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

   1 // Exception Handling support header (exception_ptr class) for -*- C++ -*-
   2
   3 // Copyright (C) 2008, 2009, 2010, 2011 Free Software Foundation
   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   /**
  48    * @addtogroup exceptions
  49    * @{
  50    */
  51   namespace __exception_ptr
  52   {
  53     class exception_ptr;
  54   }
  55
  56   using __exception_ptr::exception_ptr;
  57
  58   /** Obtain an exception_ptr to the currently handled exception. If there
  59    *  is none, or the currently handled exception is foreign, return the null
  60    *  value.
  61    */
  62   exception_ptr current_exception() _GLIBCXX_USE_NOEXCEPT;
  63
  64   /// Throw the object pointed to by the exception_ptr.
  65   void rethrow_exception(exception_ptr) __attribute__ ((__noreturn__));
  66
  67   namespace __exception_ptr
  68   {
  69     /**
  70      *  @brief An opaque pointer to an arbitrary exception.
  71      *  @ingroup exceptions
  72      */
  73     class exception_ptr
  74     {
  75       void* _M_exception_object;
  76
  77       explicit exception_ptr(void* __e) _GLIBCXX_USE_NOEXCEPT;
  78
  79       void _M_addref() _GLIBCXX_USE_NOEXCEPT;
  80       void _M_release() _GLIBCXX_USE_NOEXCEPT;
  81
  82       void *_M_get() const _GLIBCXX_NOEXCEPT __attribute__ ((__pure__));
  83
  84       friend exception_ptr std::current_exception() _GLIBCXX_USE_NOEXCEPT;
  85       friend void std::rethrow_exception(exception_ptr);
  86
  87     public:
  88       exception_ptr() _GLIBCXX_USE_NOEXCEPT;
  89
  90       exception_ptr(const exception_ptr&) _GLIBCXX_USE_NOEXCEPT;
  91
  92 #if __cplusplus >= 201103L
  93       exception_ptr(nullptr_t) noexcept
  94       : _M_exception_object(0)
  95       { }
  96
  97       exception_ptr(exception_ptr&& __o) noexcept
  98       : _M_exception_object(__o._M_exception_object)
  99       { __o._M_exception_object = 0; }
 100 #endif
 101
 102 #if (__cplusplus < 201103L) || defined (_GLIBCXX_EH_PTR_COMPAT)
 103       typedef void (exception_ptr::*__safe_bool)();
 104
 105       // For construction from nullptr or 0.
 106       exception_ptr(__safe_bool) _GLIBCXX_USE_NOEXCEPT;
 107 #endif
 108
 109       exception_ptr&
 110       operator=(const exception_ptr&) _GLIBCXX_USE_NOEXCEPT;
 111
 112 #if __cplusplus >= 201103L
 113       exception_ptr&
 114       operator=(exception_ptr&& __o) noexcept
 115       {
 116         exception_ptr(static_cast<exception_ptr&&>(__o)).swap(*this);
 117         return *this;
 118       }
 119 #endif
 120
 121       ~exception_ptr() _GLIBCXX_USE_NOEXCEPT;
 122
 123       void
 124       swap(exception_ptr&) _GLIBCXX_USE_NOEXCEPT;
 125
 126 #ifdef _GLIBCXX_EH_PTR_COMPAT
 127       // Retained for compatibility with CXXABI_1.3.
 128       void _M_safe_bool_dummy() _GLIBCXX_USE_NOEXCEPT
 129         __attribute__ ((__const__));
 130       bool operator!() const _GLIBCXX_USE_NOEXCEPT
 131         __attribute__ ((__pure__));
 132       operator __safe_bool() const _GLIBCXX_USE_NOEXCEPT;
 133 #endif
 134
 135 #if __cplusplus >= 201103L
 136       explicit operator bool() const
 137       { return _M_exception_object; }
 138 #endif
 139
 140       friend bool
 141       operator==(const exception_ptr&, const exception_ptr&)
 142         _GLIBCXX_USE_NOEXCEPT __attribute__ ((__pure__));
 143
 144       const class type_info*
 145       __cxa_exception_type() const _GLIBCXX_USE_NOEXCEPT
 146         __attribute__ ((__pure__));
 147     };
 148
 149     bool
 150     operator==(const exception_ptr&, const exception_ptr&)
 151       _GLIBCXX_USE_NOEXCEPT __attribute__ ((__pure__));
 152
 153     bool
 154     operator!=(const exception_ptr&, const exception_ptr&)
 155       _GLIBCXX_USE_NOEXCEPT __attribute__ ((__pure__));
 156
 157     inline void
 158     swap(exception_ptr& __lhs, exception_ptr& __rhs)
 159     { __lhs.swap(__rhs); }
 160
 161   } // namespace __exception_ptr
 162
 163
 164   /// Obtain an exception_ptr pointing to a copy of the supplied object.
 165   template<typename _Ex>
 166     exception_ptr
 167     copy_exception(_Ex __ex) _GLIBCXX_USE_NOEXCEPT
 168     {
 169       __try
 170         {
 171 #ifdef __EXCEPTIONS
 172           throw __ex;
 173 #endif
 174         }
 175       __catch(...)
 176         {
 177           return current_exception();
 178         }
 179     }
 180
 181   // _GLIBCXX_RESOLVE_LIB_DEFECTS
 182   // 1130. copy_exception name misleading
 183   /// Obtain an exception_ptr pointing to a copy of the supplied object.
 184   template<typename _Ex>
 185     exception_ptr
 186     make_exception_ptr(_Ex __ex) _GLIBCXX_USE_NOEXCEPT
 187     { return std::copy_exception<_Ex>(__ex); }
 188
 189   // @} group exceptions
 190 } // namespace std
 191
 192 } // extern "C++"
 193
 194 #pragma GCC visibility pop
 195
 196 #endif