[class] implement private method declarations

This patch implements the declarations of private methods, the access
of private methods would be left to a future patch.
When a private methods declaration is encountered, we now:

- Create a brand symbol during class evaluation and store it in the
  context.
- Create the closures for the private methods
- Load the brand from the context and store it in the instance in the
  constructor.

Design: https://docs.google.com/document/d/1T-Ql6HOIH2U_8YjWkwK2rTfywwb7b3Qe8d3jkz72KwA/edit#

Bug: v8:8330
Change-Id: I2d695cbdc8a7367ddc7620d627b318f779d36150
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1568708
Commit-Queue: Joyee Cheung <joyee@igalia.com>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61387}

src/ast/ast-value-factory.h

@@ -201,6 +201,7 @@ class AstBigInt {
   F(bigint, "bigint")                           \
   F(boolean, "boolean")                         \
   F(computed, "<computed>")                     \
+  F(dot_brand, ".brand")                        \
   F(constructor, "constructor")                 \
   F(default, "default")                         \
   F(done, "done")                               \

src/ast/ast.cc

@@ -282,6 +282,17 @@ std::unique_ptr<char[]> FunctionLiteral::GetDebugName() const {
   return result;
 }
 
+bool FunctionLiteral::requires_brand_initialization() const {
+  Scope* outer = scope_->outer_scope();
+
+  // If there are no variables declared in the outer scope other than
+  // the class name variable, the outer class scope may be elided when
+  // the function is deserialized after preparsing.
+  if (!outer->is_class_scope()) return false;
+
+  return outer->AsClassScope()->brand() != nullptr;
+}
+
 ObjectLiteralProperty::ObjectLiteralProperty(Expression* key, Expression* value,
                                              Kind kind, bool is_computed_name)
     : LiteralProperty(key, value, is_computed_name),

src/ast/ast.h

@@ -2342,6 +2342,8 @@ class FunctionLiteral final : public Expression {
     return RequiresInstanceMembersInitializer::decode(bit_field_);
   }
 
+  bool requires_brand_initialization() const;
+
   ProducedPreparseData* produced_preparse_data() const {
     return produced_preparse_data_;
   }
@@ -2435,12 +2437,10 @@ class ClassLiteralProperty final : public LiteralProperty {
   }
 
   void set_private_name_var(Variable* var) {
-    DCHECK_EQ(FIELD, kind());
     DCHECK(is_private());
     private_or_computed_name_var_ = var;
   }
   Variable* private_name_var() const {
-    DCHECK_EQ(FIELD, kind());
     DCHECK(is_private());
     return private_or_computed_name_var_;
   }
@@ -2476,7 +2476,7 @@ class ClassLiteral final : public Expression {
  public:
   typedef ClassLiteralProperty Property;
 
-  Scope* scope() const { return scope_; }
+  ClassScope* scope() const { return scope_; }
   Variable* class_variable() const { return class_variable_; }
   Expression* extends() const { return extends_; }
   FunctionLiteral* constructor() const { return constructor_; }
@@ -2508,7 +2508,7 @@ class ClassLiteral final : public Expression {
  private:
   friend class AstNodeFactory;
 
-  ClassLiteral(Scope* scope, Variable* class_variable, Expression* extends,
+  ClassLiteral(ClassScope* scope, Variable* class_variable, Expression* extends,
                FunctionLiteral* constructor, ZonePtrList<Property>* properties,
                FunctionLiteral* static_fields_initializer,
                FunctionLiteral* instance_members_initializer_function,
@@ -2531,7 +2531,7 @@ class ClassLiteral final : public Expression {
   }
 
   int end_position_;
-  Scope* scope_;
+  ClassScope* scope_;
   Variable* class_variable_;
   Expression* extends_;
   FunctionLiteral* constructor_;
@@ -3233,7 +3233,7 @@ class AstNodeFactory final {
   }
 
   ClassLiteral* NewClassLiteral(
-      Scope* scope, Variable* variable, Expression* extends,
+      ClassScope* scope, Variable* variable, Expression* extends,
       FunctionLiteral* constructor,
       ZonePtrList<ClassLiteral::Property>* properties,
       FunctionLiteral* static_fields_initializer,

src/ast/prettyprinter.cc

@@ -1054,12 +1054,17 @@ void AstPrinter::VisitClassLiteral(ClassLiteral* node) {
   if (node->extends() != nullptr) {
     PrintIndentedVisit("EXTENDS", node->extends());
   }
+  Scope* outer = node->constructor()->scope()->outer_scope();
+  if (outer->is_class_scope()) {
+    Variable* brand = outer->AsClassScope()->brand();
+    PrintLiteralWithModeIndented("BRAND", brand, brand->raw_name());
+  }
   if (node->static_fields_initializer() != nullptr) {
     PrintIndentedVisit("STATIC FIELDS INITIALIZER",
                        node->static_fields_initializer());
   }
   if (node->instance_members_initializer_function() != nullptr) {
-    PrintIndentedVisit("INSTANCE ELEMENTS INITIALIZER",
+    PrintIndentedVisit("INSTANCE MEMBERS INITIALIZER",
                        node->instance_members_initializer_function());
   }
   PrintClassProperties(node->properties());
@@ -1067,7 +1072,7 @@ void AstPrinter::VisitClassLiteral(ClassLiteral* node) {
 
 void AstPrinter::VisitInitializeClassMembersStatement(
     InitializeClassMembersStatement* node) {
-  IndentedScope indent(this, "INITIALIZE CLASS ELEMENTS", node->position());
+  IndentedScope indent(this, "INITIALIZE CLASS MEMBERS", node->position());
   PrintClassProperties(node->fields());
 }
 

src/ast/scopes.cc

@@ -145,9 +145,16 @@ ClassScope::ClassScope(Zone* zone, Scope* outer_scope)
   set_language_mode(LanguageMode::kStrict);
 }
 
-ClassScope::ClassScope(Zone* zone, Handle<ScopeInfo> scope_info)
+ClassScope::ClassScope(Zone* zone, AstValueFactory* ast_value_factory,
+                       Handle<ScopeInfo> scope_info)
     : Scope(zone, CLASS_SCOPE, scope_info) {
   set_language_mode(LanguageMode::kStrict);
+  if (scope_info->HasClassBrand()) {
+    Variable* brand =
+        LookupInScopeInfo(ast_value_factory->dot_brand_string(), this);
+    DCHECK_NOT_NULL(brand);
+    EnsureRareData()->brand = brand;
+  }
 }
 
