diff --git a/src/ast/scopes.h b/src/ast/scopes.h
new file mode 100644
index 0000000..6c261f6
--- /dev/null
+++ b/src/ast/scopes.h
@@ -0,0 +1,849 @@
+// 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.
+
+#ifndef V8_AST_SCOPES_H_
+#define V8_AST_SCOPES_H_
+
+#include "src/ast/ast.h"
+#include "src/hashmap.h"
+#include "src/pending-compilation-error-handler.h"
+#include "src/zone.h"
+
+namespace v8 {
+namespace internal {
+
+class ParseInfo;
+
+// A hash map to support fast variable declaration and lookup.
+class VariableMap: public ZoneHashMap {
+ public:
+  explicit VariableMap(Zone* zone);
+
+  virtual ~VariableMap();
+
+  Variable* Declare(Scope* scope, const AstRawString* name, VariableMode mode,
+                    Variable::Kind kind, InitializationFlag initialization_flag,
+                    MaybeAssignedFlag maybe_assigned_flag = kNotAssigned,
+                    int declaration_group_start = -1);
+
+  Variable* Lookup(const AstRawString* name);
+
+  Zone* zone() const { return zone_; }
+
+ private:
+  Zone* zone_;
+};
+
+
+// The dynamic scope part holds hash maps for the variables that will
+// be looked up dynamically from within eval and with scopes. The objects
+// are allocated on-demand from Scope::NonLocal to avoid wasting memory
+// and setup time for scopes that don't need them.
+class DynamicScopePart : public ZoneObject {
+ public:
+  explicit DynamicScopePart(Zone* zone) {
+    for (int i = 0; i < 3; i++)
+      maps_[i] = new(zone->New(sizeof(VariableMap))) VariableMap(zone);
+  }
+
+  VariableMap* GetMap(VariableMode mode) {
+    int index = mode - DYNAMIC;
+    DCHECK(index >= 0 && index < 3);
+    return maps_[index];
+  }
+
+ private:
+  VariableMap *maps_[3];
+};
+
+
+// Sloppy block-scoped function declarations to var-bind
+class SloppyBlockFunctionMap : public ZoneHashMap {
+ public:
+  explicit SloppyBlockFunctionMap(Zone* zone);
+
+  virtual ~SloppyBlockFunctionMap();
+
+  void Declare(const AstRawString* name,
+               SloppyBlockFunctionStatement* statement);
+
+  typedef ZoneVector<SloppyBlockFunctionStatement*> Vector;
+
+ private:
+  Zone* zone_;
+};
+
+
+// Global invariants after AST construction: Each reference (i.e. identifier)
+// to a JavaScript variable (including global properties) is represented by a
+// VariableProxy node. Immediately after AST construction and before variable
+// allocation, most VariableProxy nodes are "unresolved", i.e. not bound to a
+// corresponding variable (though some are bound during parse time). Variable
+// allocation binds each unresolved VariableProxy to one Variable and assigns
+// a location. Note that many VariableProxy nodes may refer to the same Java-
+// Script variable.
+
+class Scope: public ZoneObject {
+ public:
+  // ---------------------------------------------------------------------------
+  // Construction
+
+  Scope(Zone* zone, Scope* outer_scope, ScopeType scope_type,
+        AstValueFactory* value_factory,
+        FunctionKind function_kind = kNormalFunction);
+
+  // Compute top scope and allocate variables. For lazy compilation the top
+  // scope only contains the single lazily compiled function, so this
+  // doesn't re-allocate variables repeatedly.
+  static bool Analyze(ParseInfo* info);
+
+  static Scope* DeserializeScopeChain(Isolate* isolate, Zone* zone,
+                                      Context* context, Scope* script_scope);
+
+  // The scope name is only used for printing/debugging.
+  void SetScopeName(const AstRawString* scope_name) {
+    scope_name_ = scope_name;
+  }
+
+  void Initialize();
+
+  // Checks if the block scope is redundant, i.e. it does not contain any
+  // block scoped declarations. In that case it is removed from the scope
+  // tree and its children are reparented.
+  Scope* FinalizeBlockScope();
+
+  // Inserts outer_scope into this scope's scope chain (and removes this
+  // from the current outer_scope_'s inner_scopes_).
+  // Assumes outer_scope_ is non-null.
