libstdc++
exception_ptr.h
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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