libstdc++-v3/libsupc++/exception_ptr.h

   1 // Exception Handling support header (exception_ptr class) for -*- C++ -*-
   2
   3 // Copyright (C) 2008-2016 Free Software Foundation, Inc.
   4 //
   5 // This file is part of GCC.
   6 //
   7 // GCC is free software; you can redistribute it and/or modify
   8 // it under the terms of the GNU General Public License as published by
   9 // the Free Software Foundation; either version 3, or (at your option)
  10 // any later version.
  11 //
  12 // GCC is distributed in the hope that it will be useful,
  13 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 // GNU General Public License for more details.
  16 //
  17 // Under Section 7 of GPL version 3, you are granted additional
  18 // permissions described in the GCC Runtime Library Exception, version
  19 // 3.1, as published by the Free Software Foundation.
  20
  21 // You should have received a copy of the GNU General Public License and
  22 // a copy of the GCC Runtime Library Exception along with this program;
  23 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  24 // <http://www.gnu.org/licenses/>.
  25
  26 /** @file bits/exception_ptr.h
  27  *  This is an internal header file, included by other library headers.
  28  *  Do not attempt to use it directly. @headername{exception}
  29  */
  30
  31 #ifndef _EXCEPTION_PTR_H
  32 #define _EXCEPTION_PTR_H
  33
  34 #pragma GCC visibility push(default)
  35
  36 #include <bits/c++config.h>
  37 #include <bits/exception_defines.h>
  38
  39 #if ATOMIC_INT_LOCK_FREE < 2
  40 #  error This platform does not support exception propagation.
  41 #endif
  42
  43 extern "C++" {
  44
  45 namespace std
  46 {
  47   class type_info;
  48
  49   /**
  50    * @addtogroup exceptions
  51    * @{
  52    */
  53   namespace __exception_ptr
  54   {
  55     class exception_ptr;
  56   }
  57
  58   using __exception_ptr::exception_ptr;
  59
  60   /** Obtain an exception_ptr to the currently handled exception. If there
  61    *  is none, or the currently handled exception is foreign, return the null
  62    *  value.
  63    */
  64   exception_ptr current_exception() _GLIBCXX_USE_NOEXCEPT;
  65
  66   /// Throw the object pointed to by the exception_ptr.
  67   void rethrow_exception(exception_ptr) __attribute__ ((__noreturn__));
  68
  69   namespace __exception_ptr
  70   {
  71     using std::rethrow_exception;
  72
  73     /**
  74      *  @brief An opaque pointer to an arbitrary exception.
  75      *  @ingroup exceptions
  76      */
  77     class exception_ptr
  78     {
  79       void* _M_exception_object;
  80
  81       explicit exception_ptr(void* __e) _GLIBCXX_USE_NOEXCEPT;
  82
  83       void _M_addref() _GLIBCXX_USE_NOEXCEPT;
  84       void _M_release() _GLIBCXX_USE_NOEXCEPT;
  85
  86       void *_M_get() const _GLIBCXX_NOEXCEPT __attribute__ ((__pure__));
  87
  88       friend exception_ptr std::current_exception() _GLIBCXX_USE_NOEXCEPT;
  89       friend void std::rethrow_exception(exception_ptr);
  90
  91     public:
  92       exception_ptr() _GLIBCXX_USE_NOEXCEPT;
  93
  94       exception_ptr(const exception_ptr&) _GLIBCXX_USE_NOEXCEPT;
  95
  96 #if __cplusplus >= 201103L
  97       exception_ptr(nullptr_t) noexcept
  98       : _M_exception_object(0)
  99       { }
 100
 101       exception_ptr(exception_ptr&& __o) noexcept
 102       : _M_exception_object(__o._M_exception_object)
 103       { __o._M_exception_object = 0; }
 104 #endif
 105
 106 #if (__cplusplus < 201103L) || defined (_GLIBCXX_EH_PTR_COMPAT)
 107       typedef void (exception_ptr::*__safe_bool)();
 108
 109       // For construction from nullptr or 0.