 Scope::Scope(Zone* zone, ScopeType scope_type, Handle<ScopeInfo> scope_info)
@@ -333,7 +340,8 @@ Scope* Scope::DeserializeScopeChain(Isolate* isolate, Zone* zone,
       outer_scope = new (zone)
           DeclarationScope(zone, EVAL_SCOPE, handle(scope_info, isolate));
     } else if (scope_info->scope_type() == CLASS_SCOPE) {
-      outer_scope = new (zone) ClassScope(zone, handle(scope_info, isolate));
+      outer_scope = new (zone)
+          ClassScope(zone, ast_value_factory, handle(scope_info, isolate));
     } else if (scope_info->scope_type() == BLOCK_SCOPE) {
       if (scope_info->is_declaration_scope()) {
         outer_scope = new (zone)
@@ -1710,6 +1718,11 @@ void Scope::Print(int n) {
     if (class_scope->rare_data_ != nullptr) {
       PrintMap(n1, "// private name vars:\n",
                &(class_scope->rare_data_->private_name_map), true, function);
+      Variable* brand = class_scope->brand();
+      if (brand != nullptr) {
+        Indent(n1, "// brand var:\n");
+        PrintVar(n1, brand);
+      }
     }
   }
 
@@ -2512,5 +2525,21 @@ VariableProxy* ClassScope::ResolvePrivateNamesPartially() {
   return nullptr;
 }
 
+Variable* ClassScope::DeclareBrandVariable(AstValueFactory* ast_value_factory,
+                                           int class_token_pos) {
+  DCHECK_IMPLIES(rare_data_ != nullptr, rare_data_->brand == nullptr);
+  bool was_added;
+  Variable* brand = Declare(zone(), ast_value_factory->dot_brand_string(),
+                            VariableMode::kConst, NORMAL_VARIABLE,
+                            InitializationFlag::kNeedsInitialization,
+                            MaybeAssignedFlag::kMaybeAssigned, &was_added);
+  DCHECK(was_added);
+  brand->ForceContextAllocation();
+  brand->set_is_used();
+  EnsureRareData()->brand = brand;
+  brand->set_initializer_position(class_token_pos);
+  return brand;
+}
+
 }  // namespace internal
 }  // namespace v8

src/ast/scopes.h

@@ -1169,7 +1169,8 @@ class V8_EXPORT_PRIVATE ClassScope : public Scope {
  public:
   ClassScope(Zone* zone, Scope* outer_scope);
   // Deserialization.
-  ClassScope(Zone* zone, Handle<ScopeInfo> scope_info);
+  ClassScope(Zone* zone, AstValueFactory* ast_value_factory,
+             Handle<ScopeInfo> scope_info);
 
   // Declare a private name in the private name map and add it to the
   // local variables of this scope.
@@ -1205,6 +1206,11 @@ class V8_EXPORT_PRIVATE ClassScope : public Scope {
   // and the current tail.
   void MigrateUnresolvedPrivateNameTail(AstNodeFactory* ast_node_factory,
                                         UnresolvedList::Iterator tail);
+  Variable* DeclareBrandVariable(AstValueFactory* ast_value_factory,
+                                 int class_token_pos);
+  Variable* brand() {
+    return rare_data_ == nullptr ? nullptr : rare_data_->brand;
+  }
 
  private:
   friend class Scope;
@@ -1222,6 +1228,7 @@ class V8_EXPORT_PRIVATE ClassScope : public Scope {
     explicit RareData(Zone* zone) : private_name_map(zone) {}
     UnresolvedList unresolved_private_names;
     VariableMap private_name_map;
+    Variable* brand = nullptr;
   };
 
   V8_INLINE RareData* EnsureRareData() {

src/heap-symbols.h

@@ -147,6 +147,7 @@
   V(_, disjunction_string, "disjunction")                             \
   V(_, display_name_string, "displayName")                            \
   V(_, done_string, "done")                                           \
+  V(_, dot_brand_string, ".brand")                                    \
   V(_, dot_catch_string, ".catch")                                    \
   V(_, dot_default_string, ".default")                                \
   V(_, dot_for_string, ".for")                                        \

src/interpreter/bytecode-generator.cc

@@ -1156,10 +1156,15 @@ void BytecodeGenerator::GenerateBytecodeBody() {
   builder()->StackCheck(info()->literal()->start_position());
 
   // The derived constructor case is handled in VisitCallSuper.
-  if (IsBaseConstructor(function_kind()) &&
-      info()->literal()->requires_instance_members_initializer()) {
-    BuildInstanceMemberInitialization(Register::function_closure(),
-                                      builder()->Receiver());
+  if (IsBaseConstructor(function_kind())) {
+    if (info()->literal()->requires_brand_initialization()) {
+      BuildPrivateBrandInitialization(builder()->Receiver());
+    }
+
+    if (info()->literal()->requires_instance_members_initializer()) {
+      BuildInstanceMemberInitialization(Register::function_closure(),
+                                        builder()->Receiver());
+    }
   }
 
   // Visit statements in the function body.
@@ -1929,6 +1934,39 @@ bool BytecodeGenerator::ShouldOptimizeAsOneShot() const {
          info()->literal()->is_oneshot_iife();
 }
 
+void BytecodeGenerator::BuildPrivateClassMemberNameAssignment(
+    ClassLiteral::Property* property) {
+  DCHECK(property->is_private());
+  switch (property->kind()) {
+    case ClassLiteral::Property::FIELD: {
+      // Create the private name symbols for fields during class
+      // evaluation and store them on the context. These will be
+      // used as keys later during instance or static initialization.
+      RegisterAllocationScope private_name_register_scope(this);
+      Register private_name = register_allocator()->NewRegister();
+      VisitForRegisterValue(property->key(), private_name);
+      builder()
+          ->LoadLiteral(property->key()->AsLiteral()->AsRawPropertyName())
+          .StoreAccumulatorInRegister(private_name)
+          .CallRuntime(Runtime::kCreatePrivateNameSymbol, private_name);
+      DCHECK_NOT_NULL(property->private_name_var());
+      BuildVariableAssignment(property->private_name_var(), Token::INIT,
+                              HoleCheckMode::kElided);
+      break;
+    }
+    case ClassLiteral::Property::METHOD: {
+      // Create the closures for private methods.
+      VisitForAccumulatorValue(property->value());
+      BuildVariableAssignment(property->private_name_var(), Token::INIT,
+                              HoleCheckMode::kElided);
+      break;
+    }
+    default:
+      // TODO(joyee): Private accessors are not yet supported.
+      UNREACHABLE();
+  }
+}
+
 void BytecodeGenerator::BuildClassLiteral(ClassLiteral* expr, Register name) {
   size_t class_boilerplate_entry =
       builder()->AllocateDeferredConstantPoolEntry();
@@ -1993,19 +2031,15 @@ void BytecodeGenerator::BuildClassLiteral(ClassLiteral* expr, Register name) {
         }
       }
 
