 24-26. IteratorBindingInitialization
// (done in emitter)
// Step 27. If hasParameterExpressions is false, then
let extra_body_var_scope_data = if !self.shared.has_parameter_expressions {
debug_assert!(!has_extra_body_var_scope);
// Step 27.a. NOTE: Only a single lexical environment is needed for
// the parameters and top-level vars.
// Step 27.b. Let instantiatedVarNames be a copy of the List
// parameterBindings.
// Step 27.c. For each n in varNames, do
for n in &body_scope_builder.shared.var_names {
// Step 27.c.i. If n is not an element of instantiatedVarNames,
// then
// Step 27.c.i.1. Append n to instantiatedVarNames.
//
// NOTE: var_names is already unique.
// Check against parameters and `arguments` here.
if self.shared.parameter_names.contains(n)
|| (arguments_object_needed && *n == CommonSourceAtomSetIndices::arguments())
{
continue;
}
// Step 27.c.i.2. Perform
// ! envRec.CreateMutableBinding(n, false).
let is_closed_over = body_scope_builder
.shared
.base
.name_tracker
.is_closed_over_def(n);
function_scope_data
.base
.bindings
.push(Some(BindingName::new(*n, is_closed_over)));
// Step 27.c.i.3. Call envRec.InitializeBinding(n, undefined).
// (done in runtime)
}
// Step 27.d. Let varEnv be env.
// Step 27.e. Let varEnvRec be envRec.
ScopeData::Alias(self.scope_index)
}
// Step 28. Else,
else {
debug_assert!(has_extra_body_var_scope);
// In non-strict mode code, direct `eval` can extend function's
// scope.
let function_has_extensible_scope = !self.shared.strict && self.has_direct_eval;
// Step 28.a. NOTE: A separate Environment Record is needed to
// ensure that closures created by expressions in the
// formal parameter list do not have visibility of
// declarations in the function body.
// Step 28.b. Let varEnv be NewDeclarativeEnvironment(env).
// Step 28.c. Set the VariableEnvironment of calleeContext to
// varEnv.
let mut data = VarScopeData::new(
body_scope_builder.shared.var_names.len(),
function_has_extensible_scope,
/* encloding= */ self.scope_index,
);
// Step 28.d. Let instantiatedVarNames be a new empty List.
// Step 28.e. For each n in varNames, do
for n in &body_scope_builder.shared.var_names {
// Step 28.e.i. If n is not an element of instantiatedVarNames, then
// Step 28.e.i.1. Append n to instantiatedVarNames.
//
// NOTE: var_names is already unique.
// Step 28.e.i.2. Perform
// ! varEnv.CreateMutableBinding(n, false).
let is_closed_over = body_scope_builder
.shared
.base
.name_tracker
.is_closed_over_def(n);
data.base
.bindings
.push(BindingName::new(*n, is_closed_over));
// Step 28.e.i.3. If n is not an element of parameterBindings or if
// n is an element of functionNames, let
// initialValue be undefined.
// Step 28.e.i.4. Else,
// Step 28.e.i.4.a. Let initialValue be
// ! env.GetBindingValue(n, false).
// Step 28.e.i.5. Call varEnv.InitializeBinding(n, initialValue).
// (done in emitter)
// Step 28.e.i.6. NOTE: A var with the same name as a formal
// parameter initially has the same value as the
// corresponding initialized parameter.
}
ScopeData::Var(data)
};
// Step 30. If strict is false, then
// Step 30.a. Let lexEnv be NewDeclarativeEnvironment(varEnv).
// Step 30.b. NOTE: Non-strict functions use a separate lexical
// Environment Record for top-level lexical declarations so
// that a direct eval can determine whether any var scoped
// declarations introduced by the eval code conflict with
// pre-existing top-level lexically scoped declarations.
// This is not needed for strict functions because a strict
// direct eval always places all declarations into a new
// Environment Record.
// Step 31. Else, let lexEnv be varEnv.
// Step 32. Let lexEnvRec be lexEnv's EnvironmentRecord.
//
// NOTE: SpiderMonkey creates lexical env whenever lexical binding
// exists.
let lexical_scope_data = if body_scope_builder.shared.let_names.len() > 0
|| body_scope_builder.shared.const_names.len() > 0
{
let mut data = LexicalScopeData::new_function_lexical(
body_scope_builder.shared.let_names.len(),
body_scope_builder.shared.const_names.len(),
/* encloding= */ body_scope_builder.var_scope_index,
);
// Step 33. Set the LexicalEnvironment of calleeContext to lexEnv.
// Step 34. Let lexDeclarations be the LexicallyScopedDeclarations
// of code.
// Step 35. For each element d in lexDeclarations, do
// Step 35.a. NOTE: A lexically declared name cannot be the same as
// a function/generator declaration, formal parameter,
// or a var name. Lexically declared names are only
// instantiated here but not initialized.
// Step 35.b. For each element dn of the BoundNames of d, do
for n in &body_scope_builder.shared.let_names {
// Step 35.b.ii. Else,
// Step 35.b.ii.1. Perform
// ! lexEnvRec.CreateMutableBinding(dn, false).
let is_closed_over = body_scope_builder
.shared
.base
.name_tracker
.is_closed_over_def(n);
data.base
.bindings
.push(BindingName::new(*n, is_closed_over))
}
for n in &body_scope_builder.shared.const_names {
// Step 35.b.i. If IsConstantDeclaration of d is true, then
// Step 35.b.i.1. Perform
// ! lexEnvRec.CreateImmutableBinding(dn, true).
let is_closed_over = body_scope_builder
.shared
.base
.name_tracker
.is_closed_over_def(n);
data.base
.bindings
.push(BindingName::new(*n, is_closed_over))
}
ScopeData::Lexical(data)
} else {
ScopeData::Alias(body_scope_builder.var_scope_index)
};
// Step 36. For each Parse Node f in functionsToInitialize, do
// (done in emitter)
FunctionScopeDataSet {
function: ScopeData::Function(function_scope_data),
extra_body_var: extra_body_var_scope_data,
lexical: lexical_scope_data,
}
}
}
/// Variables declared/used in FunctionBody.
/// Shared part between full-parse and syntax-only parse.
#[derive(Debug)]
struct SharedFunctionBodyScopeBuilder {
base: BaseScopeBuilder,
/// FunctionDeclarationInstantiation ( func, argumentsList )
/// https://tc39.es/ecma262/#sec-functiondeclarationinstantiation
///
/// Step 9. Let varNames be the VarDeclaredNames of code.
var_names: IndexSet<SourceAtomSetIndex>,
/// Step 11. Let lexicalNames be the LexicallyDeclaredNames of code.
let_names: Vec<SourceAtomSetIndex>,
const_names: Vec<SourceAtomSetIndex>,
/// Step 18. Else if hasParameterExpressions is false, then
/// Step 18.a. If "arguments" is an element of functionNames or
/// if "arguments" is an element of lexicalNames, then
function_or_lexical_has_arguments: bool,
}
impl SharedFunctionBodyScopeBuilder {
fn new() -> Self {
Self {
base: BaseScopeBuilder::new(),
var_names: IndexSet::new(),
let_names: Vec::new(),
const_names: Vec::new(),
function_or_lexical_has_arguments: false,
}
}
fn declare_var(&mut self, name: SourceAtomSetIndex) {
// FunctionDeclarationInstantiation ( func, argumentsList )
// https://tc39.es/ecma262/#sec-functiondeclarationinstantiation
//
// Step 9. Let varNames be the VarDeclaredNames of code.
