[torque] generate C++ class definitions for fixed-array.h

To enable this, the following changes were necessary:
- Fix generation of accessors with MaybeObject type
  and a bunch of include problems.
- Torque-generated C++ classes now have a constructor that can allow
  Smi values to enable a hack currently used for the DescriptorArray.


Bug: v8:7793 v8:8983
Change-Id: If6e35db99199a0e2afd2698af3d84777d6d0b18f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2108036
Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Nico Hartmann <nicohartmann@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67247}

src/diagnostics/objects-debug.cc

@@ -280,8 +280,6 @@ void Symbol::SymbolVerify(Isolate* isolate) {
   CHECK_IMPLIES(IsPrivateBrand(), IsPrivateName());
 }
 
-USE_TORQUE_VERIFIER(ByteArray)
-
 void BytecodeArray::BytecodeArrayVerify(Isolate* isolate) {
   // TODO(oth): Walk bytecodes and immediate values to validate sanity.
   // - All bytecodes are known and well formed.
@@ -520,10 +518,6 @@ void EmbedderDataArray::EmbedderDataArrayVerify(Isolate* isolate) {
   }
 }
 
-USE_TORQUE_VERIFIER(FixedArrayBase)
-
-USE_TORQUE_VERIFIER(FixedArray)
-
 void WeakFixedArray::WeakFixedArrayVerify(Isolate* isolate) {
   TorqueGeneratedClassVerifiers::WeakFixedArrayVerify(*this, isolate);
   for (int i = 0; i < length(); i++) {
@@ -531,8 +525,6 @@ void WeakFixedArray::WeakFixedArrayVerify(Isolate* isolate) {
   }
 }
 
-USE_TORQUE_VERIFIER(WeakArrayList)
-
 void PropertyArray::PropertyArrayVerify(Isolate* isolate) {
   TorqueGeneratedClassVerifiers::PropertyArrayVerify(*this, isolate);
   if (length() == 0) {

src/objects/fixed-array-inl.h

@@ -21,55 +21,38 @@
 #include "src/roots/roots-inl.h"
 #include "src/sanitizer/tsan.h"
 
+#include "torque-generated/class-definitions-tq-inl.h"
+
 // Has to be the last include (doesn't have include guards):
 #include "src/objects/object-macros.h"
 
 namespace v8 {
 namespace internal {
 
-OBJECT_CONSTRUCTORS_IMPL(FixedArrayBase, HeapObject)
-OBJECT_CONSTRUCTORS_IMPL(FixedArray, FixedArrayBase)
-OBJECT_CONSTRUCTORS_IMPL(FixedDoubleArray, FixedArrayBase)
+TQ_OBJECT_CONSTRUCTORS_IMPL(FixedArrayBase)
+FixedArrayBase::FixedArrayBase(Address ptr,
+                               HeapObject::AllowInlineSmiStorage allow_smi)
+    : TorqueGeneratedFixedArrayBase(ptr, allow_smi) {}
+TQ_OBJECT_CONSTRUCTORS_IMPL(FixedArray)
+TQ_OBJECT_CONSTRUCTORS_IMPL(FixedDoubleArray)
 OBJECT_CONSTRUCTORS_IMPL(ArrayList, FixedArray)
-OBJECT_CONSTRUCTORS_IMPL(ByteArray, FixedArrayBase)
+TQ_OBJECT_CONSTRUCTORS_IMPL(ByteArray)
+ByteArray::ByteArray(Address ptr, HeapObject::AllowInlineSmiStorage allow_smi)
+    : TorqueGeneratedByteArray(ptr, allow_smi) {}
 OBJECT_CONSTRUCTORS_IMPL(TemplateList, FixedArray)
-OBJECT_CONSTRUCTORS_IMPL(WeakFixedArray, HeapObject)
-OBJECT_CONSTRUCTORS_IMPL(WeakArrayList, HeapObject)
-
-FixedArrayBase::FixedArrayBase(Address ptr, AllowInlineSmiStorage allow_smi)
-    : HeapObject(ptr, allow_smi) {
-  SLOW_DCHECK(
-      (allow_smi == AllowInlineSmiStorage::kAllowBeingASmi && IsSmi()) ||
-      IsFixedArrayBase());
-}
-
-ByteArray::ByteArray(Address ptr, AllowInlineSmiStorage allow_smi)
-    : FixedArrayBase(ptr, allow_smi) {
-  SLOW_DCHECK(
-      (allow_smi == AllowInlineSmiStorage::kAllowBeingASmi && IsSmi()) ||
-      IsByteArray());
-}
+TQ_OBJECT_CONSTRUCTORS_IMPL(WeakFixedArray)
+TQ_OBJECT_CONSTRUCTORS_IMPL(WeakArrayList)
 
 NEVER_READ_ONLY_SPACE_IMPL(WeakArrayList)
 
