libcxx/include/new

// -*- C++ -*-
//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#ifndef _LIBCPP_NEW
#define _LIBCPP_NEW

/*
    new synopsis

namespace std
{

class bad_alloc
    : public exception
{
public:
    bad_alloc() noexcept;
    bad_alloc(const bad_alloc&) noexcept;
    bad_alloc& operator=(const bad_alloc&) noexcept;
    virtual const char* what() const noexcept;
};

class bad_array_new_length : public bad_alloc // C++14
{
public:
    bad_array_new_length() noexcept;
};

enum class align_val_t : size_t {}; // C++17

struct destroying_delete_t { // C++20
  explicit destroying_delete_t() = default;
};
inline constexpr destroying_delete_t destroying_delete{}; // C++20

struct nothrow_t { explicit nothrow_t() = default; };
extern const nothrow_t nothrow;
typedef void (*new_handler)();
new_handler set_new_handler(new_handler new_p) noexcept;
new_handler get_new_handler() noexcept;

// 21.6.4, pointer optimization barrier
template <class T> [[nodiscard]] constexpr T* launder(T* p) noexcept;   // C++17, nodiscard since C++20
}  // std

void* operator new(std::size_t size);                                   // replaceable, nodiscard in C++20
void* operator new(std::size_t size, std::align_val_t alignment);       // replaceable, C++17, nodiscard in C++20
void* operator new(std::size_t size, const std::nothrow_t&) noexcept;   // replaceable, nodiscard in C++20
void* operator new(std::size_t size, std::align_val_t alignment,
                   const std::nothrow_t&) noexcept;                     // replaceable, C++17, nodiscard in C++20
void  operator delete(void* ptr) noexcept;                              // replaceable
void  operator delete(void* ptr, std::size_t size) noexcept;            // replaceable, C++14
void  operator delete(void* ptr, std::align_val_t alignment) noexcept;  // replaceable, C++17
void  operator delete(void* ptr, std::size_t size,
                      std::align_val_t alignment) noexcept;             // replaceable, C++17
void  operator delete(void* ptr, const std::nothrow_t&) noexcept;       // replaceable
void  operator delete(void* ptr, std:align_val_t alignment,
                      const std::nothrow_t&) noexcept;                  // replaceable, C++17

void* operator new[](std::size_t size);                                 // replaceable, nodiscard in C++20
void* operator new[](std::size_t size,
                     std::align_val_t alignment) noexcept;              // replaceable, C++17, nodiscard in C++20
void* operator new[](std::size_t size, const std::nothrow_t&) noexcept; // replaceable, nodiscard in C++20
void* operator new[](std::size_t size, std::align_val_t alignment,
                     const std::nothrow_t&) noexcept;                   // replaceable, C++17, nodiscard in C++20
void  operator delete[](void* ptr) noexcept;                            // replaceable
void  operator delete[](void* ptr, std::size_t size) noexcept;          // replaceable, C++14
void  operator delete[](void* ptr,
                        std::align_val_t alignment) noexcept;           // replaceable, C++17
void  operator delete[](void* ptr, std::size_t size,
                        std::align_val_t alignment) noexcept;           // replaceable, C++17
void  operator delete[](void* ptr, const std::nothrow_t&) noexcept;     // replaceable
void  operator delete[](void* ptr, std::align_val_t alignment,
                        const std::nothrow_t&) noexcept;                // replaceable, C++17

void* operator new  (std::size_t size, void* ptr) noexcept;             // nodiscard in C++20, constexpr since C++26
void* operator new[](std::size_t size, void* ptr) noexcept;             // nodiscard in C++20, constexpr since C++26
void  operator delete  (void* ptr, void*) noexcept;
void  operator delete[](void* ptr, void*) noexcept;

*/

#include <__config>
#include <__cstddef/size_t.h>
#include <__exception/exception.h>
#include <__type_traits/is_function.h>
#include <__type_traits/is_same.h>
#include <__type_traits/remove_cv.h>
#include <__verbose_abort>
#include <version>

#if defined(_LIBCPP_ABI_VCRUNTIME)
#  include <new.h>
#endif

#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
#  pragma GCC system_header
#endif

