// Copyright 2021 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_HEAP_CPPGC_MEMORY_H_

#define V8_HEAP_CPPGC_MEMORY_H_

#include <cstddef>

#include <cstdint>

#include <cstring>

#include "src/base/macros.h"

#include "src/base/sanitizer/asan.h"

#include "src/base/sanitizer/msan.h"

#include "src/heap/cppgc/globals.h"

namespace cppgc {

namespace internal {

V8_NOINLINE DISABLE_ASAN void NoSanitizeMemset(void* address, char c,

size_t bytes);

static constexpr uint8_t kZappedValue = 0xdc;

V8_INLINE void ZapMemory(void* address, size_t size) {

// The lowest bit of the zapped value should be 0 so that zapped object are

// never viewed as fully constructed objects.

memset(address, kZappedValue, size);

}

V8_INLINE void CheckMemoryIsZapped(const void* address, size_t size) {

for (size_t i = 0; i < size; i++) {

CHECK_EQ(kZappedValue, reinterpret_cast<ConstAddress>(address)[i]);

}

}

V8_INLINE void CheckMemoryIsZero(const void* address, size_t size) {

for (size_t i = 0; i < size; i++) {

CHECK_EQ(0, reinterpret_cast<ConstAddress>(address)[i]);

}

}

// Together `SetMemoryAccessible()` and `SetMemoryInaccessible()` form the

// memory access model for allocation and free.

#if defined(V8_USE_MEMORY_SANITIZER) || defined(V8_USE_ADDRESS_SANITIZER) || \

DEBUG

void SetMemoryAccessible(void* address, size_t size);

void SetMemoryInaccessible(void* address, size_t size);

void CheckMemoryIsInaccessible(const void* address, size_t size);

constexpr bool CheckMemoryIsInaccessibleIsNoop() {

#if defined(V8_USE_MEMORY_SANITIZER)

return true;

#elif defined(V8_USE_ADDRESS_SANITIZER)

return false;

#else // Debug builds.

return false;

#endif // Debug builds.

}

#else

// Nothing to be done for release builds.

V8_INLINE void SetMemoryAccessible(void* address, size_t size) {}

V8_INLINE void CheckMemoryIsInaccessible(const void* address, size_t size) {}

constexpr bool CheckMemoryIsInaccessibleIsNoop() { return true; }

V8_INLINE void SetMemoryInaccessible(void* address, size_t size) {

memset(address, 0, size);

}

#endif

} // namespace internal

} // namespace cppgc

#endif // V8_HEAP_CPPGC_MEMORY_H_