 CAST_ACCESSOR(ArrayList)
-CAST_ACCESSOR(ByteArray)
-CAST_ACCESSOR(FixedArray)
-CAST_ACCESSOR(FixedArrayBase)
-CAST_ACCESSOR(FixedDoubleArray)
 CAST_ACCESSOR(TemplateList)
-CAST_ACCESSOR(WeakFixedArray)
-CAST_ACCESSOR(WeakArrayList)
 
-SMI_ACCESSORS(FixedArrayBase, length, kLengthOffset)
 SYNCHRONIZED_SMI_ACCESSORS(FixedArrayBase, length, kLengthOffset)
 
-SMI_ACCESSORS(WeakFixedArray, length, kLengthOffset)
 SYNCHRONIZED_SMI_ACCESSORS(WeakFixedArray, length, kLengthOffset)
 
-SMI_ACCESSORS(WeakArrayList, capacity, kCapacityOffset)
 SYNCHRONIZED_SMI_ACCESSORS(WeakArrayList, capacity, kCapacityOffset)
-SMI_ACCESSORS(WeakArrayList, length, kLengthOffset)
 
 Object FixedArrayBase::unchecked_synchronized_length() const {
   return ACQUIRE_READ_FIELD(*this, kLengthOffset);
@@ -392,28 +375,15 @@ MaybeObject WeakFixedArray::Get(int index) const {
 
 MaybeObject WeakFixedArray::Get(const Isolate* isolate, int index) const {
   DCHECK_LT(static_cast<unsigned>(index), static_cast<unsigned>(length()));
-  return TaggedField<MaybeObject>::Relaxed_Load(isolate, *this,
-                                                OffsetOfElementAt(index));
-}
-
-void WeakFixedArray::Set(int index, MaybeObject value) {
-  DCHECK_GE(index, 0);
-  DCHECK_LT(index, length());
-  int offset = OffsetOfElementAt(index);
-  RELAXED_WRITE_WEAK_FIELD(*this, offset, value);
-  WEAK_WRITE_BARRIER(*this, offset, value);
+  return objects(isolate, index);
 }
 
 void WeakFixedArray::Set(int index, MaybeObject value, WriteBarrierMode mode) {
-  DCHECK_GE(index, 0);
-  DCHECK_LT(index, length());
-  int offset = OffsetOfElementAt(index);
-  RELAXED_WRITE_WEAK_FIELD(*this, offset, value);
-  CONDITIONAL_WEAK_WRITE_BARRIER(*this, offset, value, mode);
+  set_objects(index, value, mode);
 }
 
 MaybeObjectSlot WeakFixedArray::data_start() {
-  return RawMaybeWeakField(kHeaderSize);
+  return RawMaybeWeakField(kObjectsOffset);
 }
 
 MaybeObjectSlot WeakFixedArray::RawFieldOfElementAt(int index) {
@@ -440,20 +410,15 @@ MaybeObject WeakArrayList::Get(int index) const {
 
 MaybeObject WeakArrayList::Get(const Isolate* isolate, int index) const {
   DCHECK_LT(static_cast<unsigned>(index), static_cast<unsigned>(capacity()));
-  return TaggedField<MaybeObject>::Relaxed_Load(isolate, *this,
-                                                OffsetOfElementAt(index));
+  return objects(isolate, index);
 }
 
 void WeakArrayList::Set(int index, MaybeObject value, WriteBarrierMode mode) {
-  DCHECK_GE(index, 0);
-  DCHECK_LT(index, this->capacity());
-  int offset = OffsetOfElementAt(index);
-  RELAXED_WRITE_WEAK_FIELD(*this, offset, value);
-  CONDITIONAL_WEAK_WRITE_BARRIER(*this, offset, value, mode);
+  set_objects(index, value, mode);
 }
 
 MaybeObjectSlot WeakArrayList::data_start() {
-  return RawMaybeWeakField(kHeaderSize);
+  return RawMaybeWeakField(kObjectsOffset);
 }
 
 void WeakArrayList::CopyElements(Isolate* isolate, int dst_index,

src/objects/fixed-array.h

@@ -8,7 +8,7 @@
 #include "src/handles/maybe-handles.h"
 #include "src/objects/instance-type.h"
 #include "src/objects/smi.h"
-#include "torque-generated/field-offsets-tq.h"
+#include "torque-generated/class-definitions-tq.h"
 
 // Has to be the last include (doesn't have include guards):
 #include "src/objects/object-macros.h"
@@ -69,19 +69,14 @@ enum FixedArraySubInstanceType {
 
