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// Copyright 2011 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include <stdlib.h>
#include "src/objects/scope-info.h"
#include "src/ast/scopes.h"
#include "src/ast/variables.h"
#include "src/init/bootstrapper.h"
#include "src/objects/module-inl.h"
#include "src/objects/objects-inl.h"
namespace v8 {
namespace internal {
// An entry in ModuleVariableEntries consists of several slots:
enum ModuleVariableEntryOffset {
kModuleVariableNameOffset,
kModuleVariableIndexOffset,
kModuleVariablePropertiesOffset,
kModuleVariableEntryLength // Sentinel value.
};
#ifdef DEBUG
bool ScopeInfo::Equals(ScopeInfo other) const {
if (length() != other.length()) return false;
for (int index = 0; index < length(); ++index) {
Object entry = get(index);
Object other_entry = other.get(index);
if (entry.IsSmi()) {
if (entry != other_entry) return false;
} else {
if (HeapObject::cast(entry).map().instance_type() !=
HeapObject::cast(other_entry).map().instance_type()) {
return false;
}
if (entry.IsString()) {
if (!String::cast(entry).Equals(String::cast(other_entry))) {
return false;
}
} else if (entry.IsScopeInfo()) {
if (!ScopeInfo::cast(entry).Equals(ScopeInfo::cast(other_entry))) {
return false;
}
} else if (entry.IsSourceTextModuleInfo()) {
if (!SourceTextModuleInfo::cast(entry).Equals(
SourceTextModuleInfo::cast(other_entry))) {
return false;
}
} else {
UNREACHABLE();
}
}
}
return true;
}
#endif
// static
Handle<ScopeInfo> ScopeInfo::Create(Isolate* isolate, Zone* zone, Scope* scope,
MaybeHandle<ScopeInfo> outer_scope) {
// Collect variables.
int context_local_count = 0;
int module_vars_count = 0;
// Stack allocated block scope variables are allocated in the parent
// declaration scope, but are recorded in the block scope's scope info. First
// slot index indicates at which offset a particular scope starts in the
// parent declaration scope.
for (Variable* var : *scope->locals()) {
switch (var->location()) {
case VariableLocation::CONTEXT:
context_local_count++;
break;
case VariableLocation::MODULE:
module_vars_count++;
break;
default:
break;
}
}
// Determine use and location of the "this" binding if it is present.
VariableAllocationInfo receiver_info;
if (scope->is_declaration_scope() &&
scope->AsDeclarationScope()->has_this_declaration()) {
Variable* var = scope->AsDeclarationScope()->receiver();
if (!var->is_used()) {
receiver_info = UNUSED;
} else if (var->IsContextSlot()) {
receiver_info = CONTEXT;
context_local_count++;
} else {
DCHECK(var->IsParameter());
receiver_info = STACK;
}
} else {
receiver_info = NONE;
}
DCHECK(module_vars_count == 0 || scope->is_module_scope());
// Make sure we allocate the correct amount.
DCHECK_EQ(scope->ContextLocalCount(), context_local_count);
const bool has_new_target =
scope->is_declaration_scope() &&
scope->AsDeclarationScope()->new_target_var() != nullptr;
// TODO(cbruni): Don't always waste a field for the inferred name.
const bool has_inferred_function_name = scope->is_function_scope();
// Determine use and location of the function variable if it is present.
VariableAllocationInfo function_name_info;
if (scope->is_function_scope()) {
if (scope->AsDeclarationScope()->function_var() != nullptr) {
Variable* var = scope->AsDeclarationScope()->function_var();
if (!var->is_used()) {
function_name_info = UNUSED;
} else if (var->IsContextSlot()) {
function_name_info = CONTEXT;
} else {
DCHECK(var->IsStackLocal());
function_name_info = STACK;
}
} else {
// Always reserve space for the debug name in the scope info.
function_name_info = UNUSED;
}
} else if (scope->is_module_scope() || scope->is_script_scope() ||
scope->is_eval_scope()) {
// Always reserve space for the debug name in the scope info.
