[torque] Support non-tagged fields in classes

In the process add missing base	Torque functionality for 8-bit and
16-bit integers and Cast<> operators to make them easy to use.

As a poster child, port the field declarations of SharedFunctionInfo
to the class definition in base.tq.

As a drive by: Add the missing GN dependency on
class-definitions-from-dsl.h

Bug: v8:7793
Change-Id: I76a41c2e81ffd1cbb90ac7a4ef8d4003ac86e8dc
Reviewed-on: https://chromium-review.googlesource.com/c/1445882Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Commit-Queue: Daniel Clifford <danno@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59321}

BUILD.gn

@@ -930,6 +930,7 @@ action("run_torque") {
 
   outputs = [
     "$target_gen_dir/torque-generated/builtin-definitions-from-dsl.h",
+    "$target_gen_dir/torque-generated/class-definitions-from-dsl.h",
   ]
   foreach(namespace, torque_namespaces) {
     outputs += [

src/builtins/arguments.tq

@@ -28,7 +28,7 @@ namespace arguments {
 
     const shared: SharedFunctionInfo = f.shared_function_info;
     const formalParameterCount: bint =
-        Convert<bint>(shared.formal_parameter_count);
+        Convert<bint>(Convert<int32>(shared.formal_parameter_count));
     let argumentCount: bint = formalParameterCount;
 
     const adaptor: ArgumentsAdaptorFrame =

src/builtins/base.tq

@@ -28,6 +28,17 @@ class HeapObject extends Tagged {
 type Object = Smi | HeapObject;
 type int32 generates 'TNode<Int32T>' constexpr 'int32_t';
 type uint32 generates 'TNode<Uint32T>' constexpr 'uint32_t';
+type int31 extends int32
+    generates 'TNode<Int32T>' constexpr 'int31_t';
+type uint31 extends uint32
+    generates 'TNode<Uint32T>' constexpr 'uint31_t';
+type int16 extends int31
+    generates 'TNode<Int32T>' constexpr 'int16_t';
+type uint16 extends uint31
+    generates 'TNode<Uint32T>' constexpr 'uint16_t';
+type int8 extends int16 generates 'TNode<Int32T>' constexpr 'int8_t';
+type uint8 extends uint16
+    generates 'TNode<Uint32T>' constexpr 'uint8_t';
 type int64 generates 'TNode<Int64T>' constexpr 'int64_t';
 type intptr generates 'TNode<IntPtrT>' constexpr 'intptr_t';
 type uintptr generates 'TNode<UintPtrT>' constexpr 'uintptr_t';
@@ -37,8 +48,6 @@ type bool generates 'TNode<BoolT>' constexpr 'bool';
 type bint generates 'TNode<BInt>' constexpr 'BInt';
 type string constexpr 'const char*';
 
-type int31 extends int32
-    generates 'TNode<Int32T>' constexpr 'int31_t';
 type RawPtr generates 'TNode<RawPtrT>' constexpr 'void*';
 type AbstractCode extends HeapObject generates 'TNode<AbstractCode>';
 type Code extends AbstractCode generates 'TNode<Code>';
@@ -124,8 +133,28 @@ transient type FastJSArrayForCopy extends FastJSArray
 transient type FastJSArrayWithNoCustomIteration extends FastJSArray
     generates 'TNode<JSArray>';
 
-type SharedFunctionInfo extends HeapObject
-    generates 'TNode<SharedFunctionInfo>';
+type NoSharedNameSentinel extends Smi;
+type Script extends HeapObject;
+type DebugInfo extends HeapObject;
+
+type ScopeInfo extends Object generates 'TNode<ScopeInfo>';
+
+class SharedFunctionInfo extends HeapObject {
+  weak function_data: Object;
+  name_or_scope_info: String | NoSharedNameSentinel | ScopeInfo;
+  outer_scope_info_or_feedback_metadata: HeapObject;
+  script_or_debug_info: Script | DebugInfo;
+  length: int16;
+  formal_parameter_count: uint16;
+  expected_nof_properties: int8;
+  builtin_function_id: int8;
+  function_token_offset: int16;
+  flags: int32;
+}
+
+class SharedFunctionInfoWithID extends SharedFunctionInfo {
+  unique_id: int32;
+}
 
 class JSFunction extends JSObject {
   shared_function_info: SharedFunctionInfo;
@@ -135,9 +164,6 @@ class JSFunction extends JSObject {
   weak prototype_or_initial_map: JSReceiver | Map;
 }
 
-extern operator '.formal_parameter_count'
-    macro LoadSharedFunctionInfoFormalParameterCount(SharedFunctionInfo): int32;
-
 class JSBoundFunction extends JSObject {
   bound_target_function: JSReceiver;
   bound_this: Object;
@@ -870,9 +896,13 @@ extern macro ChangeUint32ToTagged(uint32): Number;
 extern macro ChangeUintPtrToFloat64(uintptr): float64;
 extern macro ChangeUintPtrToTagged(uintptr): Number;
 extern macro Unsigned(int32): uint32;
+extern macro Unsigned(int16): uint16;
+extern macro Unsigned(int8): uint8;
 extern macro Unsigned(intptr): uintptr;
 extern macro Unsigned(RawPtr): uintptr;
 extern macro Signed(uint32): int32;
+extern macro Signed(uint16): int16;
+extern macro Signed(uint8): int8;
 extern macro Signed(uintptr): intptr;
 extern macro Signed(RawPtr): intptr;
 extern macro TruncateIntPtrToInt32(intptr): int32;
@@ -1020,6 +1050,15 @@ Convert<Smi, uint32>(ui: uint32): Smi {
 Convert<uintptr, uint32>(ui: uint32): uintptr {
   return ChangeUint32ToWord(ui);
 }
+Convert<int32, uint8>(i: uint8): int32 {
+  return Signed(Convert<uint32>(i));
+}
+Convert<int32, uint16>(i: uint16): int32 {
+  return Signed(Convert<uint32>(i));
+}
+Convert<int32, uint31>(i: uint31): int32 {
+  return Signed(Convert<uint32>(i));
+}
 Convert<int32, intptr>(i: intptr): int32 {
   return TruncateIntPtrToInt32(i);
 }