 // Common superclass for FixedArrays that allow implementations to share
 // common accessors and some code paths.
-class FixedArrayBase : public HeapObject {
+class FixedArrayBase
+    : public TorqueGeneratedFixedArrayBase<FixedArrayBase, HeapObject> {
  public:
-  // [length]: length of the array.
-  DECL_INT_ACCESSORS(length)
-
   // Get and set the length using acquire loads and release stores.
   DECL_SYNCHRONIZED_INT_ACCESSORS(length)
 
   inline Object unchecked_synchronized_length() const;
 
-  DECL_CAST(FixedArrayBase)
-  DECL_VERIFIER(FixedArrayBase)
-
   static int GetMaxLengthForNewSpaceAllocation(ElementsKind kind);
 
   V8_EXPORT_PRIVATE bool IsCowArray() const;
@@ -95,20 +90,15 @@ class FixedArrayBase : public HeapObject {
   static const int kMaxSize = 128 * kTaggedSize * MB - kTaggedSize;
   STATIC_ASSERT(Smi::IsValid(kMaxSize));
 
-  // Layout description.
-  DEFINE_FIELD_OFFSET_CONSTANTS(HeapObject::kHeaderSize,
-                                TORQUE_GENERATED_FIXED_ARRAY_BASE_FIELDS)
-
  protected:
-  // Special-purpose constructor for subclasses that have fast paths where
-  // their ptr() is a Smi.
-  inline FixedArrayBase(Address ptr, AllowInlineSmiStorage allow_smi);
-
-  OBJECT_CONSTRUCTORS(FixedArrayBase, HeapObject);
+  TQ_OBJECT_CONSTRUCTORS(FixedArrayBase)
+  inline FixedArrayBase(Address ptr,
+                        HeapObject::AllowInlineSmiStorage allow_smi);
 };
 
 // FixedArray describes fixed-sized arrays with element type Object.
-class FixedArray : public FixedArrayBase {
+class FixedArray
+    : public TorqueGeneratedFixedArray<FixedArray, FixedArrayBase> {
  public:
   // Setter and getter for elements.
   inline Object get(int index) const;
@@ -171,12 +161,14 @@ class FixedArray : public FixedArrayBase {
   }
 
   // Code Generation support.
-  static constexpr int OffsetOfElementAt(int index) { return SizeFor(index); }
+  static constexpr int OffsetOfElementAt(int index) {
+    STATIC_ASSERT(kObjectsOffset == SizeFor(0));
+    return SizeFor(index);
+  }
 
   // Garbage collection support.
   inline ObjectSlot RawFieldOfElementAt(int index);
 
-  DECL_CAST(FixedArray)
   // Maximally allowed length of a FixedArray.
   static const int kMaxLength = (kMaxSize - kHeaderSize) / kTaggedSize;
   static_assert(Internals::IsValidSmi(kMaxLength),
@@ -189,7 +181,6 @@ class FixedArray : public FixedArrayBase {
 
   // Dispatched behavior.
   DECL_PRINTER(FixedArray)
-  DECL_VERIFIER(FixedArray)
 
   using BodyDescriptor = FlexibleBodyDescriptor<kHeaderSize>;
 
@@ -208,7 +199,7 @@ class FixedArray : public FixedArrayBase {
   inline void set_null(ReadOnlyRoots ro_roots, int index);
   inline void set_the_hole(ReadOnlyRoots ro_roots, int index);
 
-  OBJECT_CONSTRUCTORS(FixedArray, FixedArrayBase);
+  TQ_OBJECT_CONSTRUCTORS(FixedArray)
 };
 
 // FixedArray alias added only because of IsFixedArrayExact() predicate, which
@@ -217,7 +208,8 @@ class FixedArray : public FixedArrayBase {
 class FixedArrayExact final : public FixedArray {};
 
 // FixedDoubleArray describes fixed-sized arrays with element type double.
-class FixedDoubleArray : public FixedArrayBase {
+class FixedDoubleArray
+    : public TorqueGeneratedFixedDoubleArray<FixedDoubleArray, FixedArrayBase> {
  public:
   // Setter and getter for elements.
   inline double get_scalar(int index);
@@ -245,8 +237,6 @@ class FixedDoubleArray : public FixedArrayBase {
   // Code Generation support.
   static int OffsetOfElementAt(int index) { return SizeFor(index); }
 
-  DECL_CAST(FixedDoubleArray)
-
   // Start offset of elements.
   static constexpr int kFloatsOffset = kHeaderSize;
 
@@ -261,29 +251,20 @@ class FixedDoubleArray : public FixedArrayBase {
 
   class BodyDescriptor;
 
-  OBJECT_CONSTRUCTORS(FixedDoubleArray, FixedArrayBase);
+  TQ_OBJECT_CONSTRUCTORS(FixedDoubleArray)
 };
 