+      if (property->is_private()) {
+        BuildPrivateClassMemberNameAssignment(property);
+        // The private fields are initialized in the initializer function and
+        // the private brand for the private methods are initialized in the
+        // constructor instead.
+        continue;
+      }
+
       if (property->kind() == ClassLiteral::Property::FIELD) {
-        if (property->is_private()) {
-          RegisterAllocationScope private_name_register_scope(this);
-          Register private_name = register_allocator()->NewRegister();
-          VisitForRegisterValue(property->key(), private_name);
-          builder()
-              ->LoadLiteral(property->key()->AsLiteral()->AsRawPropertyName())
-              .StoreAccumulatorInRegister(private_name)
-              .CallRuntime(Runtime::kCreatePrivateNameSymbol, private_name);
-          DCHECK_NOT_NULL(property->private_name_var());
-          BuildVariableAssignment(property->private_name_var(), Token::INIT,
-                                  HoleCheckMode::kElided);
-        }
         // We don't compute field's value here, but instead do it in the
         // initializer function.
         continue;
@@ -2029,6 +2063,23 @@ void BytecodeGenerator::BuildClassLiteral(ClassLiteral* expr, Register name) {
                             HoleCheckMode::kElided);
   }
 
+  // Create the class brand symbol and store it on the context
+  // during class evaluation. This will be stored in the
+  // receiver later in the constructor.
+  if (expr->scope()->brand() != nullptr) {
+    Register brand = register_allocator()->NewRegister();
+    const AstRawString* class_name =
+        expr->class_variable() != nullptr
+            ? expr->class_variable()->raw_name()
+            : ast_string_constants()->empty_string();
+    builder()
+        ->LoadLiteral(class_name)
+        .StoreAccumulatorInRegister(brand)
+        .CallRuntime(Runtime::kCreatePrivateNameSymbol, brand);
+    BuildVariableAssignment(expr->scope()->brand(), Token::INIT,
+                            HoleCheckMode::kElided);
+  }
+
   if (expr->instance_members_initializer_function() != nullptr) {
     Register initializer =
         VisitForRegisterValue(expr->instance_members_initializer_function());
@@ -2110,6 +2161,10 @@ void BytecodeGenerator::VisitInitializeClassMembersStatement(
 
   for (int i = 0; i < stmt->fields()->length(); i++) {
     ClassLiteral::Property* property = stmt->fields()->at(i);
+    // Private methods are not initialized in the
+    // InitializeClassMembersStatement.
+    DCHECK_IMPLIES(property->is_private(),
+                   property->kind() == ClassLiteral::Property::FIELD);
 
     if (property->is_computed_name()) {
       DCHECK_EQ(property->kind(), ClassLiteral::Property::FIELD);
@@ -2120,8 +2175,7 @@ void BytecodeGenerator::VisitInitializeClassMembersStatement(
       // variable at class definition time.
       BuildVariableLoad(var, HoleCheckMode::kElided);
       builder()->StoreAccumulatorInRegister(key);
-    } else if (property->kind() == ClassLiteral::Property::FIELD &&
-               property->is_private()) {
+    } else if (property->is_private()) {
       Variable* private_name_var = property->private_name_var();
       DCHECK_NOT_NULL(private_name_var);
       BuildVariableLoad(private_name_var, HoleCheckMode::kElided);
@@ -2143,6 +2197,17 @@ void BytecodeGenerator::VisitInitializeClassMembersStatement(
   }
 }
 
+void BytecodeGenerator::BuildPrivateBrandInitialization(Register receiver) {
+  RegisterList brand_args = register_allocator()->NewRegisterList(2);
+  Variable* brand = info()->scope()->outer_scope()->AsClassScope()->brand();
+  DCHECK_NOT_NULL(brand);
+  BuildVariableLoad(brand, HoleCheckMode::kElided);
+  builder()
+      ->StoreAccumulatorInRegister(brand_args[1])
+      .MoveRegister(receiver, brand_args[0])
+      .CallRuntime(Runtime::kAddPrivateBrand, brand_args);
+}
+
 void BytecodeGenerator::BuildInstanceMemberInitialization(Register constructor,
                                                           Register instance) {
   RegisterList args = register_allocator()->NewRegisterList(1);
@@ -4475,6 +4540,13 @@ void BytecodeGenerator::VisitCallSuper(Call* expr) {
     BuildVariableAssignment(var, Token::INIT, HoleCheckMode::kRequired);
   }
 
+  Register instance = register_allocator()->NewRegister();
+  builder()->StoreAccumulatorInRegister(instance);
+
+  if (info()->literal()->requires_brand_initialization()) {
+    BuildPrivateBrandInitialization(instance);
+  }
+
   // The derived constructor has the correct bit set always, so we
   // don't emit code to load and call the initializer if not
   // required.
@@ -4487,11 +4559,10 @@ void BytecodeGenerator::VisitCallSuper(Call* expr) {
   // if required.
   if (info()->literal()->requires_instance_members_initializer() ||
       !IsDerivedConstructor(info()->literal()->kind())) {
-    Register instance = register_allocator()->NewRegister();
-    builder()->StoreAccumulatorInRegister(instance);
     BuildInstanceMemberInitialization(this_function, instance);
-    builder()->LoadAccumulatorWithRegister(instance);
   }
+
+  builder()->LoadAccumulatorWithRegister(instance);
 }
 
 void BytecodeGenerator::VisitCallNew(CallNew* expr) {

src/interpreter/bytecode-generator.h

@@ -291,10 +291,12 @@ class BytecodeGenerator final : public AstVisitor<BytecodeGenerator> {
   void VisitArgumentsObject(Variable* variable);
   void VisitRestArgumentsArray(Variable* rest);
   void VisitCallSuper(Call* call);
+  void BuildPrivateClassMemberNameAssignment(ClassLiteral::Property* property);
   void BuildClassLiteral(ClassLiteral* expr, Register name);
   void VisitClassLiteral(ClassLiteral* expr, Register name);
   void VisitNewTargetVariable(Variable* variable);
   void VisitThisFunctionVariable(Variable* variable);
+  void BuildPrivateBrandInitialization(Register receiver);
   void BuildInstanceMemberInitialization(Register constructor,
                                          Register instance);
   void BuildGeneratorObjectVariableInitialization();

src/objects-printer.cc

@@ -2247,6 +2247,7 @@ void ScopeInfo::ScopeInfoPrint(std::ostream& os) {  // NOLINT
   if (HasReceiver()) {
     os << "\n - receiver: " << ReceiverVariableField::decode(flags);
   }
+  if (HasClassBrand()) os << "\n - has class brand";
   if (HasNewTarget()) os << "\n - needs new target";
   if (HasFunctionName()) {
     os << "\n - function name(" << FunctionVariableField::decode(flags)

src/objects/literal-objects.cc

@@ -526,6 +526,11 @@ Handle<ClassBoilerplate> ClassBoilerplate::BuildClassBoilerplate(
   for (int i = 0; i < expr->properties()->length(); i++) {
     ClassLiteral::Property* property = expr->properties()->at(i);
 