self.var_names.insert(name);
self.base.declare_var(name);
}
fn check_lexical_or_function_name(&mut self, name: SourceAtomSetIndex) {
// FunctionDeclarationInstantiation ( func, argumentsList )
// https://tc39.es/ecma262/#sec-functiondeclarationinstantiation
//
// Step 18.a. If "arguments" is an element of functionNames or if
// "arguments" is an element of lexicalNames, then
if name == CommonSourceAtomSetIndices::arguments() {
self.function_or_lexical_has_arguments = true;
}
}
fn declare_let(&mut self, name: SourceAtomSetIndex) {
// FunctionDeclarationInstantiation ( func, argumentsList )
// https://tc39.es/ecma262/#sec-functiondeclarationinstantiation
//
// Step 11. Let lexicalNames be the LexicallyDeclaredNames of code.
self.let_names.push(name.clone());
self.check_lexical_or_function_name(name.clone());
self.base.declare_let(name);
}
fn declare_const(&mut self, name: SourceAtomSetIndex) {
// FunctionDeclarationInstantiation ( func, argumentsList )
// https://tc39.es/ecma262/#sec-functiondeclarationinstantiation
//
// Step 11. Let lexicalNames be the LexicallyDeclaredNames of code.
self.let_names.push(name.clone());
self.check_lexical_or_function_name(name.clone());
self.base.declare_const(name);
}
fn declare_function(&mut self, name: SourceAtomSetIndex) {
// FunctionDeclarationInstantiation ( func, argumentsList )
// https://tc39.es/ecma262/#sec-functiondeclarationinstantiation
//
// Step 9. Let varNames be the VarDeclaredNames of code.
self.var_names.insert(name.clone());
// Step 14. For each d in varDeclarations, in reverse list order, do
// Step 14.a. If d is neither a VariableDeclaration nor a ForBinding
// nor a BindingIdentifier , then
// (implicit)
// Step 14.a.i. Assert: d is either a FunctionDeclaration, a
// GeneratorDeclaration, an AsyncFunctionDeclaration,
// or an AsyncGeneratorDeclaration.
// Step 14.a.ii. Let fn be the sole element of the BoundNames of d.
// Step 14.a.iii. If fn is not an element of functionNames, then
//
// NOTE: Instead of iterating in reverse list oder, we iterate in
// normal order and overwrite existing item.
// Step 14.a.iii.1. Insert fn as the first element of functionNames.
// Step 14.a.iii.2. NOTE: If there are multiple function declarations
// for the same name, the last declaration is used.
self.check_lexical_or_function_name(name);
self.base.declare_function(name)
}
fn is_var_closed_over(&self) -> bool {
for name in &self.var_names {
if self.base.name_tracker.is_closed_over_def(name) {
return true;
}
}
false
}
}
/// Variables declared/used in FunctionBody.
/// For full-parse.
#[derive(Debug)]
struct FunctionBodyScopeBuilder {
shared: SharedFunctionBodyScopeBuilder,
/// FunctionDeclarationInstantiation ( func, argumentsList )
/// https://tc39.es/ecma262/#sec-functiondeclarationinstantiation
///
/// Step 13. Let functionsToInitialize be a new empty List.
functions_to_initialize: Vec<ScriptStencilIndex>,
var_scope_index: ScopeIndex,
lexical_scope_index: ScopeIndex,
}
impl FunctionBodyScopeBuilder {
fn new(var_scope_index: ScopeIndex, lexical_scope_index: ScopeIndex) -> Self {
Self {
shared: SharedFunctionBodyScopeBuilder::new(),
functions_to_initialize: Vec::new(),
var_scope_index,
lexical_scope_index,
}
}
fn declare_var(&mut self, name: SourceAtomSetIndex) {
self.shared.declare_var(name);
}
fn declare_let(&mut self, name: SourceAtomSetIndex) {
self.shared.declare_let(name);
}
fn declare_const(&mut self, name: SourceAtomSetIndex) {
self.shared.declare_const(name);
}
fn declare_function(&mut self, name: SourceAtomSetIndex, fun_index: ScriptStencilIndex) {
self.shared.declare_function(name);
// FunctionDeclarationInstantiation ( func, argumentsList )
// https://tc39.es/ecma262/#sec-functiondeclarationinstantiation
//
// Step 14.a.iii.3. Insert d as the first element of
// functionsToInitialize.
self.functions_to_initialize.push(fun_index);
}
}
#[derive(Debug)]
enum ScopeBuilder {
Global(GlobalScopeBuilder),
SyntaxOnlyGlobal(BaseScopeBuilder),
Block(BlockScopeBuilder),
SyntaxOnlyBlock(BaseScopeBuilder),
FunctionExpression(FunctionExpressionScopeBuilder),
SyntaxOnlyFunctionExpression(BaseScopeBuilder),
FunctionParameters(FunctionParametersScopeBuilder),
SyntaxOnlyFunctionParameters(SharedFunctionParametersScopeBuilder),
FunctionBody(FunctionBodyScopeBuilder),
SyntaxOnlyFunctionBody(SharedFunctionBodyScopeBuilder),
}
impl ScopeBuilder {
fn get_scope_index(&self) -> Option<ScopeIndex> {
match self {
ScopeBuilder::Global(builder) => Some(builder.scope_index),
ScopeBuilder::SyntaxOnlyGlobal(_) => None,
ScopeBuilder::Block(builder) => Some(builder.scope_index),
ScopeBuilder::SyntaxOnlyBlock(_) => None,
ScopeBuilder::FunctionExpression(builder) => Some(builder.scope_index),
ScopeBuilder::SyntaxOnlyFunctionExpression(_) => None,
ScopeBuilder::FunctionParameters(builder) => Some(builder.scope_index),
ScopeBuilder::SyntaxOnlyFunctionParameters(_) => None,
ScopeBuilder::FunctionBody(builder) => Some(builder.lexical_scope_index),
ScopeBuilder::SyntaxOnlyFunctionBody(_) => None,
}
}
fn declare_var(&mut self, name: SourceAtomSetIndex) {
match self {
ScopeBuilder::Global(ref mut builder) => builder.declare_var(name),
ScopeBuilder::SyntaxOnlyGlobal(ref mut builder) => builder.declare_var(name),
ScopeBuilder::FunctionBody(ref mut builder) => builder.declare_var(name),
ScopeBuilder::SyntaxOnlyFunctionBody(ref mut builder) => builder.declare_var(name),
_ => panic!("unexpected var scope builder"),
}
}
fn declare_let(&mut self, name: SourceAtomSetIndex) {
match self {
ScopeBuilder::Global(ref mut builder) => builder.declare_let(name),
ScopeBuilder::SyntaxOnlyGlobal(ref mut builder) => builder.declare_let(name),
ScopeBuilder::Block(ref mut builder) => builder.declare_let(name),
ScopeBuilder::SyntaxOnlyBlock(ref mut builder) => builder.declare_let(name),
ScopeBuilder::FunctionBody(ref mut builder) => builder.declare_let(name),
ScopeBuilder::SyntaxOnlyFunctionBody(ref mut builder) => builder.declare_let(name),
_ => panic!("unexpected lexical scope builder"),
}
}
fn declare_const(&mut self, name: SourceAtomSetIndex) {
match self {
ScopeBuilder::Global(ref mut builder) => builder.declare_const(name),
ScopeBuilder::SyntaxOnlyGlobal(ref mut builder) => builder.declare_const(name),
ScopeBuilder::Block(ref mut builder) => builder.declare_const(name),
ScopeBuilder::SyntaxOnlyBlock(ref mut builder) => builder.declare_const(name),
ScopeBuilder::FunctionBody(ref mut builder) => builder.declare_const(name),
ScopeBuilder::SyntaxOnlyFunctionBody(ref mut builder) => builder.declare_const(name),
_ => panic!("unexpected lexical scope builder"),
}
}
fn set_function_name(&mut self, name: SourceAtomSetIndex) {
match self {
ScopeBuilder::FunctionExpression(ref mut builder) => builder.set_function_name(name),
ScopeBuilder::SyntaxOnlyFunctionExpression(ref mut builder) => {
builder.set_function_name(name)
}
// FunctionDeclaration etc doesn't push any scope builder.