 // WeakFixedArray describes fixed-sized arrays with element type
 // MaybeObject.
-class WeakFixedArray : public HeapObject {
+class WeakFixedArray
+    : public TorqueGeneratedWeakFixedArray<WeakFixedArray, HeapObject> {
  public:
-  DECL_CAST(WeakFixedArray)
-
   inline MaybeObject Get(int index) const;
   inline MaybeObject Get(const Isolate* isolate, int index) const;
 
-  // Setter that uses write barrier.
-  inline void Set(int index, MaybeObject value);
-
-  // Setter with explicit barrier mode.
-  inline void Set(int index, MaybeObject value, WriteBarrierMode mode);
-
-  static constexpr int SizeFor(int length) {
-    return kHeaderSize + length * kTaggedSize;
-  }
-
-  DECL_INT_ACCESSORS(length)
+  inline void Set(
+      int index, MaybeObject value,
+      WriteBarrierMode mode = WriteBarrierMode::UPDATE_WRITE_BARRIER);
 
   // Get and set the length using acquire loads and release stores.
   DECL_SYNCHRONIZED_INT_ACCESSORS(length)
@@ -301,9 +282,6 @@ class WeakFixedArray : public HeapObject {
 
   using BodyDescriptor = WeakArrayBodyDescriptor;
 
-  DEFINE_FIELD_OFFSET_CONSTANTS(HeapObject::kHeaderSize,
-                                TORQUE_GENERATED_WEAK_FIXED_ARRAY_FIELDS)
-
   static const int kMaxLength =
       (FixedArray::kMaxSize - kHeaderSize) / kTaggedSize;
   static_assert(Internals::IsValidSmi(kMaxLength),
@@ -319,7 +297,7 @@ class WeakFixedArray : public HeapObject {
 
   static const int kFirstIndex = 1;
 
-  OBJECT_CONSTRUCTORS(WeakFixedArray, HeapObject);
+  TQ_OBJECT_CONSTRUCTORS(WeakFixedArray)
 };
 
 // WeakArrayList is like a WeakFixedArray with static convenience methods for
@@ -327,11 +305,10 @@ class WeakFixedArray : public HeapObject {
 // capacity() returns the allocated size. The number of elements is stored at
 // kLengthOffset and is updated with every insertion. The array grows
 // dynamically with O(1) amortized insertion.
-class WeakArrayList : public HeapObject {
+class WeakArrayList
+    : public TorqueGeneratedWeakArrayList<WeakArrayList, HeapObject> {
  public:
   NEVER_READ_ONLY_SPACE
-  DECL_CAST(WeakArrayList)
-  DECL_VERIFIER(WeakArrayList)
   DECL_PRINTER(WeakArrayList)
 
   V8_EXPORT_PRIVATE static Handle<WeakArrayList> AddToEnd(
@@ -365,7 +342,7 @@ class WeakArrayList : public HeapObject {
                   WriteBarrierMode mode = UPDATE_WRITE_BARRIER);
 
   static constexpr int SizeForCapacity(int capacity) {
-    return kHeaderSize + capacity * kTaggedSize;
+    return SizeFor(capacity);
   }
 
   static constexpr int CapacityForLength(int length) {
@@ -380,15 +357,9 @@ class WeakArrayList : public HeapObject {
 
   V8_EXPORT_PRIVATE bool IsFull();
 
-  DECL_INT_ACCESSORS(capacity)
-  DECL_INT_ACCESSORS(length)
-
   // Get and set the capacity using acquire loads and release stores.
   DECL_SYNCHRONIZED_INT_ACCESSORS(capacity)
 
-  // Layout description.
-  DEFINE_FIELD_OFFSET_CONSTANTS(HeapObject::kHeaderSize,
-                                TORQUE_GENERATED_WEAK_ARRAY_LIST_FIELDS)
 
   using BodyDescriptor = WeakArrayBodyDescriptor;
 
@@ -418,7 +389,7 @@ class WeakArrayList : public HeapObject {
     return kHeaderSize + index * kTaggedSize;
   }
 
-  OBJECT_CONSTRUCTORS(WeakArrayList, HeapObject);
+  TQ_OBJECT_CONSTRUCTORS(WeakArrayList)
 };
 
 class WeakArrayList::Iterator {
@@ -494,7 +465,7 @@ inline int Search(T* array, Name name, int valid_entries = 0,
 
 // ByteArray represents fixed sized byte arrays.  Used for the relocation info
 // that is attached to code objects.
-class ByteArray : public FixedArrayBase {
+class ByteArray : public TorqueGeneratedByteArray<ByteArray, FixedArrayBase> {
  public:
   inline int Size();
 
@@ -543,12 +514,9 @@ class ByteArray : public FixedArrayBase {
   // Returns a pointer to the ByteArray object for a given data start address.
   static inline ByteArray FromDataStartAddress(Address address);
 
-  DECL_CAST(ByteArray)
-
   // Dispatched behavior.
   inline int ByteArraySize();
   DECL_PRINTER(ByteArray)
-  DECL_VERIFIER(ByteArray)
 