+  void ReplaceOuterScope(Scope* outer_scope);
+
+  // Propagates any eagerly-gathered scope usage flags (such as calls_eval())
+  // to the passed-in scope.
+  void PropagateUsageFlagsToScope(Scope* other);
+
+  Zone* zone() const { return zone_; }
+
+  // ---------------------------------------------------------------------------
+  // Declarations
+
+  // Lookup a variable in this scope. Returns the variable or NULL if not found.
+  Variable* LookupLocal(const AstRawString* name);
+
+  // This lookup corresponds to a lookup in the "intermediate" scope sitting
+  // between this scope and the outer scope. (ECMA-262, 3rd., requires that
+  // the name of named function literal is kept in an intermediate scope
+  // in between this scope and the next outer scope.)
+  Variable* LookupFunctionVar(const AstRawString* name,
+                              AstNodeFactory* factory);
+
+  // Lookup a variable in this scope or outer scopes.
+  // Returns the variable or NULL if not found.
+  Variable* Lookup(const AstRawString* name);
+
+  // Declare the function variable for a function literal. This variable
+  // is in an intermediate scope between this function scope and the the
+  // outer scope. Only possible for function scopes; at most one variable.
+  void DeclareFunctionVar(VariableDeclaration* declaration) {
+    DCHECK(is_function_scope());
+    // Handle implicit declaration of the function name in named function
+    // expressions before other declarations.
+    decls_.InsertAt(0, declaration, zone());
+    function_ = declaration;
+  }
+
+  // Declare a parameter in this scope.  When there are duplicated
+  // parameters the rightmost one 'wins'.  However, the implementation
+  // expects all parameters to be declared and from left to right.
+  Variable* DeclareParameter(
+      const AstRawString* name, VariableMode mode,
+      bool is_optional, bool is_rest, bool* is_duplicate);
+
+  // Declare a local variable in this scope. If the variable has been
+  // declared before, the previously declared variable is returned.
+  Variable* DeclareLocal(const AstRawString* name, VariableMode mode,
+                         InitializationFlag init_flag, Variable::Kind kind,
+                         MaybeAssignedFlag maybe_assigned_flag = kNotAssigned,
+                         int declaration_group_start = -1);
+
+  // Declare an implicit global variable in this scope which must be a
+  // script scope.  The variable was introduced (possibly from an inner
+  // scope) by a reference to an unresolved variable with no intervening
+  // with statements or eval calls.
+  Variable* DeclareDynamicGlobal(const AstRawString* name);
+
+  // Create a new unresolved variable.
+  VariableProxy* NewUnresolved(AstNodeFactory* factory,
+                               const AstRawString* name,
+                               Variable::Kind kind = Variable::NORMAL,
+                               int start_position = RelocInfo::kNoPosition,
+                               int end_position = RelocInfo::kNoPosition) {
+    // Note that we must not share the unresolved variables with
+    // the same name because they may be removed selectively via
+    // RemoveUnresolved().
+    DCHECK(!already_resolved());
+    VariableProxy* proxy =
+        factory->NewVariableProxy(name, kind, start_position, end_position);
+    unresolved_.Add(proxy, zone_);
+    return proxy;
+  }
+
+  void AddUnresolved(VariableProxy* proxy) {
+    DCHECK(!already_resolved());
+    DCHECK(!proxy->is_resolved());
+    unresolved_.Add(proxy, zone_);
+  }
+
+  // Remove a unresolved variable. During parsing, an unresolved variable
+  // may have been added optimistically, but then only the variable name
+  // was used (typically for labels). If the variable was not declared, the
+  // addition introduced a new unresolved variable which may end up being
+  // allocated globally as a "ghost" variable. RemoveUnresolved removes
+  // such a variable again if it was added; otherwise this is a no-op.
+  bool RemoveUnresolved(VariableProxy* var);
+
+  // Creates a new temporary variable in this scope's TemporaryScope.  The
+  // name is only used for printing and cannot be used to find the variable.
+  // In particular, the only way to get hold of the temporary is by keeping the
+  // Variable* around.  The name should not clash with a legitimate variable
+  // names.
+  Variable* NewTemporary(const AstRawString* name);
+
+  // Remove a temporary variable. This is for adjusting the scope of
+  // temporaries used when desugaring parameter initializers.
