[wasm] Add WasmApiFunctionRef object

This object will be used for the 'ref' field of WasmCapiFunctionData and
WasmJSFunctionData, replacing the currently used pair.
Design doc: https://bit.ly/3jEVgzz

Bug: v8:11510
Change-Id: Ic5dec88458b562883d571b3463269b2308f489c5
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3236718Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Manos Koukoutos <manoskouk@chromium.org>
Cr-Commit-Position: refs/heads/main@{#77575}

src/diagnostics/objects-printer.cc

@@ -1929,6 +1929,14 @@ void WasmJSFunctionData::WasmJSFunctionDataPrint(std::ostream& os) {
   os << "\n";
 }
 
+void WasmApiFunctionRef::WasmApiFunctionRefPrint(std::ostream& os) {
+  PrintHeader(os, "WasmApiFunctionRef");
+  os << "\n - isolate_root: " << reinterpret_cast<void*>(foreign_address());
+  os << "\n - native_context: " << Brief(native_context());
+  os << "\n - callable: " << Brief(callable());
+  os << "\n";
+}
+
 void WasmCapiFunctionData::WasmCapiFunctionDataPrint(std::ostream& os) {
   PrintHeader(os, "WasmCapiFunctionData");
   WasmFunctionDataPrint(os);

src/heap/factory.cc

@@ -1473,6 +1473,22 @@ Handle<WasmTypeInfo> Factory::NewWasmTypeInfo(
   return handle(result, isolate());
 }
 
+Handle<WasmApiFunctionRef> Factory::NewWasmApiFunctionRef(
+    Handle<JSReceiver> callable) {
+  Map map = *wasm_api_function_ref_map();
+  auto result = WasmApiFunctionRef::cast(AllocateRawWithImmortalMap(
+      map.instance_size(), AllocationType::kOld, map));
+  DisallowGarbageCollection no_gc;
+  result.set_foreign_address(isolate(), isolate()->isolate_root());
+  result.set_native_context(*isolate()->native_context());
+  if (!callable.is_null()) {
+    result.set_callable(*callable);
+  } else {
+    result.set_callable(*undefined_value());
+  }
+  return handle(result, isolate());
+}
+
 Handle<WasmJSFunctionData> Factory::NewWasmJSFunctionData(
     Address opt_call_target, Handle<JSReceiver> callable, int return_count,
     int parameter_count, Handle<PodArray<wasm::ValueType>> serialized_sig,

src/heap/factory.h

@@ -576,6 +576,7 @@ class V8_EXPORT_PRIVATE Factory : public FactoryBase<Factory> {
       Handle<Code> export_wrapper, Handle<WasmInstanceObject> instance,
       Address call_target, Handle<Object> ref, int func_index,
       Address sig_address, int wrapper_budget);
+  Handle<WasmApiFunctionRef> NewWasmApiFunctionRef(Handle<JSReceiver> callable);
   // {opt_call_target} is kNullAddress for JavaScript functions, and
   // non-null for exported Wasm functions.
   Handle<WasmJSFunctionData> NewWasmJSFunctionData(

src/heap/objects-visiting.h

@@ -57,6 +57,7 @@ namespace internal {
   IF_WASM(V, WasmIndirectFunctionTable) \
   IF_WASM(V, WasmInstanceObject)        \
   IF_WASM(V, WasmJSFunctionData)        \
+  IF_WASM(V, WasmApiFunctionRef)        \
   IF_WASM(V, WasmStruct)                \
   IF_WASM(V, WasmTypeInfo)
 

src/heap/setup-heap-internal.cc

@@ -506,6 +506,8 @@ bool Heap::CreateInitialMaps() {
             WasmCapiFunctionData::kSize, wasm_capi_function_data)
     IF_WASM(ALLOCATE_MAP, WASM_EXPORTED_FUNCTION_DATA_TYPE,
             WasmExportedFunctionData::kSize, wasm_exported_function_data)
+    IF_WASM(ALLOCATE_MAP, WASM_API_FUNCTION_REF_TYPE, WasmApiFunctionRef::kSize,
+            wasm_api_function_ref)
     IF_WASM(ALLOCATE_MAP, WASM_JS_FUNCTION_DATA_TYPE, WasmJSFunctionData::kSize,
             wasm_js_function_data)
     IF_WASM(ALLOCATE_MAP, WASM_TYPE_INFO_TYPE, WasmTypeInfo::kSize,

src/objects/map.cc

@@ -368,6 +368,8 @@ VisitorId Map::GetVisitorId(Map map) {
       return kVisitWasmTypeInfo;
     case WASM_JS_FUNCTION_DATA_TYPE:
       return kVisitWasmJSFunctionData;
+    case WASM_API_FUNCTION_REF_TYPE:
+      return kVisitWasmApiFunctionRef;
     case WASM_EXPORTED_FUNCTION_DATA_TYPE:
       return kVisitWasmExportedFunctionData;
     case WASM_CAPI_FUNCTION_DATA_TYPE:

src/objects/map.h

@@ -75,6 +75,7 @@ enum InstanceType : uint16_t;
   IF_WASM(V, WasmIndirectFunctionTable) \
   IF_WASM(V, WasmInstanceObject)        \
   IF_WASM(V, WasmJSFunctionData)        \
+  IF_WASM(V, WasmApiFunctionRef)        \
   IF_WASM(V, WasmStruct)                \
   IF_WASM(V, WasmTypeInfo)              \
   V(WeakCell)

src/objects/object-list-macros.h

@@ -234,6 +234,7 @@ class ZoneForwardList;
   IF_WASM(V, WasmGlobalObject)                 \
   IF_WASM(V, WasmInstanceObject)               \
   IF_WASM(V, WasmJSFunctionData)               \
+  IF_WASM(V, WasmApiFunctionRef)               \
   IF_WASM(V, WasmMemoryObject)                 \
   IF_WASM(V, WasmModuleObject)                 \
   IF_WASM(V, WasmObject)                       \

src/objects/objects-body-descriptors-inl.h

@@ -641,6 +641,24 @@ class WasmJSFunctionData::BodyDescriptor final : public BodyDescriptorBase {
   static inline int SizeOf(Map map, HeapObject object) { return kSize; }
 };
 