   // Layout description.
   static const int kAlignedSize = OBJECT_POINTER_ALIGN(kHeaderSize);
@@ -561,11 +529,8 @@ class ByteArray : public FixedArrayBase {
   class BodyDescriptor;
 
  protected:
-  // Special-purpose constructor for subclasses that have fast paths where
-  // their ptr() is a Smi.
-  inline ByteArray(Address ptr, AllowInlineSmiStorage allow_smi);
-
-  OBJECT_CONSTRUCTORS(ByteArray, FixedArrayBase);
+  TQ_OBJECT_CONSTRUCTORS(ByteArray)
+  inline ByteArray(Address ptr, HeapObject::AllowInlineSmiStorage allow_smi);
 };
 
 // Wrapper class for ByteArray which can store arbitrary C++ classes, as long

src/objects/fixed-array.tq

@@ -3,21 +3,34 @@
 // found in the LICENSE file.
 
 @abstract
+@generateCppClass
 extern class FixedArrayBase extends HeapObject {
+  // length of the array.
   const length: Smi;
 }
 
-extern class FixedArray extends FixedArrayBase { objects[length]: Object; }
+@generateCppClass
+extern class FixedArray extends FixedArrayBase {
+  objects[length]: Object;
+}
 
 type EmptyFixedArray extends FixedArray;
 
+@generateCppClass
 extern class FixedDoubleArray extends FixedArrayBase {
   floats[length]: float64_or_hole;
 }
 
-extern class WeakFixedArray extends HeapObject { length: Smi; }
+@generateCppClass
+extern class WeakFixedArray extends HeapObject {
+  const length: Smi;
+  objects[length]: MaybeObject;
+}
 
-extern class ByteArray extends FixedArrayBase {}
+@generateCppClass
+extern class ByteArray extends FixedArrayBase {
+  bytes[length]: uint8;
+}
 
 @hasSameInstanceTypeAsParent
 extern class ArrayList extends FixedArray {
@@ -28,6 +41,7 @@ extern class ArrayList extends FixedArray {
 extern class TemplateList extends FixedArray {
 }
 
+@generateCppClass
 extern class WeakArrayList extends HeapObject {
   const capacity: Smi;
   length: Smi;

src/objects/layout-descriptor-inl.h

@@ -9,6 +9,7 @@
 
 #include "src/handles/handles-inl.h"
 #include "src/objects/descriptor-array-inl.h"
+#include "src/objects/fixed-array-inl.h"
 #include "src/objects/objects-inl.h"
 #include "src/objects/smi.h"
 

src/torque/implementation-visitor.cc

@@ -3356,7 +3356,7 @@ class CppClassGenerator {
   void GenerateFieldAccessor(const Field& f);
   void GenerateFieldAccessorForUntagged(const Field& f);
   void GenerateFieldAccessorForSmi(const Field& f);
-  void GenerateFieldAccessorForObject(const Field& f);
+  void GenerateFieldAccessorForTagged(const Field& f);
 
   void GenerateClassCasts();
 
@@ -3532,14 +3532,73 @@ void CppClassGenerator::GenerateClassConstructors() {
 
   hdr_ << "protected:\n";
   hdr_ << "  inline explicit " << gen_name_ << "(Address ptr);\n";
+  hdr_ << "  // Special-purpose constructor for subclasses that have fast "
+          "paths where\n";
+  hdr_ << "  // their ptr() is a Smi.\n";
+  hdr_ << "  inline explicit " << gen_name_
+       << "(Address ptr, HeapObject::AllowInlineSmiStorage allow_smi);\n";
 
   inl_ << "template<class D, class P>\n";
   inl_ << "inline " << gen_name_T_ << "::" << gen_name_ << "(Address ptr)\n";
   inl_ << "  : P(ptr) {\n";
   inl_ << "  SLOW_DCHECK(this->Is" << name_ << "());\n";
   inl_ << "}\n";
+
+  inl_ << "template<class D, class P>\n";
+  inl_ << "inline " << gen_name_T_ << "::" << gen_name_
+       << "(Address ptr, HeapObject::AllowInlineSmiStorage allow_smi)\n";
+  inl_ << "  : P(ptr, allow_smi) {\n";
+  inl_ << "  SLOW_DCHECK((allow_smi == "
+          "HeapObject::AllowInlineSmiStorage::kAllowBeingASmi && "
+       << "this->IsSmi()) || this->Is" << name_ << "());\n";
+  inl_ << "}\n";
+}
+
+namespace {
+std::string GenerateRuntimeTypeCheck(const Type* type,
+                                     const std::string& value) {
+  bool maybe_object = !type->IsSubtypeOf(TypeOracle::GetStrongTaggedType());
+  std::stringstream type_check;
+  bool at_start = true;
+  // If weak pointers are allowed, then start by checking for a cleared value.
+  if (maybe_object) {
+    type_check << value << ".IsCleared()";
+    at_start = false;
+  }
+  for (const RuntimeType& runtime_type : type->GetRuntimeTypes()) {
+    if (!at_start) type_check << " || ";
+    at_start = false;
+    if (maybe_object) {
+      bool strong = runtime_type.weak_ref_to.empty();
+      if (strong && runtime_type.type == "MaybeObject") {
+        // Rather than a generic Weak<T>, this is a basic type Tagged or
+        // WeakHeapObject. We can't validate anything more about the type of
+        // the object pointed to, so just check that it's weak.
+        type_check << value << ".IsWeak()";
+      } else {
+        type_check << "(" << (strong ? "!" : "") << value << ".IsWeak() && "
+                   << value << ".GetHeapObjectOrSmi().Is"
+                   << (strong ? runtime_type.type : runtime_type.weak_ref_to)
+                   << "())";
+      }
+    } else {
+      type_check << value << ".Is" << runtime_type.type << "()";
+    }
+  }
+  return type_check.str();
 }
 
