xref: /freebsd/contrib/llvm-project/libcxx/include/system_error (revision bdd1243df58e60e85101c09001d9812a789b6bc4)

// -*- 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_SYSTEM_ERROR
#define _LIBCPP_SYSTEM_ERROR

/*
    system_error synopsis

namespace std
{

class error_category
{
public:
    virtual ~error_category() noexcept;

    constexpr error_category();
    error_category(const error_category&) = delete;
    error_category& operator=(const error_category&) = delete;

    virtual const char* name() const noexcept = 0;
    virtual error_condition default_error_condition(int ev) const noexcept;
    virtual bool equivalent(int code, const error_condition& condition) const noexcept;
    virtual bool equivalent(const error_code& code, int condition) const noexcept;
    virtual string message(int ev) const = 0;

    bool operator==(const error_category& rhs) const noexcept;
    bool operator!=(const error_category& rhs) const noexcept;              // removed in C++20
    bool operator<(const error_category& rhs) const noexcept;               // removed in C++20
    strong_ordering operator<=>(const error_category& rhs) const noexcept;  // C++20
};

const error_category& generic_category() noexcept;
const error_category& system_category() noexcept;

template <class T> struct is_error_code_enum
    : public false_type {};

template <class T> struct is_error_condition_enum
    : public false_type {};

template <class _Tp>
inline constexpr bool is_error_condition_enum_v = is_error_condition_enum<_Tp>::value; // C++17

template <class _Tp>
inline constexpr bool is_error_code_enum_v = is_error_code_enum<_Tp>::value; // C++17

class error_code
{
public:
    // constructors:
    error_code() noexcept;
    error_code(int val, const error_category& cat) noexcept;
    template <class ErrorCodeEnum>
        error_code(ErrorCodeEnum e) noexcept;

    // modifiers:
    void assign(int val, const error_category& cat) noexcept;
    template <class ErrorCodeEnum>
        error_code& operator=(ErrorCodeEnum e) noexcept;
    void clear() noexcept;

    // observers:
    int value() const noexcept;
    const error_category& category() const noexcept;
    error_condition default_error_condition() const noexcept;
    string message() const;
    explicit operator bool() const noexcept;
};

// non-member functions:
template <class charT, class traits>
    basic_ostream<charT,traits>&
    operator<<(basic_ostream<charT,traits>& os, const error_code& ec);

class error_condition
{
public:
    // constructors:
    error_condition() noexcept;
    error_condition(int val, const error_category& cat) noexcept;
    template <class ErrorConditionEnum>
        error_condition(ErrorConditionEnum e) noexcept;

    // modifiers:
    void assign(int val, const error_category& cat) noexcept;
    template <class ErrorConditionEnum>
        error_condition& operator=(ErrorConditionEnum e) noexcept;
    void clear() noexcept;

    // observers:
    int value() const noexcept;
    const error_category& category() const noexcept;
    string message() const noexcept;
    explicit operator bool() const noexcept;
};

class system_error
    : public runtime_error
{
public:
    system_error(error_code ec, const string& what_arg);
    system_error(error_code ec, const char* what_arg);
    system_error(error_code ec);
    system_error(int ev, const error_category& ecat, const string& what_arg);
    system_error(int ev, const error_category& ecat, const char* what_arg);
    system_error(int ev, const error_category& ecat);

    const error_code& code() const noexcept;
    const char* what() const noexcept;
};

template <> struct is_error_condition_enum<errc>
    : true_type { }

error_code make_error_code(errc e) noexcept;
error_condition make_error_condition(errc e) noexcept;

// Comparison operators:
bool operator==(const error_code& lhs, const error_code& rhs) noexcept;
bool operator==(const error_code& lhs, const error_condition& rhs) noexcept;
bool operator==(const error_condition& lhs, const error_code& rhs) noexcept;                  // removed in C++20
bool operator==(const error_condition& lhs, const error_condition& rhs) noexcept;
bool operator!=(const error_code& lhs, const error_code& rhs) noexcept;                       // removed in C++20
bool operator!=(const error_code& lhs, const error_condition& rhs) noexcept;                  // removed in C++20
bool operator!=(const error_condition& lhs, const error_code& rhs) noexcept;                  // removed in C++20
bool operator!=(const error_condition& lhs, const error_condition& rhs) noexcept;             // removed in C++20
bool operator<(const error_condition& lhs, const error_condition& rhs) noexcept;              // removed in C++20
bool operator<(const error_code& lhs, const error_code& rhs) noexcept;                        // removed in C++20
strong_ordering operator<=>(const error_code& lhs, const error_code& rhs) noexcept;           // C++20
strong_ordering operator<=>(const error_condition& lhs, const error_condition& rhs) noexcept; // C++20

template <> struct hash<std::error_code>;
template <> struct hash<std::error_condition>;

