DestructureToVariables,

DestructureToLet,

DestructureToConst,

DestructureToCatchParameters,

DestructureToParameters,

DestructureToExpressions

VarDeclaration,

LetDeclaration,

ConstDeclaration

Imported,

ImportedNamespace,

NotImported

Valid = 0,

InvalidStrictMode = 1 << 0,

InvalidDuplicateDeclaration = 1 << 1,

InvalidPrivateStaticNonStatic = 1 << 2

WTF_MAKE_NONCOPYABLE(Scope);

Scope(const VM& vm, ImplementationVisibility implementationVisibility, LexicalScopeFeatures lexicalScopeFeatures, bool isFunction, bool isGeneratorFunction, bool isArrowFunction, bool isAsyncFunction, bool isStaticBlock)

: m_vm(vm)

, m_implementationVisibility(implementationVisibility)

, m_lexicalScopeFeatures(lexicalScopeFeatures)

, m_isFunction(isFunction)

, m_isGeneratorFunction(isGeneratorFunction)

, m_isArrowFunction(isArrowFunction)

, m_isAsyncFunction(isAsyncFunction)

, m_isStaticBlock(isStaticBlock)

{

m_usedVariables.append(UniquedStringImplPtrSet());

}

Scope(Scope&&) = default;

ImplementationVisibility implementationVisibility() const { return m_implementationVisibility; }

void resetImplementationVisibility()

{

m_implementationVisibility = ImplementationVisibility::Public;

}

void startSwitch() { m_switchDepth++; }

void endSwitch() { m_switchDepth--; }

void startLoop() { m_loopDepth++; }

void endLoop() { ASSERT(m_loopDepth); m_loopDepth--; }

bool inLoop() { return !!m_loopDepth; }

bool breakIsValid() { return m_loopDepth || m_switchDepth; }

bool continueIsValid() { return m_loopDepth; }

void pushLabel(const Identifier* label, bool isLoop)

{

if (!m_labels)

m_labels = makeUnique<LabelStack>();

m_labels->append(ScopeLabelInfo { label->impl(), isLoop });

}

void popLabel()

{

ASSERT(m_labels);

ASSERT(m_labels->size());

m_labels->removeLast();

}

ScopeLabelInfo* getLabel(const Identifier* label)

{

if (!m_labels)

return nullptr;

for (int i = m_labels->size(); i > 0; i--) {

if (m_labels->at(i - 1).uid == label->impl())

return &m_labels->at(i - 1);

}

return nullptr;

}

void setSourceParseMode(SourceParseMode mode)

{

switch (mode) {

case SourceParseMode::AsyncGeneratorBodyMode:

setIsAsyncGeneratorFunctionBody();

break;

case SourceParseMode::AsyncArrowFunctionBodyMode:

setIsAsyncArrowFunctionBody();

break;

case SourceParseMode::AsyncFunctionBodyMode:

setIsAsyncFunctionBody();

break;

case SourceParseMode::GeneratorBodyMode:

setIsGeneratorFunctionBody();

break;

case SourceParseMode::GeneratorWrapperFunctionMode:

case SourceParseMode::GeneratorWrapperMethodMode:

setIsGeneratorFunction();

break;

case SourceParseMode::AsyncGeneratorWrapperMethodMode:

case SourceParseMode::AsyncGeneratorWrapperFunctionMode:

setIsAsyncGeneratorFunction();

break;

case SourceParseMode::NormalFunctionMode:

case SourceParseMode::GetterMode:

case SourceParseMode::SetterMode:

case SourceParseMode::MethodMode:

case SourceParseMode::ClassFieldInitializerMode:

setIsFunction();

break;

case SourceParseMode::ClassStaticBlockMode:

setIsFunction();

setIsStaticBlock();

break;

case SourceParseMode::ArrowFunctionMode:

setIsArrowFunction();

break;

case SourceParseMode::AsyncFunctionMode:

case SourceParseMode::AsyncMethodMode:

setIsAsyncFunction();

break;

case SourceParseMode::AsyncArrowFunctionMode:

setIsAsyncArrowFunction();

break;

case SourceParseMode::ProgramMode:

setIsGlobalCode();

break;

case SourceParseMode::ModuleAnalyzeMode:

case SourceParseMode::ModuleEvaluateMode:

setIsModuleCode();

break;