+void GenerateBoundsDCheck(std::ostream& os, const std::string& index,
+                          const ClassType* type, const Field& f) {
+  os << "  DCHECK_GE(" << index << ", 0);\n";
+  if (base::Optional<NameAndType> array_length =
+          ExtractSimpleFieldArraySize(*type, *f.index)) {
+    os << "  DCHECK_LT(" << index << ", this->" << array_length->name
+       << "());\n";
+  }
+}
+}  // namespace
+
 // TODO(sigurds): Keep in sync with DECL_ACCESSORS and ACCESSORS macro.
 void CppClassGenerator::GenerateFieldAccessor(const Field& f) {
   const Type* field_type = f.name_and_type.type;
@@ -3554,8 +3613,8 @@ void CppClassGenerator::GenerateFieldAccessor(const Field& f) {
   if (f.name_and_type.type->IsSubtypeOf(TypeOracle::GetSmiType())) {
     return GenerateFieldAccessorForSmi(f);
   }
-  if (f.name_and_type.type->IsSubtypeOf(TypeOracle::GetObjectType())) {
-    return GenerateFieldAccessorForObject(f);
+  if (f.name_and_type.type->IsSubtypeOf(TypeOracle::GetTaggedType())) {
+    return GenerateFieldAccessorForTagged(f);
   }
 
   Error("Generation of field accessor for ", type_->name(),
@@ -3599,6 +3658,7 @@ void CppClassGenerator::GenerateFieldAccessorForUntagged(const Field& f) {
   }
   inl_ << ") const {\n";
   if (f.index) {
+    GenerateBoundsDCheck(inl_, "i", type_, f);
     size_t field_size;
     std::string size_string;
     std::tie(field_size, size_string) = f.GetFieldSizeInformation();
@@ -3617,6 +3677,7 @@ void CppClassGenerator::GenerateFieldAccessorForUntagged(const Field& f) {
   }
   inl_ << type << " value) {\n";
   if (f.index) {
+    GenerateBoundsDCheck(inl_, "i", type_, f);
     size_t field_size;
     std::string size_string;
     std::tie(field_size, size_string) = f.GetFieldSizeInformation();
@@ -3653,6 +3714,7 @@ void CppClassGenerator::GenerateFieldAccessorForSmi(const Field& f) {
   }
   inl_ << ") const {\n";
   if (f.index) {
+    GenerateBoundsDCheck(inl_, "i", type_, f);
     inl_ << "  int offset = " << offset << " + i * kTaggedSize;\n";
     inl_ << "  return this->template ReadField<Smi>(offset).value();\n";
     inl_ << "}\n";
@@ -3669,6 +3731,7 @@ void CppClassGenerator::GenerateFieldAccessorForSmi(const Field& f) {
   }
   inl_ << type << " value) {\n";
   if (f.index) {
+    GenerateBoundsDCheck(inl_, "i", type_, f);
     inl_ << "  int offset = " << offset << " + i * kTaggedSize;\n";
     inl_ << "  WRITE_FIELD(*this, offset, Smi::FromInt(value));\n";
   } else {
@@ -3677,18 +3740,16 @@ void CppClassGenerator::GenerateFieldAccessorForSmi(const Field& f) {
   inl_ << "}\n\n";
 }
 