}  // std

*/

#include <__assert> // all public C++ headers provide the assertion handler
#include <__config>
#include <__errc>
#include <__functional/hash.h>
#include <__functional/unary_function.h>
#include <__memory/addressof.h>
#include <stdexcept>
#include <string>
#include <type_traits>
#include <version>

// standard-mandated includes

// [system.error.syn]
#include <compare>

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

_LIBCPP_BEGIN_NAMESPACE_STD

// is_error_code_enum

template <class _Tp>
struct _LIBCPP_TEMPLATE_VIS is_error_code_enum
    : public false_type {};

#if _LIBCPP_STD_VER > 14
template <class _Tp>
inline constexpr bool is_error_code_enum_v = is_error_code_enum<_Tp>::value;
#endif

// is_error_condition_enum

template <class _Tp>
struct _LIBCPP_TEMPLATE_VIS is_error_condition_enum
    : public false_type {};

#if _LIBCPP_STD_VER > 14
template <class _Tp>
inline constexpr bool is_error_condition_enum_v = is_error_condition_enum<_Tp>::value;
#endif

template <>
struct _LIBCPP_TEMPLATE_VIS is_error_condition_enum<errc>
    : true_type { };

#ifdef _LIBCPP_CXX03_LANG
template <>
struct _LIBCPP_TEMPLATE_VIS is_error_condition_enum<errc::__lx>
    : true_type { };
#endif

class _LIBCPP_TYPE_VIS error_condition;
class _LIBCPP_TYPE_VIS error_code;

// class error_category

class _LIBCPP_HIDDEN __do_message;

class _LIBCPP_TYPE_VIS error_category
{
public:
    virtual ~error_category() _NOEXCEPT;

#if defined(_LIBCPP_ERROR_CATEGORY_DEFINE_LEGACY_INLINE_FUNCTIONS)
    error_category() noexcept;
#else
    _LIBCPP_INLINE_VISIBILITY
    _LIBCPP_CONSTEXPR_SINCE_CXX14 error_category() _NOEXCEPT = default;
#endif
    error_category(const error_category&) = delete;
    error_category& operator=(const error_category&) = delete;

    virtual const char* name() const _NOEXCEPT = 0;
    virtual error_condition default_error_condition(int __ev) const _NOEXCEPT;
    virtual bool equivalent(int __code, const error_condition& __condition) const _NOEXCEPT;
    virtual bool equivalent(const error_code& __code, int __condition) const _NOEXCEPT;
    virtual string message(int __ev) const = 0;

    _LIBCPP_INLINE_VISIBILITY
    bool operator==(const error_category& __rhs) const _NOEXCEPT {return this == &__rhs;}

#if _LIBCPP_STD_VER > 17

    _LIBCPP_HIDE_FROM_ABI
    strong_ordering operator<=>(const error_category& __rhs) const noexcept {return compare_three_way()(this, std::addressof(__rhs));}

#else // _LIBCPP_STD_VER > 17

    _LIBCPP_INLINE_VISIBILITY
    bool operator!=(const error_category& __rhs) const _NOEXCEPT {return !(*this == __rhs);}

    _LIBCPP_INLINE_VISIBILITY
    bool operator< (const error_category& __rhs) const _NOEXCEPT {return this < &__rhs;}

#endif // _LIBCPP_STD_VER > 17

    friend class _LIBCPP_HIDDEN __do_message;
};

class _LIBCPP_HIDDEN __do_message
    : public error_category
{
public:
    string message(int __ev) const override;
};

_LIBCPP_FUNC_VIS const error_category& generic_category() _NOEXCEPT;
_LIBCPP_FUNC_VIS const error_category& system_category() _NOEXCEPT;

namespace __adl_only {
    // Those cause ADL to trigger but they are not viable candidates,
    // so they are never actually selected.
    void make_error_condition() = delete;
    void make_error_code() = delete;
} // namespace __adl_only

class _LIBCPP_TYPE_VIS error_condition
{
    int __val_;
    const error_category* __cat_;
public:
    _LIBCPP_INLINE_VISIBILITY
    error_condition() _NOEXCEPT : __val_(0), __cat_(&generic_category()) {}