// Just ignore.
_ => {}
}
}
fn declare_param(&mut self, name: SourceAtomSetIndex) {
match self {
ScopeBuilder::FunctionParameters(ref mut builder) => builder.declare_param(name),
ScopeBuilder::SyntaxOnlyFunctionParameters(ref mut builder) => {
builder.declare_param(name)
}
_ => panic!("unexpected function scope builder"),
}
}
fn base_mut(&mut self) -> &mut BaseScopeBuilder {
match self {
ScopeBuilder::Global(builder) => &mut builder.base,
ScopeBuilder::SyntaxOnlyGlobal(builder) => builder,
ScopeBuilder::Block(builder) => &mut builder.base,
ScopeBuilder::SyntaxOnlyBlock(builder) => builder,
ScopeBuilder::FunctionExpression(builder) => &mut builder.base,
ScopeBuilder::SyntaxOnlyFunctionExpression(builder) => builder,
ScopeBuilder::FunctionParameters(builder) => &mut builder.shared.base,
ScopeBuilder::SyntaxOnlyFunctionParameters(builder) => &mut builder.base,
ScopeBuilder::FunctionBody(builder) => &mut builder.shared.base,
ScopeBuilder::SyntaxOnlyFunctionBody(builder) => &mut builder.base,
}
}
}
/// Tracks what kind of binding the BindingIdentifier node corresponds to.
#[derive(Debug)]
struct ScopeKindStack {
stack: Vec<ScopeKind>,
}
impl ScopeKindStack {
fn new() -> Self {
Self { stack: Vec::new() }
}
fn innermost<'a>(&'a self) -> &'a ScopeKind {
self.stack
.last()
.expect("There should be at least one scope on the stack")
}
fn push(&mut self, kind: ScopeKind) {
self.stack.push(kind)
}
fn pop(&mut self, kind: ScopeKind) {
match self.stack.pop() {
Some(k) if k == kind => {}
_ => panic!("unmatching scope kind"),
}
}
fn is_empty(&self) -> bool {
self.stack.len() == 0
}
}
/// The stack of scope builder for creating binding into.
#[derive(Debug)]
struct ScopeBuilderStack {
stack: Vec<ScopeBuilder>,
/// Stack of lists of names that is
/// 1. defined in the scope
/// 2. closed over by inner script
///
/// Each list is delimited by `None`, for each scope.
///
/// The order of scopes is depth-first post-order, and the order of names
/// inside each scope is in not defined.
///
/// When entering a function, empty list is pushed to this stack, and
/// when leaving each function, top-most list is popped, and
/// added to gcthings of the function, and this list is reset to empty.
closed_over_bindings_for_lazy: Vec<Vec<Option<SourceAtomSetIndex>>>,
}
impl ScopeBuilderStack {
fn new() -> Self {
Self {
stack: Vec::new(),
closed_over_bindings_for_lazy: Vec::new(),
}
}
fn innermost_var<'a>(&'a mut self) -> &'a mut ScopeBuilder {
for builder in self.stack.iter_mut().rev() {
match builder {
ScopeBuilder::Global(_) => return builder,
ScopeBuilder::SyntaxOnlyGlobal(_) => return builder,
// NOTE: Function's body-level variable goes to
// `FunctionBodyScopeBuilder`, regardless of the existence of
// extra body var scope.
// See `FunctionParametersScopeBuilder::into_scope_data_set`
// for how those vars are stored into either function scope or
// extra body var scope.
ScopeBuilder::FunctionBody(_) => return builder,
ScopeBuilder::SyntaxOnlyFunctionBody(_) => return builder,
_ => {}
}
}
panic!("There should be at least one scope on the stack");
}
fn maybe_innermost_function_parameters<'a>(
&'a mut self,
) -> Option<&'a mut FunctionParametersScopeBuilder> {
for builder in self.stack.iter_mut().rev() {
match builder {
ScopeBuilder::FunctionParameters(builder) => return Some(builder),
_ => {}
}
}
None
}
fn innermost_lexical<'a>(&'a mut self) -> &'a mut ScopeBuilder {
// FIXME: If there's no other case, merge with innermost.
self.innermost()
}
fn innermost<'a>(&'a mut self) -> &'a mut ScopeBuilder {
self.stack
.last_mut()
.expect("There should be at least one scope on the stack")
}
fn maybe_innermost<'a>(&'a mut self) -> Option<&'a mut ScopeBuilder> {
self.stack.last_mut()
}
fn current_scope_index(&self) -> ScopeIndex {
self.maybe_current_scope_index()
.expect("Shouldn't be in syntax-only mode")
}
fn maybe_current_scope_index(&self) -> Option<ScopeIndex> {
self.stack
.last()
.expect("There should be at least one scope on the stack")
.get_scope_index()
}
fn push_global(&mut self, builder: GlobalScopeBuilder) {
self.stack.push(ScopeBuilder::Global(builder))
}
fn push_syntax_only_global(&mut self, builder: BaseScopeBuilder) {
self.stack.push(ScopeBuilder::SyntaxOnlyGlobal(builder))
}
fn pop_global(&mut self) -> GlobalScopeBuilder {
match self.pop() {
ScopeBuilder::Global(builder) => {
debug_assert!(self.stack.is_empty());
builder
}
_ => panic!("unmatching scope builder"),
}
}
fn pop_syntax_only_global(&mut self) {
match self.pop() {
ScopeBuilder::SyntaxOnlyGlobal(_) => {
debug_assert!(self.stack.is_empty());
}
_ => panic!("unmatching scope builder"),
}
}
fn push_block(&mut self, builder: BlockScopeBuilder) {
self.stack.push(ScopeBuilder::Block(builder))
}
fn push_syntax_only_block(&mut self, builder: BaseScopeBuilder) {
self.stack.push(ScopeBuilder::SyntaxOnlyBlock(builder))
}
fn handle_popped_block(&mut self, builder: &BaseScopeBuilder) {
self.innermost()
.base_mut()
.propagate_from_inner_non_script(builder);
self.update_closed_over_bindings_for_lazy(builder);
}
fn pop_block(&mut self) -> BlockScopeBuilder {
match self.pop() {
ScopeBuilder::Block(builder) => {
self.handle_popped_block(&builder.base);
builder
}
_ => panic!("unmatching scope builder"),
}
}
fn pop_syntax_only_block(&mut self) {
match self.pop() {
ScopeBuilder::SyntaxOnlyBlock(builder) => self.handle_popped_block(&builder),
_ => panic!("unmatching scope builder"),
}
}
fn push_function_expression(&mut self, builder: FunctionExpressionScopeBuilder) {
self.stack.push(ScopeBuilder::FunctionExpression(builder))
}
fn push_syntax_only_function_expression(&mut self, builder: BaseScopeBuilder) {
self.stack
.push(ScopeBuilder::SyntaxOnlyFunctionExpression(builder))
}
fn handle_popped_function_expression(&mut self, builder: &BaseScopeBuilder) {
if let Some(outer) = self.maybe_innermost() {
// NOTE: Function expression's name cannot have any
// used free variables.
