[objects.h splitting] Move Struct to struct.h

along with subclasses: Tuple2, Tuple3, FeedbackCell, AccessorPair.
The latter two can be separated out later if desired.

Bug: v8:5402
Change-Id: I4e1a6d2621cc6f96b5da208cff0da7cd5de91672
Reviewed-on: https://chromium-review.googlesource.com/c/1371038Reviewed-by: Marja Hölttä <marja@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Commit-Queue: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58251}

BUILD.gn

@@ -908,6 +908,8 @@ action("postmortem-metadata") {
     "src/objects/code.h",
     "src/objects/data-handler.h",
     "src/objects/data-handler-inl.h",
+    "src/objects/feedback-cell.h",
+    "src/objects/feedback-cell-inl.h",
     "src/objects/fixed-array-inl.h",
     "src/objects/fixed-array.h",
     "src/objects/heap-object-inl.h",
@@ -936,6 +938,8 @@ action("postmortem-metadata") {
     "src/objects/shared-function-info-inl.h",
     "src/objects/string.h",
     "src/objects/string-inl.h",
+    "src/objects/struct.h",
+    "src/objects/struct-inl.h",
   ]
 
   outputs = [
@@ -2296,6 +2300,8 @@ v8_source_set("v8_base") {
     "src/objects/embedder-data-array.h",
     "src/objects/embedder-data-slot-inl.h",
     "src/objects/embedder-data-slot.h",
+    "src/objects/feedback-cell-inl.h",
+    "src/objects/feedback-cell.h",
     "src/objects/fixed-array-inl.h",
     "src/objects/fixed-array.h",
     "src/objects/frame-array-inl.h",
@@ -2406,6 +2412,8 @@ v8_source_set("v8_base") {
     "src/objects/string-table-inl.h",
     "src/objects/string-table.h",
     "src/objects/string.h",
+    "src/objects/struct-inl.h",
+    "src/objects/struct.h",
     "src/objects/template-objects.cc",
     "src/objects/template-objects.h",
     "src/objects/templates-inl.h",

src/compiler.cc

@@ -27,6 +27,7 @@
 #include "src/isolate-inl.h"
 #include "src/log-inl.h"
 #include "src/message-template.h"
+#include "src/objects/feedback-cell-inl.h"
 #include "src/objects/map.h"
 #include "src/optimized-compilation-info.h"
 #include "src/parsing/parse-info.h"

src/compiler/access-info.cc

@@ -14,6 +14,7 @@
 #include "src/ic/call-optimization.h"
 #include "src/objects-inl.h"
 #include "src/objects/module-inl.h"
+#include "src/objects/struct-inl.h"
 #include "src/objects/templates.h"
 
 namespace v8 {

src/compiler/js-inlining.cc

@@ -17,6 +17,7 @@
 #include "src/compiler/operator-properties.h"
 #include "src/compiler/simplified-operator.h"
 #include "src/isolate-inl.h"
+#include "src/objects/feedback-cell-inl.h"
 #include "src/optimized-compilation-info.h"
 #include "src/parsing/parse-info.h"
 

src/handles.h

@@ -153,6 +153,7 @@ class Handle final : public HandleBase {
            (std::is_same<S, ByteArray>::value || std::is_same<S, Code>::value ||
             std::is_same<S, Context>::value ||
             std::is_same<S, DescriptorArray>::value ||
+            std::is_same<S, FeedbackCell>::value ||
             std::is_same<S, FeedbackVector>::value ||
             std::is_same<S, FixedArray>::value ||
             std::is_same<S, FixedArrayBase>::value ||

src/heap/factory.cc

@@ -23,6 +23,7 @@
 #include "src/objects/bigint.h"
 #include "src/objects/debug-objects-inl.h"
 #include "src/objects/embedder-data-array-inl.h"
+#include "src/objects/feedback-cell-inl.h"
 #include "src/objects/fixed-array-inl.h"
 #include "src/objects/frame-array-inl.h"
 #include "src/objects/instance-type-inl.h"
@@ -37,6 +38,7 @@
 #include "src/objects/promise-inl.h"
 #include "src/objects/scope-info.h"
 #include "src/objects/stack-frame-info-inl.h"
+#include "src/objects/struct-inl.h"
 #include "src/unicode-cache.h"
 #include "src/unicode-decoder.h"
 

