1 | // Exception Handling support header (exception_ptr class) for -*- C++ -*- |
2 | |
3 | // Copyright (C) 2008-2021 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 | |
42 | #if __cplusplus >= 201103L |
43 | # include <bits/move.h> |
44 | #endif |
45 | |
46 | #ifdef _GLIBCXX_EH_PTR_RELOPS_COMPAT |
47 | # define _GLIBCXX_EH_PTR_USED __attribute__((__used__)) |
48 | #else |
49 | # define _GLIBCXX_EH_PTR_USED |
50 | #endif |
51 | |
52 | extern "C++" { |
53 | |
54 | namespace std |
55 | { |
56 | class type_info; |
57 | |
58 | /** |
59 | * @addtogroup exceptions |
60 | * @{ |
61 | */ |
62 | |
63 | namespace __exception_ptr |
64 | { |
65 | class exception_ptr; |
66 | } |
67 | |
68 | using __exception_ptr::exception_ptr; |
69 | |
70 | /** Obtain an exception_ptr to the currently handled exception. If there |
71 | * is none, or the currently handled exception is foreign, return the null |
72 | * value. |
73 | */ |
74 | exception_ptr current_exception() _GLIBCXX_USE_NOEXCEPT; |
75 | |
76 | template<typename _Ex> |
77 | exception_ptr make_exception_ptr(_Ex) _GLIBCXX_USE_NOEXCEPT; |
78 | |
79 | /// Throw the object pointed to by the exception_ptr. |
80 | void rethrow_exception(exception_ptr) __attribute__ ((__noreturn__)); |
81 | |
82 | namespace __exception_ptr |
83 | { |
84 | using std::rethrow_exception; |
85 | |
86 | /** |
87 | * @brief An opaque pointer to an arbitrary exception. |
88 | * @ingroup exceptions |
89 | */ |
90 | class exception_ptr |
91 | { |
92 | void* _M_exception_object; |
93 | |
94 | explicit exception_ptr(void* __e) _GLIBCXX_USE_NOEXCEPT; |
95 | |
96 | void _M_addref() _GLIBCXX_USE_NOEXCEPT; |
97 | void _M_release() _GLIBCXX_USE_NOEXCEPT; |
98 | |
99 | void *_M_get() const _GLIBCXX_NOEXCEPT __attribute__ ((__pure__)); |
100 | |
101 | friend exception_ptr std::current_exception() _GLIBCXX_USE_NOEXCEPT; |
102 | friend void std::rethrow_exception(exception_ptr); |
103 | template<typename _Ex> |
104 | friend exception_ptr std::make_exception_ptr(_Ex) _GLIBCXX_USE_NOEXCEPT; |
105 | |
106 | public: |
107 | exception_ptr() _GLIBCXX_USE_NOEXCEPT; |
108 | |
109 | exception_ptr(const exception_ptr&) _GLIBCXX_USE_NOEXCEPT; |
110 | |
111 | #if __cplusplus >= 201103L |
112 | exception_ptr(nullptr_t) noexcept |
113 | : _M_exception_object(nullptr) |
114 | { } |
115 | |
116 | exception_ptr(exception_ptr&& __o) noexcept |
117 | : _M_exception_object(__o._M_exception_object) |
118 | { __o._M_exception_object = nullptr; } |
119 | #endif |
120 | |
121 | #if (__cplusplus < 201103L) || defined (_GLIBCXX_EH_PTR_COMPAT) |
122 | typedef void (exception_ptr::*__safe_bool)(); |
123 | |
124 | // For construction from nullptr or 0. |
125 | exception_ptr(__safe_bool) _GLIBCXX_USE_NOEXCEPT; |
126 | #endif |
127 | |
128 | exception_ptr& |
129 | operator=(const exception_ptr&) _GLIBCXX_USE_NOEXCEPT; |
130 | |
131 | #if __cplusplus >= 201103L |
132 | exception_ptr& |
133 | operator=(exception_ptr&& __o) noexcept |
134 | { |
135 | exception_ptr(static_cast<exception_ptr&&>(__o)).swap(*this); |
136 | return *this; |
137 | } |
138 | #endif |
139 | |
140 | ~exception_ptr() _GLIBCXX_USE_NOEXCEPT; |
141 | |
142 | void |
143 | swap(exception_ptr&) _GLIBCXX_USE_NOEXCEPT; |
144 | |
145 | #ifdef _GLIBCXX_EH_PTR_COMPAT |
146 | // Retained for compatibility with CXXABI_1.3. |
147 | void _M_safe_bool_dummy() _GLIBCXX_USE_NOEXCEPT |
148 | __attribute__ ((__const__)); |
149 | bool operator!() const _GLIBCXX_USE_NOEXCEPT |
150 | __attribute__ ((__pure__)); |
151 | operator __safe_bool() const _GLIBCXX_USE_NOEXCEPT; |
152 | #endif |
153 | |
154 | #if __cplusplus >= 201103L |
155 | explicit operator bool() const noexcept |
156 | { return _M_exception_object; } |
157 | #endif |