}

}

bool isFunction() const { return m_isFunction; }

bool isFunctionBoundary() const { return m_isFunctionBoundary; }

bool isGeneratorFunction() const { return m_isGeneratorFunction; }

bool isGeneratorFunctionBoundary() const { return m_isGeneratorFunctionBoundary; }

bool isAsyncFunction() const { return m_isAsyncFunction; }

bool isAsyncFunctionBoundary() const { return m_isAsyncFunctionBoundary; }

bool isPrivateNameScope() const { return m_isClassScope; }

bool isClassScope() const { return m_isClassScope; }

bool isGlobalCode() const { return m_isGlobalCode; }

bool isModuleCode() const { return m_isModuleCode; }

bool hasArguments() const { return m_hasArguments; }

void setIsSimpleCatchParameterScope() { m_isSimpleCatchParameterScope = true; }

bool isSimpleCatchParameterScope() { return m_isSimpleCatchParameterScope; }

void setIsCatchBlockScope() { m_isCatchBlockScope = true; }

bool isCatchBlockScope() { return m_isCatchBlockScope; }

void setIsStaticBlock()

{

m_isStaticBlock = true;

m_isStaticBlockBoundary = true;

}

bool isStaticBlock() { return m_isStaticBlock; }

bool isStaticBlockBoundary() { return m_isStaticBlockBoundary; }

void setIsLexicalScope()

{

m_isLexicalScope = true;

m_allowsLexicalDeclarations = true;

}

void setIsPrivateNameScope()

{

// FIXME: Currently, isPrivateNameScope is an alias for isClassScope --- This is potentially misleading,

// particularly when parsing direct eval code which occurs within a class.

setIsClassScope();

}

void setIsClassScope()

{

m_isClassScope = true;

}

bool isLexicalScope() const { return m_isLexicalScope; }

bool usesEval() const { return m_usesEval; }

bool usesImportMeta() const { return m_usesImportMeta; }

const HashSet<UniquedStringImpl*>& closedVariableCandidates() const { return m_closedVariableCandidates; }

VariableEnvironment& declaredVariables() { return m_declaredVariables; }

VariableEnvironment& lexicalVariables() { return m_lexicalVariables; }

void finalizeLexicalEnvironment()

{

if (m_usesEval || m_needsFullActivation)

m_lexicalVariables.markAllVariablesAsCaptured();

else

computeLexicallyCapturedVariablesAndPurgeCandidates();

}

VariableEnvironment takeLexicalEnvironment() { return WTFMove(m_lexicalVariables); }

VariableEnvironment takeDeclaredVariables() { return WTFMove(m_declaredVariables); }

void computeLexicallyCapturedVariablesAndPurgeCandidates()

{

// Because variables may be defined at any time in the range of a lexical scope, we must

// track lexical variables that might be captured. Then, when we're preparing to pop the top

// lexical scope off the stack, we should find which variables are truly captured, and which

// variable still may be captured in a parent scope.

if (m_lexicalVariables.size() && m_closedVariableCandidates.size()) {

for (UniquedStringImpl* impl : m_closedVariableCandidates)

m_lexicalVariables.markVariableAsCapturedIfDefined(impl);

}

// We can now purge values from the captured candidates because they're captured in this scope.

{

for (const auto& entry : m_lexicalVariables) {

if (entry.value.isCaptured())

m_closedVariableCandidates.remove(entry.key.get());

}

}

}

DeclarationResultMask declareCallee(const Identifier* ident)

{

auto addResult = m_declaredVariables.add(ident->impl());

// We want to track if callee is captured, but we don't want to act like it's a 'var'

// because that would cause the BytecodeGenerator to emit bad code.

addResult.iterator->value.clearIsVar();

DeclarationResultMask result = DeclarationResult::Valid;

if (isEvalOrArgumentsIdentifier(m_vm, ident))

result |= DeclarationResult::InvalidStrictMode;

return result;

}

DeclarationResultMask declareVariable(const Identifier* ident)

{

ASSERT(m_allowsVarDeclarations);

DeclarationResultMask result = DeclarationResult::Valid;

bool isValidStrictMode = !isEvalOrArgumentsIdentifier(m_vm, ident);

m_isValidStrictMode = m_isValidStrictMode && isValidStrictMode;

auto addResult = m_declaredVariables.add(ident->impl());

addResult.iterator->value.setIsVar();

if (!isValidStrictMode)

result |= DeclarationResult::InvalidStrictMode;

return result;

