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/*
* Copyright 2013-2015 Max Kellermann <max.kellermann@gmail.com>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef SYSTEM_ERROR_HXX
#define SYSTEM_ERROR_HXX
#include <system_error> // IWYU pragma: export
#include <utility>
#include <stdio.h>
template<typename... Args>
static inline std::system_error
FormatSystemError(std::error_code code, const char *fmt,
Args&&... args) noexcept
{
char buffer[1024];
snprintf(buffer, sizeof(buffer), fmt, std::forward<Args>(args)...);
return std::system_error(code, buffer);
}
#ifdef _WIN32
#include <windows.h>
static inline std::system_error
MakeLastError(DWORD code, const char *msg) noexcept
{
return std::system_error(std::error_code(code, std::system_category()),
msg);
}
static inline std::system_error
MakeLastError(const char *msg) noexcept
{
return MakeLastError(GetLastError(), msg);
}
template<typename... Args>
static inline std::system_error
FormatLastError(DWORD code, const char *fmt, Args&&... args) noexcept
{
char buffer[512];
const auto end = buffer + sizeof(buffer);
size_t length = snprintf(buffer, sizeof(buffer) - 128,
fmt, std::forward<Args>(args)...);
char *p = buffer + length;
*p++ = ':';
*p++ = ' ';
FormatMessageA(FORMAT_MESSAGE_FROM_SYSTEM |
FORMAT_MESSAGE_IGNORE_INSERTS,
nullptr, code, 0, p, end - p, nullptr);
return MakeLastError(code, buffer);
}
template<typename... Args>
static inline std::system_error
FormatLastError(const char *fmt, Args&&... args) noexcept
{
return FormatLastError(GetLastError(), fmt,
std::forward<Args>(args)...);
}
#endif /* _WIN32 */
#include <cerrno> // IWYU pragma: export
#include <string.h>
/**
* Returns the error_category to be used to wrap errno values. The
* C++ standard does not define this well, so this code is based on
* observations what C++ standard library implementations actually
* use.
*
* @see https://stackoverflow.com/questions/28746372/system-error-categories-and-standard-system-error-codes
*/
static inline const std::error_category &
ErrnoCategory() noexcept
{
#ifdef _WIN32
/* on Windows, the generic_category() is used for errno
values */
return std::generic_category();
#else
/* on POSIX, system_category() appears to be the best
choice */
return std::system_category();
#endif
}
static inline std::system_error
MakeErrno(int code, const char *msg) noexcept
{
return std::system_error(std::error_code(code, ErrnoCategory()),
msg);
}
static inline std::system_error
MakeErrno(const char *msg) noexcept
{
return MakeErrno(errno, msg);
}
template<typename... Args>
static inline std::system_error
FormatErrno(int code, const char *fmt, Args&&... args) noexcept
{
char buffer[512];
snprintf(buffer, sizeof(buffer),
fmt, std::forward<Args>(args)...);
return MakeErrno(code, buffer);
}
template<typename... Args>
static inline std::system_error
FormatErrno(const char *fmt, Args&&... args) noexcept
{
return FormatErrno(errno, fmt, std::forward<Args>(args)...);
}
template<typename... Args>
static inline std::system_error
FormatFileNotFound(const char *fmt, Args&&... args) noexcept
{
#ifdef _WIN32
return FormatLastError(ERROR_FILE_NOT_FOUND, fmt,
std::forward<Args>(args)...);
#else
return FormatErrno(ENOENT, fmt, std::forward<Args>(args)...);
#endif
}
[[gnu::pure]]
inline bool
IsErrno(const std::system_error &e, int code) noexcept
{
return e.code().category() == ErrnoCategory() &&
e.code().value() == code;
}
[[gnu::pure]]
static inline bool
IsFileNotFound(const std::system_error &e) noexcept
{
#ifdef _WIN32
return e.code().category() == std::system_category() &&
e.code().value() == ERROR_FILE_NOT_FOUND;
#else
return IsErrno(e, ENOENT);
#endif
}
[[gnu::pure]]
static inline bool
IsPathNotFound(const std::system_error &e) noexcept
{
#ifdef _WIN32
return e.code().category() == std::system_category() &&
e.code().value() == ERROR_PATH_NOT_FOUND;
#else
return IsErrno(e, ENOTDIR);
#endif
}
[[gnu::pure]]
static inline bool
IsAccessDenied(const std::system_error &e) noexcept
{
#ifdef _WIN32
return e.code().category() == std::system_category() &&
e.code().value() == ERROR_ACCESS_DENIED;
#else
return IsErrno(e, EACCES);
#endif
}
#endif
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