// We can treat it as non-script here, so that
// any closed-over free variables inside this
// function is propagated from FunctionParameters
// to enclosing scope builder.
outer.base_mut().propagate_from_inner_non_script(builder);
}
self.update_closed_over_bindings_for_lazy(builder);
}
fn pop_function_expression(&mut self) -> FunctionExpressionScopeBuilder {
match self.pop() {
ScopeBuilder::FunctionExpression(builder) => {
self.handle_popped_function_expression(&builder.base);
builder
}
_ => panic!("unmatching scope builder"),
}
}
fn pop_syntax_only_function_expression(&mut self) {
match self.pop() {
ScopeBuilder::SyntaxOnlyFunctionExpression(builder) => {
self.handle_popped_function_expression(&builder);
}
_ => panic!("unmatching scope builder"),
}
}
fn push_function_parameters(&mut self, builder: FunctionParametersScopeBuilder) {
self.stack.push(ScopeBuilder::FunctionParameters(builder))
}
fn push_syntax_only_function_parameters(
&mut self,
builder: SharedFunctionParametersScopeBuilder,
) {
self.stack
.push(ScopeBuilder::SyntaxOnlyFunctionParameters(builder))
}
fn handle_popped_function_parameters_and_body(
&mut self,
function_declaration_properties: &mut FunctionDeclarationPropertyMap,
possibly_annex_b_functions: &mut PossiblyAnnexBFunctionList,
parameter_scope_builder: &mut SharedFunctionParametersScopeBuilder,
body_scope_builder: &mut SharedFunctionBodyScopeBuilder,
) {
// FunctionDeclarationInstantiation ( func, argumentsList )
// https://tc39.es/ecma262/#sec-functiondeclarationinstantiation
//
// Step 29. NOTE: Annex B adds additional steps at this point.
//
// NOTE: Reordered here in order to reflect Annex B functions
// to FreeNameTracker.
parameter_scope_builder.perform_annex_b(
function_declaration_properties,
possibly_annex_b_functions,
body_scope_builder,
);
parameter_scope_builder
.base
.propagate_from_inner_non_script(&body_scope_builder.base);
if let Some(outer) = self.maybe_innermost() {
outer
.base_mut()
.propagate_from_inner_script(¶meter_scope_builder.base);
}
let has_extra_body_var_scope = parameter_scope_builder.has_parameter_expressions;
if has_extra_body_var_scope {
self.update_closed_over_bindings_for_lazy(&body_scope_builder.base);
self.update_closed_over_bindings_for_lazy(¶meter_scope_builder.base);
} else {
self.update_closed_over_bindings_for_lazy_with_parameters_and_body(
¶meter_scope_builder.base,
&body_scope_builder.base,
);
}
}
fn pop_function_parameters_and_body(
&mut self,
function_declaration_properties: &mut FunctionDeclarationPropertyMap,
possibly_annex_b_functions: &mut PossiblyAnnexBFunctionList,
) -> (FunctionParametersScopeBuilder, FunctionBodyScopeBuilder) {
let mut body_scope_builder = match self.pop() {
ScopeBuilder::FunctionBody(builder) => builder,
_ => panic!("unmatching scope builder"),
};
let mut parameter_scope_builder = match self.pop() {
ScopeBuilder::FunctionParameters(builder) => builder,
_ => panic!("unmatching scope builder"),
};
self.handle_popped_function_parameters_and_body(
function_declaration_properties,
possibly_annex_b_functions,
&mut parameter_scope_builder.shared,
&mut body_scope_builder.shared,
);
(parameter_scope_builder, body_scope_builder)
}
fn pop_syntax_only_function_parameters_and_body(
&mut self,
function_declaration_properties: &mut FunctionDeclarationPropertyMap,
possibly_annex_b_functions: &mut PossiblyAnnexBFunctionList,
) -> (
SharedFunctionParametersScopeBuilder,
SharedFunctionBodyScopeBuilder,
) {
let mut body_scope_builder = match self.pop() {
ScopeBuilder::SyntaxOnlyFunctionBody(builder) => builder,
_ => panic!("unmatching scope builder"),
};
let mut parameter_scope_builder = match self.pop() {
ScopeBuilder::SyntaxOnlyFunctionParameters(builder) => builder,
_ => panic!("unmatching scope builder"),
};
self.handle_popped_function_parameters_and_body(
function_declaration_properties,
possibly_annex_b_functions,
&mut parameter_scope_builder,
&mut body_scope_builder,
);
(parameter_scope_builder, body_scope_builder)
}
fn get_function_parameters<'a>(&'a mut self) -> &'a mut FunctionParametersScopeBuilder {
match self.innermost() {
ScopeBuilder::FunctionParameters(builder) => builder,
_ => panic!("unmatching scope builder"),
}
}
fn get_syntax_only_function_parameters<'a>(
&'a mut self,
) -> &'a mut SharedFunctionParametersScopeBuilder {
match self.innermost() {
ScopeBuilder::SyntaxOnlyFunctionParameters(builder) => builder,
_ => panic!("unmatching scope builder"),
}
}
fn push_function_body(&mut self, builder: FunctionBodyScopeBuilder) {
self.stack.push(ScopeBuilder::FunctionBody(builder))
}
fn push_syntax_only_function_body(&mut self, builder: SharedFunctionBodyScopeBuilder) {
self.stack
.push(ScopeBuilder::SyntaxOnlyFunctionBody(builder))
}
fn update_closed_over_bindings_for_lazy(&mut self, builder: &BaseScopeBuilder) {
match self.closed_over_bindings_for_lazy.last_mut() {
Some(bindings) => {
for name in builder.name_tracker.defined_and_closed_over_vars() {
bindings.push(Some(*name));
}
bindings.push(None);
}
None => {
// We're leaving lexical scope in top-level script.
}
}
}
// Just like update_closed_over_bindings_for_lazy, but merge
// 2 builders for parameters and body, in case the function doesn't have
// extra body scope.
fn update_closed_over_bindings_for_lazy_with_parameters_and_body(
&mut self,
builder1: &BaseScopeBuilder,
builder2: &BaseScopeBuilder,
) {
match self.closed_over_bindings_for_lazy.last_mut() {
Some(bindings) => {
for name in builder1.name_tracker.defined_and_closed_over_vars() {
bindings.push(Some(*name));
}
for name in builder2.name_tracker.defined_and_closed_over_vars() {
bindings.push(Some(*name));
}
bindings.push(None);
}
None => {
// We're leaving lexical scope in top-level script.
}
}
}
/// Pop the current scope.
fn pop(&mut self) -> ScopeBuilder {
self.stack.pop().expect("unmatching scope builder")
}
fn depth(&self) -> usize {
self.stack.len()
}
}
/// Builds `ScriptStencil` for all functions (both non-lazy and lazy).
/// The script is set to lazy function, with inner functions and
/// closed over bindings populated in gcthings list.
///
/// TODO: For non-lazy function, gcthings list should be populated in the
/// emitter pass, not here.
#[derive(Debug)]
pub struct FunctionScriptStencilBuilder {
/// The map from function node to ScriptStencil.
///
/// The map is separated into `function_stencil_indicies` and `functions`,
/// because it can be referred to in different ways from multiple places:
/// * map from Function AST node (`function_stencil_indices`)
/// * enclosing script/function, to list inner functions
function_stencil_indices: AssociatedData<ScriptStencilIndex>,
scripts: ScriptStencilList,
/// The stack of functions that the current context is in.
///
/// The last element in this stack represents the current function, where
/// the inner function will be stored
function_stack: Vec<ScriptStencilIndex>,
}
impl FunctionScriptStencilBuilder {
fn new() -> Self {
let scripts = ScriptStencilList::new_with_empty_top_level();
Self {
function_stencil_indices: AssociatedData::new(),
scripts,
function_stack: Vec::new(),
}
}
/// Enter a function.
