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

   1 // Exception Handling support header (exception_ptr class) for -*- C++ -*-
   2
   3 // Copyright (C) 2008, 2009 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 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 <exception_defines.h>
  38
  39 #if !defined(_GLIBCXX_ATOMIC_BUILTINS_4)
  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() throw();
  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) throw();
  78
  79       void _M_addref() throw();
  80       void _M_release() throw();
  81
  82       void *_M_get() const throw() __attribute__ ((__pure__));
  83
  84       friend exception_ptr std::current_exception() throw();
  85       friend void std::rethrow_exception(exception_ptr);
  86
  87     public:
  88       exception_ptr() throw();
  89
  90       exception_ptr(const exception_ptr&) throw();
  91
  92 #ifdef __GXX_EXPERIMENTAL_CXX0X__
  93       exception_ptr(nullptr_t) throw()
  94       : _M_exception_object(0)
  95       { }
  96
  97       exception_ptr(exception_ptr&& __o) throw()
  98       : _M_exception_object(__o._M_exception_object)
  99       { __o._M_exception_object = 0; }
 100 #else
 101       typedef void (exception_ptr::*__safe_bool)();
 102
 103       // For construction from nullptr or 0.
 104       exception_ptr(__safe_bool) throw();
 105 #endif
 106
 107       exception_ptr&
 108       operator=(const exception_ptr&) throw();
 109
 110 #ifdef __GXX_EXPERIMENTAL_CXX0X__
 111       exception_ptr&
 112       operator=(exception_ptr&& __o) throw()
 113       {
 114         exception_ptr(static_cast<exception_ptr&&>(__o)).swap(*this);
 115         return *this;
 116       }
 117 #endif
 118
 119       ~exception_ptr() throw();
 120
 121       void
 122       swap(exception_ptr&) throw();
 123
 124 #ifdef _GLIBCXX_EH_PTR_COMPAT
 125       // Retained for compatibility with CXXABI_1.3.
 126       void _M_safe_bool_dummy() throw() __attribute__ ((__const__));
 127       bool operator!() const throw() __attribute__ ((__pure__));
 128       operator __safe_bool() const throw();
 129 #endif
 130
 131 #ifdef __GXX_EXPERIMENTAL_CXX0X__
 132       explicit operator bool() const
 133       { return _M_exception_object; }
 134 #endif
 135
 136       friend bool
 137       operator==(const exception_ptr&, const exception_ptr&) throw()
 138       __attribute__ ((__pure__));
 139
 140       const type_info*
 141       __cxa_exception_type() const throw() __attribute__ ((__pure__));
 142     };
 143
 144     bool
 145     operator==(const exception_ptr&, const exception_ptr&) throw()
 146     __attribute__ ((__pure__));
 147
 148     bool
 149     operator!=(const exception_ptr&, const exception_ptr&) throw()
 150     __attribute__ ((__pure__));
 151
 152     inline void
 153     swap(exception_ptr& __lhs, exception_ptr& __rhs)
 154     { __lhs.swap(__rhs); }
 155
 156   } // namespace __exception_ptr
 157
 158
 159   /// Obtain an exception_ptr pointing to a copy of the supplied object.
 160   template<typename _Ex>
 161     exception_ptr
 162     copy_exception(_Ex __ex) throw()
 163     {
 164       __try
 165         {
 166 #ifdef __EXCEPTIONS
 167           throw __ex;
 168 #endif
 169         }
 170       __catch(...)
 171         {
 172           return current_exception();
 173         }
 174     }
 175
 176   // _GLIBCXX_RESOLVE_LIB_DEFECTS
 177   // 1130. copy_exception name misleading
 178   /// Obtain an exception_ptr pointing to a copy of the supplied object.
 179   template<typename _Ex>
 180     exception_ptr
 181     make_exception_ptr(_Ex __ex) throw()
 182     { return std::copy_exception<_Ex>(__ex); }
 183
 184   // @} group exceptions
 185 } // namespace std
 186
 187 } // extern "C++"
 188
 189 #pragma GCC visibility pop
 190
 191 #endif