+  bool RemoveTemporary(Variable* var);
+
+  // Adds a temporary variable in this scope's TemporaryScope. This is for
+  // adjusting the scope of temporaries used when desugaring parameter
+  // initializers.
+  void AddTemporary(Variable* var) { temps_.Add(var, zone()); }
+
+  // Adds the specific declaration node to the list of declarations in
+  // this scope. The declarations are processed as part of entering
+  // the scope; see codegen.cc:ProcessDeclarations.
+  void AddDeclaration(Declaration* declaration);
+
+  // ---------------------------------------------------------------------------
+  // Illegal redeclaration support.
+
+  // Set an expression node that will be executed when the scope is
+  // entered. We only keep track of one illegal redeclaration node per
+  // scope - the first one - so if you try to set it multiple times
+  // the additional requests will be silently ignored.
+  void SetIllegalRedeclaration(Expression* expression);
+
+  // Retrieve the illegal redeclaration expression. Do not call if the
+  // scope doesn't have an illegal redeclaration node.
+  Expression* GetIllegalRedeclaration();
+
+  // Check if the scope has (at least) one illegal redeclaration.
+  bool HasIllegalRedeclaration() const { return illegal_redecl_ != NULL; }
+
+  // For harmony block scoping mode: Check if the scope has conflicting var
+  // declarations, i.e. a var declaration that has been hoisted from a nested
+  // scope over a let binding of the same name.
+  Declaration* CheckConflictingVarDeclarations();
+
+  // ---------------------------------------------------------------------------
+  // Scope-specific info.
+
+  // Inform the scope that the corresponding code contains a with statement.
+  void RecordWithStatement() { scope_contains_with_ = true; }
+
+  // Inform the scope that the corresponding code contains an eval call.
+  void RecordEvalCall() { scope_calls_eval_ = true; }
+
+  // Inform the scope that the corresponding code uses "arguments".
+  void RecordArgumentsUsage() { scope_uses_arguments_ = true; }
+
+  // Inform the scope that the corresponding code uses "super".
+  void RecordSuperPropertyUsage() { scope_uses_super_property_ = true; }
+
+  // Set the language mode flag (unless disabled by a global flag).
+  void SetLanguageMode(LanguageMode language_mode) {
+    language_mode_ = language_mode;
+  }
+
+  // Set the ASM module flag.
+  void SetAsmModule() { asm_module_ = true; }
+
+  // Inform the scope that the scope may execute declarations nonlinearly.
+  // Currently, the only nonlinear scope is a switch statement. The name is
+  // more general in case something else comes up with similar control flow,
+  // for example the ability to break out of something which does not have
+  // its own lexical scope.
+  // The bit does not need to be stored on the ScopeInfo because none of
+  // the three compilers will perform hole check elimination on a variable
+  // located in VariableLocation::CONTEXT. So, direct eval and closures
+  // will not expose holes.
+  void SetNonlinear() { scope_nonlinear_ = true; }
+
+  // Position in the source where this scope begins and ends.
+  //
+  // * For the scope of a with statement
+  //     with (obj) stmt
+  //   start position: start position of first token of 'stmt'
+  //   end position: end position of last token of 'stmt'
+  // * For the scope of a block
+  //     { stmts }
+  //   start position: start position of '{'
+  //   end position: end position of '}'
+  // * For the scope of a function literal or decalaration
+  //     function fun(a,b) { stmts }
+  //   start position: start position of '('
+  //   end position: end position of '}'
+  // * For the scope of a catch block
+  //     try { stms } catch(e) { stmts }
+  //   start position: start position of '('
+  //   end position: end position of ')'
+  // * For the scope of a for-statement
+  //     for (let x ...) stmt
+  //   start position: start position of '('
+  //   end position: end position of last token of 'stmt'
+  // * For the scope of a switch statement
+  //     switch (tag) { cases }
+  //   start position: start position of '{'
+  //   end position: end position of '}'
+  int start_position() const { return start_position_; }
+  void set_start_position(int statement_pos) {
+    start_position_ = statement_pos;
+  }
+  int end_position() const { return end_position_; }
+  void set_end_position(int statement_pos) {
+    end_position_ = statement_pos;
+  }
+
+  // In some cases we want to force context allocation for a whole scope.