src/code-stub-assembler.h

@@ -1180,13 +1180,6 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
   TNode<BytecodeArray> LoadSharedFunctionInfoBytecodeArray(
       SloppyTNode<SharedFunctionInfo> shared);
 
-  TNode<Int32T> LoadSharedFunctionInfoFormalParameterCount(
-      TNode<SharedFunctionInfo> function) {
-    return TNode<Int32T>::UncheckedCast(LoadObjectField(
-        function, SharedFunctionInfo::kFormalParameterCountOffset,
-        MachineType::Uint16()));
-  }
-
   void StoreObjectByteNoWriteBarrier(TNode<HeapObject> object, int offset,
                                      TNode<Word32T> value);
 

src/heap/factory.cc

@@ -3675,7 +3675,8 @@ Handle<SharedFunctionInfo> Factory::NewSharedFunctionInfo(
     }
     share->set_script_or_debug_info(*undefined_value(), SKIP_WRITE_BARRIER);
 #if V8_SFI_HAS_UNIQUE_ID
-    share->set_unique_id(isolate()->GetNextUniqueSharedFunctionInfoId());
+    Handle<SharedFunctionInfoWithID>::cast(share)->set_unique_id(
+        isolate()->GetNextUniqueSharedFunctionInfoId());
 #endif
 
     // Set integer fields (smi or int, depending on the architecture).

src/heap/setup-heap-internal.cc

@@ -496,8 +496,13 @@ bool Heap::CreateInitialMaps() {
     ALLOCATE_MAP(UNCOMPILED_DATA_WITH_PREPARSE_DATA_TYPE,
                  UncompiledDataWithPreparseData::kSize,
                  uncompiled_data_with_preparse_data)
+#if V8_SFI_HAS_UNIQUE_ID
+    ALLOCATE_MAP(SHARED_FUNCTION_INFO_TYPE,
+                 SharedFunctionInfoWithID::kAlignedSize, shared_function_info)
+#else
     ALLOCATE_MAP(SHARED_FUNCTION_INFO_TYPE, SharedFunctionInfo::kAlignedSize,
                  shared_function_info)
+#endif
 
     ALLOCATE_MAP(CODE_DATA_CONTAINER_TYPE, CodeDataContainer::kSize,
                  code_data_container)

src/log.cc

@@ -1664,7 +1664,7 @@ void Logger::MapEvent(const char* type, Map from, Map to, const char* reason,
       SharedFunctionInfo sfi = SharedFunctionInfo::cast(name_or_sfi);
       msg << sfi->DebugName();
 #if V8_SFI_HAS_UNIQUE_ID
-      msg << " " << sfi->unique_id();
+      msg << " " << SharedFunctionInfoWithID::cast(sfi)->unique_id();
 #endif  // V8_SFI_HAS_UNIQUE_ID
     }
   }

src/objects-body-descriptors-inl.h

@@ -247,8 +247,7 @@ class SharedFunctionInfo::BodyDescriptor final : public BodyDescriptorBase {
   static inline void IterateBody(Map map, HeapObject obj, int object_size,
                                  ObjectVisitor* v) {
     IterateCustomWeakPointer(obj, kFunctionDataOffset, v);
-    IteratePointers(obj,
-                    SharedFunctionInfo::kStartOfAlwaysStrongPointerFieldsOffset,
+    IteratePointers(obj, SharedFunctionInfo::kStartOfStrongFieldsOffset,
                     SharedFunctionInfo::kEndOfTaggedFieldsOffset, v);
   }
 

src/objects/shared-function-info-inl.h

@@ -124,15 +124,13 @@ ACCESSORS(SharedFunctionInfo, name_or_scope_info, Object,
 ACCESSORS(SharedFunctionInfo, script_or_debug_info, Object,
           kScriptOrDebugInfoOffset)
 
-#if V8_SFI_HAS_UNIQUE_ID
-INT_ACCESSORS(SharedFunctionInfo, unique_id, kUniqueIdOffset)
-#endif
 UINT16_ACCESSORS(SharedFunctionInfo, length, kLengthOffset)
 UINT16_ACCESSORS(SharedFunctionInfo, internal_formal_parameter_count,
                  kFormalParameterCountOffset)
 UINT8_ACCESSORS(SharedFunctionInfo, expected_nof_properties,
                 kExpectedNofPropertiesOffset)
-UINT8_ACCESSORS(SharedFunctionInfo, raw_builtin_function_id, kBuiltinFunctionId)
+UINT8_ACCESSORS(SharedFunctionInfo, raw_builtin_function_id,
+                kBuiltinFunctionIdOffset)
 UINT16_ACCESSORS(SharedFunctionInfo, raw_function_token_offset,
                  kFunctionTokenOffsetOffset)
 RELAXED_INT32_ACCESSORS(SharedFunctionInfo, flags, kFlagsOffset)
@@ -633,6 +631,10 @@ void SharedFunctionInfo::ClearPreparseData() {
   DCHECK(HasUncompiledDataWithoutPreparseData());
 }
 
