Create ast/ and parsing/ subdirectories and move appropriate files

src/scopes.cc

Index: src/scopes.cc
diff --git a/src/scopes.cc b/src/scopes.cc
deleted file mode 100644
index 57dcb3a9fc8647539cfe66bf17e85825678a649e..0000000000000000000000000000000000000000
--- a/src/scopes.cc
+++ /dev/null
@@ -1,1674 +0,0 @@
-// Copyright 2012 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 "src/scopes.h"
-
-#include "src/accessors.h"
-#include "src/bootstrapper.h"
-#include "src/messages.h"
-#include "src/parser.h"
-#include "src/scopeinfo.h"
-
-namespace v8 {
-namespace internal {
-
-// ----------------------------------------------------------------------------
-// Implementation of LocalsMap
-//
-// Note: We are storing the handle locations as key values in the hash map.
-//       When inserting a new variable via Declare(), we rely on the fact that
-//       the handle location remains alive for the duration of that variable
-//       use. Because a Variable holding a handle with the same location exists
-//       this is ensured.
-
-VariableMap::VariableMap(Zone* zone)
-    : ZoneHashMap(ZoneHashMap::PointersMatch, 8, ZoneAllocationPolicy(zone)),
-      zone_(zone) {}
-VariableMap::~VariableMap() {}
-
-
-Variable* VariableMap::Declare(Scope* scope, const AstRawString* name,
-                               VariableMode mode, Variable::Kind kind,
-                               InitializationFlag initialization_flag,
-                               MaybeAssignedFlag maybe_assigned_flag,
-                               int declaration_group_start) {
-  // AstRawStrings are unambiguous, i.e., the same string is always represented
-  // by the same AstRawString*.
-  // FIXME(marja): fix the type of Lookup.
-  Entry* p =
-      ZoneHashMap::LookupOrInsert(const_cast<AstRawString*>(name), name->hash(),
-                                  ZoneAllocationPolicy(zone()));
-  if (p->value == NULL) {
-    // The variable has not been declared yet -> insert it.
-    DCHECK(p->key == name);
-    if (kind == Variable::CLASS) {
-      p->value = new (zone())
-          ClassVariable(scope, name, mode, initialization_flag,
-                        maybe_assigned_flag, declaration_group_start);
-    } else {
-      p->value = new (zone()) Variable(
-          scope, name, mode, kind, initialization_flag, maybe_assigned_flag);
-    }
-  }
-  return reinterpret_cast<Variable*>(p->value);
-}
-
-
-Variable* VariableMap::Lookup(const AstRawString* name) {
-  Entry* p = ZoneHashMap::Lookup(const_cast<AstRawString*>(name), name->hash());
-  if (p != NULL) {
-    DCHECK(reinterpret_cast<const AstRawString*>(p->key) == name);
-    DCHECK(p->value != NULL);
-    return reinterpret_cast<Variable*>(p->value);
-  }
-  return NULL;
-}
-
-
-SloppyBlockFunctionMap::SloppyBlockFunctionMap(Zone* zone)
-    : ZoneHashMap(ZoneHashMap::PointersMatch, 8, ZoneAllocationPolicy(zone)),
-      zone_(zone) {}
-SloppyBlockFunctionMap::~SloppyBlockFunctionMap() {}
-
-
-void SloppyBlockFunctionMap::Declare(const AstRawString* name,
-                                     SloppyBlockFunctionStatement* stmt) {
-  // AstRawStrings are unambiguous, i.e., the same string is always represented
-  // by the same AstRawString*.
-  Entry* p =
-      ZoneHashMap::LookupOrInsert(const_cast<AstRawString*>(name), name->hash(),
-                                  ZoneAllocationPolicy(zone_));
-  if (p->value == nullptr) {
-    p->value = new (zone_->New(sizeof(Vector))) Vector(zone_);
-  }
-  Vector* delegates = static_cast<Vector*>(p->value);
-  delegates->push_back(stmt);
-}
-
-
-// ----------------------------------------------------------------------------
-// Implementation of Scope
-
-Scope::Scope(Zone* zone, Scope* outer_scope, ScopeType scope_type,
-             AstValueFactory* ast_value_factory, FunctionKind function_kind)
-    : inner_scopes_(4, zone),
-      variables_(zone),
-      temps_(4, zone),
-      params_(4, zone),
-      unresolved_(16, zone),
-      decls_(4, zone),
-      module_descriptor_(
-          scope_type == MODULE_SCOPE ? ModuleDescriptor::New(zone) : NULL),
-      sloppy_block_function_map_(zone),
-      already_resolved_(false),
-      ast_value_factory_(ast_value_factory),
-      zone_(zone),
-      class_declaration_group_start_(-1) {
-  SetDefaults(scope_type, outer_scope, Handle<ScopeInfo>::null(),
-              function_kind);
-  // The outermost scope must be a script scope.
-  DCHECK(scope_type == SCRIPT_SCOPE || outer_scope != NULL);
-  DCHECK(!HasIllegalRedeclaration());
-}
-
-
-Scope::Scope(Zone* zone, Scope* inner_scope, ScopeType scope_type,
-             Handle<ScopeInfo> scope_info, AstValueFactory* value_factory)
-    : inner_scopes_(4, zone),
-      variables_(zone),
-      temps_(4, zone),
-      params_(4, zone),
-      unresolved_(16, zone),
-      decls_(4, zone),
-      module_descriptor_(NULL),
-      sloppy_block_function_map_(zone),
-      already_resolved_(true),
-      ast_value_factory_(value_factory),
-      zone_(zone),
-      class_declaration_group_start_(-1) {
-  SetDefaults(scope_type, NULL, scope_info);
-  if (!scope_info.is_null()) {
-    num_heap_slots_ = scope_info_->ContextLength();
-  }
-  // Ensure at least MIN_CONTEXT_SLOTS to indicate a materialized context.
-  num_heap_slots_ = Max(num_heap_slots_,
-                        static_cast<int>(Context::MIN_CONTEXT_SLOTS));
-  AddInnerScope(inner_scope);
-}
-
-
-Scope::Scope(Zone* zone, Scope* inner_scope,
-             const AstRawString* catch_variable_name,
-             AstValueFactory* value_factory)
-    : inner_scopes_(1, zone),
-      variables_(zone),
-      temps_(0, zone),
-      params_(0, zone),
-      unresolved_(0, zone),
-      decls_(0, zone),
-      module_descriptor_(NULL),
-      sloppy_block_function_map_(zone),
-      already_resolved_(true),
-      ast_value_factory_(value_factory),
-      zone_(zone),
-      class_declaration_group_start_(-1) {
-  SetDefaults(CATCH_SCOPE, NULL, Handle<ScopeInfo>::null());
-  AddInnerScope(inner_scope);
-  ++num_var_or_const_;
-  num_heap_slots_ = Context::MIN_CONTEXT_SLOTS;
-  Variable* variable = variables_.Declare(this,
-                                          catch_variable_name,
-                                          VAR,
-                                          Variable::NORMAL,
-                                          kCreatedInitialized);
-  AllocateHeapSlot(variable);
-}
-
-
-void Scope::SetDefaults(ScopeType scope_type, Scope* outer_scope,
-                        Handle<ScopeInfo> scope_info,
-                        FunctionKind function_kind) {
-  outer_scope_ = outer_scope;
-  scope_type_ = scope_type;
-  is_declaration_scope_ =
-      is_eval_scope() || is_function_scope() ||
-      is_module_scope() || is_script_scope();
-  function_kind_ = function_kind;
-  scope_name_ = ast_value_factory_->empty_string();
-  dynamics_ = nullptr;
-  receiver_ = nullptr;
-  new_target_ = nullptr;
-  function_ = nullptr;
-  arguments_ = nullptr;
-  this_function_ = nullptr;
-  illegal_redecl_ = nullptr;
-  scope_inside_with_ = false;
-  scope_contains_with_ = false;
-  scope_calls_eval_ = false;
-  scope_uses_arguments_ = false;
-  scope_uses_super_property_ = false;
-  asm_module_ = false;
-  asm_function_ = outer_scope != NULL && outer_scope->asm_module_;
-  // Inherit the language mode from the parent scope.