src/heap/heap-inl.h

@@ -28,10 +28,12 @@
 #include "src/objects/allocation-site-inl.h"
 #include "src/objects/api-callbacks-inl.h"
 #include "src/objects/descriptor-array.h"
+#include "src/objects/feedback-cell-inl.h"
 #include "src/objects/literal-objects-inl.h"
 #include "src/objects/property-cell.h"
 #include "src/objects/scope-info.h"
 #include "src/objects/script-inl.h"
+#include "src/objects/struct-inl.h"
 #include "src/profiler/heap-profiler.h"
 #include "src/string-hasher.h"
 #include "src/zone/zone-list-inl.h"

src/ic/ic.cc

@@ -28,6 +28,7 @@
 #include "src/objects/hash-table-inl.h"
 #include "src/objects/js-array-inl.h"
 #include "src/objects/module-inl.h"
+#include "src/objects/struct-inl.h"
 #include "src/prototype.h"
 #include "src/runtime-profiler.h"
 #include "src/runtime/runtime-utils.h"

src/lookup.cc

@@ -11,6 +11,7 @@
 #include "src/field-type.h"
 #include "src/isolate-inl.h"
 #include "src/objects/hash-table-inl.h"
+#include "src/objects/struct-inl.h"
 
 namespace v8 {
 namespace internal {

src/messages.cc

@@ -13,6 +13,7 @@
 #include "src/keys.h"
 #include "src/objects/frame-array-inl.h"
 #include "src/objects/js-array-inl.h"
+#include "src/objects/struct-inl.h"
 #include "src/string-builder-inl.h"
 #include "src/wasm/wasm-code-manager.h"
 #include "src/wasm/wasm-objects.h"

src/objects-debug.cc

@@ -21,6 +21,7 @@
 #include "src/objects/debug-objects-inl.h"
 #include "src/objects/embedder-data-array-inl.h"
 #include "src/objects/embedder-data-slot-inl.h"
+#include "src/objects/feedback-cell-inl.h"
 #include "src/objects/hash-table-inl.h"
 #include "src/objects/js-array-inl.h"
 #ifdef V8_INTL_SUPPORT
@@ -52,6 +53,7 @@
 #include "src/objects/module-inl.h"
 #include "src/objects/promise-inl.h"
 #include "src/objects/stack-frame-info-inl.h"
+#include "src/objects/struct-inl.h"
 #include "src/ostreams.h"
 #include "src/regexp/jsregexp.h"
 #include "src/transitions.h"

src/objects-inl.h

@@ -447,7 +447,6 @@ OBJECT_CONSTRUCTORS_IMPL(FreshlyAllocatedBigInt, BigIntBase)
 // ------------------------------------
 // Cast operations
 
-CAST_ACCESSOR(AccessorPair)
 CAST_ACCESSOR2(BigInt)
 CAST_ACCESSOR2(ObjectBoilerplateDescription)
 CAST_ACCESSOR(Cell)
@@ -455,7 +454,6 @@ CAST_ACCESSOR(ArrayBoilerplateDescription)
 CAST_ACCESSOR(DataHandler)
 CAST_ACCESSOR2(EphemeronHashTable)
 CAST_ACCESSOR(EnumCache)
-CAST_ACCESSOR(FeedbackCell)
 CAST_ACCESSOR(Foreign)
 CAST_ACCESSOR(HeapObject)
 CAST_ACCESSOR(HeapNumber)
@@ -467,10 +465,7 @@ CAST_ACCESSOR2(ObjectHashTable)
 CAST_ACCESSOR(Oddball)
 CAST_ACCESSOR2(RegExpMatchInfo)
 CAST_ACCESSOR2(ScopeInfo)
-CAST_ACCESSOR(Struct)
 CAST_ACCESSOR(TemplateObjectDescription)
-CAST_ACCESSOR(Tuple2)
-CAST_ACCESSOR(Tuple3)
 
 bool Object::HasValidElements() {
   // Dictionary is covered under FixedArray.
@@ -889,7 +884,6 @@ Handle<Object> Oddball::ToNumber(Isolate* isolate, Handle<Oddball> input) {
 
 
 ACCESSORS(Cell, value, Object, kValueOffset)
-ACCESSORS(FeedbackCell, value, HeapObject, kValueOffset)
 
 inline bool IsSpecialReceiverInstanceType(InstanceType instance_type) {
   return instance_type <= LAST_SPECIAL_RECEIVER_TYPE;
@@ -914,13 +908,6 @@ bool Map::IsCustomElementsReceiverMap() const {
   return IsCustomElementsReceiverInstanceType(instance_type());
 }
 