+class WasmApiFunctionRef::BodyDescriptor final : public BodyDescriptorBase {
+ public:
+  static bool IsValidSlot(Map map, HeapObject obj, int offset) {
+    UNREACHABLE();
+  }
+
+  template <typename ObjectVisitor>
+  static inline void IterateBody(Map map, HeapObject obj, int object_size,
+                                 ObjectVisitor* v) {
+    Foreign::BodyDescriptor::IterateBody<ObjectVisitor>(map, obj, object_size,
+                                                        v);
+    IteratePointers(obj, WasmFunctionData::kStartOfStrongFieldsOffset,
+                    kEndOfStrongFieldsOffset, v);
+  }
+
+  static inline int SizeOf(Map map, HeapObject object) { return kSize; }
+};
+
 class WasmExportedFunctionData::BodyDescriptor final
     : public BodyDescriptorBase {
  public:
@@ -1060,6 +1078,9 @@ ReturnType BodyDescriptorApply(InstanceType type, T1 p1, T2 p2, T3 p3, T4 p4) {
     case WASM_JS_FUNCTION_DATA_TYPE:
       return Op::template apply<WasmJSFunctionData::BodyDescriptor>(p1, p2, p3,
                                                                     p4);
+    case WASM_API_FUNCTION_REF_TYPE:
+      return Op::template apply<WasmApiFunctionRef::BodyDescriptor>(p1, p2, p3,
+                                                                    p4);
     case WASM_STRUCT_TYPE:
       return Op::template apply<WasmStruct::BodyDescriptor>(p1, p2, p3, p4);
     case WASM_TYPE_INFO_TYPE:

src/roots/roots.h

@@ -115,6 +115,7 @@ class Symbol;
   IF_WASM(V, Map, wasm_exported_function_data_map,                             \
           WasmExportedFunctionDataMap)                                         \
   IF_WASM(V, Map, wasm_js_function_data_map, WasmJSFunctionDataMap)            \
+  IF_WASM(V, Map, wasm_api_function_ref_map, WasmApiFunctionRefMap)            \
   IF_WASM(V, Map, wasm_type_info_map, WasmTypeInfoMap)                         \
   V(Map, weak_fixed_array_map, WeakFixedArrayMap)                              \
   V(Map, weak_array_list_map, WeakArrayListMap)                                \

src/wasm/wasm-objects-inl.h

@@ -47,6 +47,7 @@ TQ_OBJECT_CONSTRUCTORS_IMPL(WasmModuleObject)
 TQ_OBJECT_CONSTRUCTORS_IMPL(WasmTableObject)
 TQ_OBJECT_CONSTRUCTORS_IMPL(AsmWasmData)
 TQ_OBJECT_CONSTRUCTORS_IMPL(WasmFunctionData)
+TQ_OBJECT_CONSTRUCTORS_IMPL(WasmApiFunctionRef)
 TQ_OBJECT_CONSTRUCTORS_IMPL(WasmTypeInfo)
 TQ_OBJECT_CONSTRUCTORS_IMPL(WasmStruct)
 TQ_OBJECT_CONSTRUCTORS_IMPL(WasmArray)

src/wasm/wasm-objects.h

@@ -733,6 +733,17 @@ class WasmExportedFunctionData
   TQ_OBJECT_CONSTRUCTORS(WasmExportedFunctionData)
 };
 
+class WasmApiFunctionRef
+    : public TorqueGeneratedWasmApiFunctionRef<WasmApiFunctionRef, Foreign> {
+ public:
+  // Dispatched behavior.
+  DECL_PRINTER(WasmApiFunctionRef)
+
+  class BodyDescriptor;
+
+  TQ_OBJECT_CONSTRUCTORS(WasmApiFunctionRef)
+};
+
 // Information for a WasmJSFunction which is referenced as the function data of
 // the SharedFunctionInfo underlying the function. For details please see the
 // {SharedFunctionInfo::HasWasmJSFunctionData} predicate.

src/wasm/wasm-objects.tq

@@ -11,6 +11,16 @@ type ManagedWasmNativeModule extends Foreign
 
 extern class WasmInstanceObject extends JSObject;
 
+// Represents the context of a function that is defined through the JS or C
+// APIs. Corresponds to the WasmInstanceObject passed to a Wasm function
+// reference.
+// The {foreign_address} field inherited from {Foreign} points the IsolateRoots
+// of the defining isolate.
+extern class WasmApiFunctionRef extends Foreign {
+  native_context: NativeContext;
+  callable: JSReceiver|Undefined;
+}
+
 extern class WasmFunctionData extends Foreign {
   // This is the "reference" value that must be passed along in the "instance"
   // register when calling the given function. It is either the target instance,