}

DeclarationResultMask declareFunctionAsVar(const Identifier* ident)

{

ASSERT(m_allowsVarDeclarations);

DeclarationResultMask result = DeclarationResult::Valid;

bool isValidStrictMode = !isEvalOrArgumentsIdentifier(m_vm, ident);

if (!isValidStrictMode)

result |= DeclarationResult::InvalidStrictMode;

m_isValidStrictMode = m_isValidStrictMode && isValidStrictMode;

auto addResult = m_declaredVariables.add(ident->impl());

addResult.iterator->value.setIsVar();

addResult.iterator->value.setIsFunction();

if (m_lexicalVariables.contains(ident->impl()))

result |= DeclarationResult::InvalidDuplicateDeclaration;

return result;

}

DeclarationResultMask declareFunctionAsLet(const Identifier* ident, bool isFunctionDeclaration)

{

ASSERT(m_allowsLexicalDeclarations);

DeclarationResultMask result = DeclarationResult::Valid;

bool isValidStrictMode = !isEvalOrArgumentsIdentifier(m_vm, ident);

if (!isValidStrictMode)

result |= DeclarationResult::InvalidStrictMode;

m_isValidStrictMode = m_isValidStrictMode && isValidStrictMode;

auto addResult = m_lexicalVariables.add(ident->impl());

if (!addResult.isNewEntry) {

if (strictMode() || !addResult.iterator->value.isFunctionDeclaration() || !isFunctionDeclaration)

result |= DeclarationResult::InvalidDuplicateDeclaration;

}

if (m_declaredVariables.contains(ident->impl()) || m_variablesBeingHoisted.contains(ident->impl()))

result |= DeclarationResult::InvalidDuplicateDeclaration;

addResult.iterator->value.setIsLet();

addResult.iterator->value.setIsFunction();

if (isFunctionDeclaration)

addResult.iterator->value.setIsFunctionDeclaration();

return result;

}

void addVariableBeingHoisted(const Identifier* ident)

{

ASSERT(!m_allowsVarDeclarations);

m_variablesBeingHoisted.add(ident->impl());

}

enum class NeedsDuplicateDeclarationCheck : bool { No, Yes };

template<NeedsDuplicateDeclarationCheck needsCheck>

void addSloppyModeFunctionHoistingCandidate(FunctionMetadataNode* node)

{

ASSERT(node);

ASSERT(!strictMode());

m_sloppyModeFunctionHoistingCandidates.set(node, needsCheck);

}

void appendFunction(FunctionMetadataNode* node)

{

ASSERT(node);

m_functionDeclarations.append(node);

}

DeclarationStacks::FunctionStack takeFunctionDeclarations() { return WTFMove(m_functionDeclarations); }

DeclarationResultMask declareLexicalVariable(const Identifier* ident, bool isConstant, DeclarationImportType importType = DeclarationImportType::NotImported)

{

ASSERT(m_allowsLexicalDeclarations);

DeclarationResultMask result = DeclarationResult::Valid;

bool isValidStrictMode = !isEvalOrArgumentsIdentifier(m_vm, ident);

m_isValidStrictMode = m_isValidStrictMode && isValidStrictMode;

auto addResult = m_lexicalVariables.add(ident->impl());

if (isConstant)

addResult.iterator->value.setIsConst();

else

addResult.iterator->value.setIsLet();

if (importType == DeclarationImportType::Imported)

addResult.iterator->value.setIsImported();

else if (importType == DeclarationImportType::ImportedNamespace) {

addResult.iterator->value.setIsImported();

addResult.iterator->value.setIsImportedNamespace();

}

if (!addResult.isNewEntry || m_variablesBeingHoisted.contains(ident->impl()))

result |= DeclarationResult::InvalidDuplicateDeclaration;

if (!isValidStrictMode)

result |= DeclarationResult::InvalidStrictMode;

return result;

}

ALWAYS_INLINE bool hasDeclaredGlobalArguments()

{

const Identifier& ident = m_vm.propertyNames->arguments;

return hasLexicallyDeclaredVariable(ident) || hasDeclaredVariable(ident) || shadowsArguments();

}

ALWAYS_INLINE bool hasDeclaredVariable(const Identifier& ident)

{

return hasDeclaredVariable(ident.impl());

}

bool hasDeclaredVariable(const RefPtr<UniquedStringImpl>& ident)

{

auto iter = m_declaredVariables.find(ident.get());

if (iter == m_declaredVariables.end())

return false;

VariableEnvironmentEntry entry = iter->value;

return entry.isVar(); // The callee isn't a "var".