+  void ForceContextAllocation() {
+    DCHECK(!already_resolved());
+    force_context_allocation_ = true;
+  }
+  bool has_forced_context_allocation() const {
+    return force_context_allocation_;
+  }
+
+  // ---------------------------------------------------------------------------
+  // Predicates.
+
+  // Specific scope types.
+  bool is_eval_scope() const { return scope_type_ == EVAL_SCOPE; }
+  bool is_function_scope() const { return scope_type_ == FUNCTION_SCOPE; }
+  bool is_module_scope() const { return scope_type_ == MODULE_SCOPE; }
+  bool is_script_scope() const { return scope_type_ == SCRIPT_SCOPE; }
+  bool is_catch_scope() const { return scope_type_ == CATCH_SCOPE; }
+  bool is_block_scope() const { return scope_type_ == BLOCK_SCOPE; }
+  bool is_with_scope() const { return scope_type_ == WITH_SCOPE; }
+  bool is_arrow_scope() const {
+    return is_function_scope() && IsArrowFunction(function_kind_);
+  }
+  bool is_declaration_scope() const { return is_declaration_scope_; }
+
+  void set_is_declaration_scope() { is_declaration_scope_ = true; }
+
+  // Information about which scopes calls eval.
+  bool calls_eval() const { return scope_calls_eval_; }
+  bool calls_sloppy_eval() const {
+    return scope_calls_eval_ && is_sloppy(language_mode_);
+  }
+  bool outer_scope_calls_sloppy_eval() const {
+    return outer_scope_calls_sloppy_eval_;
+  }
+  bool asm_module() const { return asm_module_; }
+  bool asm_function() const { return asm_function_; }
+
+  // Is this scope inside a with statement.
+  bool inside_with() const { return scope_inside_with_; }
+
+  // Does this scope access "arguments".
+  bool uses_arguments() const { return scope_uses_arguments_; }
+  // Does this scope access "super" property (super.foo).
+  bool uses_super_property() const { return scope_uses_super_property_; }
+  // Does this scope have the potential to execute declarations non-linearly?
+  bool is_nonlinear() const { return scope_nonlinear_; }
+
+  // Whether this needs to be represented by a runtime context.
+  bool NeedsContext() const {
+    // Catch and module scopes always have heap slots.
+    DCHECK(!is_catch_scope() || num_heap_slots() > 0);
+    DCHECK(!is_module_scope() || num_heap_slots() > 0);
+    return is_with_scope() || num_heap_slots() > 0;
+  }
+
+  bool NeedsHomeObject() const {
+    return scope_uses_super_property_ ||
+           ((scope_calls_eval_ || inner_scope_calls_eval_) &&
+            (IsConciseMethod(function_kind()) ||
+             IsAccessorFunction(function_kind()) ||
+             IsClassConstructor(function_kind())));
+  }
+
+  const Scope* NearestOuterEvalScope() const {
+    if (is_eval_scope()) return this;
+    if (outer_scope() == nullptr) return nullptr;
+    return outer_scope()->NearestOuterEvalScope();
+  }
+
+  // ---------------------------------------------------------------------------
+  // Accessors.
+
+  // The type of this scope.
+  ScopeType scope_type() const { return scope_type_; }
+
+  FunctionKind function_kind() const { return function_kind_; }
+
+  // The language mode of this scope.
+  LanguageMode language_mode() const { return language_mode_; }
+
+  // The variable corresponding to the 'this' value.
+  Variable* receiver() {
+    DCHECK(has_this_declaration());
+    DCHECK_NOT_NULL(receiver_);
+    return receiver_;
+  }
+
+  // TODO(wingo): Add a GLOBAL_SCOPE scope type which will lexically allocate
+  // "this" (and no other variable) on the native context.  Script scopes then
+  // will not have a "this" declaration.
+  bool has_this_declaration() const {
+    return (is_function_scope() && !is_arrow_scope()) || is_module_scope();
+  }
+
+  // The variable corresponding to the 'new.target' value.
+  Variable* new_target_var() { return new_target_; }
+
+  // The variable holding the function literal for named function
+  // literals, or NULL.  Only valid for function scopes.
+  VariableDeclaration* function() const {
+    DCHECK(is_function_scope());
+    return function_;
+  }
+
+  // Parameters. The left-most parameter has index 0.