-  language_mode_ = outer_scope != NULL ? outer_scope->language_mode_ : SLOPPY;
-  outer_scope_calls_sloppy_eval_ = false;
-  inner_scope_calls_eval_ = false;
-  scope_nonlinear_ = false;
-  force_eager_compilation_ = false;
-  force_context_allocation_ = (outer_scope != NULL && !is_function_scope())
-      ? outer_scope->has_forced_context_allocation() : false;
-  num_var_or_const_ = 0;
-  num_stack_slots_ = 0;
-  num_heap_slots_ = 0;
-  num_global_slots_ = 0;
-  num_modules_ = 0;
-  module_var_ = NULL;
-  arity_ = 0;
-  has_simple_parameters_ = true;
-  rest_parameter_ = NULL;
-  rest_index_ = -1;
-  scope_info_ = scope_info;
-  start_position_ = RelocInfo::kNoPosition;
-  end_position_ = RelocInfo::kNoPosition;
-  if (!scope_info.is_null()) {
-    scope_calls_eval_ = scope_info->CallsEval();
-    language_mode_ = scope_info->language_mode();
-    is_declaration_scope_ = scope_info->is_declaration_scope();
-    function_kind_ = scope_info->function_kind();
-  }
-}
-
-
-Scope* Scope::DeserializeScopeChain(Isolate* isolate, Zone* zone,
-                                    Context* context, Scope* script_scope) {
-  // Reconstruct the outer scope chain from a closure's context chain.
-  Scope* current_scope = NULL;
-  Scope* innermost_scope = NULL;
-  bool contains_with = false;
-  while (!context->IsNativeContext()) {
-    if (context->IsWithContext()) {
-      Scope* with_scope = new (zone)
-          Scope(zone, current_scope, WITH_SCOPE, Handle<ScopeInfo>::null(),
-                script_scope->ast_value_factory_);
-      current_scope = with_scope;
-      // All the inner scopes are inside a with.
-      contains_with = true;
-      for (Scope* s = innermost_scope; s != NULL; s = s->outer_scope()) {
-        s->scope_inside_with_ = true;
-      }
-    } else if (context->IsScriptContext()) {
-      ScopeInfo* scope_info = context->scope_info();
-      current_scope = new (zone) Scope(zone, current_scope, SCRIPT_SCOPE,
-                                       Handle<ScopeInfo>(scope_info),
-                                       script_scope->ast_value_factory_);
-    } else if (context->IsModuleContext()) {
-      ScopeInfo* scope_info = context->module()->scope_info();
-      current_scope = new (zone) Scope(zone, current_scope, MODULE_SCOPE,
-                                       Handle<ScopeInfo>(scope_info),
-                                       script_scope->ast_value_factory_);
-    } else if (context->IsFunctionContext()) {
-      ScopeInfo* scope_info = context->closure()->shared()->scope_info();
-      current_scope = new (zone) Scope(zone, current_scope, FUNCTION_SCOPE,
-                                       Handle<ScopeInfo>(scope_info),
-                                       script_scope->ast_value_factory_);
-      if (scope_info->IsAsmFunction()) current_scope->asm_function_ = true;
-      if (scope_info->IsAsmModule()) current_scope->asm_module_ = true;
-    } else if (context->IsBlockContext()) {
-      ScopeInfo* scope_info = context->scope_info();
-      current_scope = new (zone)
-          Scope(zone, current_scope, BLOCK_SCOPE, Handle<ScopeInfo>(scope_info),
-                script_scope->ast_value_factory_);
-    } else {
-      DCHECK(context->IsCatchContext());
-      String* name = context->catch_name();
-      current_scope = new (zone) Scope(
-          zone, current_scope,
-          script_scope->ast_value_factory_->GetString(Handle<String>(name)),
-          script_scope->ast_value_factory_);
-    }
-    if (contains_with) current_scope->RecordWithStatement();
-    if (innermost_scope == NULL) innermost_scope = current_scope;
-
-    // Forget about a with when we move to a context for a different function.
-    if (context->previous()->closure() != context->closure()) {
-      contains_with = false;
-    }
-    context = context->previous();
-  }
-
-  script_scope->AddInnerScope(current_scope);
-  script_scope->PropagateScopeInfo(false);
-  return (innermost_scope == NULL) ? script_scope : innermost_scope;
-}
-
-
-bool Scope::Analyze(ParseInfo* info) {
-  DCHECK(info->literal() != NULL);
-  DCHECK(info->scope() == NULL);
-  Scope* scope = info->literal()->scope();
-  Scope* top = scope;
-
-  // Traverse the scope tree up to the first unresolved scope or the global
-  // scope and start scope resolution and variable allocation from that scope.
-  while (!top->is_script_scope() &&
-         !top->outer_scope()->already_resolved()) {
-    top = top->outer_scope();
-  }
-
-  // Allocate the variables.
-  {
-    AstNodeFactory ast_node_factory(info->ast_value_factory());
-    if (!top->AllocateVariables(info, &ast_node_factory)) {
-      DCHECK(top->pending_error_handler_.has_pending_error());
-      top->pending_error_handler_.ThrowPendingError(info->isolate(),
-                                                    info->script());
-      return false;
-    }
-  }
-
-#ifdef DEBUG
-  bool native = info->isolate()->bootstrapper()->IsActive();
-  if (!info->shared_info().is_null()) {
-    Object* script = info->shared_info()->script();
-    native = script->IsScript() &&
-             Script::cast(script)->type() == Script::TYPE_NATIVE;
-  }
-
-  if (native ? FLAG_print_builtin_scopes : FLAG_print_scopes) scope->Print();
-#endif
-
-  info->set_scope(scope);
-  return true;
-}
-
-
-void Scope::Initialize() {
-  DCHECK(!already_resolved());
-
-  // Add this scope as a new inner scope of the outer scope.
-  if (outer_scope_ != NULL) {
-    outer_scope_->inner_scopes_.Add(this, zone());
-    scope_inside_with_ = outer_scope_->scope_inside_with_ || is_with_scope();
-  } else {
-    scope_inside_with_ = is_with_scope();
-  }
-
-  // Declare convenience variables and the receiver.
-  if (is_declaration_scope() && has_this_declaration()) {
-    bool subclass_constructor = IsSubclassConstructor(function_kind_);
-    Variable* var = variables_.Declare(
-        this, ast_value_factory_->this_string(),
-        subclass_constructor ? CONST : VAR, Variable::THIS,
-        subclass_constructor ? kNeedsInitialization : kCreatedInitialized);
-    receiver_ = var;
-  }
-
-  if (is_function_scope() && !is_arrow_scope()) {
-    // Declare 'arguments' variable which exists in all non arrow functions.
-    // Note that it might never be accessed, in which case it won't be
-    // allocated during variable allocation.
-    variables_.Declare(this, ast_value_factory_->arguments_string(), VAR,
-                       Variable::ARGUMENTS, kCreatedInitialized);
-
-    variables_.Declare(this, ast_value_factory_->new_target_string(), CONST,
-                       Variable::NORMAL, kCreatedInitialized);
-
-    if (IsConciseMethod(function_kind_) || IsClassConstructor(function_kind_) ||
-        IsAccessorFunction(function_kind_)) {
-      variables_.Declare(this, ast_value_factory_->this_function_string(),
-                         CONST, Variable::NORMAL, kCreatedInitialized);
-    }
-  }
-}
-
-
-Scope* Scope::FinalizeBlockScope() {
-  DCHECK(is_block_scope());
-  DCHECK(temps_.is_empty());
-  DCHECK(params_.is_empty());
-
-  if (num_var_or_const() > 0 ||
-      (is_declaration_scope() && calls_sloppy_eval())) {
-    return this;
-  }
-
-  // Remove this scope from outer scope.
-  outer_scope()->RemoveInnerScope(this);
-
-  // Reparent inner scopes.