}

ALWAYS_INLINE bool hasLexicallyDeclaredVariable(const Identifier& ident)

{

return hasLexicallyDeclaredVariable(ident.impl());

}

bool hasLexicallyDeclaredVariable(const RefPtr<UniquedStringImpl>& ident) const

{

return m_lexicalVariables.contains(ident.get());

}

bool hasPrivateName(const Identifier& ident)

{

return m_lexicalVariables.hasPrivateName(ident);

}

DeclarationResultMask declarePrivateMethod(const Identifier& ident, ClassElementTag tag)

{

ASSERT(m_allowsLexicalDeclarations);

DeclarationResultMask result = DeclarationResult::Valid;

bool addResult = tag == ClassElementTag::Static ? m_lexicalVariables.declareStaticPrivateMethod(ident) : m_lexicalVariables.declarePrivateMethod(ident);

if (!addResult) {

result |= DeclarationResult::InvalidDuplicateDeclaration;

return result;

}

return result;

}

enum class PrivateAccessorType { Setter, Getter };

DeclarationResultMask declarePrivateAccessor(const Identifier& ident, ClassElementTag tag, PrivateAccessorType accessorType)

{

DeclarationResultMask result = DeclarationResult::Valid;

VariableEnvironment::PrivateDeclarationResult addResult;

if (accessorType == PrivateAccessorType::Setter)

addResult = tag == ClassElementTag::Static ? m_lexicalVariables.declareStaticPrivateSetter(ident) : m_lexicalVariables.declarePrivateSetter(ident);

else

addResult = tag == ClassElementTag::Static ? m_lexicalVariables.declareStaticPrivateGetter(ident) : m_lexicalVariables.declarePrivateGetter(ident);

if (addResult == VariableEnvironment::PrivateDeclarationResult::DuplicatedName)

result |= DeclarationResult::InvalidDuplicateDeclaration;

if (addResult == VariableEnvironment::PrivateDeclarationResult::InvalidStaticNonStatic)

result |= DeclarationResult::InvalidPrivateStaticNonStatic;

return result;

}

DeclarationResultMask declarePrivateSetter(const Identifier& ident, ClassElementTag tag)

{

ASSERT(m_allowsLexicalDeclarations);

return declarePrivateAccessor(ident, tag, PrivateAccessorType::Setter);

}

DeclarationResultMask declarePrivateGetter(const Identifier& ident, ClassElementTag tag)

{

ASSERT(m_allowsLexicalDeclarations);

return declarePrivateAccessor(ident, tag, PrivateAccessorType::Getter);

}

DeclarationResultMask declarePrivateField(const Identifier& ident)

{

ASSERT(m_allowsLexicalDeclarations);

DeclarationResultMask result = DeclarationResult::Valid;

auto addResult = m_lexicalVariables.declarePrivateField(ident);

if (!addResult.isNewEntry)

result |= DeclarationResult::InvalidDuplicateDeclaration;

return result;

}

ALWAYS_INLINE bool hasDeclaredParameter(const Identifier& ident)

{

return hasDeclaredParameter(ident.impl());

}

bool hasDeclaredParameter(const RefPtr<UniquedStringImpl>& ident)

{

return m_declaredParameters.contains(ident.get()) || hasDeclaredVariable(ident);

}

void preventAllVariableDeclarations()

{

m_allowsVarDeclarations = false;

m_allowsLexicalDeclarations = false;

}

void preventVarDeclarations() { m_allowsVarDeclarations = false; }

bool allowsVarDeclarations() const { return m_allowsVarDeclarations; }

bool allowsLexicalDeclarations() const { return m_allowsLexicalDeclarations; }

DeclarationResultMask declareParameter(const Identifier* ident)

{

ASSERT(m_allowsVarDeclarations);

