exception_ptr.h

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00001 // Exception Handling support header (exception_ptr class) for -*- C++ -*-
00002 
00003 // Copyright (C) 2008, 2009 Free Software Foundation
00004 //
00005 // This file is part of GCC.
00006 //
00007 // GCC is free software; you can redistribute it and/or modify
00008 // it under the terms of the GNU General Public License as published by
00009 // the Free Software Foundation; either version 3, or (at your option)
00010 // any later version.
00011 // 
00012 // GCC is distributed in the hope that it will be useful,
00013 // but WITHOUT ANY WARRANTY; without even the implied warranty of
00014 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00015 // GNU General Public License for more details.
00016 // 
00017 // Under Section 7 of GPL version 3, you are granted additional
00018 // permissions described in the GCC Runtime Library Exception, version
00019 // 3.1, as published by the Free Software Foundation.
00020 
00021 // You should have received a copy of the GNU General Public License and
00022 // a copy of the GCC Runtime Library Exception along with this program;
00023 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
00024 // <http://www.gnu.org/licenses/>.
00025 
00026 /** @file exception_ptr.h
00027  *  This is an internal header file, included by other headers and the
00028  *  implementation. You should not attempt to use it directly.
00029  */
00030 
00031 #ifndef _EXCEPTION_PTR_H
00032 #define _EXCEPTION_PTR_H
00033 
00034 #pragma GCC visibility push(default)
00035 
00036 #include <bits/c++config.h>
00037 #include <exception_defines.h>
00038 
00039 #if !defined(_GLIBCXX_ATOMIC_BUILTINS_4)
00040 #  error This platform does not support exception propagation.
00041 #endif
00042 
00043 extern "C++" {
00044 
00045 namespace std 
00046 {
00047   /**
00048    * @addtogroup exceptions
00049    * @{
00050    */
00051   namespace __exception_ptr
00052   {
00053     class exception_ptr;
00054   }
00055 
00056   using __exception_ptr::exception_ptr;
00057 
00058   /** Obtain an exception_ptr to the currently handled exception. If there
00059    *  is none, or the currently handled exception is foreign, return the null
00060    *  value.
00061    */
00062   exception_ptr current_exception() throw();
00063 
00064   /// Throw the object pointed to by the exception_ptr.
00065   void rethrow_exception(exception_ptr) __attribute__ ((__noreturn__));
00066 
00067   namespace __exception_ptr
00068   {
00069     /**
00070      *  @brief An opaque pointer to an arbitrary exception.
00071      *  @ingroup exceptions
00072      */
00073     class exception_ptr
00074     {
00075       void* _M_exception_object;
00076 
00077       explicit exception_ptr(void* __e) throw();
00078 
00079       void _M_addref() throw();
00080       void _M_release() throw();
00081 
00082       void *_M_get() const throw() __attribute__ ((__pure__));
00083 
00084       void _M_safe_bool_dummy() throw() __attribute__ ((__const__));
00085 
00086       friend exception_ptr std::current_exception() throw();
00087       friend void std::rethrow_exception(exception_ptr);
00088 
00089     public:
00090       exception_ptr() throw();
00091 
00092       typedef void (exception_ptr::*__safe_bool)();
00093 
00094       // For construction from nullptr or 0.
00095       exception_ptr(__safe_bool) throw();
00096 
00097       exception_ptr(const exception_ptr&) throw();
00098 
00099 #ifdef __GXX_EXPERIMENTAL_CXX0X__
00100       exception_ptr(exception_ptr&& __o) throw()
00101       : _M_exception_object(__o._M_exception_object)
00102       { __o._M_exception_object = 0; }
00103 #endif
00104 
00105       exception_ptr& 
00106       operator=(const exception_ptr&) throw();
00107 
00108 #ifdef __GXX_EXPERIMENTAL_CXX0X__
00109       exception_ptr& 
00110       operator=(exception_ptr&& __o) throw()
00111       {
00112         exception_ptr(static_cast<exception_ptr&&>(__o)).swap(*this);
00113         return *this;
00114       }
00115 #endif
00116 
00117       ~exception_ptr() throw();
00118 
00119       void 
00120       swap(exception_ptr&) throw();
00121 
00122 #ifdef _GLIBCXX_EH_PTR_COMPAT
00123       // Retained for compatibility with CXXABI_1.3.
00124       bool operator!() const throw() __attribute__ ((__pure__));
00125       operator __safe_bool() const throw();
00126 #endif
00127 
00128       friend bool 
00129       operator==(const exception_ptr&, const exception_ptr&) throw() 
00130       __attribute__ ((__pure__));
00131 
00132       const type_info*
00133       __cxa_exception_type() const throw() __attribute__ ((__pure__));
00134     };
00135 
00136     bool 
00137     operator==(const exception_ptr&, const exception_ptr&) throw() 
00138     __attribute__ ((__pure__));
00139 
00140     bool 
00141     operator!=(const exception_ptr&, const exception_ptr&) throw() 
00142     __attribute__ ((__pure__));
00143   } // namespace __exception_ptr
00144 
00145 
00146   /// Obtain an exception_ptr pointing to a copy of the supplied object.
00147   template<typename _Ex>
00148     exception_ptr 
00149     copy_exception(_Ex __ex) throw()
00150     {
00151       __try
00152     {
00153 #ifdef __EXCEPTIONS
00154       throw __ex;
00155 #endif
00156     }
00157       __catch(...)
00158     {
00159       return current_exception();
00160     }
00161     }
00162 
00163   // @} group exceptions
00164 } // namespace std
00165 
00166 } // extern "C++"
00167 
00168 #pragma GCC visibility pop
00169 
00170 #endif