+OBJECT_CONSTRUCTORS_IMPL(SharedFunctionInfoWithID, SharedFunctionInfo)
+CAST_ACCESSOR(SharedFunctionInfoWithID)
+INT_ACCESSORS(SharedFunctionInfoWithID, unique_id, kUniqueIdOffset)
+
 // static
 void UncompiledData::Initialize(
     UncompiledData data, String inferred_name, int start_position,

src/objects/shared-function-info.h

@@ -12,6 +12,7 @@
 #include "src/objects/script.h"
 #include "src/objects/smi.h"
 #include "src/objects/struct.h"
+#include "torque-generated/class-definitions-from-dsl.h"
 
 // Has to be the last include (doesn't have include guards):
 #include "src/objects/object-macros.h"
@@ -322,12 +323,6 @@ class SharedFunctionInfo : public HeapObject {
   // function. The value is only reliable when the function has been compiled.
   DECL_UINT8_ACCESSORS(expected_nof_properties)
 
-#if V8_SFI_HAS_UNIQUE_ID
-  // [unique_id] - For --trace-maps purposes, an identifier that's persistent
-  // even if the GC moves this SharedFunctionInfo.
-  DECL_INT_ACCESSORS(unique_id)
-#endif
-
   // [function data]: This field holds some additional data for function.
   // Currently it has one of:
   //  - a FunctionTemplateInfo to make benefit the API [IsApiFunction()].
@@ -647,37 +642,8 @@ class SharedFunctionInfo : public HeapObject {
   static const uint16_t kFunctionTokenOutOfRange = static_cast<uint16_t>(-1);
   STATIC_ASSERT(kMaximumFunctionTokenOffset + 1 == kFunctionTokenOutOfRange);
 
-#if V8_SFI_HAS_UNIQUE_ID
-  static const int kUniqueIdFieldSize = kInt32Size;
-#else
-  // Just to not break the postmortrem support with conditional offsets
-  static const int kUniqueIdFieldSize = 0;
-#endif
-
-// Layout description.
-#define SHARED_FUNCTION_INFO_FIELDS(V)                    \
-  /* Pointer fields. */                                   \
-  V(kStartOfPointerFieldsOffset, 0)                       \
-  V(kFunctionDataOffset, kTaggedSize)                     \
-  V(kStartOfAlwaysStrongPointerFieldsOffset, 0)           \
-  V(kNameOrScopeInfoOffset, kTaggedSize)                  \
-  V(kOuterScopeInfoOrFeedbackMetadataOffset, kTaggedSize) \
-  V(kScriptOrDebugInfoOffset, kTaggedSize)                \
-  V(kEndOfTaggedFieldsOffset, 0)                          \
-  /* Raw data fields. */                                  \
-  V(kUniqueIdOffset, kUniqueIdFieldSize)                  \
-  V(kLengthOffset, kUInt16Size)                           \
-  V(kFormalParameterCountOffset, kUInt16Size)             \
-  V(kExpectedNofPropertiesOffset, kUInt8Size)             \
-  V(kBuiltinFunctionId, kUInt8Size)                       \
-  V(kFunctionTokenOffsetOffset, kUInt16Size)              \
-  V(kFlagsOffset, kInt32Size)                             \
-  /* Total size. */                                       \
-  V(kSize, 0)
-
   DEFINE_FIELD_OFFSET_CONSTANTS(HeapObject::kHeaderSize,
                                 SHARED_FUNCTION_INFO_FIELDS)
-#undef SHARED_FUNCTION_INFO_FIELDS
 
   static const int kAlignedSize = POINTER_SIZE_ALIGN(kSize);
 
@@ -720,6 +686,14 @@ class SharedFunctionInfo : public HeapObject {
   // This is needed to set up the [[HomeObject]] on the function instance.
   inline bool needs_home_object() const;
 
+  V8_INLINE bool IsSharedFunctionInfoWithID() const {
+#if V8_SFI_HAS_UNIQUE_ID
+    return true;
+#else
+    return false;
+#endif
+  }
+
  private:
   // [name_or_scope_info]: Function name string, kNoSharedNameSentinel or
   // ScopeInfo.
@@ -746,6 +720,22 @@ class SharedFunctionInfo : public HeapObject {
   OBJECT_CONSTRUCTORS(SharedFunctionInfo, HeapObject);
 };
 
