[torque] create constexpr versions for class types

This enables defining abstract type subtypes of classes
with constexpr version, which in turn is useful to model
custom C++ subclasses.

Bug: v8:7793
Change-Id: I07dcb62121afdddfbe2c78ecc870afcb11800c19
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2412180
Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Nico Hartmann <nicohartmann@chromium.org>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69982}

src/torque/torque-parser.cc

@@ -965,8 +965,17 @@ base::Optional<ParseResult> MakeClassDeclaration(
   std::vector<Declaration*> result;
 
   result.push_back(MakeNode<ClassDeclaration>(
-      name, flags, std::move(extends), std::move(generates), std::move(methods),
-      fields, MakeInstanceTypeConstraints(annotations)));
+      name, flags, extends, std::move(generates), std::move(methods), fields,
+      MakeInstanceTypeConstraints(annotations)));
+
+  Identifier* constexpr_name =
+      MakeNode<Identifier>(CONSTEXPR_TYPE_PREFIX + name->value);
+  constexpr_name->pos = name->pos;
+  TypeExpression* constexpr_extends = AddConstexpr(extends);
+  TypeDeclaration* constexpr_decl = MakeNode<AbstractTypeDeclaration>(
+      constexpr_name, transient, constexpr_extends, name->value);
+  constexpr_decl->pos = name->pos;
+  result.push_back(constexpr_decl);
 
   if ((flags & ClassFlag::kDoNotGenerateCast) == 0 &&
       (flags & ClassFlag::kIsShape) == 0) {

src/torque/types.cc

@@ -74,10 +74,7 @@ std::string Type::SimpleName() const {
 std::string Type::HandlifiedCppTypeName() const {
   if (IsSubtypeOf(TypeOracle::GetSmiType())) return "int";
   if (IsSubtypeOf(TypeOracle::GetTaggedType())) {
-    base::Optional<const ClassType*> class_type = ClassSupertype();
-    std::string type =
-        class_type ? (*class_type)->GetGeneratedTNodeTypeName() : "Object";
-    return "Handle<" + type + ">";
+    return "Handle<" + ConstexprVersion()->GetGeneratedTypeName() + ">";
   } else {
     return ConstexprVersion()->GetGeneratedTypeName();
   }

src/wasm/wasm-objects.tq

@@ -2,6 +2,12 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+type PodArrayOfWasmValueType extends ByteArray
+constexpr 'PodArray<wasm::ValueType>';
+type ManagedWasmNativeModule extends Foreign
+constexpr 'Managed<wasm::NativeModule>';
+type WasmValueType extends uint8 constexpr 'wasm::ValueType::Kind';
+
 extern class WasmInstanceObject extends JSObject;
 
 extern class WasmExportedFunctionData extends Struct {
@@ -22,14 +28,14 @@ extern class WasmJSFunctionData extends Struct {
   wrapper_code: Code;
   serialized_return_count: Smi;
   serialized_parameter_count: Smi;
-  serialized_signature: ByteArray;  // PodArray<wasm::ValueType>
+  serialized_signature: PodArrayOfWasmValueType;
 }
 
 extern class WasmCapiFunctionData extends Struct {
   call_target: RawPtr;
   embedder_data: Foreign;  // Managed<wasm::FuncData>
   wrapper_code: Code;
-  serialized_signature: ByteArray;  // PodArray<wasm::ValueType>
+  serialized_signature: PodArrayOfWasmValueType;
 }
 
 extern class WasmIndirectFunctionTable extends Struct {
@@ -51,7 +57,7 @@ extern class WasmExceptionTag extends Struct {
 }
 
 extern class WasmModuleObject extends JSObject {
-  native_module: Foreign;
+  native_module: ManagedWasmNativeModule;
   export_wrappers: FixedArray;
   script: Script;
 }
@@ -70,8 +76,6 @@ extern class WasmMemoryObject extends JSObject {
   instances: WeakArrayList|Undefined;
 }
 
-type WasmValueType extends uint8 constexpr 'wasm::ValueType::Kind';
-
 extern class WasmGlobalObject extends JSObject {
   instance: WasmInstanceObject|Undefined;
   untagged_buffer: JSArrayBuffer|Undefined;
@@ -82,14 +86,14 @@ extern class WasmGlobalObject extends JSObject {
 }
 
 extern class WasmExceptionObject extends JSObject {
-  serialized_signature: ByteArray;  // PodArray<wasm::ValueType>
+  serialized_signature: PodArrayOfWasmValueType;
   exception_tag: HeapObject;
 }
 
 type WasmExportedFunction extends JSFunction;
 
 extern class AsmWasmData extends Struct {
-  managed_native_module: Foreign;  // Managed<wasm::NativeModule>
+  managed_native_module: ManagedWasmNativeModule;
   export_wrappers: FixedArray;
   uses_bitset: HeapNumber;
 }