ceph/src/boost/boost/outcome/experimental/status-code/win32_code.hpp

   1 /* Proposed SG14 status_code
   2 (C) 2018-2020 Niall Douglas <http://www.nedproductions.biz/> (5 commits)
   3 File Created: Feb 2018
   4
   5
   6 Boost Software License - Version 1.0 - August 17th, 2003
   7
   8 Permission is hereby granted, free of charge, to any person or organization
   9 obtaining a copy of the software and accompanying documentation covered by
  10 this license (the "Software") to use, reproduce, display, distribute,
  11 execute, and transmit the Software, and to prepare derivative works of the
  12 Software, and to permit third-parties to whom the Software is furnished to
  13 do so, all subject to the following:
  14
  15 The copyright notices in the Software and this entire statement, including
  16 the above license grant, this restriction and the following disclaimer,
  17 must be included in all copies of the Software, in whole or in part, and
  18 all derivative works of the Software, unless such copies or derivative
  19 works are solely in the form of machine-executable object code generated by
  20 a source language processor.
  21
  22 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  23 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  24 FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
  25 SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
  26 FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
  27 ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  28 DEALINGS IN THE SOFTWARE.
  29 */
  30
  31 #ifndef BOOST_OUTCOME_SYSTEM_ERROR2_WIN32_CODE_HPP
  32 #define BOOST_OUTCOME_SYSTEM_ERROR2_WIN32_CODE_HPP
  33
  34 #if !defined(_WIN32) && !defined(BOOST_OUTCOME_STANDARDESE_IS_IN_THE_HOUSE)
  35 #error This file should only be included on Windows
  36 #endif
  37
  38 #include "quick_status_code_from_enum.hpp"
  39
  40 BOOST_OUTCOME_SYSTEM_ERROR2_NAMESPACE_BEGIN
  41
  42 //! \exclude
  43 namespace win32
  44 {
  45   // A Win32 DWORD
  46   using DWORD = unsigned long;
  47   // Used to retrieve the current Win32 error code
  48   extern DWORD __stdcall GetLastError();
  49   // Used to retrieve a locale-specific message string for some error code
  50   extern DWORD __stdcall FormatMessageW(DWORD dwFlags, const void *lpSource, DWORD dwMessageId, DWORD dwLanguageId, wchar_t *lpBuffer, DWORD nSize, void /*va_list*/ *Arguments);
  51   // Converts UTF-16 message string to UTF-8
  52   extern int __stdcall WideCharToMultiByte(unsigned int CodePage, DWORD dwFlags, const wchar_t *lpWideCharStr, int cchWideChar, char *lpMultiByteStr, int cbMultiByte, const char *lpDefaultChar, int *lpUsedDefaultChar);
  53 #pragma comment(lib, "kernel32.lib")
  54 #if defined(_WIN64)
  55 #pragma comment(linker, "/alternatename:?GetLastError@win32@system_error2@@YAKXZ=GetLastError")
  56 #pragma comment(linker, "/alternatename:?FormatMessageW@win32@system_error2@@YAKKPEBXKKPEA_WKPEAX@Z=FormatMessageW")
  57 #pragma comment(linker, "/alternatename:?WideCharToMultiByte@win32@system_error2@@YAHIKPEB_WHPEADHPEBDPEAH@Z=WideCharToMultiByte")
  58 #else
  59 #pragma comment(linker, "/alternatename:?GetLastError@win32@system_error2@@YGKXZ=__imp__GetLastError@0")
  60 #pragma comment(linker, "/alternatename:?FormatMessageW@win32@system_error2@@YGKKPBXKKPA_WKPAX@Z=__imp__FormatMessageW@28")
  61 #pragma comment(linker, "/alternatename:?WideCharToMultiByte@win32@system_error2@@YGHIKPB_WHPADHPBDPAH@Z=__imp__WideCharToMultiByte@32")
  62 #endif
  63 }  // namespace win32
  64
  65 class _win32_code_domain;
  66 class _com_code_domain;
  67 //! (Windows only) A Win32 error code, those returned by `GetLastError()`.
  68 using win32_code = status_code<_win32_code_domain>;
  69 //! (Windows only) A specialisation of `status_error` for the Win32 error code domain.
  70 using win32_error = status_error<_win32_code_domain>;
  71
  72 namespace mixins
  73 {
  74   template <class Base> struct mixin<Base, _win32_code_domain> : public Base
  75   {
  76     using Base::Base;
  77
  78     //! Returns a `win32_code` for the current value of `GetLastError()`.
  79     static inline win32_code current() noexcept;
  80   };
  81 }  // namespace mixins
  82
  83 /*! (Windows only) The implementation of the domain for Win32 error codes, those returned by `GetLastError()`.
