src/execution/isolate-utils-inl.h

// Copyright 2019 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef V8_EXECUTION_ISOLATE_UTILS_INL_H_
#define V8_EXECUTION_ISOLATE_UTILS_INL_H_

#include "src/execution/isolate-utils.h"
// Include the non-inl header before the rest of the headers.

#include "src/common/ptr-compr-inl.h"
#include "src/execution/isolate.h"
#include "src/sandbox/isolate.h"

namespace v8::internal {

V8_INLINE Heap* GetHeapFromWritableObject(Tagged<HeapObject> object) {
  MemoryChunk* chunk = MemoryChunk::FromHeapObject(object);
  // Do not use this method on shared objects. This method would always return
  // the shared space isolate for shared objects. However, on worker isolates
  // this might be different from the current isolate. In such cases either
  // require the current isolate as an additional argument from the caller or
  // use Isolate::Current(). From there you can access the shared space isolate
  // with `isolate->shared_space_isolate()` if needed.
  DCHECK(!chunk->InWritableSharedSpace());
  return chunk->GetHeap();
}

V8_INLINE Isolate* GetIsolateFromWritableObject(Tagged<HeapObject> object) {
  return Isolate::FromHeap(GetHeapFromWritableObject(object));
}

V8_INLINE Heap* GetHeapFromWritableObject(const HeapObjectLayout& object) {
  return GetHeapFromWritableObject(Tagged(&object));
}

V8_INLINE Isolate* GetIsolateFromWritableObject(
    const HeapObjectLayout& object) {
  return GetIsolateFromWritableObject(Tagged(&object));
}

V8_INLINE bool GetIsolateFromHeapObject(Tagged<HeapObject> object,
                                        Isolate** isolate) {
  MemoryChunk* chunk = MemoryChunk::FromHeapObject(object);
  if (chunk->InReadOnlySpace()) {
    *isolate = nullptr;
    return false;
  }
  *isolate = Isolate::FromHeap(chunk->GetHeap());
  return true;
}

// Use this function instead of `Internals::GetIsolateForSandbox` for internal
// code, as this function is fully inlinable.
// Note that this method might return an isolate which is not the "current" one
// as returned by `Isolate::Current()`. Use `GetCurrentIsolateForSandbox`
// instead where possible.
// TODO(396607238): Replace all callers with `GetCurrentIsolateForSandbox()`.
V8_INLINE IsolateForSandbox GetIsolateForSandbox(Tagged<HeapObject> object) {
#ifdef V8_ENABLE_SANDBOX
  // This method can be used on shared objects as opposed to
  // GetHeapFromWritableObject because it only returns IsolateForSandbox instead
  // of the Isolate. This is because shared objects will go to shared external
  // pointer table which is the same for main and all worker isolates.
  MemoryChunk* chunk = MemoryChunk::FromHeapObject(object);
  Isolate* isolate = Isolate::FromHeap(chunk->GetHeap());
  // TODO(396607238): Enable the following line, which requires resolving some
  // inl-header cycles.
  // SBXCHECK_EQ(isolate, Isolate::Current());
  return isolate;
#else
  // Not used in non-sandbox mode.
  return {};
#endif
}

}  // namespace v8::internal

#endif  // V8_EXECUTION_ISOLATE_UTILS_INL_H_