-  for (int i = 0; i < inner_scopes_.length(); i++) {
-    outer_scope()->AddInnerScope(inner_scopes_[i]);
-  }
-
-  // Move unresolved variables
-  for (int i = 0; i < unresolved_.length(); i++) {
-    outer_scope()->unresolved_.Add(unresolved_[i], zone());
-  }
-
-  PropagateUsageFlagsToScope(outer_scope_);
-
-  return NULL;
-}
-
-
-void Scope::ReplaceOuterScope(Scope* outer) {
-  DCHECK_NOT_NULL(outer);
-  DCHECK_NOT_NULL(outer_scope_);
-  DCHECK(!already_resolved());
-  DCHECK(!outer->already_resolved());
-  DCHECK(!outer_scope_->already_resolved());
-  outer_scope_->RemoveInnerScope(this);
-  outer->AddInnerScope(this);
-  outer_scope_ = outer;
-}
-
-
-void Scope::PropagateUsageFlagsToScope(Scope* other) {
-  DCHECK_NOT_NULL(other);
-  DCHECK(!already_resolved());
-  DCHECK(!other->already_resolved());
-  if (uses_arguments()) other->RecordArgumentsUsage();
-  if (uses_super_property()) other->RecordSuperPropertyUsage();
-  if (calls_eval()) other->RecordEvalCall();
-  if (scope_contains_with_) other->RecordWithStatement();
-}
-
-
-Variable* Scope::LookupLocal(const AstRawString* name) {
-  Variable* result = variables_.Lookup(name);
-  if (result != NULL || scope_info_.is_null()) {
-    return result;
-  }
-  Handle<String> name_handle = name->string();
-  // The Scope is backed up by ScopeInfo. This means it cannot operate in a
-  // heap-independent mode, and all strings must be internalized immediately. So
-  // it's ok to get the Handle<String> here.
-  // If we have a serialized scope info, we might find the variable there.
-  // There should be no local slot with the given name.
-  DCHECK(scope_info_->StackSlotIndex(*name_handle) < 0 || is_block_scope());
-
-  // Check context slot lookup.
-  VariableMode mode;
-  VariableLocation location = VariableLocation::CONTEXT;
-  InitializationFlag init_flag;
-  MaybeAssignedFlag maybe_assigned_flag;
-  int index = ScopeInfo::ContextSlotIndex(scope_info_, name_handle, &mode,
-                                          &init_flag, &maybe_assigned_flag);
-  if (index < 0) {
-    location = VariableLocation::GLOBAL;
-    index = ScopeInfo::ContextGlobalSlotIndex(scope_info_, name_handle, &mode,
-                                              &init_flag, &maybe_assigned_flag);
-  }
-  if (index < 0) {
-    // Check parameters.
-    index = scope_info_->ParameterIndex(*name_handle);
-    if (index < 0) return NULL;
-
-    mode = DYNAMIC;
-    location = VariableLocation::LOOKUP;
-    init_flag = kCreatedInitialized;
-    // Be conservative and flag parameters as maybe assigned. Better information
-    // would require ScopeInfo to serialize the maybe_assigned bit also for
-    // parameters.
-    maybe_assigned_flag = kMaybeAssigned;
-  } else {
-    DCHECK(location != VariableLocation::GLOBAL ||
-           (is_script_scope() && IsDeclaredVariableMode(mode) &&
-            !IsLexicalVariableMode(mode)));
-  }
-
-  Variable::Kind kind = Variable::NORMAL;
-  if (location == VariableLocation::CONTEXT &&
-      index == scope_info_->ReceiverContextSlotIndex()) {
-    kind = Variable::THIS;
-  }
-  // TODO(marja, rossberg): Correctly declare FUNCTION, CLASS, NEW_TARGET, and
-  // ARGUMENTS bindings as their corresponding Variable::Kind.
-
-  Variable* var = variables_.Declare(this, name, mode, kind, init_flag,
-                                     maybe_assigned_flag);
-  var->AllocateTo(location, index);
-  return var;
-}
-
-
-Variable* Scope::LookupFunctionVar(const AstRawString* name,
-                                   AstNodeFactory* factory) {
-  if (function_ != NULL && function_->proxy()->raw_name() == name) {
-    return function_->proxy()->var();
-  } else if (!scope_info_.is_null()) {
-    // If we are backed by a scope info, try to lookup the variable there.
-    VariableMode mode;
-    int index = scope_info_->FunctionContextSlotIndex(*(name->string()), &mode);
-    if (index < 0) return NULL;
-    Variable* var = new (zone())
-        Variable(this, name, mode, Variable::NORMAL, kCreatedInitialized);
-    VariableProxy* proxy = factory->NewVariableProxy(var);
-    VariableDeclaration* declaration = factory->NewVariableDeclaration(
-        proxy, mode, this, RelocInfo::kNoPosition);
-    DeclareFunctionVar(declaration);
-    var->AllocateTo(VariableLocation::CONTEXT, index);
-    return var;
-  } else {
-    return NULL;
-  }
-}
-
-
-Variable* Scope::Lookup(const AstRawString* name) {
-  for (Scope* scope = this;
-       scope != NULL;
-       scope = scope->outer_scope()) {
-    Variable* var = scope->LookupLocal(name);
-    if (var != NULL) return var;
-  }
-  return NULL;
-}
-
-
-Variable* Scope::DeclareParameter(
-    const AstRawString* name, VariableMode mode,
-    bool is_optional, bool is_rest, bool* is_duplicate) {
-  DCHECK(!already_resolved());
-  DCHECK(is_function_scope());
-  DCHECK(!is_optional || !is_rest);
-  Variable* var;
-  if (mode == TEMPORARY) {
-    var = NewTemporary(name);
-  } else {
-    var = variables_.Declare(this, name, mode, Variable::NORMAL,
-                             kCreatedInitialized);
-    // TODO(wingo): Avoid O(n^2) check.
-    *is_duplicate = IsDeclaredParameter(name);
-  }
-  if (!is_optional && !is_rest && arity_ == params_.length()) {
-    ++arity_;
-  }
-  if (is_rest) {
-    DCHECK_NULL(rest_parameter_);
-    rest_parameter_ = var;
-    rest_index_ = num_parameters();
-  }
-  params_.Add(var, zone());
-  return var;
-}
-
-
-Variable* Scope::DeclareLocal(const AstRawString* name, VariableMode mode,
-                              InitializationFlag init_flag, Variable::Kind kind,
-                              MaybeAssignedFlag maybe_assigned_flag,
-                              int declaration_group_start) {
-  DCHECK(!already_resolved());
-  // This function handles VAR, LET, and CONST modes.  DYNAMIC variables are
-  // introduces during variable allocation, and TEMPORARY variables are
-  // allocated via NewTemporary().
-  DCHECK(IsDeclaredVariableMode(mode));
-  ++num_var_or_const_;
-  return variables_.Declare(this, name, mode, kind, init_flag,
-                            maybe_assigned_flag, declaration_group_start);
-}
-
-
-Variable* Scope::DeclareDynamicGlobal(const AstRawString* name) {
-  DCHECK(is_script_scope());
-  return variables_.Declare(this,
-                            name,
-                            DYNAMIC_GLOBAL,
-                            Variable::NORMAL,
-                            kCreatedInitialized);
-}
-
-
-bool Scope::RemoveUnresolved(VariableProxy* var) {
-  // Most likely (always?) any variable we want to remove
-  // was just added before, so we search backwards.
-  for (int i = unresolved_.length(); i-- > 0;) {
-    if (unresolved_[i] == var) {
-      unresolved_.Remove(i);
-      return true;
-    }
-  }
-  return false;
-}
-
-
-Variable* Scope::NewTemporary(const AstRawString* name) {
-  DCHECK(!already_resolved());
-  Scope* scope = this->ClosureScope();
-  Variable* var = new(zone()) Variable(scope,
-                                       name,
-                                       TEMPORARY,
-                                       Variable::NORMAL,
-                                       kCreatedInitialized);
-  scope->temps_.Add(var, zone());
-  return var;
-}
-
-
-void Scope::AddDeclaration(Declaration* declaration) {
-  decls_.Add(declaration, zone());
-}
-
-
-void Scope::SetIllegalRedeclaration(Expression* expression) {
-  // Record only the first illegal redeclaration.
