1// Exception Handling support header (exception_ptr class) for -*- C++ -*- 
2 
3// Copyright (C) 2008-2019 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