DeclarationResultMask result = DeclarationResult::Valid;

bool isArgumentsIdent = isArguments(m_vm, ident);

auto addResult = m_declaredVariables.add(ident->impl());

bool isDuplicateParameter = !addResult.isNewEntry && addResult.iterator->value.isParameter();

bool isValidStrictMode = !isDuplicateParameter && m_vm.propertyNames->eval != *ident && !isArgumentsIdent;

addResult.iterator->value.clearIsVar();

addResult.iterator->value.setIsParameter();

m_isValidStrictMode = m_isValidStrictMode && isValidStrictMode;

m_declaredParameters.add(ident->impl());

if (!isValidStrictMode)

result |= DeclarationResult::InvalidStrictMode;

if (isArgumentsIdent)

m_shadowsArguments = true;

if (isDuplicateParameter)

result |= DeclarationResult::InvalidDuplicateDeclaration;

return result;

}

bool usedVariablesContains(UniquedStringImpl* impl) const

{

for (const UniquedStringImplPtrSet& set : m_usedVariables) {

if (set.contains(impl))

return true;

}

return false;

}

template <typename Func>

void forEachUsedVariable(const Func& func)

{

for (const UniquedStringImplPtrSet& set : m_usedVariables) {

for (UniquedStringImpl* impl : set) {

if (func(impl) == IterationStatus::Done)

return;

}

}

}

void useVariable(const Identifier* ident, bool isEval)

{

useVariable(ident->impl(), isEval);

}

void useVariable(UniquedStringImpl* impl, bool isEval)

{

m_usesEval |= isEval;

m_usedVariables.last().add(impl);

}

void usePrivateName(const Identifier& ident)

{

ASSERT(m_allowsLexicalDeclarations);

useVariable(&ident, false);

}

void setUsesImportMeta() { m_usesImportMeta = true; }

void pushUsedVariableSet() { m_usedVariables.append(UniquedStringImplPtrSet()); }

size_t currentUsedVariablesSize() { return m_usedVariables.size(); }

void revertToPreviousUsedVariables(size_t size) { m_usedVariables.resize(size); }

void setNeedsFullActivation() { m_needsFullActivation = true; }

bool needsFullActivation() const { return m_needsFullActivation; }

bool isArrowFunctionBoundary() { return m_isArrowFunctionBoundary; }

bool isArrowFunction() { return m_isArrowFunction; }

bool hasDirectSuper() const { return m_hasDirectSuper; }

void setHasDirectSuper() { m_hasDirectSuper = true; }

bool needsSuperBinding() const { return m_needsSuperBinding; }

void setNeedsSuperBinding() { m_needsSuperBinding = true; }

void setEvalContextType(EvalContextType evalContextType) { m_evalContextType = evalContextType; }

EvalContextType evalContextType() { return m_evalContextType; }

InnerArrowFunctionCodeFeatures innerArrowFunctionFeatures() { return m_innerArrowFunctionFeatures; }

void setExpectedSuperBinding(SuperBinding superBinding) { m_expectedSuperBinding = superBinding; }

SuperBinding expectedSuperBinding() const { return m_expectedSuperBinding; }

void setConstructorKind(ConstructorKind constructorKind) { m_constructorKind = constructorKind; }

ConstructorKind constructorKind() const { return m_constructorKind; }

void setInnerArrowFunctionUsesSuperCall() { m_innerArrowFunctionFeatures |= SuperCallInnerArrowFunctionFeature; }

void setInnerArrowFunctionUsesSuperProperty() { m_innerArrowFunctionFeatures |= SuperPropertyInnerArrowFunctionFeature; }

void setInnerArrowFunctionUsesEval() { m_innerArrowFunctionFeatures |= EvalInnerArrowFunctionFeature; }

void setInnerArrowFunctionUsesThis() { m_innerArrowFunctionFeatures |= ThisInnerArrowFunctionFeature; }

void setInnerArrowFunctionUsesNewTarget() { m_innerArrowFunctionFeatures |= NewTargetInnerArrowFunctionFeature; }

void setInnerArrowFunctionUsesArguments() { m_innerArrowFunctionFeatures |= ArgumentsInnerArrowFunctionFeature; }

bool isEvalContext() const { return m_isEvalContext; }

void setIsEvalContext(bool isEvalContext) { m_isEvalContext = isEvalContext; }

void setInnerArrowFunctionUsesEvalAndUseArgumentsIfNeeded()