-  if (!HasIllegalRedeclaration()) {
-    illegal_redecl_ = expression;
-  }
-  DCHECK(HasIllegalRedeclaration());
-}
-
-
-Expression* Scope::GetIllegalRedeclaration() {
-  DCHECK(HasIllegalRedeclaration());
-  return illegal_redecl_;
-}
-
-
-Declaration* Scope::CheckConflictingVarDeclarations() {
-  int length = decls_.length();
-  for (int i = 0; i < length; i++) {
-    Declaration* decl = decls_[i];
-    // We don't create a separate scope to hold the function name of a function
-    // expression, so we have to make sure not to consider it when checking for
-    // conflicts (since it's conceptually "outside" the declaration scope).
-    if (is_function_scope() && decl == function()) continue;
-    if (IsLexicalVariableMode(decl->mode()) && !is_block_scope()) continue;
-    const AstRawString* name = decl->proxy()->raw_name();
-
-    // Iterate through all scopes until and including the declaration scope.
-    Scope* previous = NULL;
-    Scope* current = decl->scope();
-    // Lexical vs lexical conflicts within the same scope have already been
-    // captured in Parser::Declare. The only conflicts we still need to check
-    // are lexical vs VAR, or any declarations within a declaration block scope
-    // vs lexical declarations in its surrounding (function) scope.
-    if (IsLexicalVariableMode(decl->mode())) current = current->outer_scope_;
-    do {
-      // There is a conflict if there exists a non-VAR binding.
-      Variable* other_var = current->variables_.Lookup(name);
-      if (other_var != NULL && IsLexicalVariableMode(other_var->mode())) {
-        return decl;
-      }
-      previous = current;
-      current = current->outer_scope_;
-    } while (!previous->is_declaration_scope());
-  }
-  return NULL;
-}
-
-
-class VarAndOrder {
- public:
-  VarAndOrder(Variable* var, int order) : var_(var), order_(order) { }
-  Variable* var() const { return var_; }
-  int order() const { return order_; }
-  static int Compare(const VarAndOrder* a, const VarAndOrder* b) {
-    return a->order_ - b->order_;
-  }
-
- private:
-  Variable* var_;
-  int order_;
-};
-
-
-void Scope::CollectStackAndContextLocals(
-    ZoneList<Variable*>* stack_locals, ZoneList<Variable*>* context_locals,
-    ZoneList<Variable*>* context_globals,
-    ZoneList<Variable*>* strong_mode_free_variables) {
-  DCHECK(stack_locals != NULL);
-  DCHECK(context_locals != NULL);
-  DCHECK(context_globals != NULL);
-
-  // Collect temporaries which are always allocated on the stack, unless the
-  // context as a whole has forced context allocation.
-  for (int i = 0; i < temps_.length(); i++) {
-    Variable* var = temps_[i];
-    if (var->is_used()) {
-      if (var->IsContextSlot()) {
-        DCHECK(has_forced_context_allocation());
-        context_locals->Add(var, zone());
-      } else if (var->IsStackLocal()) {
-        stack_locals->Add(var, zone());
-      } else {
-        DCHECK(var->IsParameter());
-      }
-    }
-  }
-
-  // Collect declared local variables.
-  ZoneList<VarAndOrder> vars(variables_.occupancy(), zone());
-  for (VariableMap::Entry* p = variables_.Start();
-       p != NULL;
-       p = variables_.Next(p)) {
-    Variable* var = reinterpret_cast<Variable*>(p->value);
-    if (strong_mode_free_variables && var->has_strong_mode_reference() &&
-        var->mode() == DYNAMIC_GLOBAL) {
-      strong_mode_free_variables->Add(var, zone());
-    }
-
-    if (var->is_used()) {
-      vars.Add(VarAndOrder(var, p->order), zone());
-    }
-  }
-  vars.Sort(VarAndOrder::Compare);
-  int var_count = vars.length();
-  for (int i = 0; i < var_count; i++) {
-    Variable* var = vars[i].var();
-    if (var->IsStackLocal()) {
-      stack_locals->Add(var, zone());
-    } else if (var->IsContextSlot()) {
-      context_locals->Add(var, zone());
-    } else if (var->IsGlobalSlot()) {
-      context_globals->Add(var, zone());
-    }
-  }
-}
-
-
-bool Scope::AllocateVariables(ParseInfo* info, AstNodeFactory* factory) {
-  // 1) Propagate scope information.
-  bool outer_scope_calls_sloppy_eval = false;
-  if (outer_scope_ != NULL) {
-    outer_scope_calls_sloppy_eval =
-        outer_scope_->outer_scope_calls_sloppy_eval() |
-        outer_scope_->calls_sloppy_eval();
-  }
-  PropagateScopeInfo(outer_scope_calls_sloppy_eval);
-
-  // 2) Allocate module instances.
-  if (FLAG_harmony_modules && is_script_scope()) {
-    DCHECK(num_modules_ == 0);
-    AllocateModules();
-  }
-
-  // 3) Resolve variables.
-  if (!ResolveVariablesRecursively(info, factory)) return false;
-
-  // 4) Allocate variables.
-  AllocateVariablesRecursively(info->isolate());
-
-  return true;
-}
-
-
-bool Scope::HasTrivialContext() const {
-  // A function scope has a trivial context if it always is the global
-  // context. We iteratively scan out the context chain to see if
-  // there is anything that makes this scope non-trivial; otherwise we
-  // return true.
-  for (const Scope* scope = this; scope != NULL; scope = scope->outer_scope_) {
-    if (scope->is_eval_scope()) return false;
-    if (scope->scope_inside_with_) return false;
-    if (scope->ContextLocalCount() > 0) return false;
-    if (scope->ContextGlobalCount() > 0) return false;
-  }
-  return true;
-}
-
-
-bool Scope::HasTrivialOuterContext() const {
-  Scope* outer = outer_scope_;
-  if (outer == NULL) return true;
-  // Note that the outer context may be trivial in general, but the current
-  // scope may be inside a 'with' statement in which case the outer context
-  // for this scope is not trivial.
-  return !scope_inside_with_ && outer->HasTrivialContext();
-}
-
-
-bool Scope::AllowsLazyParsing() const {
-  // If we are inside a block scope, we must parse eagerly to find out how
-  // to allocate variables on the block scope. At this point, declarations may
-  // not have yet been parsed.
-  for (const Scope* scope = this; scope != NULL; scope = scope->outer_scope_) {
-    if (scope->is_block_scope()) return false;
-  }
-  return AllowsLazyCompilation();
-}
-
-
-bool Scope::AllowsLazyCompilation() const { return !force_eager_compilation_; }
-
-
-bool Scope::AllowsLazyCompilationWithoutContext() const {
-  return !force_eager_compilation_ && HasTrivialOuterContext();
-}
-
-
-int Scope::ContextChainLength(Scope* scope) {
-  int n = 0;
-  for (Scope* s = this; s != scope; s = s->outer_scope_) {
-    DCHECK(s != NULL);  // scope must be in the scope chain
-    if (s->NeedsContext()) n++;
-  }
-  return n;
-}
-
-
-int Scope::MaxNestedContextChainLength() {
-  int max_context_chain_length = 0;
-  for (int i = 0; i < inner_scopes_.length(); i++) {
-    Scope* scope = inner_scopes_[i];
-    max_context_chain_length = std::max(scope->MaxNestedContextChainLength(),
-                                        max_context_chain_length);
-  }
-  if (NeedsContext()) {
-    max_context_chain_length += 1;
-  }
-  return max_context_chain_length;
-}
-
-
-Scope* Scope::DeclarationScope() {
-  Scope* scope = this;
-  while (!scope->is_declaration_scope()) {
-    scope = scope->outer_scope();
-  }
-  return scope;
-}
-
-
-Scope* Scope::ClosureScope() {
-  Scope* scope = this;
-  while (!scope->is_declaration_scope() || scope->is_block_scope()) {
-    scope = scope->outer_scope();
-  }
-  return scope;
-}
-
-
-Scope* Scope::ReceiverScope() {
-  Scope* scope = this;
-  while (!scope->is_script_scope() &&
-         (!scope->is_function_scope() || scope->is_arrow_scope())) {
-    scope = scope->outer_scope();
-  }
-  return scope;
-}
-
-
-
-Handle<ScopeInfo> Scope::GetScopeInfo(Isolate* isolate) {
-  if (scope_info_.is_null()) {
-    scope_info_ = ScopeInfo::Create(isolate, zone(), this);
-  }
-  return scope_info_;
-}
-
-
-void Scope::GetNestedScopeChain(Isolate* isolate,
-                                List<Handle<ScopeInfo> >* chain, int position) {
-  if (!is_eval_scope()) chain->Add(Handle<ScopeInfo>(GetScopeInfo(isolate)));
-
-  for (int i = 0; i < inner_scopes_.length(); i++) {
-    Scope* scope = inner_scopes_[i];
-    int beg_pos = scope->start_position();
-    int end_pos = scope->end_position();
-    DCHECK(beg_pos >= 0 && end_pos >= 0);
-    if (beg_pos <= position && position < end_pos) {
-      scope->GetNestedScopeChain(isolate, chain, position);
-      return;
-    }
-  }
-}
-
-
-void Scope::ReportMessage(int start_position, int end_position,
-                          MessageTemplate::Template message,
-                          const AstRawString* arg) {
-  // Propagate the error to the topmost scope targeted by this scope analysis
-  // phase.