///
/// This creates `ScriptStencil` for the function, and adds it to
/// enclosing function if exists.
fn enter<T>(
&mut self,
fun: &T,
syntax_kind: FunctionSyntaxKind,
enclosing_scope_index: Option<ScopeIndex>,
) -> ScriptStencilIndex
where
T: SourceLocationAccessor + NodeTypeIdAccessor,
{
let loc = fun.get_loc();
let source_start = loc.start as u32;
// FIXME: Map from offset to line/column.
let lineno = 1;
let column = 0;
let function_stencil = ScriptStencil::lazy_function(
SourceExtent {
source_start,
source_end: 0,
to_string_start: source_start,
to_string_end: 0,
lineno,
column,
},
None,
syntax_kind.is_generator(),
syntax_kind.is_async(),
FunctionFlags::interpreted(syntax_kind),
enclosing_scope_index,
);
let index = self.scripts.push(function_stencil);
self.function_stencil_indices.insert(fun, index);
match self.maybe_current_mut() {
Some(enclosing) => {
enclosing.push_inner_function(index);
}
None => {}
}
self.function_stack.push(index);
index
}
/// Leave a function, setting its source location.
fn leave<T>(&mut self, fun: &T)
where
T: SourceLocationAccessor + NodeTypeIdAccessor,
{
let loc = fun.get_loc();
let source_end = loc.end;
self.current_mut().set_source_end(source_end);
self.current_mut().set_to_string_end(source_end);
self.function_stack.pop();
}
/// Returns the current function's index.
/// Panics if no current function is found.
fn current_index(&self) -> ScriptStencilIndex {
*self
.function_stack
.last()
.expect("should be inside function")
}
/// Returns a immutable reference to the innermost function. None otherwise.
fn maybe_current<'a>(&'a self) -> Option<&'a ScriptStencil> {
let maybe_index = self.function_stack.last();
maybe_index.map(move |index| self.scripts.get(*index))
}
/// Returns a immutable reference to the current function.
/// Panics if no current function is found.
fn current<'a>(&'a self) -> &'a ScriptStencil {
self.maybe_current().expect("should be inside function")
}
/// Returns a mutable reference to the innermost function. None otherwise.
fn maybe_current_mut<'a>(&'a mut self) -> Option<&'a mut ScriptStencil> {
let maybe_index = self.function_stack.last().cloned();
maybe_index.map(move |index| self.scripts.get_mut(index))
}
/// Returns a mutable reference to the current function.
/// Panics if no current function is found.
fn current_mut<'a>(&'a mut self) -> &'a mut ScriptStencil {
self.maybe_current_mut().expect("should be inside function")
}
/// Sets the name of the current function.
fn set_function_name(&mut self, name: SourceAtomSetIndex) {
self.current_mut().set_fun_name(name);
}
/// Sets the position of the function parameters.
/// `params` should point to the `(` of the function parameters.
/// If it's an arrow function without parenthesis, `params` should point
/// the parameter binding.
fn on_function_parameters<T>(&mut self, params: &T)
where
T: SourceLocationAccessor + NodeTypeIdAccessor,
{
let loc = params.get_loc();
let params_start = loc.start;
self.current_mut().set_source_starts(params_start);
}
fn on_non_rest_parameter(&mut self) {
let fun = self.current_mut();
fun.add_fun_nargs();
}
/// Flags that the current function has rest parameter.
fn on_rest_parameter(&mut self) {
let fun = self.current_mut();
fun.add_fun_nargs();
fun.set_has_rest();
}
fn add_closed_over_bindings(
&mut self,
mut closed_over_bindings_for_lazy: Vec<Option<SourceAtomSetIndex>>,
) {
// Remove trailing `None`s.
loop {
match closed_over_bindings_for_lazy.last() {
Some(Some(_)) => {
// The last item isn't None.
break;
}
Some(None) => {
// The last item is None, remove it
closed_over_bindings_for_lazy.pop();
}
None => {
// List is empty.
break;
}
}
}
let current = self.current_mut();
for name in closed_over_bindings_for_lazy {
match name {
Some(name) => current.push_closed_over_bindings(name),
None => current.push_closed_over_bindings_delimiter(),
}
}
}
}
/// Scope builder shouldn't raise any error except not-implemented.
/// This struct should eventually be removed.
#[derive(Clone, Debug)]
pub enum ScopeBuildError {
NotImplemented(&'static str),
}
/// Receives method calls telling about a JS script and builds a
/// `ScopeDataMap`.
///
/// Usage: This struct's public methods must be called for each scope,
/// declaration, and identifier in a JS script, in source order. Then use
/// `ScopeDataMap::from()` to extract the results. Currently this object is
/// driven by method calls from a `pass::ScopePass`.
#[derive(Debug)]
pub struct ScopeDataMapBuilder {
scope_kind_stack: ScopeKindStack,
builder_stack: ScopeBuilderStack,
scopes: ScopeDataList,
/// The global scope information.
/// Using `Option` to make this field populated later.
global: Option<ScopeIndex>,
/// The map from non-global AST node to scope information.
non_global: AssociatedData<ScopeIndex>,
function_stencil_builder: FunctionScriptStencilBuilder,
function_declaration_properties: FunctionDeclarationPropertyMap,
possibly_annex_b_functions: PossiblyAnnexBFunctionList,
error: Option<ScopeBuildError>,
// The depth of `builder_stack` where syntax-only mode started.
// The pointed `builder_stack` item should be enclosing scope of
// function.
//
// None if not in syntax-only mode.
syntax_only_depth: Option<usize>,
}
impl ScopeDataMapBuilder {
pub fn new() -> Self {
Self {
scope_kind_stack: ScopeKindStack::new(),
builder_stack: ScopeBuilderStack::new(),
scopes: ScopeDataList::new(),
global: None,
non_global: AssociatedData::new(),
function_stencil_builder: FunctionScriptStencilBuilder::new(),
function_declaration_properties: FunctionDeclarationPropertyMap::new(),
possibly_annex_b_functions: PossiblyAnnexBFunctionList::new(),
error: None,
syntax_only_depth: None,
}
}
fn set_error(&mut self, e: ScopeBuildError) {
if self.error.is_none() {
self.error = Some(e);
}
}
pub fn enter_syntax_only_mode(&mut self) {
assert!(self.syntax_only_depth.is_none());
self.syntax_only_depth = Some(self.builder_stack.depth());
}
fn maybe_exit_syntax_only_mode(&mut self) {
if self.syntax_only_depth.is_none() {
return;
}
let depth = self.syntax_only_depth.unwrap();
if self.builder_stack.depth() == depth {
self.syntax_only_depth = None;
return;
}
debug_assert!(self.builder_stack.depth() > depth);
}
pub fn is_syntax_only_mode(&self) -> bool {
self.syntax_only_depth.is_some()
}
pub fn before_script(&mut self) {
if self.is_syntax_only_mode() {
let builder = BaseScopeBuilder::new();
self.builder_stack.push_syntax_only_global(builder);
return;
}
// SetRealmGlobalObject ( realmRec, globalObj, thisValue )
// https://tc39.es/ecma262/#sec-setrealmglobalobject
//
// Steps 1-4, 7.
// (done in runtime)
// Step 5. Let newGlobalEnv be
// NewGlobalEnvironment(globalObj, thisValue).
let index = self.scopes.allocate();
let builder = GlobalScopeBuilder::new(index);
self.global = Some(index);
// Step 6. Set realmRec.[[GlobalEnv]] to newGlobalEnv.
// (implicit)
// ScriptEvaluation ( scriptRecord )
// https://tc39.es/ecma262/#sec-runtime-semantics-scriptevaluation
//
// Step 1. Let globalEnv be scriptRecord.[[Realm]].[[GlobalEnv]].