function_name_info = UNUSED;
} else {
function_name_info = NONE;
}
const bool has_brand = scope->is_class_scope()
? scope->AsClassScope()->brand() != nullptr
: false;
const bool has_function_name = function_name_info != NONE;
const bool has_position_info = NeedsPositionInfo(scope->scope_type());
const bool has_receiver = receiver_info == STACK || receiver_info == CONTEXT;
const int parameter_count =
scope->is_declaration_scope()
? scope->AsDeclarationScope()->num_parameters()
: 0;
const bool has_outer_scope_info = !outer_scope.is_null();
const int length = kVariablePartIndex + 2 * context_local_count +
(has_receiver ? 1 : 0) +
(has_function_name ? kFunctionNameEntries : 0) +
(has_inferred_function_name ? 1 : 0) +
(has_position_info ? kPositionInfoEntries : 0) +
(has_outer_scope_info ? 1 : 0) +
(scope->is_module_scope()
? 2 + kModuleVariableEntryLength * module_vars_count
: 0);
Handle<ScopeInfo> scope_info_handle =
isolate->factory()->NewScopeInfo(length);
int index = kVariablePartIndex;
{
DisallowHeapAllocation no_gc;
ScopeInfo scope_info = *scope_info_handle;
WriteBarrierMode mode = scope_info.GetWriteBarrierMode(no_gc);
bool has_simple_parameters = false;
bool is_asm_module = false;
bool sloppy_eval_can_extend_vars = false;
if (scope->is_function_scope()) {
DeclarationScope* function_scope = scope->AsDeclarationScope();
has_simple_parameters = function_scope->has_simple_parameters();
is_asm_module = function_scope->is_asm_module();
}
FunctionKind function_kind = kNormalFunction;
if (scope->is_declaration_scope()) {
function_kind = scope->AsDeclarationScope()->function_kind();
sloppy_eval_can_extend_vars =
scope->AsDeclarationScope()->sloppy_eval_can_extend_vars();
}
// Encode the flags.
int flags =
ScopeTypeField::encode(scope->scope_type()) |
SloppyEvalCanExtendVarsField::encode(sloppy_eval_can_extend_vars) |
LanguageModeField::encode(scope->language_mode()) |
DeclarationScopeField::encode(scope->is_declaration_scope()) |
ReceiverVariableField::encode(receiver_info) |
HasClassBrandField::encode(has_brand) |
HasNewTargetField::encode(has_new_target) |
FunctionVariableField::encode(function_name_info) |
HasInferredFunctionNameField::encode(has_inferred_function_name) |
IsAsmModuleField::encode(is_asm_module) |
HasSimpleParametersField::encode(has_simple_parameters) |
FunctionKindField::encode(function_kind) |
HasOuterScopeInfoField::encode(has_outer_scope_info) |
IsDebugEvaluateScopeField::encode(scope->is_debug_evaluate_scope()) |
ForceContextAllocationField::encode(
scope->ForceContextForLanguageMode());
scope_info.SetFlags(flags);
scope_info.SetParameterCount(parameter_count);
scope_info.SetContextLocalCount(context_local_count);
// Add context locals' names and info, module variables' names and info.
// Context locals are added using their index.
int context_local_base = index;
int context_local_info_base = context_local_base + context_local_count;
int module_var_entry = scope_info.ModuleVariablesIndex();
for (Variable* var : *scope->locals()) {
switch (var->location()) {
case VariableLocation::CONTEXT: {
// Due to duplicate parameters, context locals aren't guaranteed to
// come in order.
int local_index = var->index() - Context::MIN_CONTEXT_SLOTS;
DCHECK_LE(0, local_index);
DCHECK_LT(local_index, context_local_count);
uint32_t info =
VariableModeField::encode(var->mode()) |
InitFlagField::encode(var->initialization_flag()) |
MaybeAssignedFlagField::encode(var->maybe_assigned()) |
ParameterNumberField::encode(ParameterNumberField::kMax);
scope_info.set(context_local_base + local_index, *var->name(), mode);
scope_info.set(context_local_info_base + local_index,
Smi::FromInt(info));
break;
}
case VariableLocation::MODULE: {
scope_info.set(module_var_entry + kModuleVariableNameOffset,
*var->name(), mode);
scope_info.set(module_var_entry + kModuleVariableIndexOffset,
Smi::FromInt(var->index()));
uint32_t properties =
VariableModeField::encode(var->mode()) |
InitFlagField::encode(var->initialization_flag()) |
MaybeAssignedFlagField::encode(var->maybe_assigned()) |
ParameterNumberField::encode(ParameterNumberField::kMax);
scope_info.set(module_var_entry + kModuleVariablePropertiesOffset,
Smi::FromInt(properties));
module_var_entry += kModuleVariableEntryLength;
break;
}
default:
break;
}
}
if (scope->is_declaration_scope()) {
// Mark contexts slots with the parameter number they represent. We walk
// the list of parameters. That can include duplicate entries if a
// parameter name is repeated. By walking upwards, we'll automatically
// mark the context slot with the highest parameter number that uses this
// variable. That will be the parameter number that is represented by the
// context slot. All lower parameters will only be available on the stack
// through the arguments object.