-void Struct::InitializeBody(int object_size) {
-  Object* value = GetReadOnlyRoots().undefined_value();
-  for (int offset = kHeaderSize; offset < object_size; offset += kPointerSize) {
-    WRITE_FIELD(this, offset, value);
-  }
-}
-
 bool Object::ToArrayLength(uint32_t* index) const {
   return Object::ToUint32(index);
 }
@@ -1188,18 +1175,11 @@ int HeapObject::SizeFromMap(Map map) const {
       EmbedderDataArray::unchecked_cast(this)->length());
 }
 
-ACCESSORS(Tuple2, value1, Object, kValue1Offset)
-ACCESSORS(Tuple2, value2, Object, kValue2Offset)
-ACCESSORS(Tuple3, value3, Object, kValue3Offset)
-
 ACCESSORS2(TemplateObjectDescription, raw_strings, FixedArray,
            kRawStringsOffset)
 ACCESSORS2(TemplateObjectDescription, cooked_strings, FixedArray,
            kCookedStringsOffset)
 
-ACCESSORS(AccessorPair, getter, Object, kGetterOffset)
-ACCESSORS(AccessorPair, setter, Object, kSetterOffset)
-
 // static
 bool Foreign::IsNormalized(Object* value) {
   if (value == Smi::kZero) return true;
@@ -1313,44 +1293,6 @@ MaybeHandle<Object> Object::GetPropertyOrElement(Handle<Object> receiver,
 
 
 
-Object* AccessorPair::get(AccessorComponent component) {
-  return component == ACCESSOR_GETTER ? getter() : setter();
-}
-
-
-void AccessorPair::set(AccessorComponent component, Object* value) {
-  if (component == ACCESSOR_GETTER) {
-    set_getter(value);
-  } else {
-    set_setter(value);
-  }
-}
-
-
-void AccessorPair::SetComponents(Object* getter, Object* setter) {
-  if (!getter->IsNull()) set_getter(getter);
-  if (!setter->IsNull()) set_setter(setter);
-}
-
-bool AccessorPair::Equals(AccessorPair* pair) {
-  return (this == pair) || pair->Equals(getter(), setter());
-}
-
-
-bool AccessorPair::Equals(Object* getter_value, Object* setter_value) {
-  return (getter() == getter_value) && (setter() == setter_value);
-}
-
-
-bool AccessorPair::ContainsAccessor() {
-  return IsJSAccessor(getter()) || IsJSAccessor(setter());
-}
-
-
-bool AccessorPair::IsJSAccessor(Object* obj) {
-  return obj->IsCallable() || obj->IsUndefined();
-}
-
 // static
 Object* Object::GetSimpleHash(Object* object) {
   DisallowHeapAllocation no_gc;

src/objects-printer.cc

@@ -17,6 +17,7 @@
 #include "src/objects/debug-objects-inl.h"
 #include "src/objects/embedder-data-array-inl.h"
 #include "src/objects/embedder-data-slot-inl.h"
+#include "src/objects/feedback-cell-inl.h"
 #include "src/objects/hash-table-inl.h"
 #include "src/objects/js-array-buffer-inl.h"
 #include "src/objects/js-array-inl.h"
@@ -49,6 +50,7 @@
 #include "src/objects/module-inl.h"
 #include "src/objects/promise-inl.h"
 #include "src/objects/stack-frame-info-inl.h"
+#include "src/objects/struct-inl.h"
 #include "src/ostreams.h"
 #include "src/regexp/jsregexp.h"
 #include "src/transitions-inl.h"

src/objects.cc

@@ -90,6 +90,7 @@
 #include "src/objects/promise-inl.h"
 #include "src/objects/slots-atomic-inl.h"
 #include "src/objects/stack-frame-info-inl.h"
+#include "src/objects/struct-inl.h"
 #include "src/parsing/preparsed-scope-data.h"
 #include "src/property-descriptor.h"
 #include "src/prototype.h"

src/objects.h

@@ -284,6 +284,7 @@ class PreParsedScopeData;
 class PropertyArray;
 class PropertyCell;
 class PropertyDescriptor;
+class PrototypeInfo;
 class RegExpMatchInfo;
 class RootVisitor;
 class SafepointEntry;
@@ -1360,56 +1361,6 @@ class FreeSpace: public HeapObject {
   DISALLOW_IMPLICIT_CONSTRUCTORS(FreeSpace);
 };
 