#if defined(__cpp_sized_deallocation) && __cpp_sized_deallocation >= 201309L
#  define _LIBCPP_HAS_LANGUAGE_SIZED_DEALLOCATION 1
#else
#  define _LIBCPP_HAS_LANGUAGE_SIZED_DEALLOCATION 0
#endif

#if _LIBCPP_STD_VER >= 14 || _LIBCPP_HAS_LANGUAGE_SIZED_DEALLOCATION
#  define _LIBCPP_HAS_LIBRARY_SIZED_DEALLOCATION 1
#else
#  define _LIBCPP_HAS_LIBRARY_SIZED_DEALLOCATION 0
#endif

#if _LIBCPP_HAS_LIBRARY_SIZED_DEALLOCATION && _LIBCPP_HAS_LANGUAGE_SIZED_DEALLOCATION
#  define _LIBCPP_HAS_SIZED_DEALLOCATION 1
#else
#  define _LIBCPP_HAS_SIZED_DEALLOCATION 0
#endif

namespace std // purposefully not using versioning namespace
{

#if !defined(_LIBCPP_ABI_VCRUNTIME)
struct _LIBCPP_EXPORTED_FROM_ABI nothrow_t {
  explicit nothrow_t() = default;
};
extern _LIBCPP_EXPORTED_FROM_ABI const nothrow_t nothrow;

class _LIBCPP_EXPORTED_FROM_ABI bad_alloc : public exception {
public:
  bad_alloc() _NOEXCEPT;
  _LIBCPP_HIDE_FROM_ABI bad_alloc(const bad_alloc&) _NOEXCEPT            = default;
  _LIBCPP_HIDE_FROM_ABI bad_alloc& operator=(const bad_alloc&) _NOEXCEPT = default;
  ~bad_alloc() _NOEXCEPT override;
  const char* what() const _NOEXCEPT override;
};

class _LIBCPP_EXPORTED_FROM_ABI bad_array_new_length : public bad_alloc {
public:
  bad_array_new_length() _NOEXCEPT;
  _LIBCPP_HIDE_FROM_ABI bad_array_new_length(const bad_array_new_length&) _NOEXCEPT            = default;
  _LIBCPP_HIDE_FROM_ABI bad_array_new_length& operator=(const bad_array_new_length&) _NOEXCEPT = default;
  ~bad_array_new_length() _NOEXCEPT override;
  const char* what() const _NOEXCEPT override;
};

typedef void (*new_handler)();
_LIBCPP_EXPORTED_FROM_ABI new_handler set_new_handler(new_handler) _NOEXCEPT;
_LIBCPP_EXPORTED_FROM_ABI new_handler get_new_handler() _NOEXCEPT;

#elif defined(_HAS_EXCEPTIONS) && _HAS_EXCEPTIONS == 0 // !_LIBCPP_ABI_VCRUNTIME

// When _HAS_EXCEPTIONS == 0, these complete definitions are needed,
// since they would normally be provided in vcruntime_exception.h
class bad_alloc : public exception {
public:
  bad_alloc() noexcept : exception("bad allocation") {}

private:
  friend class bad_array_new_length;

  bad_alloc(char const* const __message) noexcept : exception(__message) {}
};

class bad_array_new_length : public bad_alloc {
public:
  bad_array_new_length() noexcept : bad_alloc("bad array new length") {}
};
#endif // defined(_LIBCPP_ABI_VCRUNTIME) && defined(_HAS_EXCEPTIONS) && _HAS_EXCEPTIONS == 0

[[__noreturn__]] _LIBCPP_EXPORTED_FROM_ABI void __throw_bad_alloc(); // not in C++ spec

[[__noreturn__]] inline _LIBCPP_HIDE_FROM_ABI void __throw_bad_array_new_length() {
#if _LIBCPP_HAS_EXCEPTIONS
  throw bad_array_new_length();
#else
  _LIBCPP_VERBOSE_ABORT("bad_array_new_length was thrown in -fno-exceptions mode");
#endif
}

#if _LIBCPP_HAS_LIBRARY_ALIGNED_ALLOCATION && !defined(_LIBCPP_ABI_VCRUNTIME)
#  ifndef _LIBCPP_CXX03_LANG
enum class align_val_t : size_t {};
#  else
enum align_val_t { __zero = 0, __max = (size_t)-1 };
#  endif
#endif