-  Scope* top = this;
-  while (!top->is_script_scope() && !top->outer_scope()->already_resolved()) {
-    top = top->outer_scope();
-  }
-
-  top->pending_error_handler_.ReportMessageAt(start_position, end_position,
-                                              message, arg, kReferenceError);
-}
-
-
-#ifdef DEBUG
-static const char* Header(ScopeType scope_type, FunctionKind function_kind,
-                          bool is_declaration_scope) {
-  switch (scope_type) {
-    case EVAL_SCOPE: return "eval";
-    // TODO(adamk): Should we print concise method scopes specially?
-    case FUNCTION_SCOPE:
-      return IsArrowFunction(function_kind) ? "arrow" : "function";
-    case MODULE_SCOPE: return "module";
-    case SCRIPT_SCOPE: return "global";
-    case CATCH_SCOPE: return "catch";
-    case BLOCK_SCOPE: return is_declaration_scope ? "varblock" : "block";
-    case WITH_SCOPE: return "with";
-  }
-  UNREACHABLE();
-  return NULL;
-}
-
-
-static void Indent(int n, const char* str) {
-  PrintF("%*s%s", n, "", str);
-}
-
-
-static void PrintName(const AstRawString* name) {
-  PrintF("%.*s", name->length(), name->raw_data());
-}
-
-
-static void PrintLocation(Variable* var) {
-  switch (var->location()) {
-    case VariableLocation::UNALLOCATED:
-      break;
-    case VariableLocation::PARAMETER:
-      PrintF("parameter[%d]", var->index());
-      break;
-    case VariableLocation::LOCAL:
-      PrintF("local[%d]", var->index());
-      break;
-    case VariableLocation::CONTEXT:
-      PrintF("context[%d]", var->index());
-      break;
-    case VariableLocation::GLOBAL:
-      PrintF("global[%d]", var->index());
-      break;
-    case VariableLocation::LOOKUP:
-      PrintF("lookup");
-      break;
-  }
-}
-
-
-static void PrintVar(int indent, Variable* var) {
-  if (var->is_used() || !var->IsUnallocated()) {
-    Indent(indent, Variable::Mode2String(var->mode()));
-    PrintF(" ");
-    if (var->raw_name()->IsEmpty())
-      PrintF(".%p", reinterpret_cast<void*>(var));
-    else
-      PrintName(var->raw_name());
-    PrintF(";  // ");
-    PrintLocation(var);
-    bool comma = !var->IsUnallocated();
-    if (var->has_forced_context_allocation()) {
-      if (comma) PrintF(", ");
-      PrintF("forced context allocation");
-      comma = true;
-    }
-    if (var->maybe_assigned() == kMaybeAssigned) {
-      if (comma) PrintF(", ");
-      PrintF("maybe assigned");
-    }
-    PrintF("\n");
-  }
-}
-
-
-static void PrintMap(int indent, VariableMap* map) {
-  for (VariableMap::Entry* p = map->Start(); p != NULL; p = map->Next(p)) {
-    Variable* var = reinterpret_cast<Variable*>(p->value);
-    if (var == NULL) {
-      Indent(indent, "<?>\n");
-    } else {
-      PrintVar(indent, var);
-    }
-  }
-}
-
-
-void Scope::Print(int n) {
-  int n0 = (n > 0 ? n : 0);
-  int n1 = n0 + 2;  // indentation
-
-  // Print header.
-  Indent(n0, Header(scope_type_, function_kind_, is_declaration_scope()));
-  if (scope_name_ != nullptr && !scope_name_->IsEmpty()) {
-    PrintF(" ");
-    PrintName(scope_name_);
-  }
-
-  // Print parameters, if any.
-  if (is_function_scope()) {
-    PrintF(" (");
-    for (int i = 0; i < params_.length(); i++) {
-      if (i > 0) PrintF(", ");
-      const AstRawString* name = params_[i]->raw_name();
-      if (name->IsEmpty())
-        PrintF(".%p", reinterpret_cast<void*>(params_[i]));
-      else
-        PrintName(name);
-    }
-    PrintF(")");
-  }
-
-  PrintF(" { // (%d, %d)\n", start_position(), end_position());
-
-  // Function name, if any (named function literals, only).
-  if (function_ != NULL) {
-    Indent(n1, "// (local) function name: ");
-    PrintName(function_->proxy()->raw_name());
-    PrintF("\n");
-  }
-
-  // Scope info.
-  if (HasTrivialOuterContext()) {
-    Indent(n1, "// scope has trivial outer context\n");
-  }
-  if (is_strong(language_mode())) {
-    Indent(n1, "// strong mode scope\n");
-  } else if (is_strict(language_mode())) {
-    Indent(n1, "// strict mode scope\n");
-  }
-  if (scope_inside_with_) Indent(n1, "// scope inside 'with'\n");
-  if (scope_contains_with_) Indent(n1, "// scope contains 'with'\n");
-  if (scope_calls_eval_) Indent(n1, "// scope calls 'eval'\n");
-  if (scope_uses_arguments_) Indent(n1, "// scope uses 'arguments'\n");
-  if (scope_uses_super_property_)
-    Indent(n1, "// scope uses 'super' property\n");
-  if (outer_scope_calls_sloppy_eval_) {
-    Indent(n1, "// outer scope calls 'eval' in sloppy context\n");
-  }
-  if (inner_scope_calls_eval_) Indent(n1, "// inner scope calls 'eval'\n");
-  if (num_stack_slots_ > 0) {
-    Indent(n1, "// ");
-    PrintF("%d stack slots\n", num_stack_slots_);
-  }
-  if (num_heap_slots_ > 0) {
-    Indent(n1, "// ");
-    PrintF("%d heap slots (including %d global slots)\n", num_heap_slots_,
-           num_global_slots_);
-  }
-
-  // Print locals.
-  if (function_ != NULL) {
-    Indent(n1, "// function var:\n");
-    PrintVar(n1, function_->proxy()->var());
-  }
-
-  if (temps_.length() > 0) {
-    Indent(n1, "// temporary vars:\n");
-    for (int i = 0; i < temps_.length(); i++) {
-      PrintVar(n1, temps_[i]);
-    }
-  }
-
-  if (variables_.Start() != NULL) {
-    Indent(n1, "// local vars:\n");
-    PrintMap(n1, &variables_);
-  }
-
-  if (dynamics_ != NULL) {
-    Indent(n1, "// dynamic vars:\n");
-    PrintMap(n1, dynamics_->GetMap(DYNAMIC));
-    PrintMap(n1, dynamics_->GetMap(DYNAMIC_LOCAL));
-    PrintMap(n1, dynamics_->GetMap(DYNAMIC_GLOBAL));
-  }
-
-  // Print inner scopes (disable by providing negative n).
-  if (n >= 0) {
-    for (int i = 0; i < inner_scopes_.length(); i++) {
-      PrintF("\n");
-      inner_scopes_[i]->Print(n1);
-    }
-  }
-
-  Indent(n0, "}\n");
-}
-#endif  // DEBUG
-
-
-Variable* Scope::NonLocal(const AstRawString* name, VariableMode mode) {
-  if (dynamics_ == NULL) dynamics_ = new (zone()) DynamicScopePart(zone());
-  VariableMap* map = dynamics_->GetMap(mode);
-  Variable* var = map->Lookup(name);
-  if (var == NULL) {
-    // Declare a new non-local.
