experimental/status-code/win32_code.hpp

0001 /* Proposed SG14 status_code
0002 (C) 2018-2024 Niall Douglas <http://www.nedproductions.biz/> (5 commits)
0003 File Created: Feb 2018
0004
0005
0006 Boost Software License - Version 1.0 - August 17th, 2003
0007
0008 Permission is hereby granted, free of charge, to any person or organization
0009 obtaining a copy of the software and accompanying documentation covered by
0010 this license (the "Software") to use, reproduce, display, distribute,
0011 execute, and transmit the Software, and to prepare derivative works of the
0012 Software, and to permit third-parties to whom the Software is furnished to
0013 do so, all subject to the following:
0014
0015 The copyright notices in the Software and this entire statement, including
0016 the above license grant, this restriction and the following disclaimer,
0017 must be included in all copies of the Software, in whole or in part, and
0018 all derivative works of the Software, unless such copies or derivative
0019 works are solely in the form of machine-executable object code generated by
0020 a source language processor.
0021
0022 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
0023 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
0024 FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
0025 SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
0026 FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
0027 ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
0028 DEALINGS IN THE SOFTWARE.
0029 */
0030
0031 #ifndef BOOST_OUTCOME_SYSTEM_ERROR2_WIN32_CODE_HPP
0032 #define BOOST_OUTCOME_SYSTEM_ERROR2_WIN32_CODE_HPP
0033
0034 #if !defined(_WIN32) && !defined(BOOST_OUTCOME_STANDARDESE_IS_IN_THE_HOUSE)
0035 #error This file should only be included on Windows
0036 #endif
0037
0038 #include "quick_status_code_from_enum.hpp"
0039
0040 BOOST_OUTCOME_SYSTEM_ERROR2_NAMESPACE_BEGIN
0041
0042 //! \exclude
0043 namespace win32
0044 {
0045 #ifdef __MINGW32__
0046   extern "C"
0047   {
0048 #endif
0049     // A Win32 DWORD
0050     using DWORD = unsigned long;
0051     // Used to retrieve the current Win32 error code
0052     extern DWORD __stdcall GetLastError();
0053     // Used to retrieve a locale-specific message string for some error code
0054     extern DWORD __stdcall FormatMessageW(DWORD dwFlags, const void *lpSource, DWORD dwMessageId, DWORD dwLanguageId, wchar_t *lpBuffer, DWORD nSize,
0055                                           void /*va_list*/ *Arguments);
0056     // Converts UTF-16 message string to UTF-8
0057     extern int __stdcall WideCharToMultiByte(unsigned int CodePage, DWORD dwFlags, const wchar_t *lpWideCharStr, int cchWideChar, char *lpMultiByteStr,
0058                                              int cbMultiByte, const char *lpDefaultChar, int *lpUsedDefaultChar);
0059 #ifdef __MINGW32__
0060   }
0061 #else
0062 #pragma comment(lib, "kernel32.lib")
0063 #if(defined(__x86_64__) || defined(_M_X64)) || (defined(__aarch64__) || defined(_M_ARM64))
0064 #pragma comment(linker, "/alternatename:?GetLastError@win32@system_error2@@YAKXZ=GetLastError")
0065 #pragma comment(linker, "/alternatename:?FormatMessageW@win32@system_error2@@YAKKPEBXKKPEA_WKPEAX@Z=FormatMessageW")
0066 #pragma comment(linker, "/alternatename:?WideCharToMultiByte@win32@system_error2@@YAHIKPEB_WHPEADHPEBDPEAH@Z=WideCharToMultiByte")
0067 #elif defined(__x86__) || defined(_M_IX86) || defined(__i386__)
0068 #pragma comment(linker, "/alternatename:?GetLastError@win32@system_error2@@YGKXZ=_GetLastError@0")
0069 #pragma comment(linker, "/alternatename:?FormatMessageW@win32@system_error2@@YGKKPBXKKPA_WKPAX@Z=_FormatMessageW@28")
0070 #pragma comment(linker, "/alternatename:?WideCharToMultiByte@win32@system_error2@@YGHIKPB_WHPADHPBDPAH@Z=_WideCharToMultiByte@32")
0071 #elif defined(__arm__) || defined(_M_ARM)
0072 #pragma comment(linker, "/alternatename:?GetLastError@win32@system_error2@@YAKXZ=GetLastError")
0073 #pragma comment(linker, "/alternatename:?FormatMessageW@win32@system_error2@@YAKKPBXKKPA_WKPAX@Z=FormatMessageW")
0074 #pragma comment(linker, "/alternatename:?WideCharToMultiByte@win32@system_error2@@YAHIKPB_WHPADHPBDPAH@Z=WideCharToMultiByte")
0075 #else
0076 #error Unknown architecture
0077 #endif
0078 #endif
0079 }  // namespace win32
0080
0081 class _win32_code_domain;
0082 class _com_code_domain;
0083 //! (Windows only) A Win32 error code, those returned by `GetLastError()`.