// (implicit)
// Step 2. Let scriptContext be a new ECMAScript code execution context.
// (implicit)
// Steps 3-5.
// (done in runtime)
// Step 6. Set the VariableEnvironment of scriptContext to globalEnv.
// Step 7. Set the LexicalEnvironment of scriptContext to globalEnv.
self.builder_stack.push_global(builder);
// Steps 8-17.
// (done in runtime)
}
pub fn after_script(&mut self) {
if self.is_syntax_only_mode() {
self.builder_stack.pop_syntax_only_global();
self.maybe_exit_syntax_only_mode();
return;
}
let builder = self.builder_stack.pop_global();
// Runtime Semantics: GlobalDeclarationInstantiation ( script, env )
// https://tc39.es/ecma262/#sec-globaldeclarationinstantiation
//
// Steps 3-6.
// (done in runtime)
// Steps 12-18.
let scope_index = builder.scope_index;
let scope = builder.into_scope_data(
&mut self.function_declaration_properties,
&mut self.possibly_annex_b_functions,
);
self.scopes.populate(scope_index, scope);
}
pub fn before_block_statement<T>(&mut self, block: &T)
where
T: SourceLocationAccessor + NodeTypeIdAccessor,
{
if self.is_syntax_only_mode() {
let builder = BaseScopeBuilder::new();
self.builder_stack.push_syntax_only_block(builder);
return;
}
// Runtime Semantics: Evaluation
// https://tc39.es/ecma262/#sec-block-runtime-semantics-evaluation
//
// Block : { StatementList }
//
// Step 1. Let oldEnv be the running execution context's
// LexicalEnvironment.
// (implicit)
// Step 2. Let blockEnv be NewDeclarativeEnvironment(oldEnv).
let index = self.scopes.allocate();
let builder = BlockScopeBuilder::new(index);
self.non_global.insert(block, index);
// Step 3. Perform
// BlockDeclarationInstantiation(StatementList, blockEnv).
// (done in leave_enum_statement_variant_block_statement)
// Step 4. Set the running execution context's LexicalEnvironment to
// blockEnv.
self.builder_stack.push_block(builder);
// Step 5. Let blockValue be the result of evaluating StatementList.
// (done in runtime)
}
pub fn after_block_statement(&mut self) {
if self.is_syntax_only_mode() {
self.builder_stack.pop_syntax_only_block();
return;
}
let builder = self.builder_stack.pop_block();
let enclosing = self.builder_stack.current_scope_index();
// Runtime Semantics: Evaluation
// https://tc39.es/ecma262/#sec-block-runtime-semantics-evaluation
//
// Block : { StatementList }
//
// Step 3. Perform
// BlockDeclarationInstantiation(StatementList, blockEnv).
self.scopes.populate(
builder.scope_index,
builder.into_scope_data(enclosing, &mut self.possibly_annex_b_functions),
);
// Step 6. Set the running execution context's LexicalEnvironment to
// oldEnv.
// Step 7. Return blockValue.
// (implicit)
}
pub fn before_var_declaration(&mut self) {
self.scope_kind_stack.push(ScopeKind::Var);
}
pub fn after_var_declaration(&mut self) {
self.scope_kind_stack.pop(ScopeKind::Var);
}
pub fn before_let_declaration(&mut self) {
self.scope_kind_stack.push(ScopeKind::Let);
}
pub fn after_let_declaration(&mut self) {
self.scope_kind_stack.pop(ScopeKind::Let);
}
pub fn before_const_declaration(&mut self) {
self.scope_kind_stack.push(ScopeKind::Const);
}
pub fn after_const_declaration(&mut self) {
self.scope_kind_stack.pop(ScopeKind::Const);
}
pub fn on_binding_identifier(&mut self, name: SourceAtomSetIndex) {
if self.scope_kind_stack.is_empty() {
// FIXME
// Do nothing for unsupported case.
self.set_error(ScopeBuildError::NotImplemented(
"Unsupported binding identifier",
));
return;
}
match self.scope_kind_stack.innermost() {
ScopeKind::Var => self.builder_stack.innermost_var().declare_var(name),
ScopeKind::Let => self.builder_stack.innermost_lexical().declare_let(name),
ScopeKind::Const => self.builder_stack.innermost_lexical().declare_const(name),
ScopeKind::FunctionName => {
self.builder_stack.innermost().set_function_name(name);
self.function_stencil_builder.set_function_name(name);
}
ScopeKind::FunctionParametersAndBody => {
// FIXME
// Do nothing for unsupported case.
self.set_error(ScopeBuildError::NotImplemented(
"Unsupported binding identifier",
));
return;
}
ScopeKind::FormalParameter => self.builder_stack.innermost().declare_param(name),
_ => panic!("Not implemeneted"),
}
}
pub fn on_non_binding_identifier(&mut self, name: SourceAtomSetIndex) {
self.builder_stack
.innermost()
.base_mut()
.name_tracker
.note_use(name);
}
pub fn before_function_declaration<T>(
&mut self,
name: SourceAtomSetIndex,
fun: &T,
is_generator: bool,
is_async: bool,
) -> ScriptStencilIndex
where
T: SourceLocationAccessor + NodeTypeIdAccessor,
{
if is_generator || is_async {
// FIXME: Generator and async should mark all bindings closed over.
self.set_error(ScopeBuildError::NotImplemented(
"Generator or async function",
));
}
let fun_index = self.function_stencil_builder.enter(
fun,
FunctionSyntaxKind::function_declaration(is_generator, is_async),
self.builder_stack.maybe_current_scope_index(),
);
match self.builder_stack.innermost_lexical() {
ScopeBuilder::Global(ref mut builder) => builder.declare_function(name, fun_index),
ScopeBuilder::SyntaxOnlyGlobal(ref mut builder) => builder.declare_function(name),
ScopeBuilder::Block(ref mut builder) => builder.declare_function(name, fun_index),
ScopeBuilder::SyntaxOnlyBlock(ref mut builder) => builder.declare_function(name),
ScopeBuilder::FunctionBody(ref mut builder) => {
builder.declare_function(name, fun_index)
}
ScopeBuilder::SyntaxOnlyFunctionBody(ref mut builder) => builder.declare_function(name),
_ => panic!("unexpected lexical for FunctionDeclaration"),
}
self.scope_kind_stack.push(ScopeKind::FunctionName);
fun_index
}
pub fn after_function_declaration<T>(&mut self, fun: &T)
where
T: SourceLocationAccessor + NodeTypeIdAccessor,
{
self.function_stencil_builder.leave(fun);
self.scope_kind_stack.pop(ScopeKind::FunctionName);
}
pub fn before_function_expression<T>(&mut self, fun: &T, is_generator: bool, is_async: bool)
where
T: SourceLocationAccessor + NodeTypeIdAccessor,
{
// FIXME: Anonymous function expression needs inferred name.
