1// Exception Handling support header (exception_ptr class) for -*- C++ -*-
2
3// Copyright (C) 2008-2018 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#include <bits/cxxabi_init_exception.h>
39#include <typeinfo>
40#include <new>
41
42extern "C++" {
43
44namespace std
45{
46 class type_info;
47
48 /**
49 * @addtogroup exceptions
50 * @{
51 */
52 namespace __exception_ptr
53 {
54 class exception_ptr;
55 }
56
57 using __exception_ptr::exception_ptr;
58
59 /** Obtain an exception_ptr to the currently handled exception. If there
60 * is none, or the currently handled exception is foreign, return the null
61 * value.
62 */
63 exception_ptr current_exception() _GLIBCXX_USE_NOEXCEPT;
64
65 template<typename _Ex>
66 exception_ptr make_exception_ptr(_Ex) _GLIBCXX_USE_NOEXCEPT;
67
68 /// Throw the object pointed to by the exception_ptr.
69 void rethrow_exception(exception_ptr) __attribute__ ((__noreturn__));
70
71 namespace __exception_ptr
72 {
73 using std::rethrow_exception;
74
75 /**
76 * @brief An opaque pointer to an arbitrary exception.
77 * @ingroup exceptions
78 */
79 class exception_ptr
80 {
81 void* _M_exception_object;
82
83 explicit exception_ptr(void* __e) _GLIBCXX_USE_NOEXCEPT;
84
85 void _M_addref() _GLIBCXX_USE_NOEXCEPT;
86 void _M_release() _GLIBCXX_USE_NOEXCEPT;
87
88 void *_M_get() const _GLIBCXX_NOEXCEPT __attribute__ ((__pure__));
89
90 friend exception_ptr std::current_exception() _GLIBCXX_USE_NOEXCEPT;
91 friend void std::rethrow_exception(exception_ptr);
92 template<typename _Ex>
93 friend exception_ptr std::make_exception_ptr(_Ex) _GLIBCXX_USE_NOEXCEPT;
94
95 public:
96 exception_ptr() _GLIBCXX_USE_NOEXCEPT;
97
98 exception_ptr(const exception_ptr&) _GLIBCXX_USE_NOEXCEPT;
99
100#if __cplusplus >= 201103L
101 exception_ptr(nullptr_t) noexcept
102 : _M_exception_object(0)
103 { }
104
105 exception_ptr(exception_ptr&& __o) noexcept
106 : _M_exception_object(__o._M_exception_object)
107 { __o._M_exception_object = 0; }
108#endif
109
110#if (__cplusplus < 201103L) || defined (_GLIBCXX_EH_PTR_COMPAT)
111 typedef void (exception_ptr::*__safe_bool)();
112
113 // For construction from nullptr or 0.
114 exception_ptr(__safe_bool) _GLIBCXX_USE_NOEXCEPT;
115#endif
116
117 exception_ptr&
118 operator=(const exception_ptr&) _GLIBCXX_USE_NOEXCEPT;
119
120#if __cplusplus >= 201103L
121 exception_ptr&
122 operator=(exception_ptr&& __o) noexcept
123 {
124 exception_ptr(static_cast<exception_ptr&&>(__o)).swap(*this);
125 return *this;
126 }
127#endif
128
129 ~exception_ptr() _GLIBCXX_USE_NOEXCEPT;
130
131 void
132 swap(exception_ptr&) _GLIBCXX_USE_NOEXCEPT;
133
134#ifdef _GLIBCXX_EH_PTR_COMPAT
135 // Retained for compatibility with CXXABI_1.3.
136 void _M_safe_bool_dummy() _GLIBCXX_USE_NOEXCEPT
137 __attribute__ ((__const__));
138 bool operator!() const _GLIBCXX_USE_NOEXCEPT
139 __attribute__ ((__pure__));
140 operator __safe_bool() const _GLIBCXX_USE_NOEXCEPT;
141#endif
142
143#if __cplusplus >= 201103L
144 explicit operator bool() const
145 { return _M_exception_object; }
146#endif
147
148 friend bool
149 operator==(const exception_ptr&, const exception_ptr&)
150 _GLIBCXX_USE_NOEXCEPT __attribute__ ((__pure__));
151
152 const class std::type_info*
153 __cxa_exception_type() const _GLIBCXX_USE_NOEXCEPT
154 __attribute__ ((__pure__));
155 };
156
157 bool
158 operator==(const exception_ptr&, const exception_ptr&)
159 _GLIBCXX_USE_NOEXCEPT __attribute__ ((__pure__));
160
161 bool
162 operator!=(const exception_ptr&, const exception_ptr&)
163 _GLIBCXX_USE_NOEXCEPT __attribute__ ((__pure__));
164
165 inline void
166 swap(exception_ptr& __lhs, exception_ptr& __rhs)
167 { __lhs.swap(__rhs); }
168
169 template<typename _Ex>
170 inline void
171 __dest_thunk(void* __x)
172 { static_cast<_Ex*>(__x)->~_Ex(); }
173
174 } // namespace __exception_ptr
175
176 /// Obtain an exception_ptr pointing to a copy of the supplied object.
177 template<typename _Ex>
178 exception_ptr
179 make_exception_ptr(_Ex __ex) _GLIBCXX_USE_NOEXCEPT
180 {
181#if __cpp_exceptions && __cpp_rtti && !_GLIBCXX_HAVE_CDTOR_CALLABI
182 void* __e = __cxxabiv1::__cxa_allocate_exception(sizeof(_Ex));
183 (void) __cxxabiv1::__cxa_init_primary_exception(
184 __e, const_cast<std::type_info*>(&typeid(__ex)),
185 __exception_ptr::__dest_thunk<_Ex>);
186 try
187 {
188 ::new (__e) _Ex(__ex);
189 return exception_ptr(__e);
190 }
191 catch(...)
192 {
193 __cxxabiv1::__cxa_free_exception(__e);
194 return current_exception();
195 }
196#elif __cpp_exceptions
197 try
198 {
199 throw __ex;
200 }
201 catch(...)
202 {
203 return current_exception();
204 }
205#else // no RTTI and no exceptions
206 return exception_ptr();
207#endif
208 }
209
210 // @} group exceptions
211} // namespace std
212
213} // extern "C++"
214
215#pragma GCC visibility pop
216
217#endif
218