libstdc++
exception_ptr.h
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1 // Exception Handling support header (exception_ptr class) for -*- C++ -*-
2 
3 // Copyright (C) 2008, 2009, 2010, 2011 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 bits/exception_ptr.h
27  * This is an internal header file, included by other library headers.
28  * Do not attempt to use it directly. @headername{exception}
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 <bits/exception_defines.h>
38 
39 #if ATOMIC_INT_LOCK_FREE < 2
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() _GLIBCXX_USE_NOEXCEPT;
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  */
74  {
75  void* _M_exception_object;
76 
77  explicit exception_ptr(void* __e) _GLIBCXX_USE_NOEXCEPT;
78 
79  void _M_addref() _GLIBCXX_USE_NOEXCEPT;
80  void _M_release() _GLIBCXX_USE_NOEXCEPT;
81 
82  void *_M_get() const _GLIBCXX_NOEXCEPT __attribute__ ((__pure__));
83 
84  friend exception_ptr std::current_exception() _GLIBCXX_USE_NOEXCEPT;
86 
87  public:
88  exception_ptr() _GLIBCXX_USE_NOEXCEPT;
89 
90  exception_ptr(const exception_ptr&) _GLIBCXX_USE_NOEXCEPT;
91 
92 #ifdef __GXX_EXPERIMENTAL_CXX0X__
93  exception_ptr(nullptr_t) noexcept
94  : _M_exception_object(0)
95  { }
96 
97  exception_ptr(exception_ptr&& __o) noexcept
98  : _M_exception_object(__o._M_exception_object)
99  { __o._M_exception_object = 0; }
100 #endif
101 
102 #if !defined (__GXX_EXPERIMENTAL_CXX0X__) || defined (_GLIBCXX_EH_PTR_COMPAT)
103  typedef void (exception_ptr::*__safe_bool)();
104 
105  // For construction from nullptr or 0.
106  exception_ptr(__safe_bool) _GLIBCXX_USE_NOEXCEPT;
107 #endif
108 
109  exception_ptr&
110  operator=(const exception_ptr&) _GLIBCXX_USE_NOEXCEPT;
111 
112 #ifdef __GXX_EXPERIMENTAL_CXX0X__
113  exception_ptr&
114  operator=(exception_ptr&& __o) noexcept
115  {
116  exception_ptr(static_cast<exception_ptr&&>(__o)).swap(*this);
117  return *this;
118  }
119 #endif
120 
121  ~exception_ptr() _GLIBCXX_USE_NOEXCEPT;
122 
123  void
124  swap(exception_ptr&) _GLIBCXX_USE_NOEXCEPT;
125 
126 #ifdef _GLIBCXX_EH_PTR_COMPAT
127  // Retained for compatibility with CXXABI_1.3.
128  void _M_safe_bool_dummy() _GLIBCXX_USE_NOEXCEPT
129  __attribute__ ((__const__));
130  bool operator!() const _GLIBCXX_USE_NOEXCEPT
131  __attribute__ ((__pure__));
132  operator __safe_bool() const _GLIBCXX_USE_NOEXCEPT;
133 #endif
134 
135 #ifdef __GXX_EXPERIMENTAL_CXX0X__
136  explicit operator bool() const
137  { return _M_exception_object; }
138 #endif
139 
140  friend bool
141  operator==(const exception_ptr&, const exception_ptr&)
142  _GLIBCXX_USE_NOEXCEPT __attribute__ ((__pure__));
143 
144  const class type_info*
145  __cxa_exception_type() const _GLIBCXX_USE_NOEXCEPT
146  __attribute__ ((__pure__));
147  };
148 
149  bool
150  operator==(const exception_ptr&, const exception_ptr&)
151  _GLIBCXX_USE_NOEXCEPT __attribute__ ((__pure__));
152 
153  bool
154  operator!=(const exception_ptr&, const exception_ptr&)
155  _GLIBCXX_USE_NOEXCEPT __attribute__ ((__pure__));
156 
157  inline void
158  swap(exception_ptr& __lhs, exception_ptr& __rhs)
159  { __lhs.swap(__rhs); }
160 
161  } // namespace __exception_ptr
162 
163 
164  /// Obtain an exception_ptr pointing to a copy of the supplied object.
165  template<typename _Ex>
166  exception_ptr
167  copy_exception(_Ex __ex) _GLIBCXX_USE_NOEXCEPT
168  {
169  __try
170  {
171 #ifdef __EXCEPTIONS
172  throw __ex;
173 #endif
174  }
175  __catch(...)
176  {
177  return current_exception();
178  }
179  }
180 
181  // _GLIBCXX_RESOLVE_LIB_DEFECTS
182  // 1130. copy_exception name misleading
183  /// Obtain an exception_ptr pointing to a copy of the supplied object.
184  template<typename _Ex>
185  exception_ptr
186  make_exception_ptr(_Ex __ex) _GLIBCXX_USE_NOEXCEPT
187  { return std::copy_exception<_Ex>(__ex); }
188 
189  // @} group exceptions
190 } // namespace std
191 
192 } // extern "C++"
193 
194 #pragma GCC visibility pop
195 
196 #endif