libstdc++-v3/src/c++11/cxx11-ios_failure.cc

   1 // Iostreams base classes -*- C++ -*-
   2
   3 // Copyright (C) 2014-2024 Free Software Foundation, Inc.
   4 //
   5 // This file is part of the GNU ISO C++ Library.  This library is free
   6 // software; you can redistribute it and/or modify it under the
   7 // terms of the GNU General Public License as published by the
   8 // Free Software Foundation; either version 3, or (at your option)
   9 // any later version.
  10
  11 // This library is distributed in the hope that it will be useful,
  12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 // GNU General Public License for more details.
  15
  16 // Under Section 7 of GPL version 3, you are granted additional
  17 // permissions described in the GCC Runtime Library Exception, version
  18 // 3.1, as published by the Free Software Foundation.
  19
  20 // You should have received a copy of the GNU General Public License and
  21 // a copy of the GCC Runtime Library Exception along with this program;
  22 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  23 // <http://www.gnu.org/licenses/>.
  24
  25 //
  26 // ISO C++ 14882:2011: 27.5.3.1.1  Class ios_base::failure
  27 //
  28
  29 #define _GLIBCXX_USE_CXX11_ABI 1
  30 #include <ios>
  31 #include <bits/functexcept.h>
  32 #include <cxxabi.h>
  33
  34 #ifdef _GLIBCXX_USE_NLS
  35 # include <libintl.h>
  36 # define _(msgid)   gettext (msgid)
  37 #else
  38 # define _(msgid)   (msgid)
  39 #endif
  40
  41 #if ! _GLIBCXX_USE_DUAL_ABI
  42 # error This file should not be compiled for this configuration.
  43 #endif
  44
  45 namespace std _GLIBCXX_VISIBILITY(default)
  46 {
  47 _GLIBCXX_BEGIN_NAMESPACE_VERSION
  48
  49   ios_base::failure::failure(const string& __str)
  50   : system_error(io_errc::stream, __str) { }
  51
  52   ios_base::failure::failure(const string& __str, const error_code& __ec)
  53   : system_error(__ec, __str) { }
  54
  55   ios_base::failure::failure(const char* __str, const error_code& __ec)
  56   : system_error(__ec, __str) { }
  57
  58   ios_base::failure::~failure()
  59   { }
  60
  61   const char*
  62   ios_base::failure::what() const throw()
  63   { return runtime_error::what(); }
  64
  65 #if __cpp_rtti
  66   // These functions are defined in src/c++98/ios_failure.cc
  67   extern void __construct_ios_failure(void*, const char*);
  68   extern void __destroy_ios_failure(void*);
  69   extern bool __is_ios_failure_handler(const __cxxabiv1::__class_type_info*);
  70
  71   // The type thrown to report errors during stream buffer operations.
  72   // In addition to the ios::failure[abi:cxx11] base class it also has a
  73   // member of the gcc4-compatible ios::failure type (in an opaque buffer).
  74   struct __ios_failure : std::ios::failure
  75   {
  76     __ios_failure(const char* s) : failure(s)
  77     { __construct_ios_failure(buf, runtime_error::what()); }
  78
  79     __ios_failure(const char* s, const error_code& e) : failure(s, e)
  80     { __construct_ios_failure(buf, runtime_error::what()); }
  81
  82     ~__ios_failure()
  83     { __destroy_ios_failure(buf); }
  84
  85     // Use std::runtime_error as a proxy for the gcc4-compatible ios::failure
  86     // (which can't be declared here because _GLIBCXX_USE_CXX11_ABI == 1).
  87     // There are assertions in src/c++98/ios_failure.cc to ensure the size
  88     // and alignment assumptions are valid.
  89     alignas(runtime_error) unsigned char buf[sizeof(runtime_error)];
  90   };
  91
  92   // Custom type info for __ios_failure.
  93   class __iosfail_type_info : __cxxabiv1::__si_class_type_info
  94   {
  95     ~__iosfail_type_info();
  96
  97     using __si_class_type_info::__do_upcast;
  98
  99     bool
 100     __do_upcast (const __class_type_info *dst_type,
 101                  void **obj_ptr) const override;
 102   };
 103
 104   __iosfail_type_info::~__iosfail_type_info() = default;
 105
 106   // This function gets called to see if an exception of type
 107   // __ios_failure can be upcast to the type in a catch handler.
 108   bool
 109   __iosfail_type_info::__do_upcast(const __class_type_info *dst_type,
 110                                    void **obj_ptr) const
 111   {
 112     // If the handler is for the gcc4-compatible ios::failure type then
 113     // catch the object stored in __ios_failure::buf instead of
 114     // the __ios_failure exception object itself.
 115     if (__is_ios_failure_handler(dst_type))
 116       {
 117         *obj_ptr = static_cast<__ios_failure*>(*obj_ptr)->buf;
 118         return true;
 119       }
 120     // Otherwise proceed as normal to see if the handler matches.
 121     return __class_type_info::__do_upcast(dst_type, obj_ptr);
 122   }
 123 #else // ! __cpp_rtti
 124   using __ios_failure = ios::failure;
 125 #endif
 126
 127   void
 128   __throw_ios_failure(const char* __s __attribute__((unused)))
 129   { _GLIBCXX_THROW_OR_ABORT(__ios_failure(_(__s))); }
 130
 131   void
 132   __throw_ios_failure(const char* str __attribute__((unused)),
 133                       int err __attribute__((unused)))
 134   {
 135     _GLIBCXX_THROW_OR_ABORT(__ios_failure(_(str),
 136           err ? error_code(err, generic_category()) : io_errc::stream));
 137   }
 138
 139 _GLIBCXX_END_NAMESPACE_VERSION
 140 } // namespace