-void CppClassGenerator::GenerateFieldAccessorForObject(const Field& f) {
+void CppClassGenerator::GenerateFieldAccessorForTagged(const Field& f) {
   const Type* field_type = f.name_and_type.type;
-  DCHECK(field_type->IsSubtypeOf(TypeOracle::GetObjectType()));
+  DCHECK(field_type->IsSubtypeOf(TypeOracle::GetTaggedType()));
   const std::string& name = f.name_and_type.name;
-  const std::string offset = "k" + CamelifyString(name) + "Offset";
-  base::Optional<const ClassType*> class_type = field_type->ClassSupertype();
-
-  std::string type =
-      class_type ? (*class_type)->GetGeneratedTNodeTypeName() : "Object";
+  std::string offset = "k" + CamelifyString(name) + "Offset";
+  bool strong_pointer = field_type->IsSubtypeOf(TypeOracle::GetObjectType());
 
+  std::string type = field_type->GetRuntimeType();
   // Generate declarations in header.
-  if (!class_type && field_type != TypeOracle::GetObjectType()) {
+  if (!field_type->IsClassType() && field_type != TypeOracle::GetObjectType()) {
     hdr_ << "  // Torque type: " << field_type->ToString() << "\n";
   }
 
@@ -3699,11 +3760,7 @@ void CppClassGenerator::GenerateFieldAccessorForObject(const Field& f) {
   hdr_ << "  inline void set_" << name << "(" << (f.index ? "int i, " : "")
        << type << " value, WriteBarrierMode mode = UPDATE_WRITE_BARRIER);\n\n";
 
-  std::string type_check;
-  for (const RuntimeType& runtime_type : field_type->GetRuntimeTypes()) {
-    if (!type_check.empty()) type_check += " || ";
-    type_check += "value.Is" + runtime_type.type + "()";
-  }
+  std::string type_check = GenerateRuntimeTypeCheck(field_type, "value");
 
   // Generate implementation in inline header.
   inl_ << "template <class D, class P>\n";
@@ -3719,28 +3776,25 @@ void CppClassGenerator::GenerateFieldAccessorForObject(const Field& f) {
        << "(const Isolate* isolate" << (f.index ? ", int i" : "")
        << ") const {\n";
 
-  if (class_type) {
-    if (f.index) {
-      inl_ << "  int offset = " << offset << " + i * kTaggedSize;\n";
-      inl_ << "  return " << type
-           << "::cast(RELAXED_READ_FIELD(*this, offset));\n";
-    } else {
-      inl_ << "  return TaggedField<" << type << ", " << offset
-           << ">::load(isolate, *this);\n";
-    }
-  } else {
-    // TODO(tebbi): load value as HeapObject when possible
+  // TODO(tebbi): The distinction between relaxed and non-relaxed accesses here
+  // is pretty arbitrary and just tries to preserve what was there before.
+  // It currently doesn't really make a difference due to concurrent marking
+  // turning all loads and stores to be relaxed. We should probably drop the
+  // distinction at some point, even though in principle non-relaxed operations
+  // would give us TSAN protection.
   if (f.index) {
+    GenerateBoundsDCheck(inl_, "i", type_, f);
     inl_ << "  int offset = " << offset << " + i * kTaggedSize;\n";
-      inl_ << "  Object value = Object::cast(RELAXED_READ_FIELD(*this, "
-              "offset));\n";
+    inl_ << "  auto value = TaggedField<" << type
+         << ">::Relaxed_Load(isolate, *this, offset);\n";
   } else {
-      inl_ << "  Object value = TaggedField<Object, " << offset
+    inl_ << "  auto value = TaggedField<" << type << ", " << offset
          << ">::load(isolate, *this);\n";
   }
+  if (!type_check.empty()) {
     inl_ << "  DCHECK(" << type_check << ");\n";
-    inl_ << "  return value;\n";
   }
+  inl_ << "  return value;\n";
   inl_ << "}\n";
 
   inl_ << "template <class D, class P>\n";
@@ -3749,22 +3803,30 @@ void CppClassGenerator::GenerateFieldAccessorForObject(const Field& f) {
     inl_ << "int i, ";
   }
   inl_ << type << " value, WriteBarrierMode mode) {\n";
+  if (!type_check.empty()) {
     inl_ << "  SLOW_DCHECK(" << type_check << ");\n";
+  }
   if (f.index) {
+    GenerateBoundsDCheck(inl_, "i", type_, f);
+    const char* write_macro =
+        strong_pointer ? "WRITE_FIELD" : "RELAXED_WRITE_WEAK_FIELD";
     inl_ << "  int offset = " << offset << " + i * kTaggedSize;\n";
-    inl_ << "  WRITE_FIELD(*this, offset, value);\n";
+    offset = "offset";
+    inl_ << "  " << write_macro << "(*this, offset, value);\n";
   } else {
-    inl_ << "  WRITE_FIELD(*this, " << offset << ", value);\n";
+    const char* write_macro =
+        strong_pointer ? "RELAXED_WRITE_FIELD" : "RELAXED_WRITE_WEAK_FIELD";
+    inl_ << "  " << write_macro << "(*this, " << offset << ", value);\n";
   }
-  inl_ << "  CONDITIONAL_WRITE_BARRIER(*this, " << offset
-       << ", value, mode);\n";
+  const char* write_barrier = strong_pointer ? "CONDITIONAL_WRITE_BARRIER"
+                                             : "CONDITIONAL_WEAK_WRITE_BARRIER";
+  inl_ << "  " << write_barrier << "(*this, " << offset << ", value, mode);\n";
   inl_ << "}\n\n";
 }
 