{

ASSERT(m_isArrowFunction);

if (m_usesEval)

setInnerArrowFunctionUsesEval();

if (usedVariablesContains(m_vm.propertyNames->arguments.impl()))

setInnerArrowFunctionUsesArguments();

}

void addClosedVariableCandidateUnconditionally(UniquedStringImpl* impl)

{

m_closedVariableCandidates.add(impl);

}

void markLastUsedVariablesSetAsCaptured(unsigned from)

{

for (unsigned index = from; index < m_usedVariables.size(); ++index) {

for (UniquedStringImpl* impl : m_usedVariables[index])

m_closedVariableCandidates.add(impl);

}

}

void collectFreeVariables(Scope* nestedScope, bool shouldTrackClosedVariables)

{

if (nestedScope->m_usesEval)

m_usesEval = true;

if (nestedScope->m_usesImportMeta)

m_usesImportMeta = true;

{

UniquedStringImplPtrSet& destinationSet = m_usedVariables.last();

for (const UniquedStringImplPtrSet& usedVariablesSet : nestedScope->m_usedVariables) {

for (UniquedStringImpl* impl : usedVariablesSet) {

if (nestedScope->m_declaredVariables.contains(impl) || nestedScope->m_lexicalVariables.contains(impl))

continue;

// "arguments" reference should be resolved at function boudary.

if (nestedScope->isFunctionBoundary() && nestedScope->hasArguments() && impl == m_vm.propertyNames->arguments.impl() && !nestedScope->isArrowFunctionBoundary())

continue;

destinationSet.add(impl);

// We don't want a declared variable that is used in an inner scope to be thought of as captured if

// that inner scope is both a lexical scope and not a function. Only inner functions and "catch"

// statements can cause variables to be captured.

if (shouldTrackClosedVariables && (nestedScope->m_isFunctionBoundary || !nestedScope->m_isLexicalScope))

m_closedVariableCandidates.add(impl);

}

}

}

// Propagate closed variable candidates downwards within the same function.

// Cross function captures will be realized via m_usedVariables propagation.

if (shouldTrackClosedVariables && !nestedScope->m_isFunctionBoundary && nestedScope->m_closedVariableCandidates.size()) {

auto end = nestedScope->m_closedVariableCandidates.end();

auto begin = nestedScope->m_closedVariableCandidates.begin();

m_closedVariableCandidates.add(begin, end);

}

}

void mergeInnerArrowFunctionFeatures(InnerArrowFunctionCodeFeatures arrowFunctionCodeFeatures)

{

m_innerArrowFunctionFeatures = m_innerArrowFunctionFeatures | arrowFunctionCodeFeatures;

}

void finalizeSloppyModeFunctionHoisting()

{

ASSERT(allowsVarDeclarations());

ASSERT(!isSimpleCatchParameterScope());

for (const auto& iter : m_sloppyModeFunctionHoistingCandidates) {

// ES6 Annex B.3.3. The only time we can't hoist a function is if a syntax error would

// be caused by declaring a var with that function's name or if we have a parameter with

// that function's name. Note that we would only cause a syntax error if we had a let/const/class

// variable with the same name.

FunctionMetadataNode* metadata = iter.key;

auto* function = metadata->ident().impl();

if (!m_lexicalVariables.contains(function)) {

auto addResult = m_declaredVariables.add(function);

if (addResult.isNewEntry)

addResult.iterator->value.setIsSloppyModeHoistedFunction();

else if (addResult.iterator->value.isParameter())

continue;

addResult.iterator->value.setIsVar();

metadata->setIsSloppyModeHoistedFunction();

}

}

}

NEVER_INLINE void bubbleSloppyModeFunctionHoistingCandidates(Scope* parentScope)

{

for (const auto& iter : m_sloppyModeFunctionHoistingCandidates) {

FunctionMetadataNode* metadata = iter.key;

bool needsCheck = iter.value == NeedsDuplicateDeclarationCheck::Yes;

if (!needsCheck || !m_lexicalVariables.contains(metadata->ident().impl()) || isSimpleCatchParameterScope())

parentScope->addSloppyModeFunctionHoistingCandidate<NeedsDuplicateDeclarationCheck::Yes>(metadata);