-    InitializationFlag init_flag = (mode == VAR)
-        ? kCreatedInitialized : kNeedsInitialization;
-    var = map->Declare(NULL,
-                       name,
-                       mode,
-                       Variable::NORMAL,
-                       init_flag);
-    // Allocate it by giving it a dynamic lookup.
-    var->AllocateTo(VariableLocation::LOOKUP, -1);
-  }
-  return var;
-}
-
-
-Variable* Scope::LookupRecursive(VariableProxy* proxy,
-                                 BindingKind* binding_kind,
-                                 AstNodeFactory* factory) {
-  DCHECK(binding_kind != NULL);
-  if (already_resolved() && is_with_scope()) {
-    // Short-cut: if the scope is deserialized from a scope info, variable
-    // allocation is already fixed.  We can simply return with dynamic lookup.
-    *binding_kind = DYNAMIC_LOOKUP;
-    return NULL;
-  }
-
-  // Try to find the variable in this scope.
-  Variable* var = LookupLocal(proxy->raw_name());
-
-  // We found a variable and we are done. (Even if there is an 'eval' in
-  // this scope which introduces the same variable again, the resulting
-  // variable remains the same.)
-  if (var != NULL) {
-    *binding_kind = BOUND;
-    return var;
-  }
-
-  // We did not find a variable locally. Check against the function variable,
-  // if any. We can do this for all scopes, since the function variable is
-  // only present - if at all - for function scopes.
-  *binding_kind = UNBOUND;
-  var = LookupFunctionVar(proxy->raw_name(), factory);
-  if (var != NULL) {
-    *binding_kind = BOUND;
-  } else if (outer_scope_ != NULL) {
-    var = outer_scope_->LookupRecursive(proxy, binding_kind, factory);
-    if (*binding_kind == BOUND && (is_function_scope() || is_with_scope())) {
-      var->ForceContextAllocation();
-    }
-  } else {
-    DCHECK(is_script_scope());
-  }
-
-  // "this" can't be shadowed by "eval"-introduced bindings or by "with" scopes.
-  // TODO(wingo): There are other variables in this category; add them.
-  bool name_can_be_shadowed = var == nullptr || !var->is_this();
-
-  if (is_with_scope() && name_can_be_shadowed) {
-    DCHECK(!already_resolved());
-    // The current scope is a with scope, so the variable binding can not be
-    // statically resolved. However, note that it was necessary to do a lookup
-    // in the outer scope anyway, because if a binding exists in an outer scope,
-    // the associated variable has to be marked as potentially being accessed
-    // from inside of an inner with scope (the property may not be in the 'with'
-    // object).
-    if (var != NULL && proxy->is_assigned()) var->set_maybe_assigned();
-    *binding_kind = DYNAMIC_LOOKUP;
-    return NULL;
-  } else if (calls_sloppy_eval() && !is_script_scope() &&
-             name_can_be_shadowed) {
-    // A variable binding may have been found in an outer scope, but the current
-    // scope makes a sloppy 'eval' call, so the found variable may not be
-    // the correct one (the 'eval' may introduce a binding with the same name).
-    // In that case, change the lookup result to reflect this situation.
-    if (*binding_kind == BOUND) {
-      *binding_kind = BOUND_EVAL_SHADOWED;
-    } else if (*binding_kind == UNBOUND) {
-      *binding_kind = UNBOUND_EVAL_SHADOWED;
-    }
-  }
-  return var;
-}
-
-
-bool Scope::ResolveVariable(ParseInfo* info, VariableProxy* proxy,
-                            AstNodeFactory* factory) {
-  DCHECK(info->script_scope()->is_script_scope());
-
-  // If the proxy is already resolved there's nothing to do
-  // (functions and consts may be resolved by the parser).
-  if (proxy->is_resolved()) return true;
-
-  // Otherwise, try to resolve the variable.
-  BindingKind binding_kind;
-  Variable* var = LookupRecursive(proxy, &binding_kind, factory);
-  switch (binding_kind) {
-    case BOUND:
-      // We found a variable binding.
-      if (is_strong(language_mode())) {
-        if (!CheckStrongModeDeclaration(proxy, var)) return false;
-      }
-      break;
-
-    case BOUND_EVAL_SHADOWED:
-      // We either found a variable binding that might be shadowed by eval  or
-      // gave up on it (e.g. by encountering a local with the same in the outer
-      // scope which was not promoted to a context, this can happen if we use
-      // debugger to evaluate arbitrary expressions at a break point).
-      if (var->IsGlobalObjectProperty()) {
-        var = NonLocal(proxy->raw_name(), DYNAMIC_GLOBAL);
-      } else if (var->is_dynamic()) {
-        var = NonLocal(proxy->raw_name(), DYNAMIC);
-      } else {
-        Variable* invalidated = var;
-        var = NonLocal(proxy->raw_name(), DYNAMIC_LOCAL);
-        var->set_local_if_not_shadowed(invalidated);
-      }
-      break;
-
-    case UNBOUND:
-      // No binding has been found. Declare a variable on the global object.
-      var = info->script_scope()->DeclareDynamicGlobal(proxy->raw_name());
-      break;
-
-    case UNBOUND_EVAL_SHADOWED:
-      // No binding has been found. But some scope makes a sloppy 'eval' call.
-      var = NonLocal(proxy->raw_name(), DYNAMIC_GLOBAL);
-      break;
-
-    case DYNAMIC_LOOKUP:
-      // The variable could not be resolved statically.
-      var = NonLocal(proxy->raw_name(), DYNAMIC);
-      break;
-  }
-
-  DCHECK(var != NULL);
-  if (proxy->is_assigned()) var->set_maybe_assigned();
-
-  if (is_strong(language_mode())) {
-    // Record that the variable is referred to from strong mode. Also, record
-    // the position.
-    var->RecordStrongModeReference(proxy->position(), proxy->end_position());
-  }
-
-  proxy->BindTo(var);
-
-  return true;
-}
-
-
-bool Scope::CheckStrongModeDeclaration(VariableProxy* proxy, Variable* var) {
-  // Check for declaration-after use (for variables) in strong mode. Note that
-  // we can only do this in the case where we have seen the declaration. And we
-  // always allow referencing functions (for now).
-
-  // This might happen during lazy compilation; we don't keep track of
-  // initializer positions for variables stored in ScopeInfo, so we cannot check
-  // bindings against them. TODO(marja, rossberg): remove this hack.
-  if (var->initializer_position() == RelocInfo::kNoPosition) return true;
-
-  // Allow referencing the class name from methods of that class, even though
-  // the initializer position for class names is only after the body.
-  Scope* scope = this;
-  while (scope) {
-    if (scope->ClassVariableForMethod() == var) return true;
-    scope = scope->outer_scope();
-  }
-
-  // Allow references from methods to classes declared later, if we detect no
-  // problematic dependency cycles. Note that we can be inside multiple methods
-  // at the same time, and it's enough if we find one where the reference is
-  // allowed.
-  if (var->is_class() &&
-      var->AsClassVariable()->declaration_group_start() >= 0) {
-    for (scope = this; scope && scope != var->scope();
-         scope = scope->outer_scope()) {
-      ClassVariable* class_var = scope->ClassVariableForMethod();
-      // A method is referring to some other class, possibly declared
-      // later. Referring to a class declared earlier is always OK and covered
-      // by the code outside this if. Here we only need to allow special cases
-      // for referring to a class which is declared later.
-
-      // Referring to a class C declared later is OK under the following
-      // circumstances:
-
-      // 1. The class declarations are in a consecutive group with no other
-      // declarations or statements in between, and
-
-      // 2. There is no dependency cycle where the first edge is an
-      // initialization time dependency (computed property name or extends
-      // clause) from C to something that depends on this class directly or
-      // transitively.
-      if (class_var &&
-          class_var->declaration_group_start() ==
-              var->AsClassVariable()->declaration_group_start()) {
-        return true;
-      }
-
-      // TODO(marja,rossberg): implement the dependency cycle detection. Here we
-      // undershoot the target and allow referring to any class in the same
-      // consectuive declaration group.