-class PrototypeInfo;
-
-// An abstract superclass, a marker class really, for simple structure classes.
-// It doesn't carry much functionality but allows struct classes to be
-// identified in the type system.
-class Struct: public HeapObject {
- public:
-  inline void InitializeBody(int object_size);
-  DECL_CAST(Struct)
-  void BriefPrintDetails(std::ostream& os);
-};
-
-class Tuple2 : public Struct {
- public:
-  DECL_ACCESSORS(value1, Object)
-  DECL_ACCESSORS(value2, Object)
-
-  DECL_CAST(Tuple2)
-
-  // Dispatched behavior.
-  DECL_PRINTER(Tuple2)
-  DECL_VERIFIER(Tuple2)
-  void BriefPrintDetails(std::ostream& os);
-
-  static const int kValue1Offset = HeapObject::kHeaderSize;
-  static const int kValue2Offset = kValue1Offset + kPointerSize;
-  static const int kSize = kValue2Offset + kPointerSize;
-
- private:
-  DISALLOW_IMPLICIT_CONSTRUCTORS(Tuple2);
-};
-
-class Tuple3 : public Tuple2 {
- public:
-  DECL_ACCESSORS(value3, Object)
-
-  DECL_CAST(Tuple3)
-
-  // Dispatched behavior.
-  DECL_PRINTER(Tuple3)
-  DECL_VERIFIER(Tuple3)
-  void BriefPrintDetails(std::ostream& os);
-
-  static const int kValue3Offset = Tuple2::kSize;
-  static const int kSize = kValue3Offset + kPointerSize;
-
- private:
-  DISALLOW_IMPLICIT_CONSTRUCTORS(Tuple3);
-};
-
 // Utility superclass for stack-allocated objects that must be updated
 // on gc.  It provides two ways for the gc to update instances, either
 // iterating or updating after gc.
@@ -1535,32 +1486,6 @@ class Cell: public HeapObject {
   DISALLOW_IMPLICIT_CONSTRUCTORS(Cell);
 };
 
-// This is a special cell used to maintain both the link between a
-// closure and it's feedback vector, as well as a way to count the
-// number of closures created for a certain function per native
-// context. There's at most one FeedbackCell for each function in
-// a native context.
-class FeedbackCell : public Struct {
- public:
-  // [value]: value of the cell.
-  DECL_ACCESSORS(value, HeapObject)
-
-  DECL_CAST(FeedbackCell)
-
-  // Dispatched behavior.
-  DECL_PRINTER(FeedbackCell)
-  DECL_VERIFIER(FeedbackCell)
-
-  static const int kValueOffset = HeapObject::kHeaderSize;
-  static const int kSize = kValueOffset + kPointerSize;
-
-  typedef FixedBodyDescriptor<kValueOffset, kValueOffset + kPointerSize, kSize>
-      BodyDescriptor;
-
- private:
-  DISALLOW_IMPLICIT_CONSTRUCTORS(FeedbackCell);
-};
-
 // Foreign describes objects pointing from JavaScript to C structures.
 class Foreign: public HeapObject {
  public:
@@ -1594,56 +1519,6 @@ class Foreign: public HeapObject {
   DISALLOW_IMPLICIT_CONSTRUCTORS(Foreign);
 };
 
-// Support for JavaScript accessors: A pair of a getter and a setter. Each
-// accessor can either be
-//   * a JavaScript function or proxy: a real accessor
-//   * a FunctionTemplateInfo: a real (lazy) accessor
-//   * undefined: considered an accessor by the spec, too, strangely enough
-//   * null: an accessor which has not been set
-class AccessorPair: public Struct {
- public:
-  DECL_ACCESSORS(getter, Object)
-  DECL_ACCESSORS(setter, Object)
-
-  DECL_CAST(AccessorPair)
-
-  static Handle<AccessorPair> Copy(Isolate* isolate, Handle<AccessorPair> pair);
-
-  inline Object* get(AccessorComponent component);
-  inline void set(AccessorComponent component, Object* value);
-
-  // Note: Returns undefined if the component is not set.
-  static Handle<Object> GetComponent(Isolate* isolate,
-                                     Handle<AccessorPair> accessor_pair,
-                                     AccessorComponent component);
-
-  // Set both components, skipping arguments which are a JavaScript null.
-  inline void SetComponents(Object* getter, Object* setter);
-
-  inline bool Equals(AccessorPair* pair);
-  inline bool Equals(Object* getter_value, Object* setter_value);
-
-  inline bool ContainsAccessor();
-
-  // Dispatched behavior.
-  DECL_PRINTER(AccessorPair)
-  DECL_VERIFIER(AccessorPair)
-
-  static const int kGetterOffset = HeapObject::kHeaderSize;
-  static const int kSetterOffset = kGetterOffset + kPointerSize;
-  static const int kSize = kSetterOffset + kPointerSize;
-
- private:
-  // Strangely enough, in addition to functions and harmony proxies, the spec
-  // requires us to consider undefined as a kind of accessor, too:
-  //    var obj = {};
-  //    Object.defineProperty(obj, "foo", {get: undefined});
-  //    assertTrue("foo" in obj);
-  inline bool IsJSAccessor(Object* obj);
-
-  DISALLOW_IMPLICIT_CONSTRUCTORS(AccessorPair);
-};
-
 // BooleanBit is a helper class for setting and getting a bit in an integer.
 class BooleanBit : public AllStatic {
  public:

src/objects/allocation-site.h

@@ -6,6 +6,7 @@
 #define V8_OBJECTS_ALLOCATION_SITE_H_
 
 #include "src/objects.h"
+#include "src/objects/struct.h"
 
 // Has to be the last include (doesn't have include guards):
 #include "src/objects/object-macros.h"

src/objects/api-callbacks.h

@@ -5,7 +5,7 @@
 #ifndef V8_OBJECTS_API_CALLBACKS_H_
 #define V8_OBJECTS_API_CALLBACKS_H_
 
-#include "src/objects.h"
+#include "src/objects/struct.h"
 
 // Has to be the last include (doesn't have include guards):
 #include "src/objects/object-macros.h"

src/objects/arguments.h

@@ -7,6 +7,7 @@
 
 #include "src/objects/fixed-array.h"
 #include "src/objects/js-objects.h"
+#include "src/objects/struct.h"
 
 // Has to be the last include (doesn't have include guards):
 #include "src/objects/object-macros.h"

src/objects/code.h

@@ -10,6 +10,7 @@
 #include "src/objects.h"
 #include "src/objects/fixed-array.h"
 #include "src/objects/heap-object.h"
+#include "src/objects/struct.h"
 
 // Has to be the last include (doesn't have include guards):
 #include "src/objects/object-macros.h"

src/objects/data-handler.h

@@ -5,7 +5,7 @@
 #ifndef V8_OBJECTS_DATA_HANDLER_H_
 #define V8_OBJECTS_DATA_HANDLER_H_
 
-#include "src/objects.h"
+#include "src/objects/struct.h"
 
 // Has to be the last include (doesn't have include guards):
 #include "src/objects/object-macros.h"

src/objects/debug-objects.h

@@ -7,6 +7,7 @@
 
 #include "src/objects.h"
 #include "src/objects/fixed-array.h"
+#include "src/objects/struct.h"
 
 // Has to be the last include (doesn't have include guards):
 #include "src/objects/object-macros.h"

src/objects/descriptor-array-inl.h

@@ -14,6 +14,7 @@
 #include "src/lookup-cache.h"
 #include "src/objects/heap-object-inl.h"
 #include "src/objects/maybe-object.h"
+#include "src/objects/struct-inl.h"
 #include "src/property.h"
 
 // Has to be the last include (doesn't have include guards):

src/objects/descriptor-array.h

@@ -7,6 +7,7 @@
 
 #include "src/objects.h"
 #include "src/objects/fixed-array.h"
+#include "src/objects/struct.h"
 
 // Has to be the last include (doesn't have include guards):
 #include "src/objects/object-macros.h"

src/objects/feedback-cell-inl.h

+// Copyright 2018 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_OBJECTS_FEEDBACK_CELL_INL_H_
+#define V8_OBJECTS_FEEDBACK_CELL_INL_H_
+
+#include "src/objects/feedback-cell.h"
+
+#include "src/heap/heap-write-barrier-inl.h"
+
+// Has to be the last include (doesn't have include guards):
+#include "src/objects/object-macros.h"
+
+namespace v8 {
+namespace internal {
+
+CAST_ACCESSOR(FeedbackCell)
+
+ACCESSORS(FeedbackCell, value, HeapObject, kValueOffset)
+
+}  // namespace internal
+}  // namespace v8
+
+#include "src/objects/object-macros-undef.h"
+
+#endif  // V8_OBJECTS_FEEDBACK_CELL_INL_H_