158 | |
159 | #if __cpp_impl_three_way_comparison >= 201907L \ |
160 | && ! defined _GLIBCXX_EH_PTR_RELOPS_COMPAT |
161 | friend bool |
162 | operator==(const exception_ptr&, const exception_ptr&) noexcept = default; |
163 | #else |
164 | friend _GLIBCXX_EH_PTR_USED bool |
165 | operator==(const exception_ptr& __x, const exception_ptr& __y) |
166 | _GLIBCXX_USE_NOEXCEPT |
167 | { return __x._M_exception_object == __y._M_exception_object; } |
168 | |
169 | friend _GLIBCXX_EH_PTR_USED bool |
170 | operator!=(const exception_ptr& __x, const exception_ptr& __y) |
171 | _GLIBCXX_USE_NOEXCEPT |
172 | { return __x._M_exception_object != __y._M_exception_object; } |
173 | #endif |
174 | |
175 | const class std::type_info* |
176 | __cxa_exception_type() const _GLIBCXX_USE_NOEXCEPT |
177 | __attribute__ ((__pure__)); |
178 | }; |
179 | |
180 | _GLIBCXX_EH_PTR_USED |
181 | inline |
182 | exception_ptr::exception_ptr() _GLIBCXX_USE_NOEXCEPT |
183 | : _M_exception_object(0) |
184 | { } |
185 | |
186 | _GLIBCXX_EH_PTR_USED |
187 | inline |
188 | exception_ptr::exception_ptr(const exception_ptr& __other) |
189 | _GLIBCXX_USE_NOEXCEPT |
190 | : _M_exception_object(__other._M_exception_object) |
191 | { |
192 | if (_M_exception_object) |
193 | _M_addref(); |
194 | } |
195 | |
196 | _GLIBCXX_EH_PTR_USED |
197 | inline |
198 | exception_ptr::~exception_ptr() _GLIBCXX_USE_NOEXCEPT |
199 | { |
200 | if (_M_exception_object) |
201 | _M_release(); |
202 | } |
203 | |
204 | _GLIBCXX_EH_PTR_USED |
205 | inline exception_ptr& |
206 | exception_ptr::operator=(const exception_ptr& __other) _GLIBCXX_USE_NOEXCEPT |
207 | { |
208 | exception_ptr(__other).swap(*this); |
209 | return *this; |
210 | } |
211 | |
212 | _GLIBCXX_EH_PTR_USED |
213 | inline void |
214 | exception_ptr::swap(exception_ptr &__other) _GLIBCXX_USE_NOEXCEPT |
215 | { |
216 | void *__tmp = _M_exception_object; |
217 | _M_exception_object = __other._M_exception_object; |
218 | __other._M_exception_object = __tmp; |
219 | } |
220 | |
221 | /// @relates exception_ptr |
222 | inline void |
223 | swap(exception_ptr& __lhs, exception_ptr& __rhs) |
224 | { __lhs.swap(__rhs); } |
225 | |
226 | /// @cond undocumented |
227 | template<typename _Ex> |
228 | inline void |
229 | __dest_thunk(void* __x) |
230 | { static_cast<_Ex*>(__x)->~_Ex(); } |
231 | /// @endcond |
232 | |
233 | } // namespace __exception_ptr |
234 | |
235 | /// Obtain an exception_ptr pointing to a copy of the supplied object. |
236 | template<typename _Ex> |
237 | exception_ptr |
238 | make_exception_ptr(_Ex __ex) _GLIBCXX_USE_NOEXCEPT |
239 | { |
240 | #if __cpp_exceptions && __cpp_rtti && !_GLIBCXX_HAVE_CDTOR_CALLABI \ |
241 | && __cplusplus >= 201103L |
242 | using _Ex2 = typename remove_reference<_Ex>::type; |
243 | void* __e = __cxxabiv1::__cxa_allocate_exception(sizeof(_Ex)); |
244 | (void) __cxxabiv1::__cxa_init_primary_exception( |
245 | __e, const_cast<std::type_info*>(&typeid(_Ex)), |
246 | __exception_ptr::__dest_thunk<_Ex2>); |
247 | try |
248 | { |
249 | ::new (__e) _Ex2(std::forward<_Ex>(__ex)); |
250 | return exception_ptr(__e); |
251 | } |
252 | catch(...) |
253 | { |
254 | __cxxabiv1::__cxa_free_exception(__e); |
255 | return current_exception(); |
256 | } |
257 | #elif __cpp_exceptions |
258 | try |
259 | { |
260 | throw __ex; |
261 | } |
262 | catch(...) |
263 | { |
264 | return current_exception(); |
265 | } |
266 | #else // no RTTI and no exceptions |
267 | return exception_ptr(); |
268 | #endif |
269 | } |
270 | |
271 | #undef _GLIBCXX_EH_PTR_USED |
272 | |
273 | /// @} group exceptions |
274 | } // namespace std |
275 | |
276 | } // extern "C++" |
277 | |
278 | #pragma GCC visibility pop |
279 | |
280 | #endif |
281 | |