+    // Private members are not processed using the class boilerplate.
+    if (property->is_private()) {
+      continue;
+    }
+
     ClassBoilerplate::ValueKind value_kind;
     switch (property->kind()) {
       case ClassLiteral::Property::METHOD:

src/objects/scope-info.cc

@@ -134,6 +134,9 @@ Handle<ScopeInfo> ScopeInfo::Create(Isolate* isolate, Zone* zone, Scope* scope,
     function_name_info = NONE;
   }
 
+  const bool has_brand = scope->is_class_scope()
+                             ? scope->AsClassScope()->brand() != nullptr
+                             : false;
   const bool has_function_name = function_name_info != NONE;
   const bool has_position_info = NeedsPositionInfo(scope->scope_type());
   const bool has_receiver = receiver_info == STACK || receiver_info == CONTEXT;
@@ -181,6 +184,7 @@ Handle<ScopeInfo> ScopeInfo::Create(Isolate* isolate, Zone* zone, Scope* scope,
         LanguageModeField::encode(scope->language_mode()) |
         DeclarationScopeField::encode(scope->is_declaration_scope()) |
         ReceiverVariableField::encode(receiver_info) |
+        HasClassBrandField::encode(has_brand) |
         HasNewTargetField::encode(has_new_target) |
         FunctionVariableField::encode(function_name_info) |
         HasInferredFunctionNameField::encode(has_inferred_function_name) |
@@ -354,9 +358,9 @@ Handle<ScopeInfo> ScopeInfo::CreateForWithScope(
       ScopeTypeField::encode(WITH_SCOPE) | CallsSloppyEvalField::encode(false) |
       LanguageModeField::encode(LanguageMode::kSloppy) |
       DeclarationScopeField::encode(false) |
-      ReceiverVariableField::encode(NONE) | HasNewTargetField::encode(false) |
-      FunctionVariableField::encode(NONE) | IsAsmModuleField::encode(false) |
-      HasSimpleParametersField::encode(true) |
+      ReceiverVariableField::encode(NONE) | HasClassBrandField::encode(false) |
+      HasNewTargetField::encode(false) | FunctionVariableField::encode(NONE) |
+      IsAsmModuleField::encode(false) | HasSimpleParametersField::encode(true) |
       FunctionKindField::encode(kNormalFunction) |
       HasOuterScopeInfoField::encode(has_outer_scope_info) |
       IsDebugEvaluateScopeField::encode(false);
@@ -416,7 +420,7 @@ Handle<ScopeInfo> ScopeInfo::CreateForBootstrapping(Isolate* isolate,
       LanguageModeField::encode(LanguageMode::kSloppy) |
       DeclarationScopeField::encode(true) |
       ReceiverVariableField::encode(is_empty_function ? UNUSED : CONTEXT) |
-      HasNewTargetField::encode(false) |
+      HasClassBrandField::encode(false) | HasNewTargetField::encode(false) |
       FunctionVariableField::encode(is_empty_function ? UNUSED : NONE) |
       HasInferredFunctionNameField::encode(has_inferred_function_name) |
       IsAsmModuleField::encode(false) | HasSimpleParametersField::encode(true) |
@@ -536,6 +540,10 @@ bool ScopeInfo::HasAllocatedReceiver() const {
   return allocation == STACK || allocation == CONTEXT;
 }
 
+bool ScopeInfo::HasClassBrand() const {
+  return HasClassBrandField::decode(Flags());
+}
+
 bool ScopeInfo::HasNewTarget() const {
   return HasNewTargetField::decode(Flags());
 }

src/objects/scope-info.h

@@ -69,6 +69,9 @@ class ScopeInfo : public FixedArray {
   // or context-allocated?
   bool HasAllocatedReceiver() const;
 
+  // Does this scope has class brand (for private methods)?
+  bool HasClassBrand() const;
+
   // Does this scope declare a "new.target" binding?
   bool HasNewTarget() const;
 
@@ -228,8 +231,10 @@ class ScopeInfo : public FixedArray {
   class ReceiverVariableField
       : public BitField<VariableAllocationInfo, DeclarationScopeField::kNext,
                         2> {};
-  class HasNewTargetField
+  class HasClassBrandField
       : public BitField<bool, ReceiverVariableField::kNext, 1> {};
+  class HasNewTargetField
+      : public BitField<bool, HasClassBrandField::kNext, 1> {};
   class FunctionVariableField
       : public BitField<VariableAllocationInfo, HasNewTargetField::kNext, 2> {};
   // TODO(cbruni): Combine with function variable field when only storing the

src/parsing/parser-base.h

@@ -527,6 +527,7 @@ class ParserBase {
           has_static_computed_names(false),
           has_static_class_fields(false),
           has_instance_members(false),
+          requires_brand(false),
           is_anonymous(false),
           static_fields_scope(nullptr),
           instance_members_scope(nullptr),
@@ -543,6 +544,7 @@ class ParserBase {
     bool has_static_computed_names;
     bool has_static_class_fields;
     bool has_instance_members;
+    bool requires_brand;
     bool is_anonymous;
     DeclarationScope* static_fields_scope;
     DeclarationScope* instance_members_scope;
@@ -4249,19 +4251,32 @@ typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParseClassLiteral(
     }
     is_constructor &= class_info.has_seen_constructor;
 
-    if (V8_UNLIKELY(property_kind == ClassLiteralProperty::FIELD)) {
+    bool is_field = property_kind == ClassLiteralProperty::FIELD;
+
+    if (V8_UNLIKELY(prop_info.is_private)) {
+      DCHECK(!is_constructor);
+      class_info.requires_brand |= !is_field;
+      impl()->DeclarePrivateClassMember(class_scope, prop_info.name, property,
+                                        property_kind, prop_info.is_static,
+                                        &class_info);
+      impl()->InferFunctionName();
+      continue;
+    }
+
+    if (V8_UNLIKELY(is_field)) {
+      DCHECK(!prop_info.is_private);
       if (prop_info.is_computed_name) {
-        DCHECK(!prop_info.is_private);
         class_info.computed_field_count++;
       }
-
-      impl()->DeclareClassField(class_scope, property, prop_info.name,
-                                prop_info.is_static, prop_info.is_computed_name,
-                                prop_info.is_private, &class_info);
-    } else {
-      impl()->DeclareClassProperty(class_scope, name, property, is_constructor,
-                                   &class_info);
+      impl()->DeclarePublicClassField(class_scope, property,
+                                      prop_info.is_static,
+                                      prop_info.is_computed_name, &class_info);
+      impl()->InferFunctionName();
+      continue;
     }
+
+    impl()->DeclarePublicClassMethod(name, property, is_constructor,
+                                     &class_info);
     impl()->InferFunctionName();
   }
 