    _LIBCPP_INLINE_VISIBILITY
    error_condition(int __val, const error_category& __cat) _NOEXCEPT
        : __val_(__val), __cat_(&__cat) {}

    template <class _Ep>
        _LIBCPP_INLINE_VISIBILITY
        error_condition(_Ep __e,
              typename enable_if<is_error_condition_enum<_Ep>::value>::type* = nullptr
                                                                     ) _NOEXCEPT
            {
                using __adl_only::make_error_condition;
                *this = make_error_condition(__e);
            }

    _LIBCPP_INLINE_VISIBILITY
    void assign(int __val, const error_category& __cat) _NOEXCEPT
    {
        __val_ = __val;
        __cat_ = &__cat;
    }

    template <class _Ep>
        _LIBCPP_INLINE_VISIBILITY
        typename enable_if
        <
            is_error_condition_enum<_Ep>::value,
            error_condition&
        >::type
        operator=(_Ep __e) _NOEXCEPT
            {
                using __adl_only::make_error_condition;
                *this = make_error_condition(__e);
                return *this;
            }

    _LIBCPP_INLINE_VISIBILITY
    void clear() _NOEXCEPT
    {
        __val_ = 0;
        __cat_ = &generic_category();
    }

    _LIBCPP_INLINE_VISIBILITY
    int value() const _NOEXCEPT {return __val_;}

    _LIBCPP_INLINE_VISIBILITY
    const error_category& category() const _NOEXCEPT {return *__cat_;}
    string message() const;

    _LIBCPP_INLINE_VISIBILITY
    explicit operator bool() const _NOEXCEPT {return __val_ != 0;}
};

inline _LIBCPP_INLINE_VISIBILITY
error_condition
make_error_condition(errc __e) _NOEXCEPT
{
    return error_condition(static_cast<int>(__e), generic_category());
}

// error_code

class _LIBCPP_TYPE_VIS error_code
{
    int __val_;
    const error_category* __cat_;
public:
    _LIBCPP_INLINE_VISIBILITY
    error_code() _NOEXCEPT : __val_(0), __cat_(&system_category()) {}

    _LIBCPP_INLINE_VISIBILITY
    error_code(int __val, const error_category& __cat) _NOEXCEPT
        : __val_(__val), __cat_(&__cat) {}

    template <class _Ep>
        _LIBCPP_INLINE_VISIBILITY
        error_code(_Ep __e,
                   typename enable_if<is_error_code_enum<_Ep>::value>::type* = nullptr
                                                                     ) _NOEXCEPT
            {
                using __adl_only::make_error_code;
                *this = make_error_code(__e);
            }

    _LIBCPP_INLINE_VISIBILITY
    void assign(int __val, const error_category& __cat) _NOEXCEPT
    {
        __val_ = __val;
        __cat_ = &__cat;
    }

    template <class _Ep>
        _LIBCPP_INLINE_VISIBILITY
        typename enable_if
        <
            is_error_code_enum<_Ep>::value,
            error_code&
        >::type
        operator=(_Ep __e) _NOEXCEPT
            {
                using __adl_only::make_error_code;
                *this = make_error_code(__e);
                return *this;
            }

    _LIBCPP_INLINE_VISIBILITY
    void clear() _NOEXCEPT
    {
        __val_ = 0;
        __cat_ = &system_category();
    }

    _LIBCPP_INLINE_VISIBILITY
    int value() const _NOEXCEPT {return __val_;}

    _LIBCPP_INLINE_VISIBILITY
    const error_category& category() const _NOEXCEPT {return *__cat_;}

    _LIBCPP_INLINE_VISIBILITY
    error_condition default_error_condition() const _NOEXCEPT
        {return __cat_->default_error_condition(__val_);}

    string message() const;

    _LIBCPP_INLINE_VISIBILITY
    explicit operator bool() const _NOEXCEPT {return __val_ != 0;}
};

inline _LIBCPP_INLINE_VISIBILITY
error_code
make_error_code(errc __e) _NOEXCEPT
{
    return error_code(static_cast<int>(__e), generic_category());
}

inline _LIBCPP_INLINE_VISIBILITY
bool
operator==(const error_code& __x, const error_code& __y) _NOEXCEPT
{
    return __x.category() == __y.category() && __x.value() == __y.value();
}

inline _LIBCPP_INLINE_VISIBILITY
bool
operator==(const error_code& __x, const error_condition& __y) _NOEXCEPT
{
    return __x.category().equivalent(__x.value(), __y)
        || __y.category().equivalent(__x, __y.value());
}