for (int i = 0; i < parameter_count; i++) {
Variable* parameter = scope->AsDeclarationScope()->parameter(i);
if (parameter->location() != VariableLocation::CONTEXT) continue;
int index = parameter->index() - Context::MIN_CONTEXT_SLOTS;
int info_index = context_local_info_base + index;
int info = Smi::ToInt(scope_info.get(info_index));
info = ParameterNumberField::update(info, i);
scope_info.set(info_index, Smi::FromInt(info));
}
// TODO(verwaest): Remove this unnecessary entry.
if (scope->AsDeclarationScope()->has_this_declaration()) {
Variable* var = scope->AsDeclarationScope()->receiver();
if (var->location() == VariableLocation::CONTEXT) {
int local_index = var->index() - Context::MIN_CONTEXT_SLOTS;
uint32_t info =
VariableModeField::encode(var->mode()) |
InitFlagField::encode(var->initialization_flag()) |
MaybeAssignedFlagField::encode(var->maybe_assigned()) |
ParameterNumberField::encode(ParameterNumberField::kMax);
scope_info.set(context_local_base + local_index, *var->name(), mode);
scope_info.set(context_local_info_base + local_index,
Smi::FromInt(info));
}
}
}
index += 2 * context_local_count;
// If the receiver is allocated, add its index.
DCHECK_EQ(index, scope_info.ReceiverInfoIndex());
if (has_receiver) {
int var_index = scope->AsDeclarationScope()->receiver()->index();
scope_info.set(index++, Smi::FromInt(var_index));
// ?? DCHECK(receiver_info != CONTEXT || var_index ==
// scope_info->ContextLength() - 1);
}
// If present, add the function variable name and its index.
DCHECK_EQ(index, scope_info.FunctionNameInfoIndex());
if (has_function_name) {
Variable* var = scope->AsDeclarationScope()->function_var();
int var_index = -1;
Object name = Smi::kZero;
if (var != nullptr) {
var_index = var->index();
name = *var->name();
}
scope_info.set(index++, name, mode);
scope_info.set(index++, Smi::FromInt(var_index));
DCHECK(function_name_info != CONTEXT ||
var_index == scope_info.ContextLength() - 1);
}
DCHECK_EQ(index, scope_info.InferredFunctionNameIndex());
if (has_inferred_function_name) {
// The inferred function name is taken from the SFI.
index++;
}
DCHECK_EQ(index, scope_info.PositionInfoIndex());
if (has_position_info) {
scope_info.set(index++, Smi::FromInt(scope->start_position()));
scope_info.set(index++, Smi::FromInt(scope->end_position()));
}
// If present, add the outer scope info.
DCHECK(index == scope_info.OuterScopeInfoIndex());
if (has_outer_scope_info) {
scope_info.set(index++, *outer_scope.ToHandleChecked(), mode);
}
}
// Module-specific information (only for module scopes).
if (scope->is_module_scope()) {
Handle<SourceTextModuleInfo> module_info = SourceTextModuleInfo::New(
isolate, zone, scope->AsModuleScope()->module());
DCHECK_EQ(index, scope_info_handle->ModuleInfoIndex());
scope_info_handle->set(index++, *module_info);
DCHECK_EQ(index, scope_info_handle->ModuleVariableCountIndex());
scope_info_handle->set(index++, Smi::FromInt(module_vars_count));
DCHECK_EQ(index, scope_info_handle->ModuleVariablesIndex());
// The variable entries themselves have already been written above.
index += kModuleVariableEntryLength * module_vars_count;
}
DCHECK_EQ(index, scope_info_handle->length());
DCHECK_EQ(parameter_count, scope_info_handle->ParameterCount());
DCHECK_EQ(scope->num_heap_slots(), scope_info_handle->ContextLength());
return scope_info_handle;
}
// static
Handle<ScopeInfo> ScopeInfo::CreateForWithScope(
Isolate* isolate, MaybeHandle<ScopeInfo> outer_scope) {
const bool has_outer_scope_info = !outer_scope.is_null();
const int length = kVariablePartIndex + (has_outer_scope_info ? 1 : 0);
Factory* factory = isolate->factory();
Handle<ScopeInfo> scope_info = factory->NewScopeInfo(length);
// Encode the flags.