+  // Only valid for function scopes.
+  Variable* parameter(int index) const {
+    DCHECK(is_function_scope());
+    return params_[index];
+  }
+
+  // Returns the default function arity excluding default or rest parameters.
+  int default_function_length() const { return arity_; }
+
+  int num_parameters() const { return params_.length(); }
+
+  // A function can have at most one rest parameter. Returns Variable* or NULL.
+  Variable* rest_parameter(int* index) const {
+    *index = rest_index_;
+    if (rest_index_ < 0) return NULL;
+    return rest_parameter_;
+  }
+
+  bool has_rest_parameter() const { return rest_index_ >= 0; }
+
+  bool has_simple_parameters() const {
+    return has_simple_parameters_;
+  }
+
+  // TODO(caitp): manage this state in a better way. PreParser must be able to
+  // communicate that the scope is non-simple, without allocating any parameters
+  // as the Parser does. This is necessary to ensure that TC39's proposed early
+  // error can be reported consistently regardless of whether lazily parsed or
+  // not.
+  void SetHasNonSimpleParameters() {
+    DCHECK(is_function_scope());
+    has_simple_parameters_ = false;
+  }
+
+  // Retrieve `IsSimpleParameterList` of current or outer function.
+  bool HasSimpleParameters() {
+    Scope* scope = ClosureScope();
+    return !scope->is_function_scope() || scope->has_simple_parameters();
+  }
+
+  // The local variable 'arguments' if we need to allocate it; NULL otherwise.
+  Variable* arguments() const {
+    DCHECK(!is_arrow_scope() || arguments_ == nullptr);
+    return arguments_;
+  }
+
+  Variable* this_function_var() const {
+    // This is only used in derived constructors atm.
+    DCHECK(this_function_ == nullptr ||
+           (is_function_scope() && (IsClassConstructor(function_kind()) ||
+                                    IsConciseMethod(function_kind()) ||
+                                    IsAccessorFunction(function_kind()))));
+    return this_function_;
+  }
+
+  // Declarations list.
+  ZoneList<Declaration*>* declarations() { return &decls_; }
+
+  // Inner scope list.
+  ZoneList<Scope*>* inner_scopes() { return &inner_scopes_; }
+
+  // The scope immediately surrounding this scope, or NULL.
+  Scope* outer_scope() const { return outer_scope_; }
+
+  // The ModuleDescriptor for this scope; only for module scopes.
+  ModuleDescriptor* module() const { return module_descriptor_; }
+
+
+  void set_class_declaration_group_start(int position) {
+    class_declaration_group_start_ = position;
+  }
+
+  int class_declaration_group_start() const {
+    return class_declaration_group_start_;
+  }
+
+  // ---------------------------------------------------------------------------
+  // Variable allocation.
+
+  // Collect stack and context allocated local variables in this scope. Note
+  // that the function variable - if present - is not collected and should be
+  // handled separately.
+  void CollectStackAndContextLocals(
+      ZoneList<Variable*>* stack_locals, ZoneList<Variable*>* context_locals,
+      ZoneList<Variable*>* context_globals,
+      ZoneList<Variable*>* strong_mode_free_variables = nullptr);
+
+  // Current number of var or const locals.
+  int num_var_or_const() { return num_var_or_const_; }
+
+  // Result of variable allocation.
+  int num_stack_slots() const { return num_stack_slots_; }
+  int num_heap_slots() const { return num_heap_slots_; }
+  int num_global_slots() const { return num_global_slots_; }
+
+  int StackLocalCount() const;
+  int ContextLocalCount() const;
+  int ContextGlobalCount() const;
+
+  // Make sure this scope and all outer scopes are eagerly compiled.
+  void ForceEagerCompilation()  { force_eager_compilation_ = true; }
+
+  // Determine if we can parse a function literal in this scope lazily.
+  bool AllowsLazyParsing() const;
+
+  // Determine if we can use lazy compilation for this scope.
+  bool AllowsLazyCompilation() const;
+
+  // Determine if we can use lazy compilation for this scope without a context.
+  bool AllowsLazyCompilationWithoutContext() const;
+
+  // True if the outer context of this scope is always the native context.