 110       exception_ptr(__safe_bool) _GLIBCXX_USE_NOEXCEPT;
 111 #endif
 112
 113       exception_ptr&
 114       operator=(const exception_ptr&) _GLIBCXX_USE_NOEXCEPT;
 115
 116 #if __cplusplus >= 201103L
 117       exception_ptr&
 118       operator=(exception_ptr&& __o) noexcept
 119       {
 120         exception_ptr(static_cast<exception_ptr&&>(__o)).swap(*this);
 121         return *this;
 122       }
 123 #endif
 124
 125       ~exception_ptr() _GLIBCXX_USE_NOEXCEPT;
 126
 127       void
 128       swap(exception_ptr&) _GLIBCXX_USE_NOEXCEPT;
 129
 130 #ifdef _GLIBCXX_EH_PTR_COMPAT
 131       // Retained for compatibility with CXXABI_1.3.
 132       void _M_safe_bool_dummy() _GLIBCXX_USE_NOEXCEPT
 133         __attribute__ ((__const__));
 134       bool operator!() const _GLIBCXX_USE_NOEXCEPT
 135         __attribute__ ((__pure__));
 136       operator __safe_bool() const _GLIBCXX_USE_NOEXCEPT;
 137 #endif
 138
 139 #if __cplusplus >= 201103L
 140       explicit operator bool() const
 141       { return _M_exception_object; }
 142 #endif
 143
 144       friend bool
 145       operator==(const exception_ptr&, const exception_ptr&)
 146         _GLIBCXX_USE_NOEXCEPT __attribute__ ((__pure__));
 147
 148       const class std::type_info*
 149       __cxa_exception_type() const _GLIBCXX_USE_NOEXCEPT
 150         __attribute__ ((__pure__));
 151     };
 152
 153     bool
 154     operator==(const exception_ptr&, const exception_ptr&)
 155       _GLIBCXX_USE_NOEXCEPT __attribute__ ((__pure__));
 156
 157     bool
 158     operator!=(const exception_ptr&, const exception_ptr&)
 159       _GLIBCXX_USE_NOEXCEPT __attribute__ ((__pure__));
 160
 161     inline void
 162     swap(exception_ptr& __lhs, exception_ptr& __rhs)
 163     { __lhs.swap(__rhs); }
 164
 165   } // namespace __exception_ptr
 166
 167
 168   /// Obtain an exception_ptr pointing to a copy of the supplied object.
 169   template<typename _Ex>
 170     exception_ptr
 171     make_exception_ptr(_Ex __ex) _GLIBCXX_USE_NOEXCEPT
 172     {
 173 #if __cpp_exceptions
 174       try
 175         {
 176           throw __ex;
 177         }
 178       catch(...)
 179         {
 180           return current_exception();
 181         }
 182 #else
 183       return exception_ptr();
 184 #endif
 185     }
 186
 187   // _GLIBCXX_RESOLVE_LIB_DEFECTS
 188   // 1130. copy_exception name misleading
 189   /// Obtain an exception_ptr pointing to a copy of the supplied object.
 190   /// This function is deprecated, use std::make_exception_ptr instead.
 191   template<typename _Ex>
 192     exception_ptr
 193     copy_exception(_Ex __ex) _GLIBCXX_USE_NOEXCEPT _GLIBCXX_DEPRECATED;
 194
 195   template<typename _Ex>
 196     exception_ptr
 197     copy_exception(_Ex __ex) _GLIBCXX_USE_NOEXCEPT
 198     { return std::make_exception_ptr<_Ex>(__ex); }
 199
 200   // @} group exceptions
 201 } // namespace std
 202
 203 } // extern "C++"
 204
 205 #pragma GCC visibility pop
 206
 207 #endif