1// -*- C++ -*-
2//===-------------------------- exception ---------------------------------===//
3//
4//                     The LLVM Compiler Infrastructure
5//
6// This file is dual licensed under the MIT and the University of Illinois Open
7// Source Licenses. See LICENSE.TXT for details.
8//
9//===----------------------------------------------------------------------===//
10
11#ifndef _LIBCPP_EXCEPTION
12#define _LIBCPP_EXCEPTION
13
14/*
15    exception synopsis
16
17namespace std
18{
19
20class exception
21{
22public:
23    exception() noexcept;
24    exception(const exception&) noexcept;
25    exception& operator=(const exception&) noexcept;
26    virtual ~exception() noexcept;
27    virtual const char* what() const noexcept;
28};
29
30class bad_exception
31    : public exception
32{
33public:
34    bad_exception() noexcept;
35    bad_exception(const bad_exception&) noexcept;
36    bad_exception& operator=(const bad_exception&) noexcept;
37    virtual ~bad_exception() noexcept;
38    virtual const char* what() const noexcept;
39};
40
41typedef void (*unexpected_handler)();
42unexpected_handler set_unexpected(unexpected_handler  f ) noexcept;
43unexpected_handler get_unexpected() noexcept;
44[[noreturn]] void unexpected();
45
46typedef void (*terminate_handler)();
47terminate_handler set_terminate(terminate_handler  f ) noexcept;
48terminate_handler get_terminate() noexcept;
49[[noreturn]] void terminate() noexcept;
50
51bool uncaught_exception()  noexcept;
52int  uncaught_exceptions() noexcept;  // C++17
53
54typedef unspecified exception_ptr;
55
56exception_ptr current_exception() noexcept;
57void rethrow_exception [[noreturn]] (exception_ptr p);
58template<class E> exception_ptr make_exception_ptr(E e) noexcept;
59
60class nested_exception
61{
62public:
63    nested_exception() noexcept;
64    nested_exception(const nested_exception&) noexcept = default;
65    nested_exception& operator=(const nested_exception&) noexcept = default;
66    virtual ~nested_exception() = default;
67
68    // access functions
69    [[noreturn]] void rethrow_nested() const;
70    exception_ptr nested_ptr() const noexcept;
71};
72
73template <class T> [[noreturn]] void throw_with_nested(T&& t);
74template <class E> void rethrow_if_nested(const E& e);
75
76}  // std
77
78*/
79
80#include <__config>
81#include <cstddef>
82#include <type_traits>
83
84#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
85#pragma GCC system_header
86#endif
87
88namespace std  // purposefully not using versioning namespace
89{
90
91class _LIBCPP_EXCEPTION_ABI exception
92{
93public:
94    _LIBCPP_INLINE_VISIBILITY exception() _NOEXCEPT {}
95    virtual ~exception() _NOEXCEPT;
96    virtual const char* what() const _NOEXCEPT;
97};
98
99class _LIBCPP_EXCEPTION_ABI bad_exception
100    : public exception
101{
102public:
103    _LIBCPP_INLINE_VISIBILITY bad_exception() _NOEXCEPT {}
104    virtual ~bad_exception() _NOEXCEPT;
105    virtual const char* what() const _NOEXCEPT;
106};
107
108typedef void (*unexpected_handler)();
109_LIBCPP_FUNC_VIS unexpected_handler set_unexpected(unexpected_handler) _NOEXCEPT;
110_LIBCPP_FUNC_VIS unexpected_handler get_unexpected() _NOEXCEPT;
111_LIBCPP_NORETURN _LIBCPP_FUNC_VIS void unexpected();
112
113typedef void (*terminate_handler)();
114_LIBCPP_FUNC_VIS terminate_handler set_terminate(terminate_handler) _NOEXCEPT;
115_LIBCPP_FUNC_VIS terminate_handler get_terminate() _NOEXCEPT;
116_LIBCPP_NORETURN _LIBCPP_FUNC_VIS void terminate() _NOEXCEPT;
117
118_LIBCPP_FUNC_VIS bool uncaught_exception() _NOEXCEPT;
119_LIBCPP_FUNC_VIS int uncaught_exceptions() _NOEXCEPT;
120
121class _LIBCPP_TYPE_VIS exception_ptr;
122
123_LIBCPP_FUNC_VIS exception_ptr current_exception() _NOEXCEPT;
124_LIBCPP_NORETURN _LIBCPP_FUNC_VIS void rethrow_exception(exception_ptr);
125
126class _LIBCPP_TYPE_VIS exception_ptr
127{
128    void* __ptr_;
129public:
130    _LIBCPP_INLINE_VISIBILITY exception_ptr() _NOEXCEPT : __ptr_() {}
131    _LIBCPP_INLINE_VISIBILITY exception_ptr(nullptr_t) _NOEXCEPT : __ptr_() {}
132    exception_ptr(const exception_ptr&) _NOEXCEPT;
133    exception_ptr& operator=(const exception_ptr&) _NOEXCEPT;
134    ~exception_ptr() _NOEXCEPT;
135
136    _LIBCPP_INLINE_VISIBILITY
137    _LIBCPP_EXPLICIT
138        operator bool() const _NOEXCEPT {return __ptr_ != nullptr;}
139
140    friend _LIBCPP_INLINE_VISIBILITY
141    bool operator==(const exception_ptr& __x, const exception_ptr& __y) _NOEXCEPT
142        {return __x.__ptr_ == __y.__ptr_;}
143    friend _LIBCPP_INLINE_VISIBILITY
144    bool operator!=(const exception_ptr& __x, const exception_ptr& __y) _NOEXCEPT
145        {return !(__x == __y);}
146
147    friend _LIBCPP_FUNC_VIS exception_ptr current_exception() _NOEXCEPT;
148    friend _LIBCPP_FUNC_VIS void rethrow_exception(exception_ptr);
149};
150
151template<class _Ep>
152exception_ptr
153make_exception_ptr(_Ep __e) _NOEXCEPT
154{
155#ifndef _LIBCPP_NO_EXCEPTIONS
156    try
157    {
158        throw __e;
159    }
160    catch (...)