+  bool HasTrivialOuterContext() const;
+
+  // The number of contexts between this and scope; zero if this == scope.
+  int ContextChainLength(Scope* scope);
+
+  // The maximum number of nested contexts required for this scope and any inner
+  // scopes.
+  int MaxNestedContextChainLength();
+
+  // Find the first function, script, eval or (declaration) block scope. This is
+  // the scope where var declarations will be hoisted to in the implementation.
+  Scope* DeclarationScope();
+
+  // Find the first non-block declaration scope. This should be either a script,
+  // function, or eval scope. Same as DeclarationScope(), but skips
+  // declaration "block" scopes. Used for differentiating associated
+  // function objects (i.e., the scope for which a function prologue allocates
+  // a context) or declaring temporaries.
+  Scope* ClosureScope();
+
+  // Find the first (non-arrow) function or script scope.  This is where
+  // 'this' is bound, and what determines the function kind.
+  Scope* ReceiverScope();
+
+  Handle<ScopeInfo> GetScopeInfo(Isolate* isolate);
+
+  // Get the chain of nested scopes within this scope for the source statement
+  // position. The scopes will be added to the list from the outermost scope to
+  // the innermost scope. Only nested block, catch or with scopes are tracked
+  // and will be returned, but no inner function scopes.
+  void GetNestedScopeChain(Isolate* isolate, List<Handle<ScopeInfo> >* chain,
+                           int statement_position);
+
+  void CollectNonLocals(HashMap* non_locals);
+
+  // ---------------------------------------------------------------------------
+  // Strict mode support.
+  bool IsDeclared(const AstRawString* name) {
+    // During formal parameter list parsing the scope only contains
+    // two variables inserted at initialization: "this" and "arguments".
+    // "this" is an invalid parameter name and "arguments" is invalid parameter
+    // name in strict mode. Therefore looking up with the map which includes
+    // "this" and "arguments" in addition to all formal parameters is safe.
+    return variables_.Lookup(name) != NULL;
+  }
+
+  bool IsDeclaredParameter(const AstRawString* name) {
+    // If IsSimpleParameterList is false, duplicate parameters are not allowed,
+    // however `arguments` may be allowed if function is not strict code. Thus,
+    // the assumptions explained above do not hold.
+    return params_.Contains(variables_.Lookup(name));
+  }
+
+  SloppyBlockFunctionMap* sloppy_block_function_map() {
+    return &sloppy_block_function_map_;
+  }
+
+  // Error handling.
+  void ReportMessage(int start_position, int end_position,
+                     MessageTemplate::Template message,
+                     const AstRawString* arg);
+
+  // ---------------------------------------------------------------------------
+  // Debugging.
+
+#ifdef DEBUG
+  void Print(int n = 0);  // n = indentation; n < 0 => don't print recursively
+#endif
+
+  // ---------------------------------------------------------------------------
+  // Implementation.
+ private:
+  // Scope tree.
+  Scope* outer_scope_;  // the immediately enclosing outer scope, or NULL
+  ZoneList<Scope*> inner_scopes_;  // the immediately enclosed inner scopes
+
+  // The scope type.
+  ScopeType scope_type_;
+  // If the scope is a function scope, this is the function kind.
+  FunctionKind function_kind_;
+
+  // Debugging support.
+  const AstRawString* scope_name_;
+
+  // The variables declared in this scope:
+  //
+  // All user-declared variables (incl. parameters).  For script scopes
+  // variables may be implicitly 'declared' by being used (possibly in
+  // an inner scope) with no intervening with statements or eval calls.
+  VariableMap variables_;
+  // Compiler-allocated (user-invisible) temporaries.
+  ZoneList<Variable*> temps_;
+  // Parameter list in source order.
+  ZoneList<Variable*> params_;
+  // Variables that must be looked up dynamically.
+  DynamicScopePart* dynamics_;
+  // Unresolved variables referred to from this scope.
+  ZoneList<VariableProxy*> unresolved_;
+  // Declarations.
+  ZoneList<Declaration*> decls_;
+  // Convenience variable.
+  Variable* receiver_;
+  // Function variable, if any; function scopes only.
+  VariableDeclaration* function_;
+  // new.target variable, function scopes only.
+  Variable* new_target_;
+  // Convenience variable; function scopes only.
