[cleanup] Remove two unused fields from the isolate

gahaas · V8 LUCI CQ · commit 599866f6f1f3 · 2025-07-21T06:17:02.000-07:00
Isolate::embedder_wrapper_type_index and Isolate::embedder_wrapper_object_index do get initialized but never read within V8. Bug: 345640553 Change-Id: Iaf1c2b59880a3ffac477c4f6aeae78ef6fd9cbe6 Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/6771910 Reviewed-by: Michael Lippautz <mlippautz@chromium.org> Commit-Queue: Andreas Haas <ahaas@chromium.org> Cr-Commit-Position: refs/heads/main@{#101541}
diff --git a/include/v8-fast-api-calls.h b/include/v8-fast-api-calls.h
@@ -93,27 +93,11 @@
  *      }
  *    };
  *
- *    // TODO(mslekova): Clean-up these constants
- *    // The constants kV8EmbedderWrapperTypeIndex and
- *    // kV8EmbedderWrapperObjectIndex describe the offsets for the type info
- *    // struct and the native object, when expressed as internal field indices
- *    // within a JSObject. The existance of this helper function assumes that
- *    // all embedder objects have their JSObject-side type info at the same
- *    // offset, but this is not a limitation of the API itself. For a detailed
- *    // use case, see the third example.
- *    static constexpr int kV8EmbedderWrapperTypeIndex = 0;
- *    static constexpr int kV8EmbedderWrapperObjectIndex = 1;
- *
  *    // The following setup function can be templatized based on
  *    // the {embedder_object} argument.
  *    void SetupCustomEmbedderObject(v8::Isolate* isolate,
  *                                   v8::Local<v8::Context> context,
  *                                   CustomEmbedderType* embedder_object) {
- *      isolate->set_embedder_wrapper_type_index(
- *        kV8EmbedderWrapperTypeIndex);
- *      isolate->set_embedder_wrapper_object_index(
- *        kV8EmbedderWrapperObjectIndex);
- *
  *      v8::CFunction c_func =
  *        MakeV8CFunction(CustomEmbedderType::FastMethod);
  *
diff --git a/include/v8-isolate.h b/include/v8-isolate.h
@@ -361,7 +361,9 @@ class V8_EXPORT Isolate {
      * for wrapped API objects and are used by the fast C API
      * (for details see v8-fast-api-calls.h).
      */
+    V8_DEPRECATE_SOON("This field is unused.")
     int embedder_wrapper_type_index = -1;
+    V8_DEPRECATE_SOON("This field is unused.")
     int embedder_wrapper_object_index = -1;
 
     /**
diff --git a/src/api/api.cc b/src/api/api.cc
@@ -10100,11 +10100,6 @@ void Isolate::Initialize(Isolate* v8_isolate,
     }
   }
 
-  i_isolate->set_embedder_wrapper_type_index(
-      params.embedder_wrapper_type_index);
-  i_isolate->set_embedder_wrapper_object_index(
-      params.embedder_wrapper_object_index);
-
   if (!i::V8::GetCurrentPlatform()
            ->GetForegroundTaskRunner(v8_isolate)
            ->NonNestableTasksEnabled()) {
diff --git a/src/execution/isolate.h b/src/execution/isolate.h
@@ -522,8 +522,6 @@ using DebugObjectCache = std::vector<Handle<HeapObject>>;
   V(bool, disable_bytecode_flushing, false)                                 \
   V(int, last_console_context_id, 0)                                        \
   V(v8_inspector::V8Inspector*, inspector, nullptr)                         \
-  V(int, embedder_wrapper_type_index, -1)                                   \
-  V(int, embedder_wrapper_object_index, -1)                                 \
   V(compiler::NodeObserver*, node_observer, nullptr)                        \
   V(bool, javascript_execution_assert, true)                                \
   V(bool, javascript_execution_throws, true)                                \
diff --git a/test/cctest/test-api.cc b/test/cctest/test-api.cc
@@ -28983,8 +28983,6 @@ void FastApiCallWithAllocationAndGC(AllocationChecker::GCLocation gc_location) {
   v8::Isolate* isolate = CcTest::isolate();
 
   i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
-  i_isolate->set_embedder_wrapper_type_index(kV8WrapperTypeIndex);
-  i_isolate->set_embedder_wrapper_object_index(kV8WrapperObjectIndex);
 
   v8::HandleScope scope(isolate);
 