+class SharedFunctionInfoWithID : public SharedFunctionInfo {
+ public:
+  // [unique_id] - For --trace-maps purposes, an identifier that's persistent
+  // even if the GC moves this SharedFunctionInfo.
+  DECL_INT_ACCESSORS(unique_id)
+
+  DECL_CAST(SharedFunctionInfoWithID)
+
+  DEFINE_FIELD_OFFSET_CONSTANTS(SharedFunctionInfo::kSize,
+                                SHARED_FUNCTION_INFO_WITH_ID_FIELDS)
+
+  static const int kAlignedSize = POINTER_SIZE_ALIGN(kSize);
+
+  OBJECT_CONSTRUCTORS(SharedFunctionInfoWithID, SharedFunctionInfo)
+};
+
 // Printing support.
 struct SourceCodeOf {
   explicit SourceCodeOf(SharedFunctionInfo v, int max = -1)

src/torque/csa-generator.cc

@@ -683,17 +683,21 @@ void CSAGenerator::EmitInstruction(
   const Field& field =
       instruction.class_type->LookupField(instruction.field_name);
   std::string result_name = FreshNodeName();
-  std::string type_string =
-      field.name_and_type.type->IsSubtypeOf(TypeOracle::GetSmiType())
-          ? "MachineType::TaggedSigned()"
-          : "MachineType::AnyTagged()";
+
+  size_t field_size;
+  std::string size_string;
+  std::string machine_type;
+  std::tie(field_size, size_string, machine_type) =
+      field.GetFieldSizeInformation();
+
   out_ << field.name_and_type.type->GetGeneratedTypeName() << " " << result_name
        << " = "
        << "ca_.UncheckedCast<"
        << field.name_and_type.type->GetGeneratedTNodeTypeName()
        << ">(CodeStubAssembler(state_).LoadObjectField("
-       << stack->Top() + ", " + std::to_string(field.offset) + ", "
-       << type_string + "));\n";
+       << stack->Top() + ", " + field.aggregate->GetGeneratedTNodeTypeName() +
+              "::k" + CamelifyString(field.name_and_type.name) + "Offset, "
+       << machine_type + "));\n";
   stack->Poke(stack->AboveTop() - 1, result_name);
 }
 

src/torque/declarable.cc

@@ -6,6 +6,7 @@
 #include <iostream>
 
 #include "src/torque/declarable.h"
+#include "src/torque/global-context.h"
 
 namespace v8 {
 namespace internal {
@@ -95,6 +96,12 @@ base::Optional<TypeVector> Generic::InferSpecializationTypes(
   return result;
 }
 
+bool Namespace::IsDefaultNamespace() const {
+  return this == GlobalContext::GetDefaultNamespace();
+}
+
+bool Namespace::IsTestNamespace() const { return name() == kTestNamespaceName; }
+
 }  // namespace torque
 }  // namespace internal
 }  // namespace v8

src/torque/declarable.h

@@ -158,6 +158,8 @@ class Namespace : public Scope {
   std::string ExternalName() const {
     return CamelifyString(name()) + "BuiltinsFromDSLAssembler";
   }
+  bool IsDefaultNamespace() const;
+  bool IsTestNamespace() const;
   std::ostream& source_stream() { return source_stream_; }
   std::ostream& header_stream() { return header_stream_; }
   std::string source() { return source_stream_.str(); }

src/torque/declaration-visitor.cc

@@ -515,6 +515,7 @@ void DeclarationVisitor::FinalizeStructFieldsAndMethods(
   for (auto& field : struct_declaration->fields) {
     const Type* field_type = Declarations::GetType(field.name_and_type.type);
     struct_type->RegisterField({field.name_and_type.type->pos,
+                                struct_type,
                                 {field.name_and_type.name, field_type},
                                 offset,
                                 false});
@@ -528,40 +529,29 @@ void DeclarationVisitor::FinalizeClassFieldsAndMethods(
     ClassType* class_type, ClassDeclaration* class_declaration) {
   const ClassType* super_class = class_type->GetSuperClass();
   size_t class_offset = super_class ? super_class->size() : 0;
-  bool seen_strong = false;
-  bool seen_weak = false;
-  for (ClassFieldExpression& field : class_declaration->fields) {
+  for (ClassFieldExpression& field_expression : class_declaration->fields) {
     CurrentSourcePosition::Scope position_activator(
-        field.name_and_type.type->pos);
-    const Type* field_type = Declarations::GetType(field.name_and_type.type);
-    if (field_type->IsSubtypeOf(TypeOracle::GetTaggedType())) {
-      if (field.weak) {
-        seen_weak = true;
-      } else {
-        if (seen_weak) {
-          ReportError("cannot declare strong field \"",
-                      field.name_and_type.name,
-                      "\" after weak Tagged references");
-        }
-        seen_strong = true;
-      }
-    } else {
-      if (seen_strong || seen_weak) {
-        ReportError("cannot declare scalar field \"", field.name_and_type.name,
-                    "\" after strong or weak Tagged references");
-      }
-    }
-    if (!field_type->IsSubtypeOf(TypeOracle::GetTaggedType())) {
-      ReportError(
-          "field \"", field.name_and_type.name, "\" of class \"",
-          class_declaration->name,
-          "\" must be a subtype of Tagged (other types not yet supported)");
+        field_expression.name_and_type.type->pos);
+    const Type* field_type =
+        Declarations::GetType(field_expression.name_and_type.type);
+    const Field& field = class_type->RegisterField(
+        {field_expression.name_and_type.type->pos,
+         class_type,
+         {field_expression.name_and_type.name, field_type},
+         class_offset,
+         field_expression.weak});
+    size_t field_size;
+    std::string size_string;
+    std::string machine_type;
+    std::tie(field_size, size_string, machine_type) =
+        field.GetFieldSizeInformation();
+    size_t aligned_offset = class_offset & ~(field_size - 1);
+    if (class_offset != aligned_offset) {
+      ReportError("field ", field_expression.name_and_type.name,
+                  " is not aligned to its size (", aligned_offset, " vs ",
+                  class_offset, " for field size ", field_size, ")");
     }
-    class_type->RegisterField({field.name_and_type.type->pos,
-                               {field.name_and_type.name, field_type},
-                               class_offset,
-                               field.weak});
-    class_offset += kTaggedSize;
+    class_offset += field_size;
   }
   class_type->SetSize(class_offset);
 
