1 // Exception Handling support header (exception_ptr class) for -*- C++ -*-
2 
3 // Copyright (C) 2008-2015 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   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      */
75     class exception_ptr
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;
87       friend void std::rethrow_exception(exception_ptr);
88 
89     public:
90       exception_ptr() _GLIBCXX_USE_NOEXCEPT;
91 
92       exception_ptr(const exception_ptr&) _GLIBCXX_USE_NOEXCEPT;
93 
94 #if __cplusplus >= 201103L
exception_ptr(nullptr_t)95       exception_ptr(nullptr_t) noexcept
96       : _M_exception_object(0)
97       { }
98 
exception_ptr(exception_ptr && __o)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 (__cplusplus < 201103L) || 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 #if __cplusplus >= 201103L
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 #if __cplusplus >= 201103L
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
swap(exception_ptr & __lhs,exception_ptr & __rhs)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
make_exception_ptr(_Ex __ex)169     make_exception_ptr(_Ex __ex) _GLIBCXX_USE_NOEXCEPT
170     {
171 #if __cpp_exceptions
172       try
173 	{
174 	  throw __ex;
175 	}
176       catch(...)
177 	{
178 	  return current_exception();
179 	}
180 #else
181       return exception_ptr();
182 #endif
183     }
184 
185   // _GLIBCXX_RESOLVE_LIB_DEFECTS
186   // 1130. copy_exception name misleading
187   /// Obtain an exception_ptr pointing to a copy of the supplied object.
188   /// This function is deprecated, use std::make_exception_ptr instead.
189   template<typename _Ex>
190     exception_ptr
191     copy_exception(_Ex __ex) _GLIBCXX_USE_NOEXCEPT _GLIBCXX_DEPRECATED;
192 
193   template<typename _Ex>
194     exception_ptr
copy_exception(_Ex __ex)195     copy_exception(_Ex __ex) _GLIBCXX_USE_NOEXCEPT
196     { return std::make_exception_ptr<_Ex>(__ex); }
197 
198   // @} group exceptions
199 } // namespace std
200 
201 } // extern "C++"
202 
203 #pragma GCC visibility pop
204 
205 #endif
206