@@ -29030,8 +29028,6 @@ TEST(FastApiCallWithThrowInReentrantCode) {
   v8::Isolate* isolate = CcTest::isolate();
 
   i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
-  i_isolate->set_embedder_wrapper_type_index(kV8WrapperTypeIndex);
-  i_isolate->set_embedder_wrapper_object_index(kV8WrapperObjectIndex);
 
   v8::HandleScope scope(isolate);
 
@@ -29140,8 +29136,6 @@ void FastApiCallRecursion(bool inner_most_throws) {
   v8::Isolate* isolate = CcTest::isolate();
 
   i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
-  i_isolate->set_embedder_wrapper_type_index(kV8WrapperTypeIndex);
-  i_isolate->set_embedder_wrapper_object_index(kV8WrapperObjectIndex);
 
   v8::HandleScope scope(isolate);
 
@@ -29234,9 +29228,6 @@ TEST(FastApiStackSlot) {
   i::FlagList::EnforceFlagImplications();
 
   v8::Isolate* isolate = CcTest::isolate();
-  i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
-  i_isolate->set_embedder_wrapper_type_index(kV8WrapperTypeIndex);
-  i_isolate->set_embedder_wrapper_object_index(kV8WrapperObjectIndex);
 
   v8::HandleScope scope(isolate);
   LocalContext env;
@@ -29290,9 +29281,6 @@ TEST(FastApiCalls) {
 
   CcTest::InitializeVM();
   v8::Isolate* isolate = CcTest::isolate();
-  i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
-  i_isolate->set_embedder_wrapper_type_index(kV8WrapperTypeIndex);
-  i_isolate->set_embedder_wrapper_object_index(kV8WrapperObjectIndex);
 
   v8::HandleScope scope(isolate);
   LocalContext env;
@@ -29868,9 +29856,6 @@ TEST(FastApiCallsString) {
 
   CcTest::InitializeVM();
   v8::Isolate* isolate = CcTest::isolate();
-  i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
-  i_isolate->set_embedder_wrapper_type_index(kV8WrapperTypeIndex);
-  i_isolate->set_embedder_wrapper_object_index(kV8WrapperObjectIndex);
 
   v8::HandleScope scope(isolate);
   LocalContext env;
@@ -29992,9 +29977,6 @@ TEST(FastApiCallsFromWasm) {
 
   CcTest::InitializeVM();
   v8::Isolate* isolate = CcTest::isolate();
-  i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
-  i_isolate->set_embedder_wrapper_type_index(kV8WrapperTypeIndex);
-  i_isolate->set_embedder_wrapper_object_index(kV8WrapperObjectIndex);
 
   v8::HandleScope scope(isolate);
   LocalContext env;
diff --git a/test/cctest/test-cpu-profiler.cc b/test/cctest/test-cpu-profiler.cc
@@ -4631,8 +4631,6 @@ TEST(FastApiCPUProfiler) {
   LocalContext env;
   v8::Isolate* isolate = env.isolate();
   i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
-  i_isolate->set_embedder_wrapper_type_index(kV8WrapperTypeIndex);
-  i_isolate->set_embedder_wrapper_object_index(kV8WrapperObjectIndex);
 
   i::HandleScope scope(i_isolate);
 

Original file line number	Diff line number	Diff line change
`@@ -10100,11 +10100,6 @@ void Isolate::Initialize(Isolate* v8_isolate,`
`10100`	`10100`	`}`
`10101`	`10101`	`}`
`10102`	`10102`
`10103`		`- i_isolate->set_embedder_wrapper_type_index(`
`10104`		`- params.embedder_wrapper_type_index);`
`10105`		`- i_isolate->set_embedder_wrapper_object_index(`
`10106`		`- params.embedder_wrapper_object_index);`
`10107`		`-`
`10108`	`10103`	`if (!i::V8::GetCurrentPlatform()`
`10109`	`10104`	`->GetForegroundTaskRunner(v8_isolate)`
`10110`	`10105`	`->NonNestableTasksEnabled()) {`