int flags =
ScopeTypeField::encode(WITH_SCOPE) |
SloppyEvalCanExtendVarsField::encode(false) |
LanguageModeField::encode(LanguageMode::kSloppy) |
DeclarationScopeField::encode(false) |
ReceiverVariableField::encode(NONE) | HasClassBrandField::encode(false) |
HasNewTargetField::encode(false) | FunctionVariableField::encode(NONE) |
IsAsmModuleField::encode(false) | HasSimpleParametersField::encode(true) |
FunctionKindField::encode(kNormalFunction) |
HasOuterScopeInfoField::encode(has_outer_scope_info) |
IsDebugEvaluateScopeField::encode(false);
scope_info->SetFlags(flags);
scope_info->SetParameterCount(0);
scope_info->SetContextLocalCount(0);
int index = kVariablePartIndex;
DCHECK_EQ(index, scope_info->ReceiverInfoIndex());
DCHECK_EQ(index, scope_info->FunctionNameInfoIndex());
DCHECK_EQ(index, scope_info->InferredFunctionNameIndex());
DCHECK_EQ(index, scope_info->PositionInfoIndex());
DCHECK(index == scope_info->OuterScopeInfoIndex());
if (has_outer_scope_info) {
scope_info->set(index++, *outer_scope.ToHandleChecked());
}
DCHECK_EQ(index, scope_info->length());
DCHECK_EQ(0, scope_info->ParameterCount());
DCHECK_EQ(Context::MIN_CONTEXT_SLOTS, scope_info->ContextLength());
return scope_info;
}
// static
Handle<ScopeInfo> ScopeInfo::CreateGlobalThisBinding(Isolate* isolate) {
return CreateForBootstrapping(isolate, SCRIPT_SCOPE);
}
// static
Handle<ScopeInfo> ScopeInfo::CreateForEmptyFunction(Isolate* isolate) {
return CreateForBootstrapping(isolate, FUNCTION_SCOPE);
}
// static
Handle<ScopeInfo> ScopeInfo::CreateForBootstrapping(Isolate* isolate,
ScopeType type) {
DCHECK(type == SCRIPT_SCOPE || type == FUNCTION_SCOPE);
const int parameter_count = 0;
const bool is_empty_function = type == FUNCTION_SCOPE;
const int context_local_count = is_empty_function ? 0 : 1;
const bool has_receiver = !is_empty_function;
const bool has_inferred_function_name = is_empty_function;
const bool has_position_info = true;
const int length = kVariablePartIndex + 2 * context_local_count +
(has_receiver ? 1 : 0) +
(is_empty_function ? kFunctionNameEntries : 0) +
(has_inferred_function_name ? 1 : 0) +
(has_position_info ? kPositionInfoEntries : 0);
Factory* factory = isolate->factory();
Handle<ScopeInfo> scope_info =
factory->NewScopeInfo(length, AllocationType::kReadOnly);
// Encode the flags.
int flags =
ScopeTypeField::encode(type) |
SloppyEvalCanExtendVarsField::encode(false) |
LanguageModeField::encode(LanguageMode::kSloppy) |
DeclarationScopeField::encode(true) |
ReceiverVariableField::encode(is_empty_function ? UNUSED : CONTEXT) |
HasClassBrandField::encode(false) | HasNewTargetField::encode(false) |
FunctionVariableField::encode(is_empty_function ? UNUSED : NONE) |
HasInferredFunctionNameField::encode(has_inferred_function_name) |
IsAsmModuleField::encode(false) | HasSimpleParametersField::encode(true) |
FunctionKindField::encode(FunctionKind::kNormalFunction) |
HasOuterScopeInfoField::encode(false) |
IsDebugEvaluateScopeField::encode(false);
scope_info->SetFlags(flags);
scope_info->SetParameterCount(parameter_count);
scope_info->SetContextLocalCount(context_local_count);
int index = kVariablePartIndex;
// Here we add info for context-allocated "this".
DCHECK_EQ(index, scope_info->ContextLocalNamesIndex());
if (context_local_count) {
scope_info->set(index++, ReadOnlyRoots(isolate).this_string());
}
DCHECK_EQ(index, scope_info->ContextLocalInfosIndex());
if (context_local_count) {
const uint32_t value =
VariableModeField::encode(VariableMode::kConst) |
InitFlagField::encode(kCreatedInitialized) |
MaybeAssignedFlagField::encode(kNotAssigned) |
ParameterNumberField::encode(ParameterNumberField::kMax);
scope_info->set(index++, Smi::FromInt(value));
}
// And here we record that this scopeinfo binds a receiver.
DCHECK_EQ(index, scope_info->ReceiverInfoIndex());
const int receiver_index = Context::MIN_CONTEXT_SLOTS + 0;
if (!is_empty_function) {
scope_info->set(index++, Smi::FromInt(receiver_index));
}
DCHECK_EQ(index, scope_info->FunctionNameInfoIndex());
if (is_empty_function) {
scope_info->set(index++, *isolate->factory()->empty_string());
scope_info->set(index++, Smi::kZero);
}
DCHECK_EQ(index, scope_info->InferredFunctionNameIndex());
if (has_inferred_function_name) {
scope_info->set(index++, *isolate->factory()->empty_string());
}
DCHECK_EQ(index, scope_info->PositionInfoIndex());
// Store dummy position to be in sync with the {scope_type}.