@@ -579,6 +569,7 @@ void DeclarationVisitor::FinalizeClassFieldsAndMethods(
     super_struct_type = super_class->struct_type();
     this_struct_type->RegisterField(
         {CurrentSourcePosition::Get(),
+         super_struct_type,
          {kConstructorStructSuperFieldName, super_struct_type},
          struct_offset,
          false});
@@ -587,6 +578,7 @@ void DeclarationVisitor::FinalizeClassFieldsAndMethods(
   for (auto& field : class_type->fields()) {
     const Type* field_type = field.name_and_type.type;
     this_struct_type->RegisterField({field.pos,
+                                     class_type,
                                      {field.name_and_type.name, field_type},
                                      struct_offset,
                                      false});

src/torque/global-context.h

@@ -22,7 +22,7 @@ class GlobalContext : public ContextualClass<GlobalContext> {
     CurrentSourcePosition::Scope current_source_position(
         SourcePosition{CurrentSourceFile::Get(), -1, -1});
     default_namespace_ =
-        RegisterDeclarable(base::make_unique<Namespace>("base"));
+        RegisterDeclarable(base::make_unique<Namespace>(kBaseNamespaceName));
   }
   static Namespace* GetDefaultNamespace() { return Get().default_namespace_; }
   template <class T>
@@ -46,12 +46,11 @@ class GlobalContext : public ContextualClass<GlobalContext> {
     return result;
   }
 
-  static void RegisterClass(const std::string& name,
-                            const ClassType* new_class) {
+  static void RegisterClass(const std::string& name, ClassType* new_class) {
     Get().classes_[name] = new_class;
   }
 
-  static const std::map<std::string, const ClassType*>& GetClasses() {
+  static const std::map<std::string, ClassType*>& GetClasses() {
     return Get().classes_;
   }
 
@@ -72,7 +71,7 @@ class GlobalContext : public ContextualClass<GlobalContext> {
   Ast ast_;
   std::vector<std::unique_ptr<Declarable>> declarables_;
   std::vector<std::string> cpp_includes_;
-  std::map<std::string, const ClassType*> classes_;
+  std::map<std::string, ClassType*> classes_;
 };
 
 template <class T>

src/torque/implementation-visitor.cc

@@ -74,6 +74,8 @@ void ImplementationVisitor::BeginNamespaceFile(Namespace* nspace) {
   if (nspace != GlobalContext::GetDefaultNamespace()) {
     header << "#include \"src/code-stub-assembler.h\"\n";
   }
+  header << "#include \"src/utils.h\"\n";
+  header << "#include \"torque-generated/class-definitions-from-dsl.h\"\n";
   header << "\n";
 
   header << "namespace v8 {\n"
@@ -147,6 +149,32 @@ void ImplementationVisitor::Visit(NamespaceConstant* decl) {
 
 void ImplementationVisitor::Visit(TypeAlias* alias) {
   if (alias->IsRedeclaration()) return;
+  const ClassType* class_type = ClassType::DynamicCast(alias->type());
+  if (class_type) {
+    // Classes that are in the default namespace are defined in the C++
+    // world and all of their fields and methods are declared explicitly.
+    // Internal classes (e.g. ones used for testing that are not in the default
+    // name space) need to be defined by Torque.
+    // TODO(danno): This is a pretty cheesy hack for now. There should be a more
+    // robust mechanism for this, e.g. declaring classes 'extern' or something.
+    if (class_type->nspace()->IsTestNamespace()) {
+      std::string class_name{
+          class_type->GetSuperClass()->GetGeneratedTNodeTypeName()};
+      header_out() << "  class " << class_type->name() << " : public "
+                   << class_name << " {\n";
+      header_out() << "   public:\n";
+      header_out() << "    DEFINE_FIELD_OFFSET_CONSTANTS(" << class_name
+                   << "::kSize, "
+                   << CapifyStringWithUnderscores(class_type->name())
+                   << "_FIELDS)\n";
+      header_out() << "  };\n";
+    } else if (!class_type->nspace()->IsDefaultNamespace()) {
+      ReportError(
+          "classes are currently only supported in the default and test "
+          "namespaces");
+    }
+    return;
+  }
   const StructType* struct_type = StructType::DynamicCast(alias->type());
   if (!struct_type) return;
   const std::string& name = struct_type->name();
@@ -1224,6 +1252,12 @@ VisitResult ImplementationVisitor::Visit(NewExpression* expr) {
                 "\" is not");
   }
 
+  if (!class_type->AllowInstantiation()) {
+    // Classes that are only used for testing should never be instantiated.
+    ReportError(*class_type,
+                " cannot be allocated with new (it's used for testing)");
+  }
+
   // In order to ensure "atomicity" of object allocation, a class' constructors
   // operate on a per-class internal struct rather than the class directly until
   // the constructor has successfully completed and all class members are
@@ -2510,6 +2544,79 @@ void ImplementationVisitor::GenerateBuiltinDefinitions(std::string& file_name) {
   ReplaceFileContentsIfDifferent(file_name, new_contents);
 }
 