src/objects/feedback-cell.h

+// Copyright 2018 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_OBJECTS_FEEDBACK_CELL_H_
+#define V8_OBJECTS_FEEDBACK_CELL_H_
+
+#include "src/objects/struct.h"
+
+// Has to be the last include (doesn't have include guards):
+#include "src/objects/object-macros.h"
+
+namespace v8 {
+namespace internal {
+
+// This is a special cell used to maintain both the link between a
+// closure and it's feedback vector, as well as a way to count the
+// number of closures created for a certain function per native
+// context. There's at most one FeedbackCell for each function in
+// a native context.
+class FeedbackCell : public Struct {
+ public:
+  // [value]: value of the cell.
+  DECL_ACCESSORS(value, HeapObject)
+
+  DECL_CAST(FeedbackCell)
+
+  // Dispatched behavior.
+  DECL_PRINTER(FeedbackCell)
+  DECL_VERIFIER(FeedbackCell)
+
+  static const int kValueOffset = HeapObject::kHeaderSize;
+  static const int kSize = kValueOffset + kPointerSize;
+
+  typedef FixedBodyDescriptor<kValueOffset, kValueOffset + kPointerSize, kSize>
+      BodyDescriptor;
+
+ private:
+  DISALLOW_IMPLICIT_CONSTRUCTORS(FeedbackCell);
+};
+
+}  // namespace internal
+}  // namespace v8
+
+#include "src/objects/object-macros-undef.h"
+
+#endif  // V8_OBJECTS_FEEDBACK_CELL_H_

src/objects/js-generator.h

@@ -6,6 +6,7 @@
 #define V8_OBJECTS_JS_GENERATOR_H_
 
 #include "src/objects/js-objects.h"
+#include "src/objects/struct.h"
 
 // Has to be the last include (doesn't have include guards):
 #include "src/objects/object-macros.h"

src/objects/js-objects-inl.h

@@ -12,6 +12,7 @@
 #include "src/keys.h"
 #include "src/lookup-inl.h"
 #include "src/objects/embedder-data-slot-inl.h"
+#include "src/objects/feedback-cell-inl.h"
 #include "src/objects/property-array-inl.h"
 #include "src/objects/shared-function-info.h"
 #include "src/objects/slots.h"

src/objects/literal-objects.cc

@@ -12,6 +12,7 @@
 #include "src/objects/hash-table-inl.h"
 #include "src/objects/literal-objects-inl.h"
 #include "src/objects/smi.h"
+#include "src/objects/struct-inl.h"
 
 namespace v8 {
 namespace internal {

src/objects/literal-objects.h

@@ -5,8 +5,8 @@
 #ifndef V8_OBJECTS_LITERAL_OBJECTS_H_
 #define V8_OBJECTS_LITERAL_OBJECTS_H_
 
-#include "src/objects.h"
 #include "src/objects/fixed-array.h"
+#include "src/objects/struct.h"
 
 // Has to be the last include (doesn't have include guards):
 #include "src/objects/object-macros.h"

src/objects/microtask.h

@@ -6,6 +6,7 @@
 #define V8_OBJECTS_MICROTASK_H_
 
 #include "src/objects.h"
+#include "src/objects/struct.h"
 
 // Has to be the last include (doesn't have include guards):
 #include "src/objects/object-macros.h"

src/objects/module.h

@@ -8,6 +8,7 @@
 #include "src/objects.h"
 #include "src/objects/fixed-array.h"
 #include "src/objects/js-objects.h"
+#include "src/objects/struct.h"
 
 // Has to be the last include (doesn't have include guards):
 #include "src/objects/object-macros.h"

src/objects/prototype-info.h

@@ -7,6 +7,7 @@
 
 #include "src/objects.h"
 #include "src/objects/fixed-array.h"
+#include "src/objects/struct.h"
 
 // Has to be the last include (doesn't have include guards):
 #include "src/objects/object-macros.h"

src/objects/script.h

@@ -7,6 +7,7 @@
 
 #include "src/objects.h"
 #include "src/objects/fixed-array.h"
+#include "src/objects/struct.h"
 
 // Has to be the last include (doesn't have include guards):
 #include "src/objects/object-macros.h"

src/objects/shared-function-info.h

@@ -10,6 +10,7 @@
 #include "src/objects/builtin-function-id.h"
 #include "src/objects/script.h"
 #include "src/objects/smi.h"
+#include "src/objects/struct.h"
 
 // Has to be the last include (doesn't have include guards):
 #include "src/objects/object-macros.h"

src/objects/stack-frame-info.h

@@ -5,7 +5,7 @@
 #ifndef V8_OBJECTS_STACK_FRAME_INFO_H_
 #define V8_OBJECTS_STACK_FRAME_INFO_H_
 
-#include "src/objects.h"
+#include "src/objects/struct.h"
 