0084 using win32_code = status_code<_win32_code_domain>;
0085 //! (Windows only) A specialisation of `status_error` for the Win32 error code domain.
0086 using win32_error = status_error<_win32_code_domain>;
0087
0088 namespace mixins
0089 {
0090   template <class Base> struct mixin<Base, _win32_code_domain> : public Base
0091   {
0092     using Base::Base;
0093
0094     //! Returns a `win32_code` for the current value of `GetLastError()`.
0095     static inline win32_code current() noexcept;
0096   };
0097 }  // namespace mixins
0098
0099 /*! (Windows only) The implementation of the domain for Win32 error codes, those returned by `GetLastError()`.
0100  */
0101 class _win32_code_domain : public status_code_domain
0102 {
0103   template <class DomainType> friend class status_code;
0104   friend class _com_code_domain;
0105   using _base = status_code_domain;
0106   static int _win32_code_to_errno(win32::DWORD c)
0107   {
0108     switch(c)
0109     {
0110     case 0:
0111       return 0;
0112 #include "detail/win32_code_to_generic_code.ipp"
0113     }
0114     return -1;
0115   }
0116   //! Construct from a Win32 error code
0117   static _base::string_ref _make_string_ref(win32::DWORD c) noexcept
0118   {
0119     wchar_t buffer[32768];
0120     win32::DWORD wlen =
0121     win32::FormatMessageW(0x00001000 /*FORMAT_MESSAGE_FROM_SYSTEM*/ | 0x00000200 /*FORMAT_MESSAGE_IGNORE_INSERTS*/, nullptr, c, 0, buffer, 32768, nullptr);
0122     size_t allocation = wlen + (wlen >> 1);
0123     win32::DWORD bytes;
0124     if(wlen == 0)
0125     {
0126       return _base::string_ref("failed to get message from system");
0127     }
0128     for(;;)
0129     {
0130       auto *p = static_cast<char *>(malloc(allocation));  // NOLINT
0131       if(p == nullptr)
0132       {
0133         return _base::string_ref("failed to get message from system");
0134       }
0135       bytes = win32::WideCharToMultiByte(65001 /*CP_UTF8*/, 0, buffer, (int) (wlen + 1), p, (int) allocation, nullptr, nullptr);
0136       if(bytes != 0)
0137       {
0138         char *end = strchr(p, 0);
0139         while(end[-1] == 10 || end[-1] == 13)
0140         {
0141           --end;
0142         }
0143         *end = 0;  // NOLINT
0144         return _base::atomic_refcounted_string_ref(p, end - p);
0145       }
0146       free(p);  // NOLINT
0147       if(win32::GetLastError() == 0x7a /*ERROR_INSUFFICIENT_BUFFER*/)
0148       {
0149         allocation += allocation >> 2;
0150         continue;
0151       }
0152       return _base::string_ref("failed to get message from system");
0153     }
0154   }
0155
0156 public:
0157   //! The value type of the win32 code, which is a `win32::DWORD`
0158   using value_type = win32::DWORD;
0159   using _base::string_ref;
0160
0161 public:
0162   //! Default constructor
0163   constexpr explicit _win32_code_domain(typename _base::unique_id_type id = 0x8cd18ee72d680f1b) noexcept
0164       : _base(id)
0165   {
0166   }
0167   _win32_code_domain(const _win32_code_domain &) = default;
0168   _win32_code_domain(_win32_code_domain &&) = default;
0169   _win32_code_domain &operator=(const _win32_code_domain &) = default;
0170   _win32_code_domain &operator=(_win32_code_domain &&) = default;
0171   ~_win32_code_domain() = default;
0172
0173   //! Constexpr singleton getter. Returns the constexpr win32_code_domain variable.