#if _LIBCPP_STD_VER >= 20
// Enable the declaration even if the compiler doesn't support the language
// feature.
struct destroying_delete_t {
  explicit destroying_delete_t() = default;
};
inline constexpr destroying_delete_t destroying_delete{};
#endif // _LIBCPP_STD_VER >= 20

} // namespace std

#if defined(_LIBCPP_CXX03_LANG)
#  define _THROW_BAD_ALLOC throw(std::bad_alloc)
#else
#  define _THROW_BAD_ALLOC
#endif

#if !defined(_LIBCPP_ABI_VCRUNTIME)

[[__nodiscard__]] _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new(std::size_t __sz) _THROW_BAD_ALLOC;
[[__nodiscard__]] _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new(std::size_t __sz, const std::nothrow_t&) _NOEXCEPT
    _LIBCPP_NOALIAS;
_LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete(void* __p) _NOEXCEPT;
_LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete(void* __p, const std::nothrow_t&) _NOEXCEPT;
#  if _LIBCPP_HAS_LIBRARY_SIZED_DEALLOCATION
_LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete(void* __p, std::size_t __sz) _NOEXCEPT;
#  endif

[[__nodiscard__]] _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new[](std::size_t __sz) _THROW_BAD_ALLOC;
[[__nodiscard__]] _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new[](std::size_t __sz, const std::nothrow_t&) _NOEXCEPT
    _LIBCPP_NOALIAS;
_LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete[](void* __p) _NOEXCEPT;
_LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete[](void* __p, const std::nothrow_t&) _NOEXCEPT;
#  if _LIBCPP_HAS_LIBRARY_SIZED_DEALLOCATION
_LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete[](void* __p, std::size_t __sz) _NOEXCEPT;
#  endif

#  if _LIBCPP_HAS_LIBRARY_ALIGNED_ALLOCATION
[[__nodiscard__]] _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new(std::size_t __sz, std::align_val_t) _THROW_BAD_ALLOC;
[[__nodiscard__]] _LIBCPP_OVERRIDABLE_FUNC_VIS void*
operator new(std::size_t __sz, std::align_val_t, const std::nothrow_t&) _NOEXCEPT _LIBCPP_NOALIAS;
_LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete(void* __p, std::align_val_t) _NOEXCEPT;
_LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete(void* __p, std::align_val_t, const std::nothrow_t&) _NOEXCEPT;
#    if _LIBCPP_HAS_LIBRARY_SIZED_DEALLOCATION
_LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete(void* __p, std::size_t __sz, std::align_val_t) _NOEXCEPT;
#    endif

[[__nodiscard__]] _LIBCPP_OVERRIDABLE_FUNC_VIS void*
operator new[](std::size_t __sz, std::align_val_t) _THROW_BAD_ALLOC;
[[__nodiscard__]] _LIBCPP_OVERRIDABLE_FUNC_VIS void*
operator new[](std::size_t __sz, std::align_val_t, const std::nothrow_t&) _NOEXCEPT _LIBCPP_NOALIAS;
_LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete[](void* __p, std::align_val_t) _NOEXCEPT;
_LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete[](void* __p, std::align_val_t, const std::nothrow_t&) _NOEXCEPT;
#    if _LIBCPP_HAS_LIBRARY_SIZED_DEALLOCATION
_LIBCPP_OVERRIDABLE_FUNC_VIS void operator delete[](void* __p, std::size_t __sz, std::align_val_t) _NOEXCEPT;
#    endif
#  endif

[[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 void*
operator new(std::size_t, void* __p) _NOEXCEPT {
  return __p;
}
[[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 void*
operator new[](std::size_t, void* __p) _NOEXCEPT {
  return __p;
}
inline _LIBCPP_HIDE_FROM_ABI void operator delete(void*, void*) _NOEXCEPT {}
inline _LIBCPP_HIDE_FROM_ABI void operator delete[](void*, void*) _NOEXCEPT {}