 void EmitClassDefinitionHeadersIncludes(const std::string& basename,
                                         std::stringstream& header,
                                         std::stringstream& inline_header) {
-  header << "#include \"src/objects/fixed-array.h\"\n";
   header << "#include \"src/objects/objects.h\"\n";
   header << "#include \"src/objects/smi.h\"\n";
   header << "#include \"torque-generated/field-offsets-tq.h\"\n";
@@ -3834,8 +3896,12 @@ void ImplementationVisitor::GenerateClassDefinitions(
     IncludeGuardScope internal_inline_header_guard(
         inline_internal_header, internal_basename + "-inl.h");
 
-    external_header
+    internal_header << "#include \"torque-generated/class-definitions-tq.h\"\n";
+    internal_header << "#include \"src/objects/fixed-array.h\"\n";
+    inline_internal_header
         << "#include \"torque-generated/internal-class-definitions-tq.h\"\n";
+    inline_internal_header
+        << "#include \"torque-generated/class-definitions-tq-inl.h\"\n";
 
     EmitClassDefinitionHeadersIncludes(basename, external_header,
                                        inline_external_header);
@@ -4255,34 +4321,8 @@ void GenerateFieldValueVerifier(const std::string& class_name,
   // the Object type because it would not check anything beyond what we already
   // checked with VerifyPointer.
   if (field_type != TypeOracle::GetObjectType()) {
-    std::stringstream type_check;
-    bool at_start = true;
-    // If weak pointers are allowed, then start by checking for a cleared value.
-    if (maybe_object) {
-      type_check << value << ".IsCleared()";
-      at_start = false;
-    }
-    for (const RuntimeType& runtime_type : field_type->GetRuntimeTypes()) {
-      if (!at_start) type_check << " || ";
-      at_start = false;
-      if (maybe_object) {
-        bool strong = runtime_type.weak_ref_to.empty();
-        if (strong && runtime_type.type == "MaybeObject") {
-          // Rather than a generic Weak<T>, this is a basic type Tagged or
-          // WeakHeapObject. We can't validate anything more about the type of
-          // the object pointed to, so just check that it's weak.
-          type_check << value << ".IsWeak()";
-        } else {
-          type_check << "(" << (strong ? "!" : "") << value << ".IsWeak() && "
-                     << value << ".GetHeapObjectOrSmi().Is"
-                     << (strong ? runtime_type.type : runtime_type.weak_ref_to)
-                     << "())";
-        }
-      } else {
-        type_check << value << ".Is" << runtime_type.type << "()";
-      }
-    }
-    cc_contents << "    CHECK(" << type_check.str() << ");\n";
+    cc_contents << "    CHECK(" << GenerateRuntimeTypeCheck(field_type, value)
+                << ");\n";
   }
 }
 

src/torque/types.cc

@@ -946,6 +946,13 @@ base::Optional<NameAndType> ExtractSimpleFieldArraySize(
   return class_type.LookupField(identifier->name->value).name_and_type;
 }
 
+std::string Type::GetRuntimeType() const {
+  // TODO(tebbi): Other types are currently unsupported, since there the TNode
+  // types and the C++ runtime types disagree.
+  DCHECK(this->IsSubtypeOf(TypeOracle::GetTaggedType()));
+  return GetGeneratedTNodeTypeName();
+}
+
 }  // namespace torque
 }  // namespace internal
 }  // namespace v8

src/torque/types.h

@@ -135,6 +135,7 @@ class V8_EXPORT_PRIVATE Type : public TypeBase {
   base::Optional<const ClassType*> ClassSupertype() const;
   base::Optional<const StructType*> StructSupertype() const;
   virtual std::vector<RuntimeType> GetRuntimeTypes() const { return {}; }
+  virtual std::string GetRuntimeType() const;
   static const Type* CommonSupertype(const Type* a, const Type* b);
   void AddAlias(std::string alias) const { aliases_.insert(std::move(alias)); }
   size_t id() const { return id_; }
@@ -375,6 +376,9 @@ class V8_EXPORT_PRIVATE UnionType final : public Type {
     return "TNode<" + GetGeneratedTNodeTypeName() + ">";
   }
   std::string GetGeneratedTNodeTypeNameImpl() const override;
+  std::string GetRuntimeType() const override {
+    return parent()->GetRuntimeType();
+  }
 
   friend size_t hash_value(const UnionType& p) {
     size_t result = 0;