@@ -4278,6 +4293,10 @@ typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParseClassLiteral(
     return impl()->FailureExpression();
   }
 
+  if (class_info.requires_brand) {
+    class_scope->DeclareBrandVariable(ast_value_factory(), kNoSourcePosition);
+  }
+
   return impl()->RewriteClassLiteral(class_scope, name, &class_info,
                                      class_token_pos, end_pos);
 }

src/parsing/parser.cc

@@ -2800,18 +2800,16 @@ Variable* Parser::CreatePrivateNameVariable(ClassScope* scope,
   return proxy->var();
 }
 
-void Parser::DeclareClassField(ClassScope* scope,
-                               ClassLiteralProperty* property,
-                               const AstRawString* property_name,
-                               bool is_static, bool is_computed_name,
-                               bool is_private, ClassInfo* class_info) {
+void Parser::DeclarePublicClassField(ClassScope* scope,
+                                     ClassLiteralProperty* property,
+                                     bool is_static, bool is_computed_name,
+                                     ClassInfo* class_info) {
   if (is_static) {
     class_info->static_fields->Add(property, zone());
   } else {
     class_info->instance_fields->Add(property, zone());
   }
 
-  DCHECK_IMPLIES(is_computed_name, !is_private);
   if (is_computed_name) {
     // We create a synthetic variable name here so that scope
     // analysis doesn't dedupe the vars.
@@ -2820,27 +2818,49 @@ void Parser::DeclareClassField(ClassScope* scope,
             ast_value_factory(), class_info->computed_field_count));
     property->set_computed_name_var(computed_name_var);
     class_info->properties->Add(property, zone());
-  } else if (is_private) {
-    Variable* private_name_var =
-        CreatePrivateNameVariable(scope, property_name);
-    int pos = property->value()->position();
-    if (pos == kNoSourcePosition) {
-      pos = property->key()->position();
+  }
+}
+
+void Parser::DeclarePrivateClassMember(ClassScope* scope,
+                                       const AstRawString* property_name,
+                                       ClassLiteralProperty* property,
+                                       ClassLiteralProperty::Kind kind,
+                                       bool is_static, ClassInfo* class_info) {
+  DCHECK_IMPLIES(kind == ClassLiteralProperty::Kind::METHOD,
+                 allow_harmony_private_methods());
+  // TODO(joyee): We do not support private accessors yet (which allow
+  // declaring the same private name twice). Make them noops.
+  if (kind != ClassLiteralProperty::Kind::FIELD &&
+      kind != ClassLiteralProperty::Kind::METHOD) {
+    return;
+  }
+
+  if (kind == ClassLiteralProperty::Kind::FIELD) {
+    if (is_static) {
+      class_info->static_fields->Add(property, zone());
+    } else {
+      class_info->instance_fields->Add(property, zone());
     }
-    private_name_var->set_initializer_position(pos);
-    property->set_private_name_var(private_name_var);
-    class_info->properties->Add(property, zone());
   }
+
+  Variable* private_name_var = CreatePrivateNameVariable(scope, property_name);
+  int pos = property->value()->position();
+  if (pos == kNoSourcePosition) {
+    pos = property->key()->position();
+  }
+  private_name_var->set_initializer_position(pos);
+  property->set_private_name_var(private_name_var);
+  class_info->properties->Add(property, zone());
 }
 
 // This method declares a property of the given class.  It updates the
 // following fields of class_info, as appropriate:
 //   - constructor
 //   - properties
-void Parser::DeclareClassProperty(ClassScope* scope,
-                                  const AstRawString* class_name,
-                                  ClassLiteralProperty* property,
-                                  bool is_constructor, ClassInfo* class_info) {
+void Parser::DeclarePublicClassMethod(const AstRawString* class_name,
+                                      ClassLiteralProperty* property,
+                                      bool is_constructor,
+                                      ClassInfo* class_info) {
   if (is_constructor) {
     DCHECK(!class_info->constructor);
     class_info->constructor = property->value()->AsFunctionLiteral();
@@ -2861,9 +2881,9 @@ FunctionLiteral* Parser::CreateInitializerFunction(
             FunctionKind::kClassMembersInitializerFunction);
   // function() { .. class fields initializer .. }
   ScopedPtrList<Statement> statements(pointer_buffer());
-  InitializeClassMembersStatement* static_fields =
+  InitializeClassMembersStatement* stmt =
       factory()->NewInitializeClassMembersStatement(fields, kNoSourcePosition);
-  statements.Add(static_fields);
+  statements.Add(stmt);
   return factory()->NewFunctionLiteral(
       ast_value_factory()->GetOneByteString(name), scope, statements, 0, 0, 0,
       FunctionLiteral::kNoDuplicateParameters,

src/parsing/parser.h

@@ -313,6 +313,19 @@ class V8_EXPORT_PRIVATE Parser : public NON_EXPORTED_BASE(ParserBase<Parser>) {
                           int class_token_pos, int end_pos);
   void DeclareClassVariable(const AstRawString* name, ClassInfo* class_info,
                             int class_token_pos);
+  void DeclareClassBrandVariable(ClassScope* scope, ClassInfo* class_info,
+                                 int class_token_pos);
+  void DeclarePrivateClassMember(ClassScope* scope,
+                                 const AstRawString* property_name,
+                                 ClassLiteralProperty* property,
+                                 ClassLiteralProperty::Kind kind,
+                                 bool is_static, ClassInfo* class_info);
+  void DeclarePublicClassMethod(const AstRawString* class_name,
+                                ClassLiteralProperty* property,
+                                bool is_constructor, ClassInfo* class_info);
+  void DeclarePublicClassField(ClassScope* scope,
+                               ClassLiteralProperty* property, bool is_static,
+                               bool is_computed_name, ClassInfo* class_info);
   void DeclareClassProperty(ClassScope* scope, const AstRawString* class_name,
                             ClassLiteralProperty* property, bool is_constructor,
                             ClassInfo* class_info);