 // Has to be the last include (doesn't have include guards):
 #include "src/objects/object-macros.h"

src/objects/struct-inl.h

+// Copyright 2018 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_OBJECTS_STRUCT_INL_H_
+#define V8_OBJECTS_STRUCT_INL_H_
+
+#include "src/objects/struct.h"
+
+#include "src/heap/heap-write-barrier-inl.h"
+
+// Has to be the last include (doesn't have include guards):
+#include "src/objects/object-macros.h"
+
+namespace v8 {
+namespace internal {
+
+CAST_ACCESSOR(AccessorPair)
+CAST_ACCESSOR(Struct)
+CAST_ACCESSOR(Tuple2)
+CAST_ACCESSOR(Tuple3)
+
+void Struct::InitializeBody(int object_size) {
+  Object* value = GetReadOnlyRoots().undefined_value();
+  for (int offset = kHeaderSize; offset < object_size; offset += kPointerSize) {
+    WRITE_FIELD(this, offset, value);
+  }
+}
+
+ACCESSORS(Tuple2, value1, Object, kValue1Offset)
+ACCESSORS(Tuple2, value2, Object, kValue2Offset)
+ACCESSORS(Tuple3, value3, Object, kValue3Offset)
+
+ACCESSORS(AccessorPair, getter, Object, kGetterOffset)
+ACCESSORS(AccessorPair, setter, Object, kSetterOffset)
+
+Object* AccessorPair::get(AccessorComponent component) {
+  return component == ACCESSOR_GETTER ? getter() : setter();
+}
+
+void AccessorPair::set(AccessorComponent component, Object* value) {
+  if (component == ACCESSOR_GETTER) {
+    set_getter(value);
+  } else {
+    set_setter(value);
+  }
+}
+
+void AccessorPair::SetComponents(Object* getter, Object* setter) {
+  if (!getter->IsNull()) set_getter(getter);
+  if (!setter->IsNull()) set_setter(setter);
+}
+
+bool AccessorPair::Equals(Object* getter_value, Object* setter_value) {
+  return (getter() == getter_value) && (setter() == setter_value);
+}
+
+}  // namespace internal
+}  // namespace v8
+
+#include "src/objects/object-macros-undef.h"
+
+#endif  // V8_OBJECTS_STRUCT_INL_H_

src/objects/struct.h

+// Copyright 2018 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_OBJECTS_STRUCT_H_
+#define V8_OBJECTS_STRUCT_H_
+
+#include "src/objects.h"
+#include "src/objects/heap-object.h"
+
+// Has to be the last include (doesn't have include guards):
+#include "src/objects/object-macros.h"
+
+namespace v8 {
+namespace internal {
+
+// An abstract superclass, a marker class really, for simple structure classes.
+// It doesn't carry much functionality but allows struct classes to be
+// identified in the type system.
+class Struct : public HeapObject {
+ public:
+  inline void InitializeBody(int object_size);
+  DECL_CAST(Struct)
+  void BriefPrintDetails(std::ostream& os);
+};
+
+class Tuple2 : public Struct {
+ public:
+  DECL_ACCESSORS(value1, Object)
+  DECL_ACCESSORS(value2, Object)
+
+  DECL_CAST(Tuple2)
+
+  // Dispatched behavior.
+  DECL_PRINTER(Tuple2)
+  DECL_VERIFIER(Tuple2)
+  void BriefPrintDetails(std::ostream& os);
+
+  static const int kValue1Offset = HeapObject::kHeaderSize;
+  static const int kValue2Offset = kValue1Offset + kPointerSize;
+  static const int kSize = kValue2Offset + kPointerSize;
+
+ private:
+  DISALLOW_IMPLICIT_CONSTRUCTORS(Tuple2);
+};
+
+class Tuple3 : public Tuple2 {
+ public:
+  DECL_ACCESSORS(value3, Object)
+
+  DECL_CAST(Tuple3)
+
+  // Dispatched behavior.
+  DECL_PRINTER(Tuple3)
+  DECL_VERIFIER(Tuple3)
+  void BriefPrintDetails(std::ostream& os);
+
+  static const int kValue3Offset = Tuple2::kSize;
+  static const int kSize = kValue3Offset + kPointerSize;
+
+ private:
+  DISALLOW_IMPLICIT_CONSTRUCTORS(Tuple3);
+};
+
+// Support for JavaScript accessors: A pair of a getter and a setter. Each
+// accessor can either be
+//   * a JavaScript function or proxy: a real accessor
+//   * a FunctionTemplateInfo: a real (lazy) accessor
+//   * undefined: considered an accessor by the spec, too, strangely enough
+//   * null: an accessor which has not been set
+class AccessorPair : public Struct {
+ public:
+  DECL_ACCESSORS(getter, Object)
+  DECL_ACCESSORS(setter, Object)
+
+  DECL_CAST(AccessorPair)
+
+  static Handle<AccessorPair> Copy(Isolate* isolate, Handle<AccessorPair> pair);
+
+  inline Object* get(AccessorComponent component);
+  inline void set(AccessorComponent component, Object* value);
+
+  // Note: Returns undefined if the component is not set.
+  static Handle<Object> GetComponent(Isolate* isolate,
+                                     Handle<AccessorPair> accessor_pair,
+                                     AccessorComponent component);
+
+  // Set both components, skipping arguments which are a JavaScript null.
+  inline void SetComponents(Object* getter, Object* setter);
+
+  inline bool Equals(Object* getter_value, Object* setter_value);
+
+  // Dispatched behavior.
+  DECL_PRINTER(AccessorPair)
+  DECL_VERIFIER(AccessorPair)
+
+  static const int kGetterOffset = HeapObject::kHeaderSize;
+  static const int kSetterOffset = kGetterOffset + kPointerSize;
+  static const int kSize = kSetterOffset + kPointerSize;
+
+ private:
+  DISALLOW_IMPLICIT_CONSTRUCTORS(AccessorPair);
+};
+
+}  // namespace internal
+}  // namespace v8
+
+#include "src/objects/object-macros-undef.h"
+
+#endif  // V8_OBJECTS_STRUCT_H_