scope_info->set(index++, Smi::kZero);
scope_info->set(index++, Smi::kZero);
DCHECK_EQ(index, scope_info->OuterScopeInfoIndex());
DCHECK_EQ(index, scope_info->length());
DCHECK_EQ(scope_info->ParameterCount(), parameter_count);
if (type == FUNCTION_SCOPE) {
DCHECK_EQ(scope_info->ContextLength(), 0);
} else {
DCHECK_EQ(scope_info->ContextLength(), Context::MIN_CONTEXT_SLOTS + 1);
}
return scope_info;
}
ScopeInfo ScopeInfo::Empty(Isolate* isolate) {
return ReadOnlyRoots(isolate).empty_scope_info();
}
ScopeType ScopeInfo::scope_type() const {
DCHECK_LT(0, length());
return ScopeTypeField::decode(Flags());
}
bool ScopeInfo::SloppyEvalCanExtendVars() const {
bool sloppy_eval_can_extend_vars =
length() > 0 && SloppyEvalCanExtendVarsField::decode(Flags());
DCHECK_IMPLIES(sloppy_eval_can_extend_vars, is_sloppy(language_mode()));
DCHECK_IMPLIES(sloppy_eval_can_extend_vars, is_declaration_scope());
return sloppy_eval_can_extend_vars;
}
LanguageMode ScopeInfo::language_mode() const {
return length() > 0 ? LanguageModeField::decode(Flags())
: LanguageMode::kSloppy;
}
bool ScopeInfo::is_declaration_scope() const {
return DeclarationScopeField::decode(Flags());
}
int ScopeInfo::ContextLength() const {
if (length() > 0) {
int context_locals = ContextLocalCount();
bool function_name_context_slot =
FunctionVariableField::decode(Flags()) == CONTEXT;
bool force_context = ForceContextAllocationField::decode(Flags());
bool has_context =
context_locals > 0 || force_context || function_name_context_slot ||
scope_type() == WITH_SCOPE || scope_type() == CLASS_SCOPE ||
(scope_type() == BLOCK_SCOPE && SloppyEvalCanExtendVars() &&
is_declaration_scope()) ||
(scope_type() == FUNCTION_SCOPE && SloppyEvalCanExtendVars()) ||
(scope_type() == FUNCTION_SCOPE && IsAsmModule()) ||
scope_type() == MODULE_SCOPE;
if (has_context) {
return Context::MIN_CONTEXT_SLOTS + context_locals +
(function_name_context_slot ? 1 : 0);
}
}
return 0;
}
bool ScopeInfo::HasReceiver() const {
if (length() == 0) return false;
return NONE != ReceiverVariableField::decode(Flags());
}
bool ScopeInfo::HasAllocatedReceiver() const {
if (length() == 0) return false;
VariableAllocationInfo allocation = ReceiverVariableField::decode(Flags());
return allocation == STACK || allocation == CONTEXT;
}
bool ScopeInfo::HasClassBrand() const {
return HasClassBrandField::decode(Flags());
}
bool ScopeInfo::HasNewTarget() const {
return HasNewTargetField::decode(Flags());
}
bool ScopeInfo::HasFunctionName() const {
if (length() == 0) return false;
return NONE != FunctionVariableField::decode(Flags());
}
bool ScopeInfo::HasInferredFunctionName() const {
if (length() == 0) return false;
return HasInferredFunctionNameField::decode(Flags());
}
bool ScopeInfo::HasPositionInfo() const {
if (length() == 0) return false;
return NeedsPositionInfo(scope_type());
}
// static
bool ScopeInfo::NeedsPositionInfo(ScopeType type) {
return type == FUNCTION_SCOPE || type == SCRIPT_SCOPE || type == EVAL_SCOPE ||
type == MODULE_SCOPE;
}
bool ScopeInfo::HasSharedFunctionName() const {
return FunctionName() != SharedFunctionInfo::kNoSharedNameSentinel;
}
void ScopeInfo::SetFunctionName(Object name) {
DCHECK(HasFunctionName());
DCHECK(name.IsString() || name == SharedFunctionInfo::kNoSharedNameSentinel);
set(FunctionNameInfoIndex(), name);
}
void ScopeInfo::SetInferredFunctionName(String name) {
DCHECK(HasInferredFunctionName());
set(InferredFunctionNameIndex(), name);
}
bool ScopeInfo::HasOuterScopeInfo() const {
if (length() == 0) return false;
return HasOuterScopeInfoField::decode(Flags());