-
-      // The cycle detection can work roughly like this: 1) detect init-time
-      // references here (they are free variables which are inside the class
-      // scope but not inside a method scope - no parser changes needed to
-      // detect them) 2) if we encounter an init-time reference here, allow it,
-      // but record it for a later dependency cycle check 3) also record
-      // non-init-time references here 4) after scope analysis is done, analyse
-      // the dependency cycles: an illegal cycle is one starting with an
-      // init-time reference and leading back to the starting point with either
-      // non-init-time and init-time references.
-    }
-  }
-
-  // If both the use and the declaration are inside an eval scope (possibly
-  // indirectly), or one of them is, we need to check whether they are inside
-  // the same eval scope or different ones.
-
-  // TODO(marja,rossberg): Detect errors across different evals (depends on the
-  // future of eval in strong mode).
-  const Scope* eval_for_use = NearestOuterEvalScope();
-  const Scope* eval_for_declaration = var->scope()->NearestOuterEvalScope();
-
-  if (proxy->position() != RelocInfo::kNoPosition &&
-      proxy->position() < var->initializer_position() && !var->is_function() &&
-      eval_for_use == eval_for_declaration) {
-    DCHECK(proxy->end_position() != RelocInfo::kNoPosition);
-    ReportMessage(proxy->position(), proxy->end_position(),
-                  MessageTemplate::kStrongUseBeforeDeclaration,
-                  proxy->raw_name());
-    return false;
-  }
-  return true;
-}
-
-
-ClassVariable* Scope::ClassVariableForMethod() const {
-  // TODO(marja, rossberg): This fails to find a class variable in the following
-  // cases:
-  // let A = class { ... }
-  // It needs to be investigated whether this causes any practical problems.
-  if (!is_function_scope()) return nullptr;
-  if (IsInObjectLiteral(function_kind_)) return nullptr;
-  if (!IsConciseMethod(function_kind_) && !IsClassConstructor(function_kind_) &&
-      !IsAccessorFunction(function_kind_)) {
-    return nullptr;
-  }
-  DCHECK_NOT_NULL(outer_scope_);
-  // The class scope contains at most one variable, the class name.
-  DCHECK(outer_scope_->variables_.occupancy() <= 1);
-  if (outer_scope_->variables_.occupancy() == 0) return nullptr;
-  VariableMap::Entry* p = outer_scope_->variables_.Start();
-  Variable* var = reinterpret_cast<Variable*>(p->value);
-  if (!var->is_class()) return nullptr;
-  return var->AsClassVariable();
-}
-
-
-bool Scope::ResolveVariablesRecursively(ParseInfo* info,
-                                        AstNodeFactory* factory) {
-  DCHECK(info->script_scope()->is_script_scope());
-
-  // Resolve unresolved variables for this scope.
-  for (int i = 0; i < unresolved_.length(); i++) {
-    if (!ResolveVariable(info, unresolved_[i], factory)) return false;
-  }
-
-  // Resolve unresolved variables for inner scopes.
-  for (int i = 0; i < inner_scopes_.length(); i++) {
-    if (!inner_scopes_[i]->ResolveVariablesRecursively(info, factory))
-      return false;
-  }
-
-  return true;
-}
-
-
-void Scope::PropagateScopeInfo(bool outer_scope_calls_sloppy_eval ) {
-  if (outer_scope_calls_sloppy_eval) {
-    outer_scope_calls_sloppy_eval_ = true;
-  }
-
-  bool calls_sloppy_eval =
-      this->calls_sloppy_eval() || outer_scope_calls_sloppy_eval_;
-  for (int i = 0; i < inner_scopes_.length(); i++) {
-    Scope* inner = inner_scopes_[i];
-    inner->PropagateScopeInfo(calls_sloppy_eval);
-    if (inner->scope_calls_eval_ || inner->inner_scope_calls_eval_) {
-      inner_scope_calls_eval_ = true;
-    }
-    if (inner->force_eager_compilation_) {
-      force_eager_compilation_ = true;
-    }
-    if (asm_module_ && inner->scope_type() == FUNCTION_SCOPE) {
-      inner->asm_function_ = true;
-    }
-  }
-}
-
-
-bool Scope::MustAllocate(Variable* var) {
-  // Give var a read/write use if there is a chance it might be accessed
-  // via an eval() call.  This is only possible if the variable has a
-  // visible name.
-  if ((var->is_this() || !var->raw_name()->IsEmpty()) &&
-      (var->has_forced_context_allocation() || scope_calls_eval_ ||
-       inner_scope_calls_eval_ || scope_contains_with_ || is_catch_scope() ||
-       is_block_scope() || is_module_scope() || is_script_scope())) {
-    var->set_is_used();
-    if (scope_calls_eval_ || inner_scope_calls_eval_) var->set_maybe_assigned();
-  }
-  // Global variables do not need to be allocated.
-  return !var->IsGlobalObjectProperty() && var->is_used();
-}
-
-
-bool Scope::MustAllocateInContext(Variable* var) {
-  // If var is accessed from an inner scope, or if there is a possibility
-  // that it might be accessed from the current or an inner scope (through
-  // an eval() call or a runtime with lookup), it must be allocated in the
-  // context.
-  //
-  // Exceptions: If the scope as a whole has forced context allocation, all
-  // variables will have context allocation, even temporaries.  Otherwise
-  // temporary variables are always stack-allocated.  Catch-bound variables are
-  // always context-allocated.
-  if (has_forced_context_allocation()) return true;
-  if (var->mode() == TEMPORARY) return false;
-  if (is_catch_scope() || is_module_scope()) return true;
-  if (is_script_scope() && IsLexicalVariableMode(var->mode())) return true;
-  return var->has_forced_context_allocation() ||
-      scope_calls_eval_ ||
-      inner_scope_calls_eval_ ||
-      scope_contains_with_;
-}
-
-
-bool Scope::HasArgumentsParameter(Isolate* isolate) {
-  for (int i = 0; i < params_.length(); i++) {
-    if (params_[i]->name().is_identical_to(
-            isolate->factory()->arguments_string())) {
-      return true;
-    }
-  }
-  return false;
-}
-
-
-void Scope::AllocateStackSlot(Variable* var) {
-  if (is_block_scope()) {
-    outer_scope()->DeclarationScope()->AllocateStackSlot(var);
-  } else {
-    var->AllocateTo(VariableLocation::LOCAL, num_stack_slots_++);
-  }
-}
-
-
-void Scope::AllocateHeapSlot(Variable* var) {
-  var->AllocateTo(VariableLocation::CONTEXT, num_heap_slots_++);
-}
-
-
-void Scope::AllocateParameterLocals(Isolate* isolate) {
-  DCHECK(is_function_scope());
-  Variable* arguments = LookupLocal(ast_value_factory_->arguments_string());
-  // Functions have 'arguments' declared implicitly in all non arrow functions.
-  DCHECK(arguments != nullptr || is_arrow_scope());
-
-  bool uses_sloppy_arguments = false;
-
-  if (arguments != nullptr && MustAllocate(arguments) &&
-      !HasArgumentsParameter(isolate)) {
-    // 'arguments' is used. Unless there is also a parameter called
-    // 'arguments', we must be conservative and allocate all parameters to
-    // the context assuming they will be captured by the arguments object.
-    // If we have a parameter named 'arguments', a (new) value is always
-    // assigned to it via the function invocation. Then 'arguments' denotes
-    // that specific parameter value and cannot be used to access the
-    // parameters, which is why we don't need to allocate an arguments
-    // object in that case.
-
-    // We are using 'arguments'. Tell the code generator that is needs to
-    // allocate the arguments object by setting 'arguments_'.
-    arguments_ = arguments;
-
-    // In strict mode 'arguments' does not alias formal parameters.
-    // Therefore in strict mode we allocate parameters as if 'arguments'
-    // were not used.
-    // If the parameter list is not simple, arguments isn't sloppy either.