src/parsing/preparser.h

@@ -1230,32 +1230,39 @@ class PreParser : public ParserBase<PreParser> {
                           &was_added);
     }
   }
-  V8_INLINE void DeclareClassProperty(ClassScope* scope,
-                                      const PreParserIdentifier& class_name,
-                                      const PreParserExpression& property,
-                                      bool is_constructor,
-                                      ClassInfo* class_info) {}
-
-  V8_INLINE void DeclareClassField(ClassScope* scope,
-                                   const PreParserExpression& property,
-                                   const PreParserIdentifier& property_name,
-                                   bool is_static, bool is_computed_name,
-                                   bool is_private, ClassInfo* class_info) {
-    DCHECK_IMPLIES(is_computed_name, !is_private);
+  V8_INLINE void DeclarePublicClassMethod(const PreParserIdentifier& class_name,
+                                          const PreParserExpression& property,
+                                          bool is_constructor,
+                                          ClassInfo* class_info) {}
+  V8_INLINE void DeclarePublicClassField(ClassScope* scope,
+                                         const PreParserExpression& property,
+                                         bool is_static, bool is_computed_name,
+                                         ClassInfo* class_info) {
     if (is_computed_name) {
       bool was_added;
       DeclareVariableName(
           ClassFieldVariableName(ast_value_factory(),
                                  class_info->computed_field_count),
           VariableMode::kConst, scope, &was_added);
-    } else if (is_private) {
-      bool was_added;
-      DeclarePrivateVariableName(property_name.string_, scope, &was_added);
-      if (!was_added) {
-        Scanner::Location loc(property.position(), property.position() + 1);
-        ReportMessageAt(loc, MessageTemplate::kVarRedeclaration,
-                        property_name.string_);
-      }
+    }
+  }
+
+  V8_INLINE void DeclarePrivateClassMember(
+      ClassScope* scope, const PreParserIdentifier& property_name,
+      const PreParserExpression& property, ClassLiteralProperty::Kind kind,
+      bool is_static, ClassInfo* class_info) {
+    // TODO(joyee): We do not support private accessors yet (which allow
+    // declaring the same private name twice). Make them noops.
+    if (kind != ClassLiteralProperty::Kind::FIELD &&
+        kind != ClassLiteralProperty::Kind::METHOD) {
+      return;
+    }
+    bool was_added;
+    DeclarePrivateVariableName(property_name.string_, scope, &was_added);
+    if (!was_added) {
+      Scanner::Location loc(property.position(), property.position() + 1);
+      ReportMessageAt(loc, MessageTemplate::kVarRedeclaration,
+                      property_name.string_);
     }
   }
 

src/runtime/runtime-object.cc

@@ -1113,6 +1113,31 @@ RUNTIME_FUNCTION(Runtime_GetOwnPropertyDescriptor) {
   return *desc.ToPropertyDescriptorObject(isolate);
 }
 
+RUNTIME_FUNCTION(Runtime_AddPrivateBrand) {
+  HandleScope scope(isolate);
+  DCHECK_EQ(args.length(), 2);
+  CONVERT_ARG_HANDLE_CHECKED(JSReceiver, receiver, 0);
+  CONVERT_ARG_HANDLE_CHECKED(Symbol, brand, 1);
+  DCHECK(brand->is_private_name());
+
+  LookupIterator it = LookupIterator::PropertyOrElement(
+      isolate, receiver, brand, LookupIterator::OWN);
+
+  if (it.IsFound()) {
+    THROW_NEW_ERROR_RETURN_FAILURE(
+        isolate, NewTypeError(MessageTemplate::kVarRedeclaration, brand));
+  }
+
+  PropertyAttributes attributes =
+      static_cast<PropertyAttributes>(DONT_ENUM | DONT_DELETE | READ_ONLY);
+  // TODO(joyee): we could use this slot to store something useful. For now,
+  // store the brand itself.
+  CHECK(Object::AddDataProperty(&it, brand, attributes, Just(kDontThrow),
+                                StoreOrigin::kMaybeKeyed)
+            .FromJust());
+  return *receiver;
+}
+
 RUNTIME_FUNCTION(Runtime_AddPrivateField) {
   HandleScope scope(isolate);
   DCHECK_EQ(3, args.length());

src/runtime/runtime.cc

@@ -106,6 +106,7 @@ bool Runtime::NeedsExactContext(FunctionId id) {
       // try-catch in async function.
       return false;
     case Runtime::kAddPrivateField:
+    case Runtime::kAddPrivateBrand:
     case Runtime::kCopyDataProperties:
     case Runtime::kCreateDataProperty:
     case Runtime::kCreatePrivateNameSymbol:

src/runtime/runtime.h

@@ -282,6 +282,7 @@ namespace internal {
 #define FOR_EACH_INTRINSIC_OBJECT(F, I)                         \
   F(AddDictionaryProperty, 3, 1)                                \
   F(AddPrivateField, 3, 1)                                      \
+  F(AddPrivateBrand, 2, 1)                                      \
   F(AllocateHeapNumber, 0, 1)                                   \
   F(ClassOf, 1, 1)                                              \
   F(CollectTypeProfile, 3, 1)                                   \