#endif // !_LIBCPP_ABI_VCRUNTIME

_LIBCPP_BEGIN_NAMESPACE_STD

_LIBCPP_CONSTEXPR inline _LIBCPP_HIDE_FROM_ABI bool __is_overaligned_for_new(size_t __align) _NOEXCEPT {
#ifdef __STDCPP_DEFAULT_NEW_ALIGNMENT__
  return __align > __STDCPP_DEFAULT_NEW_ALIGNMENT__;
#else
  return __align > _LIBCPP_ALIGNOF(max_align_t);
#endif
}

template <class... _Args>
_LIBCPP_HIDE_FROM_ABI void* __libcpp_operator_new(_Args... __args) {
#if __has_builtin(__builtin_operator_new) && __has_builtin(__builtin_operator_delete)
  return __builtin_operator_new(__args...);
#else
  return ::operator new(__args...);
#endif
}

template <class... _Args>
_LIBCPP_HIDE_FROM_ABI void __libcpp_operator_delete(_Args... __args) _NOEXCEPT {
#if __has_builtin(__builtin_operator_new) && __has_builtin(__builtin_operator_delete)
  __builtin_operator_delete(__args...);
#else
  ::operator delete(__args...);
#endif
}

inline _LIBCPP_HIDE_FROM_ABI void* __libcpp_allocate(size_t __size, size_t __align) {
#if _LIBCPP_HAS_ALIGNED_ALLOCATION
  if (__is_overaligned_for_new(__align)) {
    const align_val_t __align_val = static_cast<align_val_t>(__align);
    return __libcpp_operator_new(__size, __align_val);
  }
#endif

  (void)__align;
  return __libcpp_operator_new(__size);
}

template <class... _Args>
_LIBCPP_HIDE_FROM_ABI void __do_deallocate_handle_size(void* __ptr, size_t __size, _Args... __args) _NOEXCEPT {
#if !_LIBCPP_HAS_SIZED_DEALLOCATION
  (void)__size;
  return std::__libcpp_operator_delete(__ptr, __args...);
#else
  return std::__libcpp_operator_delete(__ptr, __size, __args...);
#endif
}

inline _LIBCPP_HIDE_FROM_ABI void __libcpp_deallocate(void* __ptr, size_t __size, size_t __align) _NOEXCEPT {
#if !_LIBCPP_HAS_ALIGNED_ALLOCATION
  (void)__align;
  return __do_deallocate_handle_size(__ptr, __size);
#else
  if (__is_overaligned_for_new(__align)) {
    const align_val_t __align_val = static_cast<align_val_t>(__align);
    return __do_deallocate_handle_size(__ptr, __size, __align_val);
  } else {
    return __do_deallocate_handle_size(__ptr, __size);
  }
#endif
}

inline _LIBCPP_HIDE_FROM_ABI void __libcpp_deallocate_unsized(void* __ptr, size_t __align) _NOEXCEPT {
#if !_LIBCPP_HAS_ALIGNED_ALLOCATION
  (void)__align;
  return __libcpp_operator_delete(__ptr);
#else
  if (__is_overaligned_for_new(__align)) {
    const align_val_t __align_val = static_cast<align_val_t>(__align);
    return __libcpp_operator_delete(__ptr, __align_val);
  } else {
    return __libcpp_operator_delete(__ptr);
  }
#endif
}

template <class _Tp>
[[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR _Tp* __launder(_Tp* __p) _NOEXCEPT {
  static_assert(!(is_function<_Tp>::value), "can't launder functions");
  static_assert(!(is_same<void, __remove_cv_t<_Tp> >::value), "can't launder cv-void");
  return __builtin_launder(__p);
}

#if _LIBCPP_STD_VER >= 17
template <class _Tp>
[[nodiscard]] inline _LIBCPP_HIDE_FROM_ABI constexpr _Tp* launder(_Tp* __p) noexcept {
  return std::__launder(__p);
}
#endif

#if _LIBCPP_STD_VER >= 17

#  if defined(__GCC_DESTRUCTIVE_SIZE) && defined(__GCC_CONSTRUCTIVE_SIZE)

inline constexpr size_t hardware_destructive_interference_size  = __GCC_DESTRUCTIVE_SIZE;
inline constexpr size_t hardware_constructive_interference_size = __GCC_CONSTRUCTIVE_SIZE;

#  endif // defined(__GCC_DESTRUCTIVE_SIZE) && defined(__GCC_CONSTRUCTIVE_SIZE)

#endif // _LIBCPP_STD_VER >= 17

_LIBCPP_END_NAMESPACE_STD

#if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 20
#  include <cstddef>
#  include <cstdlib>
#  include <type_traits>
#endif

#endif // _LIBCPP_NEW