Home | History | Annotate | Download | only in include
      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 
     52   // Hide the free operators from other types
     53   namespace __exception_ptr
     54   {
     55     /**
     56      * @brief An opaque pointer to an arbitrary exception.
     57      */
     58     class exception_ptr;
     59   }
     60 
     61   using __exception_ptr::exception_ptr;
     62 
     63   /** Obtain an %exception_ptr to the currently handled exception. If there
     64    *  is none, or the currently handled exception is foreign, return the null
     65    *  value.
     66    */
     67   exception_ptr current_exception() throw();
     68 
     69   /// Throw the object pointed to by the %exception_ptr.
     70   void rethrow_exception(exception_ptr) __attribute__ ((__noreturn__));
     71 
     72   /// Obtain an %exception_ptr pointing to a copy of the supplied object.
     73   template<typename _Ex>
     74     exception_ptr
     75     copy_exception(_Ex __ex) throw();
     76 
     77   namespace __exception_ptr
     78   {
     79     bool
     80     operator==(const exception_ptr&, const exception_ptr&) throw();
     81 
     82     bool
     83     operator!=(const exception_ptr&, const exception_ptr&) throw();
     84 
     85     class exception_ptr
     86     {
     87       void* _M_exception_object;
     88 
     89       explicit exception_ptr(void* __e) throw();
     90 
     91       void _M_addref() throw();
     92       void _M_release() throw();
     93 
     94       void *_M_get() const throw();
     95 
     96       void _M_safe_bool_dummy();
     97 
     98       friend exception_ptr std::current_exception() throw();
     99       friend void std::rethrow_exception(exception_ptr);
    100 
    101     public:
    102       exception_ptr() throw();
    103 
    104       typedef void (exception_ptr::*__safe_bool)();
    105 
    106       // For construction from nullptr or 0.
    107       exception_ptr(__safe_bool) throw();
    108 
    109       exception_ptr(const exception_ptr&) throw();
    110 
    111 #ifdef __GXX_EXPERIMENTAL_CXX0X__
    112       exception_ptr(exception_ptr&& __o) throw()
    113       : _M_exception_object(__o._M_exception_object)
    114       { __o._M_exception_object = 0; }
    115 #endif
    116 
    117       exception_ptr&
    118       operator=(const exception_ptr&) throw();
    119 
    120 #ifdef __GXX_EXPERIMENTAL_CXX0X__
    121       exception_ptr&
    122       operator=(exception_ptr&& __o) throw()
    123       {
    124         exception_ptr(static_cast<exception_ptr&&>(__o)).swap(*this);
    125         return *this;
    126       }
    127 #endif
    128 
    129       ~exception_ptr() throw();
    130 
    131       void
    132       swap(exception_ptr&) throw();
    133 
    134 #ifdef _GLIBCXX_EH_PTR_COMPAT
    135       // Retained for compatibility with CXXABI_1.3.
    136       bool operator!() const throw();
    137       operator __safe_bool() const throw();
    138 #endif
    139 
    140       friend bool
    141       operator==(const exception_ptr&, const exception_ptr&) throw();
    142 
    143       const type_info*
    144       __cxa_exception_type() const throw();
    145     };
    146 
    147   } // namespace __exception_ptr
    148 
    149 
    150   template<typename _Ex>
    151     exception_ptr
    152     copy_exception(_Ex __ex) throw()
    153     {
    154       __try
    155 	{
    156 	  throw __ex;
    157 	}
    158       __catch(...)
    159 	{
    160 	  return current_exception ();
    161 	}
    162     }
    163 
    164   // @} group exceptions
    165 } // namespace std
    166 
    167 } // extern "C++"
    168 
    169 #pragma GCC visibility pop
    170 
    171 #endif
    172