test/cctest/interpreter/bytecode_expectations/PrivateMethods.golden

+#
+# Autogenerated by generate-bytecode-expectations.
+#
+
+---
+wrap: yes
+private methods: yes
+
+---
+snippet: "
+  {
+    class A {
+      #a() { return 1; }
+    }
+  
+    new A;
+  }
+"
+frame size: 7
+parameter count: 1
+bytecode array length: 62
+bytecodes: [
+  /*   30 E> */ B(StackCheck),
+                B(CreateBlockContext), U8(0),
+                B(PushContext), R(2),
+                B(LdaTheHole),
+                B(Star), R(6),
+                B(CreateClosure), U8(2), U8(0), U8(2),
+                B(Star), R(3),
+                B(LdaConstant), U8(1),
+                B(Star), R(4),
+                B(CreateClosure), U8(3), U8(1), U8(2),
+                B(StaCurrentContextSlot), U8(4),
+                B(Mov), R(3), R(5),
+                B(CallRuntime), U16(Runtime::kDefineClass), R(4), U8(3),
+                B(Star), R(4),
+                B(Mov), R(5), R(1),
+                B(LdaConstant), U8(4),
+                B(Star), R(5),
+                B(CallRuntime), U16(Runtime::kCreatePrivateNameSymbol), R(5), U8(1),
+                B(StaCurrentContextSlot), U8(5),
+                B(PopContext), R(2),
+                B(Mov), R(1), R(0),
+  /*   78 S> */ B(Ldar), R(0),
+  /*   78 E> */ B(Construct), R(0), R(0), U8(0), U8(0),
+                B(LdaUndefined),
+  /*   87 S> */ B(Return),
+]
+constant pool: [
+  SCOPE_INFO_TYPE,
+  FIXED_ARRAY_TYPE,
+  SHARED_FUNCTION_INFO_TYPE,
+  SHARED_FUNCTION_INFO_TYPE,
+  ONE_BYTE_INTERNALIZED_STRING_TYPE ["A"],
+]
+handlers: [
+]
+
+---
+snippet: "
+  {
+    class D {
+      #d() {}
+    }
+  
+    class E extends D {
+      #e() {}
+    }
+  
+    new D;
+    new E;
+  }
+"
+frame size: 9
+parameter count: 1
+bytecode array length: 121
+bytecodes: [
+  /*   30 E> */ B(StackCheck),
+                B(CreateBlockContext), U8(0),
+                B(PushContext), R(4),
+                B(LdaTheHole),
+                B(Star), R(8),
+                B(CreateClosure), U8(2), U8(0), U8(2),
+                B(Star), R(5),
+                B(LdaConstant), U8(1),
+                B(Star), R(6),
+                B(CreateClosure), U8(3), U8(1), U8(2),
+                B(StaCurrentContextSlot), U8(4),
+                B(Mov), R(5), R(7),
+                B(CallRuntime), U16(Runtime::kDefineClass), R(6), U8(3),
+                B(Star), R(6),
+                B(Mov), R(7), R(3),
+                B(LdaConstant), U8(4),
+                B(Star), R(7),
+                B(CallRuntime), U16(Runtime::kCreatePrivateNameSymbol), R(7), U8(1),
+                B(StaCurrentContextSlot), U8(5),
+                B(PopContext), R(4),
+                B(Mov), R(3), R(0),
+  /*   38 E> */ B(CreateBlockContext), U8(5),
+                B(PushContext), R(4),
+  /*   83 E> */ B(CreateClosure), U8(7), U8(2), U8(2),
+                B(Star), R(5),
+                B(LdaConstant), U8(6),
+                B(Star), R(6),
+                B(CreateClosure), U8(8), U8(3), U8(2),
+                B(StaCurrentContextSlot), U8(4),
+                B(Mov), R(5), R(7),
+                B(Mov), R(3), R(8),
+                B(CallRuntime), U16(Runtime::kDefineClass), R(6), U8(3),
+                B(Star), R(6),
+                B(Mov), R(7), R(2),
+                B(LdaConstant), U8(9),
+                B(Star), R(7),
+                B(CallRuntime), U16(Runtime::kCreatePrivateNameSymbol), R(7), U8(1),
+                B(StaCurrentContextSlot), U8(5),
+                B(PopContext), R(4),
+                B(Mov), R(2), R(1),
+  /*  106 S> */ B(Ldar), R(3),
+  /*  106 E> */ B(Construct), R(3), R(0), U8(0), U8(0),
+  /*  115 S> */ B(Ldar), R(2),
+  /*  115 E> */ B(Construct), R(2), R(0), U8(0), U8(2),
+                B(LdaUndefined),
+  /*  124 S> */ B(Return),
+]
+constant pool: [
+  SCOPE_INFO_TYPE,
+  FIXED_ARRAY_TYPE,
+  SHARED_FUNCTION_INFO_TYPE,
+  SHARED_FUNCTION_INFO_TYPE,
+  ONE_BYTE_INTERNALIZED_STRING_TYPE ["D"],
+  SCOPE_INFO_TYPE,
+  FIXED_ARRAY_TYPE,
+  SHARED_FUNCTION_INFO_TYPE,
+  SHARED_FUNCTION_INFO_TYPE,
+  ONE_BYTE_INTERNALIZED_STRING_TYPE ["E"],
+]
+handlers: [
+]
+

test/cctest/interpreter/test-bytecode-generator.cc

@@ -2757,6 +2757,38 @@ TEST(PrivateClassFields) {
                      LoadGolden("PrivateClassFields.golden")));
 }
 
+TEST(PrivateMethods) {
+  bool old_methods_flag = i::FLAG_harmony_private_methods;
+  i::FLAG_harmony_private_methods = true;
+  InitializedIgnitionHandleScope scope;
+  BytecodeExpectationsPrinter printer(CcTest::isolate());
+
+  const char* snippets[] = {
+      "{\n"
+      "  class A {\n"
+      "    #a() { return 1; }\n"
+      "  }\n"
+      "\n"
+      "  new A;\n"
+      "}\n",
+
+      "{\n"
+      "  class D {\n"
+      "    #d() {}\n"
+      "  }\n"
+      "\n"
+      "  class E extends D {\n"
+      "    #e() {}\n"
+      "  }\n"
+      "\n"
+      "  new D;\n"
+      "  new E;\n"
+      "}\n"};
+  CHECK(CompareTexts(BuildActual(printer, snippets),
+                     LoadGolden("PrivateMethods.golden")));
+  i::FLAG_harmony_private_methods = old_methods_flag;
+}
+
 TEST(StaticClassFields) {
   InitializedIgnitionHandleScope scope;
   BytecodeExpectationsPrinter printer(CcTest::isolate());

test/mjsunit/harmony/private-methods.js

+// Copyright 2019 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.
+
+// Flags: --harmony-private-methods
+
+"use strict";
+
+{
+  class C {
+    #a() {}
+  }
+  new C;
+}
+
+{
+  class C {
+    #a() {
+      class B {
+        #a() {  }
+      }
+      new B;
+    }
+  }
+  new C;
+}
+
+{
+  class A {
+    #a() {
+      class C extends A {
+        #c() { }
+      }
+      new C;
+    }
+  }
+
+  new A;
+}
+
+{
+  const C = class {
+    #a() { }
+  }
+  new C;
+}
+
+{
+  const C = class {
+    #a() {
+      const B = class {
+        #a() {  }
+      }
+      new B;
+    }
+  }
+  new C;
+}
+
+{
+  class A {
+    constructor(arg) {
+      return arg;
+    }
+  }
+
+  class C extends A {
+    #x() { }
+
+    constructor(arg) {
+      super(arg);
+    }
+  }
+
+  // Add the brand twice on the same object.
+  let c1 = new C({});
+  assertThrows(() => new C(c1), TypeError);
+}
+
+{
+  // TODO(v8:9177): test extending a class expression that does not have
+  // a private method.
+  class D extends class {
+    #c() {}
+  } {
+    #d() {}
+  }
+
+  class E extends D {
+    #e() {}
+  }
+
+  new D;
+  new E;
+}