+namespace {
+
+enum class FieldSectionType {
+  kNoSection = 0,
+  kWeakSection,
+  kStrongSection,
+  kScalarSection
+};
+
+void PossiblyStartTagged(FieldSectionType* section,
+                         std::set<FieldSectionType>* completed_sections,
+                         std::stringstream* o) {
+  if (completed_sections->count(FieldSectionType::kWeakSection) == 0 &&
+      completed_sections->count(FieldSectionType::kStrongSection) == 0 &&
+      *section != FieldSectionType::kWeakSection &&
+      *section != FieldSectionType::kStrongSection) {
+    *o << "V(kStartOfPointerFieldsOffset, 0) \\\n";
+  }
+}
+
+void PossiblyEndTagged(FieldSectionType* section,
+                       std::set<FieldSectionType>* completed_sections,
+                       std::stringstream* o) {
+  if (completed_sections->count(FieldSectionType::kWeakSection) != 0 &&
+      completed_sections->count(FieldSectionType::kStrongSection) != 0) {
+    *o << "V(kEndOfTaggedFieldsOffset, 0) \\\n";
+  }
+}
+
+void ProcessFieldInSection(FieldSectionType* section,
+                           std::set<FieldSectionType>* completed_sections,
+                           FieldSectionType field_section,
+                           std::stringstream* o) {
+  if (*section != FieldSectionType::kNoSection) {
+    if (*section != field_section) {
+      if (completed_sections->count(field_section) != 0) {
+        ReportError("reopening of weak, strong or scalar field section");
+      }
+      completed_sections->insert(*section);
+      if (*section == FieldSectionType::kWeakSection) {
+        *o << "V(kEndOfWeakFieldsOffset, 0) \\\n";
+        PossiblyEndTagged(section, completed_sections, o);
+      } else if (*section == FieldSectionType::kStrongSection) {
+        *o << "V(kEndOfStrongFieldsOffset, 0) \\\n";
+        PossiblyEndTagged(section, completed_sections, o);
+      }
+    }
+  }
+  if (*section != field_section) {
+    if (field_section == FieldSectionType::kWeakSection) {
+      PossiblyStartTagged(section, completed_sections, o);
+      *o << "V(kStartOfWeakFieldsOffset, 0) \\\n";
+    } else if (field_section == FieldSectionType::kStrongSection) {
+      PossiblyStartTagged(section, completed_sections, o);
+      *o << "V(kStartOfStrongFieldsOffset, 0) \\\n";
+    }
+  }
+  *section = field_section;
+}
+
+void CompleteFieldSection(FieldSectionType* section,
+                          std::set<FieldSectionType>* completed_sections,
+                          FieldSectionType field_section,
+                          std::stringstream* o) {
+  if (completed_sections->count(field_section) == 0) {
+    ProcessFieldInSection(section, completed_sections, field_section, o);
+    ProcessFieldInSection(section, completed_sections,
+                          FieldSectionType::kNoSection, o);
+  }
+}
+
+}  // namespace
+
 void ImplementationVisitor::GenerateClassDefinitions(std::string& file_name) {
   std::stringstream new_contents_stream;
   new_contents_stream << "#ifndef V8_CLASS_BUILTIN_DEFINITIONS_FROM_DSL_H_\n"
@@ -2525,24 +2632,44 @@ void ImplementationVisitor::GenerateClassDefinitions(std::string& file_name) {
     new_contents_stream << "#define ";
     new_contents_stream << CapifyStringWithUnderscores(i.first)
                         << "_FIELDS(V) \\\n";
-    const ClassType* type = i.second;
+    ClassType* type = i.second;
     std::vector<Field> fields = type->fields();
-    new_contents_stream << "V(kStartOfStrongFieldsOffset, 0) \\\n";
+    FieldSectionType section = FieldSectionType::kNoSection;
+    std::set<FieldSectionType> completed_sections;
     for (auto f : fields) {
-      if (!f.is_weak) {
-        new_contents_stream << "V(k" << CamelifyString(f.name_and_type.name)
-                            << "Offset, kTaggedSize) \\\n";
-      }
-    }
-    new_contents_stream << "V(kEndOfStrongFieldsOffset, 0) \\\n";
-    new_contents_stream << "V(kStartOfWeakFieldsOffset, 0) \\\n";
-    for (auto f : fields) {
-      if (f.is_weak) {
-        new_contents_stream << "V(k" << CamelifyString(f.name_and_type.name)
-                            << "Offset, kTaggedSize) \\\n";
+      CurrentSourcePosition::Scope scope(f.pos);
+      if (f.name_and_type.type->IsSubtypeOf(TypeOracle::GetTaggedType())) {
+        if (f.is_weak) {
+          ProcessFieldInSection(&section, &completed_sections,
+                                FieldSectionType::kWeakSection,
+                                &new_contents_stream);
+        } else {
+          ProcessFieldInSection(&section, &completed_sections,
+                                FieldSectionType::kStrongSection,
+                                &new_contents_stream);
+        }
+      } else {
+        ProcessFieldInSection(&section, &completed_sections,
+                              FieldSectionType::kScalarSection,
+                              &new_contents_stream);
       }
-    }
-    new_contents_stream << "V(kEndOfWeakFieldsOffset, 0) \\\n";
+      size_t field_size;
+      std::string size_string;
+      std::string machine_type;
+      std::tie(field_size, size_string, machine_type) =
+          f.GetFieldSizeInformation();
+      new_contents_stream << "V(k" << CamelifyString(f.name_and_type.name)
+                          << "Offset, " << size_string << ") \\\n";
+    }
+
+    ProcessFieldInSection(&section, &completed_sections,
+                          FieldSectionType::kNoSection, &new_contents_stream);
+    CompleteFieldSection(&section, &completed_sections,
+                         FieldSectionType::kWeakSection, &new_contents_stream);
+    CompleteFieldSection(&section, &completed_sections,
+                         FieldSectionType::kStrongSection,
+                         &new_contents_stream);
+
     new_contents_stream << "V(kSize, 0) \\\n";
     new_contents_stream << "\n";
   }