}

}

void getCapturedVars(IdentifierSet& capturedVariables)

{

if (m_needsFullActivation || m_usesEval) {

for (auto& entry : m_declaredVariables)

capturedVariables.add(entry.key);

return;

}

for (UniquedStringImpl* impl : m_closedVariableCandidates) {

// We refer to m_declaredVariables here directly instead of a hasDeclaredVariable because we want to mark the callee as captured.

if (!m_declaredVariables.contains(impl))

continue;

capturedVariables.add(impl);

}

}

LexicalScopeFeatures lexicalScopeFeatures() const { return m_lexicalScopeFeatures; }

void setStrictMode() { m_lexicalScopeFeatures |= StrictModeLexicalFeature; }

bool strictMode() const { return m_lexicalScopeFeatures & StrictModeLexicalFeature; }

bool isValidStrictMode() const { return m_isValidStrictMode; }

bool shadowsArguments() const { return m_shadowsArguments; }

void setHasNonSimpleParameterList()

{

m_isValidStrictMode = false;

m_hasNonSimpleParameterList = true;

}

bool hasNonSimpleParameterList() const { return m_hasNonSimpleParameterList; }

bool hasSloppyModeFunctionHoistingCandidates() const { return !m_sloppyModeFunctionHoistingCandidates.isEmpty(); }

void copyCapturedVariablesToVector(const UniquedStringImplPtrSet& usedVariables, Vector<UniquedStringImpl*, 8>& vector)

{

for (UniquedStringImpl* impl : usedVariables) {

if (m_declaredVariables.contains(impl) || m_lexicalVariables.contains(impl))

continue;

vector.append(impl);

}

}

void fillParametersForSourceProviderCache(SourceProviderCacheItemCreationParameters& parameters, const UniquedStringImplPtrSet& capturesFromParameterExpressions)

{

ASSERT(m_isFunction);

parameters.usesEval = m_usesEval;

parameters.usesImportMeta = m_usesImportMeta;

parameters.lexicalScopeFeatures = m_lexicalScopeFeatures;

parameters.needsFullActivation = m_needsFullActivation;

parameters.innerArrowFunctionFeatures = m_innerArrowFunctionFeatures;

parameters.needsSuperBinding = m_needsSuperBinding;

for (const UniquedStringImplPtrSet& set : m_usedVariables)

copyCapturedVariablesToVector(set, parameters.usedVariables);

// FIXME: https://bugs.webkit.org/show_bug.cgi?id=156962

// We add these unconditionally because we currently don't keep a separate

// declaration scope for a function's parameters and its var/let/const declarations.

// This is somewhat unfortunate and we should refactor to do this at some point

// because parameters logically form a parent scope to var/let/const variables.

// But because we don't do this, we must grab capture candidates from a parameter

// list before we parse the body of a function because the body's declarations

// might make us believe something isn't actually a capture candidate when it really

// is.

for (UniquedStringImpl* impl : capturesFromParameterExpressions)

parameters.usedVariables.append(impl);

}

void restoreFromSourceProviderCache(const SourceProviderCacheItem* info)

{

ASSERT(m_isFunction);

m_usesEval = info->usesEval;

m_usesImportMeta = info->usesImportMeta;

m_lexicalScopeFeatures = info->lexicalScopeFeatures();

m_innerArrowFunctionFeatures = info->innerArrowFunctionFeatures;

m_needsFullActivation = info->needsFullActivation;

m_needsSuperBinding = info->needsSuperBinding;

UniquedStringImplPtrSet& destSet = m_usedVariables.last();

for (unsigned i = 0; i < info->usedVariablesCount; ++i)

destSet.add(info->usedVariables()[i].get());

}

class MaybeParseAsGeneratorFunctionForScope;

void setIsFunction()

{

m_isFunction = true;

m_isFunctionBoundary = true;

m_hasArguments = true;

setIsLexicalScope();

m_isGeneratorFunction = false;

m_isGeneratorFunctionBoundary = false;

m_isArrowFunctionBoundary = false;

m_isArrowFunction = false;

m_isAsyncFunction = false;

m_isAsyncFunctionBoundary = false;

m_isStaticBlock = false;

m_isStaticBlockBoundary = false;

}

void setIsGeneratorFunction()