  84  */
  85 class _win32_code_domain : public status_code_domain
  86 {
  87   template <class DomainType> friend class status_code;
  88   template <class StatusCode> friend class detail::indirecting_domain;
  89   friend class _com_code_domain;
  90   using _base = status_code_domain;
  91   static int _win32_code_to_errno(win32::DWORD c)
  92   {
  93     switch(c)
  94     {
  95     case 0:
  96       return 0;
  97 #include "detail/win32_code_to_generic_code.ipp"
  98     }
  99     return -1;
 100   }
 101   //! Construct from a Win32 error code
 102   static _base::string_ref _make_string_ref(win32::DWORD c) noexcept
 103   {
 104     wchar_t buffer[32768];
 105     win32::DWORD wlen = win32::FormatMessageW(0x00001000 /*FORMAT_MESSAGE_FROM_SYSTEM*/ | 0x00000200 /*FORMAT_MESSAGE_IGNORE_INSERTS*/, nullptr, c, 0, buffer, 32768, nullptr);
 106     size_t allocation = wlen + (wlen >> 1);
 107     win32::DWORD bytes;
 108     if(wlen == 0)
 109     {
 110       return _base::string_ref("failed to get message from system");
 111     }
 112     for(;;)
 113     {
 114       auto *p = static_cast<char *>(malloc(allocation));  // NOLINT
 115       if(p == nullptr)
 116       {
 117         return _base::string_ref("failed to get message from system");
 118       }
 119       bytes = win32::WideCharToMultiByte(65001 /*CP_UTF8*/, 0, buffer, (int) (wlen + 1), p, (int) allocation, nullptr, nullptr);
 120       if(bytes != 0)
 121       {
 122         char *end = strchr(p, 0);
 123         while(end[-1] == 10 || end[-1] == 13)
 124         {
 125           --end;
 126         }
 127         *end = 0;  // NOLINT
 128         return _base::atomic_refcounted_string_ref(p, end - p);
 129       }
 130       free(p);  // NOLINT
 131       if(win32::GetLastError() == 0x7a /*ERROR_INSUFFICIENT_BUFFER*/)
 132       {
 133         allocation += allocation >> 2;
 134         continue;
 135       }
 136       return _base::string_ref("failed to get message from system");
 137     }
 138   }
 139
 140 public:
 141   //! The value type of the win32 code, which is a `win32::DWORD`
 142   using value_type = win32::DWORD;
 143   using _base::string_ref;
 144
 145 public:
 146   //! Default constructor
 147   constexpr explicit _win32_code_domain(typename _base::unique_id_type id = 0x8cd18ee72d680f1b) noexcept
 148       : _base(id)
 149   {
 150   }
 151   _win32_code_domain(const _win32_code_domain &) = default;
 152   _win32_code_domain(_win32_code_domain &&) = default;
 153   _win32_code_domain &operator=(const _win32_code_domain &) = default;
 154   _win32_code_domain &operator=(_win32_code_domain &&) = default;
 155   ~_win32_code_domain() = default;
 156
 157   //! Constexpr singleton getter. Returns the constexpr win32_code_domain variable.
 158   static inline constexpr const _win32_code_domain &get();
 159
 160   virtual string_ref name() const noexcept override { return string_ref("win32 domain"); }  // NOLINT
 161 protected:
 162   virtual bool _do_failure(const status_code<void> &code) const noexcept override  // NOLINT
 163   {
 164     assert(code.domain() == *this);
 165     return static_cast<const win32_code &>(code).value() != 0;  // NOLINT
 166   }
 167   virtual bool _do_equivalent(const status_code<void> &code1, const status_code<void> &code2) const noexcept override  // NOLINT
 168   {
 169     assert(code1.domain() == *this);
 170     const auto &c1 = static_cast<const win32_code &>(code1);  // NOLINT
 171     if(code2.domain() == *this)
 172     {
 173       const auto &c2 = static_cast<const win32_code &>(code2);  // NOLINT
 174       return c1.value() == c2.value();
 175     }
 176     if(code2.domain() == generic_code_domain)
 177     {
 178       const auto &c2 = static_cast<const generic_code &>(code2);  // NOLINT
 179       if(static_cast<int>(c2.value()) == _win32_code_to_errno(c1.value()))
 180       {
 181         return true;
 182       }
 183     }
 184     return false;
 185   }
 186   virtual generic_code _generic_code(const status_code<void> &code) const noexcept override  // NOLINT
 187   {
 188     assert(code.domain() == *this);
 189     const auto &c = static_cast<const win32_code &>(code);  // NOLINT
 190     return generic_code(static_cast<errc>(_win32_code_to_errno(c.value())));
 191   }
 192   virtual string_ref _do_message(const status_code<void> &code) const noexcept override  // NOLINT
 193   {
 194     assert(code.domain() == *this);
 195     const auto &c = static_cast<const win32_code &>(code);  // NOLINT
 196     return _make_string_ref(c.value());
 197   }
 198 #if defined(_CPPUNWIND) || defined(__EXCEPTIONS) || defined(BOOST_OUTCOME_STANDARDESE_IS_IN_THE_HOUSE)
 199   BOOST_OUTCOME_SYSTEM_ERROR2_NORETURN virtual void _do_throw_exception(const status_code<void> &code) const override  // NOLINT
 200   {
 201     assert(code.domain() == *this);
 202     const auto &c = static_cast<const win32_code &>(code);  // NOLINT
 203     throw status_error<_win32_code_domain>(c);
 204   }
 205 #endif
 206 };
 207 //! (Windows only) A constexpr source variable for the win32 code domain, which is that of `GetLastError()` (Windows). Returned by `_win32_code_domain::get()`.
 208 constexpr _win32_code_domain win32_code_domain;
 209 inline constexpr const _win32_code_domain &_win32_code_domain::get()
 210 {
 211   return win32_code_domain;
 212 }
 213
 214 namespace mixins
 215 {
 216   template <class Base> inline win32_code mixin<Base, _win32_code_domain>::current() noexcept { return win32_code(win32::GetLastError()); }
 217 }  // namespace mixins
 218
 219 BOOST_OUTCOME_SYSTEM_ERROR2_NAMESPACE_END
 220
 221 #endif