self.set_error(ScopeBuildError::NotImplemented(
"Function expression (name analysis)",
));
self.scope_kind_stack.push(ScopeKind::FunctionName);
self.function_stencil_builder.enter(
fun,
FunctionSyntaxKind::function_expression(is_generator, is_async),
self.builder_stack.maybe_current_scope_index(),
);
if self.is_syntax_only_mode() {
let builder = BaseScopeBuilder::new();
self.builder_stack
.push_syntax_only_function_expression(builder);
return;
}
let index = self.scopes.allocate();
let builder = FunctionExpressionScopeBuilder::new(index);
self.non_global.insert(fun, index);
self.builder_stack.push_function_expression(builder);
}
pub fn after_function_expression<T>(&mut self, fun: &T)
where
T: SourceLocationAccessor + NodeTypeIdAccessor,
{
self.function_stencil_builder.leave(fun);
self.scope_kind_stack.pop(ScopeKind::FunctionName);
if self.is_syntax_only_mode() {
self.builder_stack.pop_syntax_only_function_expression();
self.maybe_exit_syntax_only_mode();
return;
}
let builder = self.builder_stack.pop_function_expression();
let enclosing = self.builder_stack.current_scope_index();
self.scopes
.populate(builder.scope_index, builder.into_scope_data(enclosing));
}
pub fn before_method<T>(&mut self, fun: &T, is_generator: bool, is_async: bool)
where
T: SourceLocationAccessor + NodeTypeIdAccessor,
{
// FIXME: Support PropertyName as function name.
self.set_error(ScopeBuildError::NotImplemented("Method (name calculation)"));
self.function_stencil_builder.enter(
fun,
FunctionSyntaxKind::method(is_generator, is_async),
self.builder_stack.maybe_current_scope_index(),
);
}
pub fn after_method<T>(&mut self, fun: &T)
where
T: SourceLocationAccessor + NodeTypeIdAccessor,
{
self.function_stencil_builder.leave(fun);
}
pub fn before_getter<T>(&mut self, fun: &T)
where
T: SourceLocationAccessor + NodeTypeIdAccessor,
{
// FIXME: Support PropertyName as function name.
self.set_error(ScopeBuildError::NotImplemented("Getter (name calculation)"));
self.function_stencil_builder.enter(
fun,
FunctionSyntaxKind::getter(),
self.builder_stack.maybe_current_scope_index(),
);
}
pub fn on_getter_parameter<T>(&mut self, param: &T)
where
T: SourceLocationAccessor + NodeTypeIdAccessor,
{
self.before_function_parameters(param);
self.after_function_parameters();
}
pub fn after_getter<T>(&mut self, fun: &T)
where
T: SourceLocationAccessor + NodeTypeIdAccessor,
{
self.function_stencil_builder.leave(fun);
}
pub fn before_setter<T>(&mut self, fun: &T)
where
T: SourceLocationAccessor + NodeTypeIdAccessor,
{
// FIXME: Support PropertyName as function name.
self.set_error(ScopeBuildError::NotImplemented("Setter (name calculation)"));
self.function_stencil_builder.enter(
fun,
FunctionSyntaxKind::setter(),
self.builder_stack.maybe_current_scope_index(),
);
}
pub fn before_setter_parameter<T>(&mut self, param: &T)
where
T: SourceLocationAccessor + NodeTypeIdAccessor,
{
self.before_function_parameters(param);
self.before_parameter();
}
pub fn after_setter_parameter(&mut self) {
self.after_function_parameters();
}
pub fn after_setter<T>(&mut self, fun: &T)
where
T: SourceLocationAccessor + NodeTypeIdAccessor,
{
self.function_stencil_builder.leave(fun);
}
pub fn before_arrow_function<T>(&mut self, is_async: bool, params: &T)
where
T: SourceLocationAccessor + NodeTypeIdAccessor,
{
// FIXME: Arrow function needs to access enclosing scope's
// `this` and `arguments`.
self.set_error(ScopeBuildError::NotImplemented(
"Arrow function (special name handling)",
));
self.function_stencil_builder.enter(
params,
FunctionSyntaxKind::arrow(is_async),
self.builder_stack.maybe_current_scope_index(),
);
}
pub fn after_arrow_function<T>(&mut self, body: &T)
where
T: SourceLocationAccessor + NodeTypeIdAccessor,
{
self.function_stencil_builder.leave(body);
}
pub fn before_function_parameters<T>(&mut self, params: &T)
where
T: SourceLocationAccessor + NodeTypeIdAccessor,
{
self.scope_kind_stack
.push(ScopeKind::FunctionParametersAndBody);
self.builder_stack
.closed_over_bindings_for_lazy
.push(Vec::new());
self.function_stencil_builder.on_function_parameters(params);
self.scope_kind_stack.push(ScopeKind::FormalParameter);
let is_arrow = self.function_stencil_builder.current().is_arrow_function();
if self.is_syntax_only_mode() {
let builder = SharedFunctionParametersScopeBuilder::new(is_arrow);
self.builder_stack
.push_syntax_only_function_parameters(builder);
return;
}
let index = self.scopes.allocate();
let builder = FunctionParametersScopeBuilder::new(
index,
is_arrow,
self.function_stencil_builder.current_index(),
);
self.non_global.insert(params, index);
self.builder_stack.push_function_parameters(builder);
}
pub fn after_function_parameters(&mut self) {
self.scope_kind_stack.pop(ScopeKind::FormalParameter);
}
pub fn before_parameter(&mut self) {
self.function_stencil_builder.on_non_rest_parameter();
if self.is_syntax_only_mode() {
return;
}
let builder = self.builder_stack.get_function_parameters();
builder.before_parameter();
}
pub fn before_binding_pattern(&mut self) {
match self.builder_stack.innermost() {
ScopeBuilder::FunctionParameters(builder) => {
builder.before_binding_pattern();
}
ScopeBuilder::SyntaxOnlyFunctionParameters(builder) => {
builder.before_binding_pattern();
}
_ => {}
}
}
pub fn after_initializer(&mut self) {
match self.builder_stack.innermost() {
ScopeBuilder::FunctionParameters(builder) => {
builder.after_initializer();
}
ScopeBuilder::SyntaxOnlyFunctionParameters(builder) => {
builder.after_initializer();
}
_ => {}
}
}
pub fn before_computed_property_name(&mut self) {
match self.builder_stack.innermost() {
ScopeBuilder::FunctionParameters(builder) => {
builder.before_computed_property_name();
}
ScopeBuilder::SyntaxOnlyFunctionParameters(builder) => {
builder.before_computed_property_name();
}
_ => {}
}
}
pub fn before_rest_parameter(&mut self) {
self.function_stencil_builder.on_rest_parameter();
if self.is_syntax_only_mode() {
let builder = self.builder_stack.get_syntax_only_function_parameters();
builder.before_rest_parameter();
return;
}
let builder = self.builder_stack.get_function_parameters();
builder.before_rest_parameter();
}
pub fn before_function_body<T>(&mut self, body: &T)
where
T: SourceLocationAccessor + NodeTypeIdAccessor,
{
if self.is_syntax_only_mode() {
let builder = SharedFunctionBodyScopeBuilder::new();
self.builder_stack.push_syntax_only_function_body(builder);
return;
}
let var_index = self.scopes.allocate();
let lexical_index = self.scopes.allocate();
debug_assert!(lexical_index == var_index.next());
let builder = FunctionBodyScopeBuilder::new(var_index, lexical_index);
self.non_global.insert(body, var_index);
self.builder_stack.push_function_body(builder);
}
fn add_closed_over_bindings(&mut self) {
self.function_stencil_builder.add_closed_over_bindings(
self.builder_stack
.closed_over_bindings_for_lazy
.pop()
.expect("Vector should be pushed by before_function_parameters"),
);
}
fn update_function_stencil(
&mut self,
parameter_scope_builder: &SharedFunctionParametersScopeBuilder,
body_scope_builder: &SharedFunctionBodyScopeBuilder,
) {
let has_extra_body_var_scope = parameter_scope_builder.has_parameter_expressions;
let bindings_accessed_dynamically =
parameter_scope_builder.base.bindings_accessed_dynamically;
let needs_environment_object = if has_extra_body_var_scope {
bindings_accessed_dynamically || parameter_scope_builder.is_parameter_closed_over()
} else {
bindings_accessed_dynamically
|| parameter_scope_builder.is_parameter_closed_over()
|| body_scope_builder.is_var_closed_over()
};
let fun_stencil = self.function_stencil_builder.current_mut();
if needs_environment_object {
fun_stencil.set_needs_function_environment_objects();
}
if has_extra_body_var_scope {
if body_scope_builder.var_names.len() > 0 {
fun_stencil.set_function_has_extra_body_var_scope();
}
}
let strict = parameter_scope_builder.strict;
let simple_parameter_list = parameter_scope_builder.simple_parameter_list;
let has_mapped_arguments = !strict && simple_parameter_list;
if has_mapped_arguments {
fun_stencil.set_has_mapped_args_obj();
}
if !fun_stencil.is_arrow_function() {
let has_used_this = parameter_scope_builder
.base
.name_tracker
.is_used_or_closed_over(CommonSourceAtomSetIndices::this())
|| bindings_accessed_dynamically;
if has_used_this {
fun_stencil.set_function_has_this_binding();
}
let has_used_arguments = parameter_scope_builder
.base
.name_tracker
.is_used_or_closed_over(CommonSourceAtomSetIndices::arguments())
|| bindings_accessed_dynamically;
let mut uses_arguments = false;
let mut try_declare_arguments = has_used_arguments;
let parameter_has_arguments = parameter_scope_builder.parameter_has_arguments;
let var_names_has_arguments = body_scope_builder
.var_names
.contains(&CommonSourceAtomSetIndices::arguments());
let body_has_defined_arguments =
var_names_has_arguments || body_scope_builder.function_or_lexical_has_arguments;
// FunctionDeclarationInstantiation ( func, argumentsList )
// https://tc39.es/ecma262/#sec-functiondeclarationinstantiation
//
// Step 17 (Else if "arguments" is an element of parameterNames...)