}
bool ScopeInfo::IsDebugEvaluateScope() const {
if (length() == 0) return false;
return IsDebugEvaluateScopeField::decode(Flags());
}
void ScopeInfo::SetIsDebugEvaluateScope() {
if (length() > 0) {
DCHECK_EQ(scope_type(), WITH_SCOPE);
SetFlags(Flags() | IsDebugEvaluateScopeField::encode(true));
} else {
UNREACHABLE();
}
}
bool ScopeInfo::HasContext() const { return ContextLength() > 0; }
Object ScopeInfo::FunctionName() const {
DCHECK(HasFunctionName());
return get(FunctionNameInfoIndex());
}
Object ScopeInfo::InferredFunctionName() const {
DCHECK(HasInferredFunctionName());
return get(InferredFunctionNameIndex());
}
String ScopeInfo::FunctionDebugName() const {
Object name = FunctionName();
if (name.IsString() && String::cast(name).length() > 0) {
return String::cast(name);
}
if (HasInferredFunctionName()) {
name = InferredFunctionName();
if (name.IsString()) return String::cast(name);
}
return GetReadOnlyRoots().empty_string();
}
int ScopeInfo::StartPosition() const {
DCHECK(HasPositionInfo());
return Smi::ToInt(get(PositionInfoIndex()));
}
int ScopeInfo::EndPosition() const {
DCHECK(HasPositionInfo());
return Smi::ToInt(get(PositionInfoIndex() + 1));
}
void ScopeInfo::SetPositionInfo(int start, int end) {
DCHECK(HasPositionInfo());
DCHECK_LE(start, end);
set(PositionInfoIndex(), Smi::FromInt(start));
set(PositionInfoIndex() + 1, Smi::FromInt(end));
}
ScopeInfo ScopeInfo::OuterScopeInfo() const {
DCHECK(HasOuterScopeInfo());
return ScopeInfo::cast(get(OuterScopeInfoIndex()));
}
SourceTextModuleInfo ScopeInfo::ModuleDescriptorInfo() const {
DCHECK(scope_type() == MODULE_SCOPE);
return SourceTextModuleInfo::cast(get(ModuleInfoIndex()));
}
String ScopeInfo::ContextLocalName(int var) const {
DCHECK_LE(0, var);
DCHECK_LT(var, ContextLocalCount());
int info_index = ContextLocalNamesIndex() + var;
return String::cast(get(info_index));
}
VariableMode ScopeInfo::ContextLocalMode(int var) const {
DCHECK_LE(0, var);
DCHECK_LT(var, ContextLocalCount());
int info_index = ContextLocalInfosIndex() + var;
int value = Smi::ToInt(get(info_index));
return VariableModeField::decode(value);
}
InitializationFlag ScopeInfo::ContextLocalInitFlag(int var) const {
DCHECK_LE(0, var);
DCHECK_LT(var, ContextLocalCount());
int info_index = ContextLocalInfosIndex() + var;
int value = Smi::ToInt(get(info_index));
return InitFlagField::decode(value);
}
bool ScopeInfo::ContextLocalIsParameter(int var) const {
DCHECK_LE(0, var);
DCHECK_LT(var, ContextLocalCount());
int info_index = ContextLocalInfosIndex() + var;
int value = Smi::ToInt(get(info_index));
return ParameterNumberField::decode(value) != ParameterNumberField::kMax;
}
uint32_t ScopeInfo::ContextLocalParameterNumber(int var) const {
DCHECK(ContextLocalIsParameter(var));
int info_index = ContextLocalInfosIndex() + var;
int value = Smi::ToInt(get(info_index));
return ParameterNumberField::decode(value);
}
MaybeAssignedFlag ScopeInfo::ContextLocalMaybeAssignedFlag(int var) const {
DCHECK_LE(0, var);
DCHECK_LT(var, ContextLocalCount());
int info_index = ContextLocalInfosIndex() + var;
int value = Smi::ToInt(get(info_index));
return MaybeAssignedFlagField::decode(value);
}
// static
bool ScopeInfo::VariableIsSynthetic(String name) {
// There's currently no flag stored on the ScopeInfo to indicate that a
// variable is a compiler-introduced temporary. However, to avoid conflict
// with user declarations, the current temporaries like .generator_object and
// .result start with a dot, so we can use that as a flag. It's a hack!