-    uses_sloppy_arguments =
-        is_sloppy(language_mode()) && has_simple_parameters();
-  }
-
-  if (rest_parameter_ && !MustAllocate(rest_parameter_)) {
-    rest_parameter_ = NULL;
-  }
-
-  // The same parameter may occur multiple times in the parameters_ list.
-  // If it does, and if it is not copied into the context object, it must
-  // receive the highest parameter index for that parameter; thus iteration
-  // order is relevant!
-  for (int i = params_.length() - 1; i >= 0; --i) {
-    Variable* var = params_[i];
-    if (var == rest_parameter_) continue;
-
-    DCHECK(var->scope() == this);
-    if (uses_sloppy_arguments || has_forced_context_allocation()) {
-      // Force context allocation of the parameter.
-      var->ForceContextAllocation();
-    }
-    AllocateParameter(var, i);
-  }
-}
-
-
-void Scope::AllocateParameter(Variable* var, int index) {
-  if (MustAllocate(var)) {
-    if (MustAllocateInContext(var)) {
-      DCHECK(var->IsUnallocated() || var->IsContextSlot());
-      if (var->IsUnallocated()) {
-        AllocateHeapSlot(var);
-      }
-    } else {
-      DCHECK(var->IsUnallocated() || var->IsParameter());
-      if (var->IsUnallocated()) {
-        var->AllocateTo(VariableLocation::PARAMETER, index);
-      }
-    }
-  } else {
-    DCHECK(!var->IsGlobalSlot());
-  }
-}
-
-
-void Scope::AllocateReceiver() {
-  DCHECK_NOT_NULL(receiver());
-  DCHECK_EQ(receiver()->scope(), this);
-
-  if (has_forced_context_allocation()) {
-    // Force context allocation of the receiver.
-    receiver()->ForceContextAllocation();
-  }
-  AllocateParameter(receiver(), -1);
-}
-
-
-void Scope::AllocateNonParameterLocal(Isolate* isolate, Variable* var) {
-  DCHECK(var->scope() == this);
-  DCHECK(!var->IsVariable(isolate->factory()->dot_result_string()) ||
-         !var->IsStackLocal());
-  if (var->IsUnallocated() && MustAllocate(var)) {
-    if (MustAllocateInContext(var)) {
-      AllocateHeapSlot(var);
-    } else {
-      AllocateStackSlot(var);
-    }
-  }
-}
-
-
-void Scope::AllocateDeclaredGlobal(Isolate* isolate, Variable* var) {
-  DCHECK(var->scope() == this);
-  DCHECK(!var->IsVariable(isolate->factory()->dot_result_string()) ||
-         !var->IsStackLocal());
-  if (var->IsUnallocated()) {
-    if (var->IsStaticGlobalObjectProperty()) {
-      DCHECK_EQ(-1, var->index());
-      DCHECK(var->name()->IsString());
-      var->AllocateTo(VariableLocation::GLOBAL, num_heap_slots_++);
-      num_global_slots_++;
-    } else {
-      // There must be only DYNAMIC_GLOBAL in the script scope.
-      DCHECK(!is_script_scope() || DYNAMIC_GLOBAL == var->mode());
-    }
-  }
-}
-
-
-void Scope::AllocateNonParameterLocalsAndDeclaredGlobals(Isolate* isolate) {
-  // All variables that have no rewrite yet are non-parameter locals.
-  for (int i = 0; i < temps_.length(); i++) {
-    AllocateNonParameterLocal(isolate, temps_[i]);
-  }
-
-  ZoneList<VarAndOrder> vars(variables_.occupancy(), zone());
-  for (VariableMap::Entry* p = variables_.Start();
-       p != NULL;
-       p = variables_.Next(p)) {
-    Variable* var = reinterpret_cast<Variable*>(p->value);
-    vars.Add(VarAndOrder(var, p->order), zone());
-  }
-  vars.Sort(VarAndOrder::Compare);
-  int var_count = vars.length();
-  for (int i = 0; i < var_count; i++) {
-    AllocateNonParameterLocal(isolate, vars[i].var());
-  }
-
-  if (FLAG_global_var_shortcuts) {
-    for (int i = 0; i < var_count; i++) {
-      AllocateDeclaredGlobal(isolate, vars[i].var());
-    }
-  }
-
-  // For now, function_ must be allocated at the very end.  If it gets
-  // allocated in the context, it must be the last slot in the context,
-  // because of the current ScopeInfo implementation (see
-  // ScopeInfo::ScopeInfo(FunctionScope* scope) constructor).
-  if (function_ != nullptr) {
-    AllocateNonParameterLocal(isolate, function_->proxy()->var());
-  }
-
-  if (rest_parameter_ != nullptr) {
-    AllocateNonParameterLocal(isolate, rest_parameter_);
-  }
-
-  Variable* new_target_var =
-      LookupLocal(ast_value_factory_->new_target_string());
-  if (new_target_var != nullptr && MustAllocate(new_target_var)) {
-    new_target_ = new_target_var;
-  }
-
-  Variable* this_function_var =
-      LookupLocal(ast_value_factory_->this_function_string());
-  if (this_function_var != nullptr && MustAllocate(this_function_var)) {
-    this_function_ = this_function_var;
-  }
-}
-
-
-void Scope::AllocateVariablesRecursively(Isolate* isolate) {
-  if (!already_resolved()) {
-    num_stack_slots_ = 0;
-  }
-  // Allocate variables for inner scopes.
-  for (int i = 0; i < inner_scopes_.length(); i++) {
-    inner_scopes_[i]->AllocateVariablesRecursively(isolate);
-  }
-
-  // If scope is already resolved, we still need to allocate
-  // variables in inner scopes which might not had been resolved yet.
-  if (already_resolved()) return;
-  // The number of slots required for variables.
-  num_heap_slots_ = Context::MIN_CONTEXT_SLOTS;
-
-  // Allocate variables for this scope.
-  // Parameters must be allocated first, if any.
-  if (is_function_scope()) AllocateParameterLocals(isolate);
-  if (has_this_declaration()) AllocateReceiver();
-  AllocateNonParameterLocalsAndDeclaredGlobals(isolate);
-
-  // Force allocation of a context for this scope if necessary. For a 'with'
-  // scope and for a function scope that makes an 'eval' call we need a context,
-  // even if no local variables were statically allocated in the scope.
-  // Likewise for modules.
-  bool must_have_context =
-      is_with_scope() || is_module_scope() ||
-      (is_function_scope() && calls_sloppy_eval()) ||
-      (is_block_scope() && is_declaration_scope() && calls_sloppy_eval());
-
-  // If we didn't allocate any locals in the local context, then we only
-  // need the minimal number of slots if we must have a context.
-  if (num_heap_slots_ == Context::MIN_CONTEXT_SLOTS && !must_have_context) {
-    num_heap_slots_ = 0;
-  }
-
-  // Allocation done.
-  DCHECK(num_heap_slots_ == 0 || num_heap_slots_ >= Context::MIN_CONTEXT_SLOTS);
-}
-
-
-void Scope::AllocateModules() {
-  DCHECK(is_script_scope());
-  DCHECK(!already_resolved());
-  for (int i = 0; i < inner_scopes_.length(); i++) {
-    Scope* scope = inner_scopes_.at(i);
-    if (scope->is_module_scope()) {
-      DCHECK(!scope->already_resolved());
-      DCHECK(scope->module_descriptor_->IsFrozen());
-      DCHECK_NULL(scope->module_var_);
-      scope->module_var_ =
-          NewTemporary(ast_value_factory_->dot_module_string());
-      ++num_modules_;
-    }
-  }
-}
-
-
-int Scope::StackLocalCount() const {
-  return num_stack_slots() -
-      (function_ != NULL && function_->proxy()->var()->IsStackLocal() ? 1 : 0);
-}
-
-
-int Scope::ContextLocalCount() const {
-  if (num_heap_slots() == 0) return 0;
-  bool is_function_var_in_context =
-      function_ != NULL && function_->proxy()->var()->IsContextSlot();
-  return num_heap_slots() - Context::MIN_CONTEXT_SLOTS - num_global_slots() -
-         (is_function_var_in_context ? 1 : 0);
-}
-
-
-int Scope::ContextGlobalCount() const { return num_global_slots(); }
-
-}  // namespace internal
-}  // namespace v8