xref: /netbsd-src/external/gpl3/gcc.old/dist/libstdc++-v3/libsupc++/exception_ptr.h (revision b7b7574d3bf8eeb51a1fa3977b59142ec6434a55)
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 class 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
171