src/torque/type-oracle.h

@@ -147,6 +147,26 @@ class TypeOracle : public ContextualClass<TypeOracle> {
     return Get().GetBuiltinType(INT32_TYPE_STRING);
   }
 
+  static const Type* GetUint32Type() {
+    return Get().GetBuiltinType(UINT32_TYPE_STRING);
+  }
+
+  static const Type* GetInt16Type() {
+    return Get().GetBuiltinType(INT16_TYPE_STRING);
+  }
+
+  static const Type* GetUint16Type() {
+    return Get().GetBuiltinType(UINT16_TYPE_STRING);
+  }
+
+  static const Type* GetInt8Type() {
+    return Get().GetBuiltinType(INT8_TYPE_STRING);
+  }
+
+  static const Type* GetUint8Type() {
+    return Get().GetBuiltinType(UINT8_TYPE_STRING);
+  }
+
   static const Type* GetNeverType() {
     return Get().GetBuiltinType(NEVER_TYPE_STRING);
   }

src/torque/types.cc

@@ -4,6 +4,7 @@
 
 #include <iostream>
 
+#include "src/globals.h"
 #include "src/torque/declarable.h"
 #include "src/torque/type-oracle.h"
 #include "src/torque/types.h"
@@ -78,8 +79,6 @@ std::string AbstractType::GetGeneratedTNodeTypeName() const {
   return generated_type_;
 }
 
-std::string ClassType::GetGeneratedTNodeTypeName() const { return generates_; }
-
 std::string BuiltinPointerType::ToExplicitString() const {
   std::stringstream result;
   result << "builtin (";
@@ -262,6 +261,18 @@ std::string StructType::ToExplicitString() const {
   return result.str();
 }
 
+std::string ClassType::GetGeneratedTNodeTypeName() const {
+  std::string prefix = nspace()->IsDefaultNamespace()
+                           ? std::string{}
+                           : (nspace()->ExternalName() + "::");
+  return prefix + generates_;
+}
+
+std::string ClassType::GetGeneratedTypeName() const {
+  return IsConstexpr() ? GetGeneratedTNodeTypeName()
+                       : "compiler::TNode<" + GetGeneratedTNodeTypeName() + ">";
+}
+
 std::string ClassType::ToExplicitString() const {
   std::stringstream result;
   result << "class " << name() << "{";
@@ -270,6 +281,10 @@ std::string ClassType::ToExplicitString() const {
   return result.str();
 }
 
+bool ClassType::AllowInstantiation() const {
+  return nspace()->IsDefaultNamespace();
+}
+
 void PrintSignature(std::ostream& os, const Signature& sig, bool with_names) {
   os << "(";
   for (size_t i = 0; i < sig.parameter_types.types.size(); ++i) {
@@ -469,6 +484,60 @@ VisitResult VisitResult::NeverResult() {
   return result;
 }
 
+std::tuple<size_t, std::string, std::string> Field::GetFieldSizeInformation()
+    const {
+  std::string size_string = "#no size";
+  std::string machine_type = "#no machine type";
+  const Type* field_type = this->name_and_type.type;
+  size_t field_size = 0;
+  if (field_type->IsSubtypeOf(TypeOracle::GetTaggedType())) {
+    field_size = kTaggedSize;
+    size_string = "kTaggedSize";
+    machine_type = field_type->IsSubtypeOf(TypeOracle::GetSmiType())
+                       ? "MachineType::TaggedSigned()"
+                       : "MachineType::AnyTagged()";
+  } else if (field_type->IsSubtypeOf(TypeOracle::GetRawPtrType())) {
+    field_size = kSystemPointerSize;
+    size_string = "kSystemPointerSize";
+    machine_type = "MachineType::Pointer()";
+  } else if (field_type == TypeOracle::GetInt32Type()) {
+    field_size = kInt32Size;
+    size_string = "kInt32Size";
+    machine_type = "MachineType::Int32()";
+  } else if (field_type == TypeOracle::GetUint32Type()) {
+    field_size = kInt32Size;
+    size_string = "kInt32Size";
+    machine_type = "MachineType::Uint32()";
+  } else if (field_type == TypeOracle::GetInt16Type()) {
+    field_size = kUInt16Size;
+    size_string = "kUInt16Size";
+    machine_type = "MachineType::Int16()";
+  } else if (field_type == TypeOracle::GetUint16Type()) {
+    field_size = kUInt16Size;
+    size_string = "kUInt16Size";
+    machine_type = "MachineType::Uint16()";
+  } else if (field_type == TypeOracle::GetInt8Type()) {
+    field_size = kUInt8Size;
+    size_string = "kUInt8Size";
+    machine_type = "MachineType::Int8()";
+  } else if (field_type == TypeOracle::GetUint8Type()) {
+    field_size = kUInt8Size;
+    size_string = "kUInt8Size";
+    machine_type = "MachineType::Uint8()";
+  } else if (field_type == TypeOracle::GetIntPtrType()) {
+    field_size = kIntptrSize;
+    size_string = "kIntptrSize";
+    machine_type = "MachineType::IntPtr()";
+  } else if (field_type == TypeOracle::GetUIntPtrType()) {
+    field_size = kIntptrSize;
+    size_string = "kIntptrSize";
+    machine_type = "MachineType::IntPtr()";
+  } else {
+    ReportError("fields of type ", *field_type, " are not (yet) supported");
+  }
+  return std::make_tuple(field_size, size_string, machine_type);
+}
+
 }  // namespace torque
 }  // namespace internal
 }  // namespace v8