// and step 18 (Else if hasParameterExpressions is false...) say
// formal parameters, lexical bindings, and body-level functions
// named 'arguments' shadow the arguments object.
//
// So even if there wasn't a free use of 'arguments' but there is a
// var binding of 'arguments', we still might need the arguments
// object.
//
// If we have an extra var scope due to parameter expressions and
// the body declared 'var arguments', we still need to declare
// 'arguments' in the function scope.
//
// NOTE: This is implementation-specfic optimization, and has
// no corresponding steps in the spec.
if var_names_has_arguments {
if has_extra_body_var_scope {
try_declare_arguments = true;
} else if !parameter_has_arguments {
uses_arguments = true;
}
}
if try_declare_arguments {
// if extra body var scope exists, the existence of `arguments`
// binding in function body doesn't affect.
let declare_arguments = !parameter_has_arguments
&& (has_extra_body_var_scope || !body_has_defined_arguments);
if declare_arguments {
fun_stencil.set_should_declare_arguments();
uses_arguments = true;
}
}
if uses_arguments {
fun_stencil.set_needs_args_obj();
if has_used_this {
// FIXME
// IsLikelyConstructorWrapper should be set if
// `.apply()` is used and `return` isn't used.
self.set_error(ScopeBuildError::NotImplemented(
"IsLikelyConstructorWrapper condition",
));
}
}
}
}
pub fn after_function_body(&mut self) {
self.scope_kind_stack
.pop(ScopeKind::FunctionParametersAndBody);
if self.is_syntax_only_mode() {
let (parameter_scope_builder, body_scope_builder) = self
.builder_stack
.pop_syntax_only_function_parameters_and_body(
&mut self.function_declaration_properties,
&mut self.possibly_annex_b_functions,
);
self.possibly_annex_b_functions.clear();
self.add_closed_over_bindings();
self.update_function_stencil(¶meter_scope_builder, &body_scope_builder);
self.maybe_exit_syntax_only_mode();
return;
}
let (parameter_scope_builder, body_scope_builder) =
self.builder_stack.pop_function_parameters_and_body(
&mut self.function_declaration_properties,
&mut self.possibly_annex_b_functions,
);
self.possibly_annex_b_functions.clear();
self.add_closed_over_bindings();
self.update_function_stencil(¶meter_scope_builder.shared, &body_scope_builder.shared);
let enclosing = self.builder_stack.current_scope_index();
let function_scope_index = parameter_scope_builder.scope_index;
let var_scope_index = body_scope_builder.var_scope_index;
let lexical_scope_index = body_scope_builder.lexical_scope_index;
// Runtime Semantics: EvaluateBody
// https://tc39.es/ecma262/#sec-function-definitions-runtime-semantics-evaluatebody
//
// With parameters functionObject and List argumentsList.
//
// FunctionBody : FunctionStatementList
//
// Step 1. Perform ? FunctionDeclarationInstantiation(functionObject,
// argumentsList).
let scope_data_set =
parameter_scope_builder.into_scope_data_set(enclosing, body_scope_builder);
self.scopes
.populate(function_scope_index, scope_data_set.function);
self.scopes
.populate(var_scope_index, scope_data_set.extra_body_var);
self.scopes
.populate(lexical_scope_index, scope_data_set.lexical);
}
pub fn before_catch_clause(&mut self) {
// FIXME: NewDeclarativeEnvironment for catch parameter.
self.set_error(ScopeBuildError::NotImplemented("try-catch"));
}
pub fn on_direct_eval(&mut self) {
// FIXME: Propagate to script flags.
self.set_error(ScopeBuildError::NotImplemented(
"direct eval (script flags)",
));
if let Some(parameter_scope_builder) =
self.builder_stack.maybe_innermost_function_parameters()
{
parameter_scope_builder.has_direct_eval = true;
}
self.builder_stack
.innermost()
.base_mut()
.bindings_accessed_dynamically = true;
}
pub fn on_class(&mut self) {
// FIXME: NewDeclarativeEnvironment for class tail.
self.set_error(ScopeBuildError::NotImplemented("class"));
}
pub fn on_with(&mut self) {
// FIXME: Propagate to script flags.
self.set_error(ScopeBuildError::NotImplemented("with statement"));
}
pub fn on_delete(&mut self) {
// FIXME: Propagate to script flags.
self.set_error(ScopeBuildError::NotImplemented("delete operator"));
}
pub fn on_lexical_for(&mut self) {
// FIXME: NewDeclarativeEnvironment in for statement
self.set_error(ScopeBuildError::NotImplemented("lexical for"));
}
pub fn on_switch(&mut self) {
// FIXME: NewDeclarativeEnvironment in for case block
self.set_error(ScopeBuildError::NotImplemented("switch"));
}
pub fn on_new_target(&mut self) {
if let Some(fun_stencil) = self.function_stencil_builder.maybe_current_mut() {
fun_stencil.set_function_has_new_target_binding()
}
}
}
pub struct ScopeDataMapAndScriptStencilList {
pub scope_data_map: ScopeDataMap,
pub function_stencil_indices: AssociatedData<ScriptStencilIndex>,
pub function_declaration_properties: FunctionDeclarationPropertyMap,
pub scripts: ScriptStencilList,
pub error: Option<ScopeBuildError>,
}
impl From<ScopeDataMapBuilder> for ScopeDataMapAndScriptStencilList {
fn from(builder: ScopeDataMapBuilder) -> ScopeDataMapAndScriptStencilList {
ScopeDataMapAndScriptStencilList {
scope_data_map: ScopeDataMap::new(
builder.scopes,
builder.global.expect("There should be global scope data"),
builder.non_global,
),
function_stencil_indices: builder.function_stencil_builder.function_stencil_indices,
function_declaration_properties: builder.function_declaration_properties,
scripts: builder.function_stencil_builder.scripts,
error: builder.error,
}
}
}
[0.74QuellennavigatorsProjekt 2026-04-25]
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2026-05-26
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