+  Variable* arguments_;
+  // Convenience variable; Subclass constructor only
+  Variable* this_function_;
+  // Module descriptor; module scopes only.
+  ModuleDescriptor* module_descriptor_;
+
+  // Map of function names to lists of functions defined in sloppy blocks
+  SloppyBlockFunctionMap sloppy_block_function_map_;
+
+  // Illegal redeclaration.
+  Expression* illegal_redecl_;
+
+  // Scope-specific information computed during parsing.
+  //
+  // This scope is inside a 'with' of some outer scope.
+  bool scope_inside_with_;
+  // This scope contains a 'with' statement.
+  bool scope_contains_with_;
+  // This scope or a nested catch scope or with scope contain an 'eval' call. At
+  // the 'eval' call site this scope is the declaration scope.
+  bool scope_calls_eval_;
+  // This scope uses "arguments".
+  bool scope_uses_arguments_;
+  // This scope uses "super" property ('super.foo').
+  bool scope_uses_super_property_;
+  // This scope contains an "use asm" annotation.
+  bool asm_module_;
+  // This scope's outer context is an asm module.
+  bool asm_function_;
+  // This scope's declarations might not be executed in order (e.g., switch).
+  bool scope_nonlinear_;
+  // The language mode of this scope.
+  LanguageMode language_mode_;
+  // Source positions.
+  int start_position_;
+  int end_position_;
+
+  // Computed via PropagateScopeInfo.
+  bool outer_scope_calls_sloppy_eval_;
+  bool inner_scope_calls_eval_;
+  bool force_eager_compilation_;
+  bool force_context_allocation_;
+
+  // True if it doesn't need scope resolution (e.g., if the scope was
+  // constructed based on a serialized scope info or a catch context).
+  bool already_resolved_;
+
+  // True if it holds 'var' declarations.
+  bool is_declaration_scope_;
+
+  // Computed as variables are declared.
+  int num_var_or_const_;
+
+  // Computed via AllocateVariables; function, block and catch scopes only.
+  int num_stack_slots_;
+  int num_heap_slots_;
+  int num_global_slots_;
+
+  // Info about the parameter list of a function.
+  int arity_;
+  bool has_simple_parameters_;
+  Variable* rest_parameter_;
+  int rest_index_;
+
+  // Serialized scope info support.
+  Handle<ScopeInfo> scope_info_;
+  bool already_resolved() { return already_resolved_; }
+
+  // Create a non-local variable with a given name.
+  // These variables are looked up dynamically at runtime.
+  Variable* NonLocal(const AstRawString* name, VariableMode mode);
+
+  // Variable resolution.
+  // Possible results of a recursive variable lookup telling if and how a
+  // variable is bound. These are returned in the output parameter *binding_kind
+  // of the LookupRecursive function.
+  enum BindingKind {
+    // The variable reference could be statically resolved to a variable binding
+    // which is returned. There is no 'with' statement between the reference and
+    // the binding and no scope between the reference scope (inclusive) and
+    // binding scope (exclusive) makes a sloppy 'eval' call.
+    BOUND,
+
+    // The variable reference could be statically resolved to a variable binding
+    // which is returned. There is no 'with' statement between the reference and
+    // the binding, but some scope between the reference scope (inclusive) and
+    // binding scope (exclusive) makes a sloppy 'eval' call, that might
+    // possibly introduce variable bindings shadowing the found one. Thus the
+    // found variable binding is just a guess.
+    BOUND_EVAL_SHADOWED,
+
+    // The variable reference could not be statically resolved to any binding
+    // and thus should be considered referencing a global variable. NULL is
+    // returned. The variable reference is not inside any 'with' statement and
+    // no scope between the reference scope (inclusive) and script scope
+    // (exclusive) makes a sloppy 'eval' call.
+    UNBOUND,
+
+    // The variable reference could not be statically resolved to any binding
+    // NULL is returned. The variable reference is not inside any 'with'
+    // statement, but some scope between the reference scope (inclusive) and
+    // script scope (exclusive) makes a sloppy 'eval' call, that might
+    // possibly introduce a variable binding. Thus the reference should be
+    // considered referencing a global variable unless it is shadowed by an
+    // 'eval' introduced binding.