return name.length() == 0 || name.Get(0) == '.' || name.Get(0) == '#' ||
name.Equals(name.GetReadOnlyRoots().this_string());
}
int ScopeInfo::ModuleIndex(String name, VariableMode* mode,
InitializationFlag* init_flag,
MaybeAssignedFlag* maybe_assigned_flag) {
DisallowHeapAllocation no_gc;
DCHECK(name.IsInternalizedString());
DCHECK_EQ(scope_type(), MODULE_SCOPE);
DCHECK_NOT_NULL(mode);
DCHECK_NOT_NULL(init_flag);
DCHECK_NOT_NULL(maybe_assigned_flag);
int module_vars_count = Smi::ToInt(get(ModuleVariableCountIndex()));
int entry = ModuleVariablesIndex();
for (int i = 0; i < module_vars_count; ++i) {
String var_name = String::cast(get(entry + kModuleVariableNameOffset));
if (name.Equals(var_name)) {
int index;
ModuleVariable(i, nullptr, &index, mode, init_flag, maybe_assigned_flag);
return index;
}
entry += kModuleVariableEntryLength;
}
return 0;
}
// static
int ScopeInfo::ContextSlotIndex(ScopeInfo scope_info, String name,
VariableMode* mode,
InitializationFlag* init_flag,
MaybeAssignedFlag* maybe_assigned_flag) {
DisallowHeapAllocation no_gc;
DCHECK(name.IsInternalizedString());
DCHECK_NOT_NULL(mode);
DCHECK_NOT_NULL(init_flag);
DCHECK_NOT_NULL(maybe_assigned_flag);
if (scope_info.length() == 0) return -1;
int start = scope_info.ContextLocalNamesIndex();
int end = start + scope_info.ContextLocalCount();
for (int i = start; i < end; ++i) {
if (name != scope_info.get(i)) continue;
int var = i - start;
*mode = scope_info.ContextLocalMode(var);
*init_flag = scope_info.ContextLocalInitFlag(var);
*maybe_assigned_flag = scope_info.ContextLocalMaybeAssignedFlag(var);
int result = Context::MIN_CONTEXT_SLOTS + var;
DCHECK_LT(result, scope_info.ContextLength());
return result;
}
return -1;
}
int ScopeInfo::ReceiverContextSlotIndex() const {
if (length() > 0 && ReceiverVariableField::decode(Flags()) == CONTEXT) {
return Smi::ToInt(get(ReceiverInfoIndex()));
}
return -1;
}
int ScopeInfo::FunctionContextSlotIndex(String name) const {
DCHECK(name.IsInternalizedString());
if (length() > 0) {
if (FunctionVariableField::decode(Flags()) == CONTEXT &&
FunctionName() == name) {
return Smi::ToInt(get(FunctionNameInfoIndex() + 1));
}
}
return -1;
}
FunctionKind ScopeInfo::function_kind() const {
return FunctionKindField::decode(Flags());
}
int ScopeInfo::ContextLocalNamesIndex() const {
DCHECK_LT(0, length());
return kVariablePartIndex;
}
int ScopeInfo::ContextLocalInfosIndex() const {
return ContextLocalNamesIndex() + ContextLocalCount();
}
int ScopeInfo::ReceiverInfoIndex() const {
return ContextLocalInfosIndex() + ContextLocalCount();
}
int ScopeInfo::FunctionNameInfoIndex() const {
return ReceiverInfoIndex() + (HasAllocatedReceiver() ? 1 : 0);
}
int ScopeInfo::InferredFunctionNameIndex() const {
return FunctionNameInfoIndex() +
(HasFunctionName() ? kFunctionNameEntries : 0);
}
int ScopeInfo::PositionInfoIndex() const {
return InferredFunctionNameIndex() + (HasInferredFunctionName() ? 1 : 0);
}
int ScopeInfo::OuterScopeInfoIndex() const {
return PositionInfoIndex() + (HasPositionInfo() ? kPositionInfoEntries : 0);
}
int ScopeInfo::ModuleInfoIndex() const {
return OuterScopeInfoIndex() + (HasOuterScopeInfo() ? 1 : 0);
}
int ScopeInfo::ModuleVariableCountIndex() const {
return ModuleInfoIndex() + 1;
}
int ScopeInfo::ModuleVariablesIndex() const {
return ModuleVariableCountIndex() + 1;
}
void ScopeInfo::ModuleVariable(int i, String* name, int* index,
VariableMode* mode,
InitializationFlag* init_flag,
MaybeAssignedFlag* maybe_assigned_flag) {
DCHECK_LE(0, i);
DCHECK_LT(i, Smi::ToInt(get(ModuleVariableCountIndex())));
int entry = ModuleVariablesIndex() + i * kModuleVariableEntryLength;
int properties = Smi::ToInt(get(entry + kModuleVariablePropertiesOffset));
if (name != nullptr) {
*name = String::cast(get(entry + kModuleVariableNameOffset));
}
if (index != nullptr) {
*index = Smi::ToInt(get(entry + kModuleVariableIndexOffset));
DCHECK_NE(*index, 0);
}
if (mode != nullptr) {
*mode = VariableModeField::decode(properties);
}
if (init_flag != nullptr) {
*init_flag = InitFlagField::decode(properties);
}
if (maybe_assigned_flag != nullptr) {