src/torque/types.h

@@ -39,10 +39,16 @@ static const char* const BUILTIN_POINTER_TYPE_STRING = "BuiltinPtr";
 static const char* const INTPTR_TYPE_STRING = "intptr";
 static const char* const UINTPTR_TYPE_STRING = "uintptr";
 static const char* const INT32_TYPE_STRING = "int32";
+static const char* const UINT32_TYPE_STRING = "uint32";
+static const char* const INT16_TYPE_STRING = "int16";
+static const char* const UINT16_TYPE_STRING = "uint16";
+static const char* const INT8_TYPE_STRING = "int8";
+static const char* const UINT8_TYPE_STRING = "uint8";
 static const char* const CONST_INT31_TYPE_STRING = "constexpr int31";
 static const char* const CONST_INT32_TYPE_STRING = "constexpr int32";
 static const char* const CONST_FLOAT64_TYPE_STRING = "constexpr float64";
 
+class AggregateType;
 class Macro;
 class Method;
 class StructType;
@@ -154,7 +160,10 @@ struct NameAndType {
 std::ostream& operator<<(std::ostream& os, const NameAndType& name_and_type);
 
 struct Field {
+  std::tuple<size_t, std::string, std::string> GetFieldSizeInformation() const;
+
   SourcePosition pos;
+  const AggregateType* aggregate;
   NameAndType name_and_type;
   size_t offset;
   bool is_weak;
@@ -402,7 +411,10 @@ class AggregateType : public Type {
     return "_method_" + name_ + "_" + name;
   }
 
-  void RegisterField(Field field) { fields_.push_back(field); }
+  const Field& RegisterField(Field field) {
+    fields_.push_back(field);
+    return fields_.back();
+  }
 
   void RegisterMethod(Method* method) { methods_.push_back(method); }
   std::vector<Method*> Constructors() const;
@@ -454,9 +466,7 @@ class ClassType final : public AggregateType {
  public:
   DECLARE_TYPE_BOILERPLATE(ClassType);
   std::string ToExplicitString() const override;
-  std::string GetGeneratedTypeName() const override {
-    return IsConstexpr() ? generates_ : "compiler::TNode<" + generates_ + ">";
-  }
+  std::string GetGeneratedTypeName() const override;
   std::string GetGeneratedTNodeTypeName() const override;
   bool IsTransient() const override { return transient_; }
   size_t size() const { return size_; }
@@ -467,6 +477,7 @@ class ClassType final : public AggregateType {
   }
   void SetSize(size_t size) { size_ = size; }
   void SetThisStruct(StructType* this_struct) { this_struct_ = this_struct; }
+  bool AllowInstantiation() const;
 
  private:
   friend class TypeOracle;

src/torque/utils.cc

@@ -125,8 +125,9 @@ bool IsKeywordLikeName(const std::string& s) {
 // naming convention and are those exempt from the normal type convention.
 bool IsMachineType(const std::string& s) {
   static const char* const machine_types[]{
-      "void",    "never",   "int32", "uint32", "int64", "intptr", "uintptr",
-      "float32", "float64", "bool",  "string", "bint",  "int31"};
+      "void",    "never",   "int8",    "uint8",  "int16",  "uint16",
+      "int31",   "uint31",  "int32",   "uint32", "int64",  "intptr",
+      "uintptr", "float32", "float64", "bool",   "string", "bint"};
 
   return std::find(std::begin(machine_types), std::end(machine_types), s) !=
          std::end(machine_types);

src/torque/utils.h

@@ -272,6 +272,8 @@ class ToString {
 
 constexpr int kTaggedSize = sizeof(void*);
 
+static const char* const kBaseNamespaceName = "base";
+static const char* const kTestNamespaceName = "test";
 static const char* const kConstructMethodName = "constructor";
 static const char* const kSuperMethodName = "super";
 static const char* const kConstructorStructSuperFieldName = "_super";

test/torque/test-torque.tq

@@ -768,4 +768,18 @@ namespace test {
     assert(w.c == 1);
     assert(w.d == 2);
   }
+
+  class TestClassWithAllTypes extends JSObject {
+    a: int8;
+    b: uint8;
+    b2: uint8;
+    b3: uint8;
+    c: int16;
+    d: uint16;
+    e: int32;
+    f: uint32;
+    g: RawPtr;
+    h: intptr;
+    i: uintptr;
+  }
 }