libstdc++

exception_ptr.h
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1 // Exception Handling support header (exception_ptr class) for -*- C++ -*-
2
3 // Copyright (C) 2008-2013 Free Software Foundation, Inc.
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 */
73 class exception_ptr
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;
85 friend void std::rethrow_exception(exception_ptr);
86
87 public:
88 exception_ptr() _GLIBCXX_USE_NOEXCEPT;
89
90 exception_ptr(const exception_ptr&) _GLIBCXX_USE_NOEXCEPT;
91
92 #if __cplusplus >= 201103L
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 (__cplusplus < 201103L) || 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 #if __cplusplus >= 201103L
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 #if __cplusplus >= 201103L
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