161    {
162        return current_exception();
163    }
164#endif  // _LIBCPP_NO_EXCEPTIONS
165}
166
167// nested_exception
168
169class _LIBCPP_EXCEPTION_ABI nested_exception
170{
171    exception_ptr __ptr_;
172public:
173    nested_exception() _NOEXCEPT;
174//     nested_exception(const nested_exception&) noexcept = default;
175//     nested_exception& operator=(const nested_exception&) noexcept = default;
176    virtual ~nested_exception() _NOEXCEPT;
177
178    // access functions
179    _LIBCPP_NORETURN void rethrow_nested() const;
180    _LIBCPP_INLINE_VISIBILITY exception_ptr nested_ptr() const _NOEXCEPT {return __ptr_;}
181};
182
183template <class _Tp>
184struct __nested
185    : public _Tp,
186      public nested_exception
187{
188    _LIBCPP_INLINE_VISIBILITY explicit __nested(const _Tp& __t) : _Tp(__t) {}
189};
190
191template <class _Tp>
192_LIBCPP_NORETURN
193void
194#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
195throw_with_nested(_Tp&& __t, typename enable_if<
196                  is_class<typename remove_reference<_Tp>::type>::value &&
197                  !is_base_of<nested_exception, typename remove_reference<_Tp>::type>::value
198                  && !__libcpp_is_final<typename remove_reference<_Tp>::type>::value
199                                    >::type* = 0)
200#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
201throw_with_nested (_Tp& __t, typename enable_if<
202                  is_class<_Tp>::value && !is_base_of<nested_exception, _Tp>::value
203                                    >::type* = 0)
204#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
205{
206#ifndef _LIBCPP_NO_EXCEPTIONS
207    throw __nested<typename remove_reference<_Tp>::type>(_VSTD::forward<_Tp>(__t));
208#endif
209}
210
211template <class _Tp>
212_LIBCPP_NORETURN
213void
214#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
215throw_with_nested(_Tp&& __t, typename enable_if<
216                  !is_class<typename remove_reference<_Tp>::type>::value ||
217                  is_base_of<nested_exception, typename remove_reference<_Tp>::type>::value
218                  || __libcpp_is_final<typename remove_reference<_Tp>::type>::value
219                                    >::type* = 0)
220#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
221throw_with_nested (_Tp& __t, typename enable_if<
222                  !is_class<_Tp>::value || is_base_of<nested_exception, _Tp>::value
223                                    >::type* = 0)
224#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
225{
226#ifndef _LIBCPP_NO_EXCEPTIONS
227    throw _VSTD::forward<_Tp>(__t);
228#endif
229}
230
231template <class _Ep>
232inline _LIBCPP_INLINE_VISIBILITY
233void
234rethrow_if_nested(const _Ep& __e, typename enable_if<
235                                   is_polymorphic<_Ep>::value
236                                                   >::type* = 0)
237{
238    const nested_exception* __nep = dynamic_cast<const nested_exception*>(_VSTD::addressof(__e));
239    if (__nep)
240        __nep->rethrow_nested();
241}
242
243template <class _Ep>
244inline _LIBCPP_INLINE_VISIBILITY
245void
246rethrow_if_nested(const _Ep&, typename enable_if<
247                                   !is_polymorphic<_Ep>::value
248                                                   >::type* = 0)
249{
250}
251
252}  // std
253
254#endif  // _LIBCPP_EXCEPTION
255