src/objects/template-objects.h

@@ -7,6 +7,7 @@
 
 #include "src/objects.h"
 #include "src/objects/hash-table.h"
+#include "src/objects/struct.h"
 
 // Has to be the last include (doesn't have include guards):
 #include "src/objects/object-macros.h"

src/objects/templates.h

@@ -5,7 +5,7 @@
 #ifndef V8_OBJECTS_TEMPLATES_H_
 #define V8_OBJECTS_TEMPLATES_H_
 
-#include "src/objects.h"
+#include "src/objects/struct.h"
 
 // Has to be the last include (doesn't have include guards):
 #include "src/objects/object-macros.h"

src/profiler/heap-snapshot-generator.cc

@@ -15,6 +15,7 @@
 #include "src/objects-body-descriptors.h"
 #include "src/objects-inl.h"
 #include "src/objects/api-callbacks.h"
+#include "src/objects/feedback-cell-inl.h"
 #include "src/objects/hash-table-inl.h"
 #include "src/objects/js-array-buffer-inl.h"
 #include "src/objects/js-array-inl.h"
@@ -24,6 +25,7 @@
 #include "src/objects/js-regexp-inl.h"
 #include "src/objects/literal-objects-inl.h"
 #include "src/objects/slots-inl.h"
+#include "src/objects/struct-inl.h"
 #include "src/profiler/allocation-tracker.h"
 #include "src/profiler/heap-profiler.h"
 #include "src/profiler/heap-snapshot-generator-inl.h"

src/runtime/runtime-classes.cc

@@ -17,6 +17,7 @@
 #include "src/objects/hash-table-inl.h"
 #include "src/objects/literal-objects-inl.h"
 #include "src/objects/smi.h"
+#include "src/objects/struct-inl.h"
 #include "src/runtime/runtime.h"
 
 namespace v8 {

src/wasm/wasm-objects.cc

@@ -14,6 +14,7 @@
 #include "src/objects-inl.h"
 #include "src/objects/debug-objects-inl.h"
 #include "src/objects/shared-function-info.h"
+#include "src/objects/struct-inl.h"
 #include "src/trap-handler/trap-handler.h"
 #include "src/wasm/jump-table-assembler.h"
 #include "src/wasm/module-compiler.h"

test/cctest/test-code-stub-assembler.cc

@@ -22,6 +22,7 @@
 #include "src/objects/js-array-inl.h"
 #include "src/objects/promise-inl.h"
 #include "src/objects/smi.h"
+#include "src/objects/struct-inl.h"
 #include "test/cctest/compiler/code-assembler-tester.h"
 #include "test/cctest/compiler/function-tester.h"
 

test/cctest/test-feedback-vector.cc

@@ -12,6 +12,7 @@
 #include "src/heap/factory.h"
 #include "src/macro-assembler.h"
 #include "src/objects-inl.h"
+#include "src/objects/feedback-cell-inl.h"
 #include "test/cctest/test-feedback-vector.h"
 
 namespace v8 {

test/cctest/test-field-type-tracking.cc

@@ -19,6 +19,7 @@
 #include "src/ic/stub-cache.h"
 #include "src/macro-assembler.h"
 #include "src/objects-inl.h"
+#include "src/objects/struct-inl.h"
 #include "src/optimized-compilation-info.h"
 #include "src/property.h"
 #include "src/transitions.h"