{

setIsFunction();

m_isGeneratorFunction = true;

}

void setIsGeneratorFunctionBody()

{

setIsFunction();

m_hasArguments = false;

m_isGeneratorFunction = true;

m_isGeneratorFunctionBoundary = true;

}

void setIsArrowFunction()

{

setIsFunction();

m_isArrowFunctionBoundary = true;

m_isArrowFunction = true;

}

void setIsAsyncArrowFunction()

{

setIsArrowFunction();

m_isAsyncFunction = true;

}

void setIsAsyncFunction()

{

setIsFunction();

m_isAsyncFunction = true;

}

void setIsAsyncGeneratorFunction()

{

setIsFunction();

m_isAsyncFunction = true;

m_isGeneratorFunction = true;

}

void setIsAsyncGeneratorFunctionBody()

{

setIsFunction();

m_hasArguments = false;

m_isGeneratorFunction = true;

m_isGeneratorFunctionBoundary = true;

m_isAsyncFunction = true;

m_isAsyncFunctionBoundary = true;

}

void setIsAsyncFunctionBody()

{

setIsFunction();

m_hasArguments = false;

m_isAsyncFunction = true;

m_isAsyncFunctionBoundary = true;

}

void setIsAsyncArrowFunctionBody()

{

setIsArrowFunction();

m_hasArguments = false;

m_isAsyncFunction = true;

m_isAsyncFunctionBoundary = true;

}

void setIsGlobalCode()

{

m_isGlobalCode = true;

}

void setIsModuleCode()

{

setIsGlobalCode();

m_isModuleCode = true;

}

const VM& m_vm;

ImplementationVisibility m_implementationVisibility;

LexicalScopeFeatures m_lexicalScopeFeatures;

bool m_shadowsArguments : 1 { false };

bool m_usesEval : 1 { false };

bool m_usesImportMeta : 1 { false };

bool m_needsFullActivation : 1 { false };

bool m_hasDirectSuper : 1 { false };

bool m_needsSuperBinding : 1 { false };

bool m_allowsVarDeclarations : 1 { true };

bool m_allowsLexicalDeclarations : 1 { true };

bool m_isFunction : 1;

bool m_isGeneratorFunction : 1;

bool m_isGeneratorFunctionBoundary : 1 { false };

bool m_isArrowFunction : 1;

bool m_isArrowFunctionBoundary : 1 { false };

bool m_isAsyncFunction : 1;

bool m_isAsyncFunctionBoundary : 1 { false };

bool m_isLexicalScope : 1 { false };

bool m_isGlobalCode : 1 { false };

bool m_isModuleCode : 1 { false };

bool m_isSimpleCatchParameterScope : 1 { false };

bool m_isCatchBlockScope : 1 { false };

bool m_isStaticBlock : 1 { false };

bool m_isStaticBlockBoundary : 1 { false };

bool m_isFunctionBoundary : 1 { false };

bool m_isValidStrictMode : 1 { true };

bool m_hasArguments : 1 { false };

bool m_isEvalContext : 1 { false };

bool m_hasNonSimpleParameterList : 1 { false };

bool m_isClassScope : 1 { false };

EvalContextType m_evalContextType { EvalContextType::None };

ConstructorKind m_constructorKind { ConstructorKind::None };

SuperBinding m_expectedSuperBinding { SuperBinding::NotNeeded };

int m_loopDepth { 0 };

int m_switchDepth { 0 };

InnerArrowFunctionCodeFeatures m_innerArrowFunctionFeatures { 0 };

typedef Vector<ScopeLabelInfo, 2> LabelStack;

std::unique_ptr<LabelStack> m_labels;

UniquedStringImplPtrSet m_declaredParameters;

VariableEnvironment m_declaredVariables;

VariableEnvironment m_lexicalVariables;

Vector<UniquedStringImplPtrSet, 6> m_usedVariables;

UniquedStringImplPtrSet m_variablesBeingHoisted;

HashMap<FunctionMetadataNode*, NeedsDuplicateDeclarationCheck> m_sloppyModeFunctionHoistingCandidates;

HashSet<UniquedStringImpl*> m_closedVariableCandidates;

DeclarationStacks::FunctionStack m_functionDeclarations;

ScopeRef(ScopeStack* scopeStack, unsigned index)

: m_scopeStack(scopeStack)