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  class type_info;
48 
49  /**
50  * @addtogroup exceptions
51  * @{
52  */
53  namespace __exception_ptr
54  {
55  class exception_ptr;
56  }
57 
58  using __exception_ptr::exception_ptr;
59 
60  /** Obtain an exception_ptr to the currently handled exception. If there
61  * is none, or the currently handled exception is foreign, return the null
62  * value.
63  */
64  exception_ptr current_exception() _GLIBCXX_USE_NOEXCEPT;
65 
66  /// Throw the object pointed to by the exception_ptr.
67  void rethrow_exception(exception_ptr) __attribute__ ((__noreturn__));
68 
69  namespace __exception_ptr
70  {
71  /**
72  * @brief An opaque pointer to an arbitrary exception.
73  * @ingroup exceptions
74  */
76  {
77  void* _M_exception_object;
78 
79  explicit exception_ptr(void* __e) _GLIBCXX_USE_NOEXCEPT;
80 
81  void _M_addref() _GLIBCXX_USE_NOEXCEPT;
82  void _M_release() _GLIBCXX_USE_NOEXCEPT;
83 
84  void *_M_get() const _GLIBCXX_NOEXCEPT __attribute__ ((__pure__));
85 
86  friend exception_ptr std::current_exception() _GLIBCXX_USE_NOEXCEPT;
88 
89  public:
90  exception_ptr() _GLIBCXX_USE_NOEXCEPT;
91 
92  exception_ptr(const exception_ptr&) _GLIBCXX_USE_NOEXCEPT;
93 
94 #ifdef __GXX_EXPERIMENTAL_CXX0X__
95  exception_ptr(nullptr_t) noexcept
96  : _M_exception_object(0)
97  { }
98 
99  exception_ptr(exception_ptr&& __o) noexcept
100  : _M_exception_object(__o._M_exception_object)
101  { __o._M_exception_object = 0; }
102 #endif
103 
104 #if !defined (__GXX_EXPERIMENTAL_CXX0X__) || defined (_GLIBCXX_EH_PTR_COMPAT)
105  typedef void (exception_ptr::*__safe_bool)();
106 
107  // For construction from nullptr or 0.
108  exception_ptr(__safe_bool) _GLIBCXX_USE_NOEXCEPT;
109 #endif
110 
111  exception_ptr&
112  operator=(const exception_ptr&) _GLIBCXX_USE_NOEXCEPT;
113 
114 #ifdef __GXX_EXPERIMENTAL_CXX0X__
115  exception_ptr&
116  operator=(exception_ptr&& __o) noexcept
117  {
118  exception_ptr(static_cast<exception_ptr&&>(__o)).swap(*this);
119  return *this;
120  }
121 #endif
122 
123  ~exception_ptr() _GLIBCXX_USE_NOEXCEPT;
124 
125  void
126  swap(exception_ptr&) _GLIBCXX_USE_NOEXCEPT;
127 
128 #ifdef _GLIBCXX_EH_PTR_COMPAT
129  // Retained for compatibility with CXXABI_1.3.
130  void _M_safe_bool_dummy() _GLIBCXX_USE_NOEXCEPT
131  __attribute__ ((__const__));
132  bool operator!() const _GLIBCXX_USE_NOEXCEPT
133  __attribute__ ((__pure__));
134  operator __safe_bool() const _GLIBCXX_USE_NOEXCEPT;
135 #endif
136 
137 #ifdef __GXX_EXPERIMENTAL_CXX0X__
138  explicit operator bool() const
139  { return _M_exception_object; }
140 #endif
141 
142  friend bool
143  operator==(const exception_ptr&, const exception_ptr&)
144  _GLIBCXX_USE_NOEXCEPT __attribute__ ((__pure__));
145 
146  const class std::type_info*
147  __cxa_exception_type() const _GLIBCXX_USE_NOEXCEPT
148  __attribute__ ((__pure__));
149  };
150 
151  bool
152  operator==(const exception_ptr&, const exception_ptr&)
153  _GLIBCXX_USE_NOEXCEPT __attribute__ ((__pure__));
154 
155  bool
156  operator!=(const exception_ptr&, const exception_ptr&)
157  _GLIBCXX_USE_NOEXCEPT __attribute__ ((__pure__));
158 
159  inline void
160  swap(exception_ptr& __lhs, exception_ptr& __rhs)
161  { __lhs.swap(__rhs); }
162 
163  } // namespace __exception_ptr
164 
165 
166  /// Obtain an exception_ptr pointing to a copy of the supplied object.
167  template<typename _Ex>
168  exception_ptr
169  copy_exception(_Ex __ex) _GLIBCXX_USE_NOEXCEPT
170  {
171  __try
172  {
173 #ifdef __EXCEPTIONS
174  throw __ex;
175 #endif
176  }
177  __catch(...)
178  {
179  return current_exception();
180  }
181  }
182 
183  // _GLIBCXX_RESOLVE_LIB_DEFECTS
184  // 1130. copy_exception name misleading
185  /// Obtain an exception_ptr pointing to a copy of the supplied object.
186  template<typename _Ex>
187  exception_ptr
188  make_exception_ptr(_Ex __ex) _GLIBCXX_USE_NOEXCEPT
189  { return std::copy_exception<_Ex>(__ex); }
190 
191  // @} group exceptions
192 } // namespace std
193 
194 } // extern "C++"
195 
196 #pragma GCC visibility pop
197 
198 #endif