#if _LIBCPP_STD_VER <= 17
inline _LIBCPP_INLINE_VISIBILITY
bool
operator==(const error_condition& __x, const error_code& __y) _NOEXCEPT
{
    return __y == __x;
}
#endif

inline _LIBCPP_INLINE_VISIBILITY
bool
operator==(const error_condition& __x, const error_condition& __y) _NOEXCEPT
{
    return __x.category() == __y.category() && __x.value() == __y.value();
}

#if _LIBCPP_STD_VER <= 17

inline _LIBCPP_INLINE_VISIBILITY
bool
operator!=(const error_code& __x, const error_code& __y) _NOEXCEPT
{return !(__x == __y);}

inline _LIBCPP_INLINE_VISIBILITY
bool
operator!=(const error_code& __x, const error_condition& __y) _NOEXCEPT
{return !(__x == __y);}

inline _LIBCPP_INLINE_VISIBILITY
bool
operator!=(const error_condition& __x, const error_code& __y) _NOEXCEPT
{return !(__x == __y);}

inline _LIBCPP_INLINE_VISIBILITY
bool
operator!=(const error_condition& __x, const error_condition& __y) _NOEXCEPT
{return !(__x == __y);}

inline _LIBCPP_INLINE_VISIBILITY
bool
operator<(const error_condition& __x, const error_condition& __y) _NOEXCEPT
{
    return __x.category() < __y.category()
        || (__x.category() == __y.category() && __x.value() < __y.value());
}

inline _LIBCPP_INLINE_VISIBILITY
bool
operator<(const error_code& __x, const error_code& __y) _NOEXCEPT
{
    return __x.category() < __y.category()
        || (__x.category() == __y.category() && __x.value() < __y.value());
}

#else // _LIBCPP_STD_VER <= 17

inline _LIBCPP_HIDE_FROM_ABI strong_ordering
operator<=>(const error_code& __x, const error_code& __y) noexcept
{
    if (auto __c = __x.category() <=> __y.category(); __c != 0)
        return __c;
    return __x.value() <=> __y.value();
}

inline _LIBCPP_HIDE_FROM_ABI strong_ordering
operator<=>(const error_condition& __x, const error_condition& __y) noexcept
{
    if (auto __c = __x.category() <=> __y.category(); __c != 0)
       return __c;
    return __x.value() <=> __y.value();
}

#endif // _LIBCPP_STD_VER <= 17

template <>
struct _LIBCPP_TEMPLATE_VIS hash<error_code>
    : public __unary_function<error_code, size_t>
{
    _LIBCPP_INLINE_VISIBILITY
    size_t operator()(const error_code& __ec) const _NOEXCEPT
    {
        return static_cast<size_t>(__ec.value());
    }
};

template <>
struct _LIBCPP_TEMPLATE_VIS hash<error_condition>
    : public __unary_function<error_condition, size_t>
{
    _LIBCPP_INLINE_VISIBILITY
    size_t operator()(const error_condition& __ec) const _NOEXCEPT
    {
        return static_cast<size_t>(__ec.value());
    }
};

// system_error

class _LIBCPP_TYPE_VIS system_error
    : public runtime_error
{
    error_code __ec_;
public:
    system_error(error_code __ec, const string& __what_arg);
    system_error(error_code __ec, const char* __what_arg);
    system_error(error_code __ec);
    system_error(int __ev, const error_category& __ecat, const string& __what_arg);
    system_error(int __ev, const error_category& __ecat, const char* __what_arg);
    system_error(int __ev, const error_category& __ecat);
    system_error(const system_error&) _NOEXCEPT = default;
    ~system_error() _NOEXCEPT override;

    _LIBCPP_INLINE_VISIBILITY
    const error_code& code() const _NOEXCEPT {return __ec_;}

private:
    static string __init(const error_code&, string);
};

_LIBCPP_NORETURN _LIBCPP_FUNC_VIS
void __throw_system_error(int __ev, const char* __what_arg);

_LIBCPP_END_NAMESPACE_STD

#endif // _LIBCPP_SYSTEM_ERROR