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 headers and the
  28  *  implementation. You should not attempt to use it directly.
  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       void _M_safe_bool_dummy() throw() __attribute__ ((__const__));
  85
  86       friend exception_ptr std::current_exception() throw();
  87       friend void std::rethrow_exception(exception_ptr);
  88
  89     public:
  90       exception_ptr() throw();
  91
  92       typedef void (exception_ptr::*__safe_bool)();
  93
  94       // For construction from nullptr or 0.
  95       exception_ptr(__safe_bool) throw();
  96
  97       exception_ptr(const exception_ptr&) throw();
  98
  99 #ifdef __GXX_EXPERIMENTAL_CXX0X__
 100       exception_ptr(exception_ptr&& __o) throw()
 101       : _M_exception_object(__o._M_exception_object)
 102       { __o._M_exception_object = 0; }
 103 #endif
 104
 105       exception_ptr&
 106       operator=(const exception_ptr&) throw();
 107
 108 #ifdef __GXX_EXPERIMENTAL_CXX0X__
 109       exception_ptr&
 110       operator=(exception_ptr&& __o) throw()
 111       {
 112         exception_ptr(static_cast<exception_ptr&&>(__o)).swap(*this);
 113         return *this;
 114       }
 115 #endif
 116
 117       ~exception_ptr() throw();
 118
 119       void
 120       swap(exception_ptr&) throw();
 121
 122 #ifdef _GLIBCXX_EH_PTR_COMPAT
 123       // Retained for compatibility with CXXABI_1.3.
 124       bool operator!() const throw() __attribute__ ((__pure__));
 125       operator __safe_bool() const throw();
 126 #endif
 127
 128       friend bool
 129       operator==(const exception_ptr&, const exception_ptr&) throw()
 130       __attribute__ ((__pure__));
 131
 132       const type_info*
 133       __cxa_exception_type() const throw() __attribute__ ((__pure__));
 134     };
 135
 136     bool
 137     operator==(const exception_ptr&, const exception_ptr&) throw()
 138     __attribute__ ((__pure__));
 139
 140     bool
 141     operator!=(const exception_ptr&, const exception_ptr&) throw()
 142     __attribute__ ((__pure__));
 143   } // namespace __exception_ptr
 144
 145
 146   /// Obtain an exception_ptr pointing to a copy of the supplied object.
 147   template<typename _Ex>
 148     exception_ptr
 149     copy_exception(_Ex __ex) throw()
 150     {
 151       __try
 152         {
 153 #ifdef __EXCEPTIONS
 154           throw __ex;
 155 #endif
 156         }
 157       __catch(...)
 158         {
 159           return current_exception();
 160         }
 161     }
 162
 163   // @} group exceptions
 164 } // namespace std
 165
 166 } // extern "C++"
 167
 168 #pragma GCC visibility pop
 169
 170 #endif