tools/v8heapconst.py

@@ -306,49 +306,49 @@ KNOWN_MAPS = {
   ("read_only_space", 0x026e9): (98, "EnumCacheMap"),
   ("read_only_space", 0x02789): (115, "ArrayBoilerplateDescriptionMap"),
   ("read_only_space", 0x02ad9): (101, "InterceptorInfoMap"),
-  ("read_only_space", 0x05141): (89, "AccessCheckInfoMap"),
-  ("read_only_space", 0x05191): (90, "AccessorInfoMap"),
-  ("read_only_space", 0x051e1): (91, "AccessorPairMap"),
-  ("read_only_space", 0x05231): (92, "AliasedArgumentsEntryMap"),
-  ("read_only_space", 0x05281): (93, "AllocationMementoMap"),
-  ("read_only_space", 0x052d1): (94, "AsmWasmDataMap"),
-  ("read_only_space", 0x05321): (95, "AsyncGeneratorRequestMap"),
-  ("read_only_space", 0x05371): (96, "ClassPositionsMap"),
-  ("read_only_space", 0x053c1): (97, "DebugInfoMap"),
-  ("read_only_space", 0x05411): (99, "FunctionTemplateInfoMap"),
-  ("read_only_space", 0x05461): (100, "FunctionTemplateRareDataMap"),
-  ("read_only_space", 0x054b1): (102, "InterpreterDataMap"),
-  ("read_only_space", 0x05501): (103, "ModuleInfoEntryMap"),
-  ("read_only_space", 0x05551): (104, "ModuleMap"),
-  ("read_only_space", 0x055a1): (105, "ObjectTemplateInfoMap"),
-  ("read_only_space", 0x055f1): (106, "PromiseCapabilityMap"),
-  ("read_only_space", 0x05641): (107, "PromiseReactionMap"),
-  ("read_only_space", 0x05691): (108, "PrototypeInfoMap"),
-  ("read_only_space", 0x056e1): (109, "ScriptMap"),
-  ("read_only_space", 0x05731): (110, "SourcePositionTableWithFrameCacheMap"),
-  ("read_only_space", 0x05781): (111, "StackFrameInfoMap"),
-  ("read_only_space", 0x057d1): (112, "StackTraceFrameMap"),
-  ("read_only_space", 0x05821): (113, "Tuple2Map"),
-  ("read_only_space", 0x05871): (114, "Tuple3Map"),
-  ("read_only_space", 0x058c1): (116, "WasmCapiFunctionDataMap"),
-  ("read_only_space", 0x05911): (117, "WasmDebugInfoMap"),
-  ("read_only_space", 0x05961): (118, "WasmExceptionTagMap"),
-  ("read_only_space", 0x059b1): (119, "WasmExportedFunctionDataMap"),
-  ("read_only_space", 0x05a01): (120, "CallableTaskMap"),
-  ("read_only_space", 0x05a51): (121, "CallbackTaskMap"),
-  ("read_only_space", 0x05aa1): (122, "PromiseFulfillReactionJobTaskMap"),
-  ("read_only_space", 0x05af1): (123, "PromiseRejectReactionJobTaskMap"),
-  ("read_only_space", 0x05b41): (124, "PromiseResolveThenableJobTaskMap"),
-  ("read_only_space", 0x05b91): (125, "FinalizationGroupCleanupJobTaskMap"),
-  ("read_only_space", 0x05be1): (126, "AllocationSiteWithWeakNextMap"),
-  ("read_only_space", 0x05c31): (126, "AllocationSiteWithoutWeakNextMap"),
-  ("read_only_space", 0x05c81): (161, "LoadHandler1Map"),
-  ("read_only_space", 0x05cd1): (161, "LoadHandler2Map"),
-  ("read_only_space", 0x05d21): (161, "LoadHandler3Map"),
-  ("read_only_space", 0x05d71): (169, "StoreHandler0Map"),
-  ("read_only_space", 0x05dc1): (169, "StoreHandler1Map"),
-  ("read_only_space", 0x05e11): (169, "StoreHandler2Map"),
-  ("read_only_space", 0x05e61): (169, "StoreHandler3Map"),
+  ("read_only_space", 0x05159): (89, "AccessCheckInfoMap"),
+  ("read_only_space", 0x051a9): (90, "AccessorInfoMap"),
+  ("read_only_space", 0x051f9): (91, "AccessorPairMap"),
+  ("read_only_space", 0x05249): (92, "AliasedArgumentsEntryMap"),
+  ("read_only_space", 0x05299): (93, "AllocationMementoMap"),
+  ("read_only_space", 0x052e9): (94, "AsmWasmDataMap"),
+  ("read_only_space", 0x05339): (95, "AsyncGeneratorRequestMap"),
+  ("read_only_space", 0x05389): (96, "ClassPositionsMap"),
+  ("read_only_space", 0x053d9): (97, "DebugInfoMap"),
+  ("read_only_space", 0x05429): (99, "FunctionTemplateInfoMap"),
+  ("read_only_space", 0x05479): (100, "FunctionTemplateRareDataMap"),
+  ("read_only_space", 0x054c9): (102, "InterpreterDataMap"),
+  ("read_only_space", 0x05519): (103, "ModuleInfoEntryMap"),
+  ("read_only_space", 0x05569): (104, "ModuleMap"),
+  ("read_only_space", 0x055b9): (105, "ObjectTemplateInfoMap"),
+  ("read_only_space", 0x05609): (106, "PromiseCapabilityMap"),
+  ("read_only_space", 0x05659): (107, "PromiseReactionMap"),
+  ("read_only_space", 0x056a9): (108, "PrototypeInfoMap"),
+  ("read_only_space", 0x056f9): (109, "ScriptMap"),
+  ("read_only_space", 0x05749): (110, "SourcePositionTableWithFrameCacheMap"),
+  ("read_only_space", 0x05799): (111, "StackFrameInfoMap"),
+  ("read_only_space", 0x057e9): (112, "StackTraceFrameMap"),
+  ("read_only_space", 0x05839): (113, "Tuple2Map"),
+  ("read_only_space", 0x05889): (114, "Tuple3Map"),
+  ("read_only_space", 0x058d9): (116, "WasmCapiFunctionDataMap"),
+  ("read_only_space", 0x05929): (117, "WasmDebugInfoMap"),
+  ("read_only_space", 0x05979): (118, "WasmExceptionTagMap"),
+  ("read_only_space", 0x059c9): (119, "WasmExportedFunctionDataMap"),
+  ("read_only_space", 0x05a19): (120, "CallableTaskMap"),
+  ("read_only_space", 0x05a69): (121, "CallbackTaskMap"),
+  ("read_only_space", 0x05ab9): (122, "PromiseFulfillReactionJobTaskMap"),
+  ("read_only_space", 0x05b09): (123, "PromiseRejectReactionJobTaskMap"),
+  ("read_only_space", 0x05b59): (124, "PromiseResolveThenableJobTaskMap"),
+  ("read_only_space", 0x05ba9): (125, "FinalizationGroupCleanupJobTaskMap"),
+  ("read_only_space", 0x05bf9): (126, "AllocationSiteWithWeakNextMap"),
+  ("read_only_space", 0x05c49): (126, "AllocationSiteWithoutWeakNextMap"),
+  ("read_only_space", 0x05c99): (161, "LoadHandler1Map"),
+  ("read_only_space", 0x05ce9): (161, "LoadHandler2Map"),
+  ("read_only_space", 0x05d39): (161, "LoadHandler3Map"),
+  ("read_only_space", 0x05d89): (169, "StoreHandler0Map"),
+  ("read_only_space", 0x05dd9): (169, "StoreHandler1Map"),
+  ("read_only_space", 0x05e29): (169, "StoreHandler2Map"),
+  ("read_only_space", 0x05e79): (169, "StoreHandler3Map"),
   ("map_space", 0x00141): (1057, "ExternalMap"),
   ("map_space", 0x00191): (1073, "JSMessageObjectMap"),
 }