0174   static inline constexpr const _win32_code_domain &get();
0175
0176   virtual string_ref name() const noexcept override { return string_ref("win32 domain"); }  // NOLINT
0177
0178   virtual payload_info_t payload_info() const noexcept override
0179   {
0180     return {sizeof(value_type), sizeof(status_code_domain *) + sizeof(value_type),
0181             (alignof(value_type) > alignof(status_code_domain *)) ? alignof(value_type) : alignof(status_code_domain *)};
0182   }
0183
0184 protected:
0185   virtual bool _do_failure(const status_code<void> &code) const noexcept override  // NOLINT
0186   {
0187     assert(code.domain() == *this);
0188     return static_cast<const win32_code &>(code).value() != 0;  // NOLINT
0189   }
0190   virtual bool _do_equivalent(const status_code<void> &code1, const status_code<void> &code2) const noexcept override  // NOLINT
0191   {
0192     assert(code1.domain() == *this);
0193     const auto &c1 = static_cast<const win32_code &>(code1);  // NOLINT
0194     if(code2.domain() == *this)
0195     {
0196       const auto &c2 = static_cast<const win32_code &>(code2);  // NOLINT
0197       return c1.value() == c2.value();
0198     }
0199     if(code2.domain() == generic_code_domain)
0200     {
0201       const auto &c2 = static_cast<const generic_code &>(code2);  // NOLINT
0202       if(static_cast<int>(c2.value()) == _win32_code_to_errno(c1.value()))
0203       {
0204         return true;
0205       }
0206     }
0207     return false;
0208   }
0209   virtual generic_code _generic_code(const status_code<void> &code) const noexcept override  // NOLINT
0210   {
0211     assert(code.domain() == *this);
0212     const auto &c = static_cast<const win32_code &>(code);  // NOLINT
0213     return generic_code(static_cast<errc>(_win32_code_to_errno(c.value())));
0214   }
0215   virtual string_ref _do_message(const status_code<void> &code) const noexcept override  // NOLINT
0216   {
0217     assert(code.domain() == *this);
0218     const auto &c = static_cast<const win32_code &>(code);  // NOLINT
0219     return _make_string_ref(c.value());
0220   }
0221 #if defined(_CPPUNWIND) || defined(__EXCEPTIONS) || defined(BOOST_OUTCOME_STANDARDESE_IS_IN_THE_HOUSE)
0222   BOOST_OUTCOME_SYSTEM_ERROR2_NORETURN virtual void _do_throw_exception(const status_code<void> &code) const override  // NOLINT
0223   {
0224     assert(code.domain() == *this);
0225     const auto &c = static_cast<const win32_code &>(code);  // NOLINT
0226     throw status_error<_win32_code_domain>(c);
0227   }
0228 #endif
0229 };
0230 //! (Windows only) A constexpr source variable for the win32 code domain, which is that of `GetLastError()` (Windows). Returned by
0231 //! `_win32_code_domain::get()`.
0232 constexpr _win32_code_domain win32_code_domain;
0233 inline constexpr const _win32_code_domain &_win32_code_domain::get()
0234 {
0235   return win32_code_domain;
0236 }
0237
0238 namespace mixins
0239 {
0240   template <class Base> inline win32_code mixin<Base, _win32_code_domain>::current() noexcept
0241   {
0242     return win32_code(win32::GetLastError());
0243   }
0244 }  // namespace mixins
0245
0246 BOOST_OUTCOME_SYSTEM_ERROR2_NAMESPACE_END
0247
0248 #endif