+    UNBOUND_EVAL_SHADOWED,
+
+    // The variable could not be statically resolved and needs to be looked up
+    // dynamically. NULL is returned. There are two possible reasons:
+    // * A 'with' statement has been encountered and there is no variable
+    //   binding for the name between the variable reference and the 'with'.
+    //   The variable potentially references a property of the 'with' object.
+    // * The code is being executed as part of a call to 'eval' and the calling
+    //   context chain contains either a variable binding for the name or it
+    //   contains a 'with' context.
+    DYNAMIC_LOOKUP
+  };
+
+  // Lookup a variable reference given by name recursively starting with this
+  // scope. If the code is executed because of a call to 'eval', the context
+  // parameter should be set to the calling context of 'eval'.
+  Variable* LookupRecursive(VariableProxy* proxy, BindingKind* binding_kind,
+                            AstNodeFactory* factory);
+  MUST_USE_RESULT
+  bool ResolveVariable(ParseInfo* info, VariableProxy* proxy,
+                       AstNodeFactory* factory);
+  MUST_USE_RESULT
+  bool ResolveVariablesRecursively(ParseInfo* info, AstNodeFactory* factory);
+
+  bool CheckStrongModeDeclaration(VariableProxy* proxy, Variable* var);
+
+  // If this scope is a method scope of a class, return the corresponding
+  // class variable, otherwise nullptr.
+  ClassVariable* ClassVariableForMethod() const;
+
+  // Scope analysis.
+  void PropagateScopeInfo(bool outer_scope_calls_sloppy_eval);
+  bool HasTrivialContext() const;
+
+  // Predicates.
+  bool MustAllocate(Variable* var);
+  bool MustAllocateInContext(Variable* var);
+  bool HasArgumentsParameter(Isolate* isolate);
+
+  // Variable allocation.
+  void AllocateStackSlot(Variable* var);
+  void AllocateHeapSlot(Variable* var);
+  void AllocateParameterLocals(Isolate* isolate);
+  void AllocateNonParameterLocal(Isolate* isolate, Variable* var);
+  void AllocateDeclaredGlobal(Isolate* isolate, Variable* var);
+  void AllocateNonParameterLocalsAndDeclaredGlobals(Isolate* isolate);
+  void AllocateVariablesRecursively(Isolate* isolate);
+  void AllocateParameter(Variable* var, int index);
+  void AllocateReceiver();
+
+  // Resolve and fill in the allocation information for all variables
+  // in this scopes. Must be called *after* all scopes have been
+  // processed (parsed) to ensure that unresolved variables can be
+  // resolved properly.
+  //
+  // In the case of code compiled and run using 'eval', the context
+  // parameter is the context in which eval was called.  In all other
+  // cases the context parameter is an empty handle.
+  MUST_USE_RESULT
+  bool AllocateVariables(ParseInfo* info, AstNodeFactory* factory);
+
+  // Construct a scope based on the scope info.
+  Scope(Zone* zone, Scope* inner_scope, ScopeType type,
+        Handle<ScopeInfo> scope_info, AstValueFactory* value_factory);
+
+  // Construct a catch scope with a binding for the name.
+  Scope(Zone* zone, Scope* inner_scope, const AstRawString* catch_variable_name,
+        AstValueFactory* value_factory);
+
+  void AddInnerScope(Scope* inner_scope) {
+    if (inner_scope != NULL) {
+      inner_scopes_.Add(inner_scope, zone_);
+      inner_scope->outer_scope_ = this;
+    }
+  }
+
+  void RemoveInnerScope(Scope* inner_scope) {
+    DCHECK_NOT_NULL(inner_scope);
+    for (int i = 0; i < inner_scopes_.length(); i++) {
+      if (inner_scopes_[i] == inner_scope) {
+        inner_scopes_.Remove(i);
+        break;
+      }
+    }
+  }
+
+  void SetDefaults(ScopeType type, Scope* outer_scope,
+                   Handle<ScopeInfo> scope_info,
+                   FunctionKind function_kind = kNormalFunction);
+
+  AstValueFactory* ast_value_factory_;
+  Zone* zone_;
+
+  PendingCompilationErrorHandler pending_error_handler_;
+
+  // For tracking which classes are declared consecutively. Needed for strong
+  // mode.
+  int class_declaration_group_start_;
+};
+
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_AST_SCOPES_H_