*maybe_assigned_flag = MaybeAssignedFlagField::decode(properties);
}
}
std::ostream& operator<<(std::ostream& os,
ScopeInfo::VariableAllocationInfo var_info) {
switch (var_info) {
case ScopeInfo::VariableAllocationInfo::NONE:
return os << "NONE";
case ScopeInfo::VariableAllocationInfo::STACK:
return os << "STACK";
case ScopeInfo::VariableAllocationInfo::CONTEXT:
return os << "CONTEXT";
case ScopeInfo::VariableAllocationInfo::UNUSED:
return os << "UNUSED";
}
UNREACHABLE();
return os;
}
Handle<SourceTextModuleInfoEntry> SourceTextModuleInfoEntry::New(
Isolate* isolate, Handle<HeapObject> export_name,
Handle<HeapObject> local_name, Handle<HeapObject> import_name,
int module_request, int cell_index, int beg_pos, int end_pos) {
Handle<SourceTextModuleInfoEntry> result =
Handle<SourceTextModuleInfoEntry>::cast(isolate->factory()->NewStruct(
SOURCE_TEXT_MODULE_INFO_ENTRY_TYPE, AllocationType::kOld));
result->set_export_name(*export_name);
result->set_local_name(*local_name);
result->set_import_name(*import_name);
result->set_module_request(module_request);
result->set_cell_index(cell_index);
result->set_beg_pos(beg_pos);
result->set_end_pos(end_pos);
return result;
}
Handle<SourceTextModuleInfo> SourceTextModuleInfo::New(
Isolate* isolate, Zone* zone, SourceTextModuleDescriptor* descr) {
// Serialize module requests.
int size = static_cast<int>(descr->module_requests().size());
Handle<FixedArray> module_requests = isolate->factory()->NewFixedArray(size);
Handle<FixedArray> module_request_positions =
isolate->factory()->NewFixedArray(size);
for (const auto& elem : descr->module_requests()) {
module_requests->set(elem.second.index, *elem.first->string());
module_request_positions->set(elem.second.index,
Smi::FromInt(elem.second.position));
}
// Serialize special exports.
Handle<FixedArray> special_exports = isolate->factory()->NewFixedArray(
static_cast<int>(descr->special_exports().size()));
{
int i = 0;
for (auto entry : descr->special_exports()) {
Handle<SourceTextModuleInfoEntry> serialized_entry =
entry->Serialize(isolate);
special_exports->set(i++, *serialized_entry);
}
}
// Serialize namespace imports.
Handle<FixedArray> namespace_imports = isolate->factory()->NewFixedArray(
static_cast<int>(descr->namespace_imports().size()));
{
int i = 0;
for (auto entry : descr->namespace_imports()) {
Handle<SourceTextModuleInfoEntry> serialized_entry =
entry->Serialize(isolate);
namespace_imports->set(i++, *serialized_entry);
}
}
// Serialize regular exports.
Handle<FixedArray> regular_exports =
descr->SerializeRegularExports(isolate, zone);
// Serialize regular imports.
Handle<FixedArray> regular_imports = isolate->factory()->NewFixedArray(
static_cast<int>(descr->regular_imports().size()));
{
int i = 0;
for (const auto& elem : descr->regular_imports()) {
Handle<SourceTextModuleInfoEntry> serialized_entry =
elem.second->Serialize(isolate);
regular_imports->set(i++, *serialized_entry);
}
}
Handle<SourceTextModuleInfo> result =
isolate->factory()->NewSourceTextModuleInfo();
result->set(kModuleRequestsIndex, *module_requests);
result->set(kSpecialExportsIndex, *special_exports);
result->set(kRegularExportsIndex, *regular_exports);
result->set(kNamespaceImportsIndex, *namespace_imports);
result->set(kRegularImportsIndex, *regular_imports);
result->set(kModuleRequestPositionsIndex, *module_request_positions);
return result;
}
int SourceTextModuleInfo::RegularExportCount() const {
DCHECK_EQ(regular_exports().length() % kRegularExportLength, 0);
return regular_exports().length() / kRegularExportLength;
}
String SourceTextModuleInfo::RegularExportLocalName(int i) const {
return String::cast(regular_exports().get(i * kRegularExportLength +
kRegularExportLocalNameOffset));
}
int SourceTextModuleInfo::RegularExportCellIndex(int i) const {
return Smi::ToInt(regular_exports().get(i * kRegularExportLength +
kRegularExportCellIndexOffset));
}
FixedArray SourceTextModuleInfo::RegularExportExportNames(int i) const {
return FixedArray::cast(regular_exports().get(
i * kRegularExportLength + kRegularExportExportNamesOffset));
}
} // namespace internal
} // namespace v8