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;
52
53typedef unspecified exception_ptr;
54
55exception_ptr current_exception() noexcept;
56void rethrow_exception [[noreturn]] (exception_ptr p);
57template<class E> exception_ptr make_exception_ptr(E e) noexcept;
58
59class nested_exception
60{
61public:
62    nested_exception() noexcept;
63    nested_exception(const nested_exception&) noexcept = default;
64    nested_exception& operator=(const nested_exception&) noexcept = default;
65    virtual ~nested_exception() = default;
66
67    // access functions
68    [[noreturn]] void rethrow_nested() const;
69    exception_ptr nested_ptr() const noexcept;
70};
71
72template <class T> [[noreturn]] void throw_with_nested(T&& t);
73template <class E> void rethrow_if_nested(const E& e);
74
75}  // std
76
77*/
78
79#include <__config>
80#include <cstddef>
81#include <type_traits>
82
83#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
84#pragma GCC system_header
85#endif
86
87namespace std  // purposefully not using versioning namespace
88{
89
90class _LIBCPP_EXCEPTION_ABI exception
91{
92public:
93    _LIBCPP_INLINE_VISIBILITY exception() _NOEXCEPT {}
94    virtual ~exception() _NOEXCEPT;
95    virtual const char* what() const _NOEXCEPT;
96};
97
98class _LIBCPP_EXCEPTION_ABI bad_exception
99    : public exception
100{
101public:
102    _LIBCPP_INLINE_VISIBILITY bad_exception() _NOEXCEPT {}
103    virtual ~bad_exception() _NOEXCEPT;
104    virtual const char* what() const _NOEXCEPT;
105};
106
107typedef void (*unexpected_handler)();
108_LIBCPP_FUNC_VIS unexpected_handler set_unexpected(unexpected_handler) _NOEXCEPT;
109_LIBCPP_FUNC_VIS unexpected_handler get_unexpected() _NOEXCEPT;
110_LIBCPP_NORETURN _LIBCPP_FUNC_VIS void unexpected();
111
112typedef void (*terminate_handler)();
113_LIBCPP_FUNC_VIS terminate_handler set_terminate(terminate_handler) _NOEXCEPT;
114_LIBCPP_FUNC_VIS terminate_handler get_terminate() _NOEXCEPT;
115#if __cplusplus >= 201103L
116_LIBCPP_NORETURN _LIBCPP_FUNC_VIS void terminate() _NOEXCEPT;
117#else
118_LIBCPP_NORETURN _LIBCPP_FUNC_VIS void terminate();
119#endif
120
121_LIBCPP_FUNC_VIS bool uncaught_exception() _NOEXCEPT;
122
123class _LIBCPP_TYPE_VIS exception_ptr;
124
125_LIBCPP_FUNC_VIS exception_ptr current_exception() _NOEXCEPT;
126_LIBCPP_NORETURN _LIBCPP_FUNC_VIS void rethrow_exception(exception_ptr);
127
128class _LIBCPP_TYPE_VIS exception_ptr
129{
130    void* __ptr_;
131public:
132    _LIBCPP_INLINE_VISIBILITY exception_ptr() _NOEXCEPT : __ptr_() {}
133    _LIBCPP_INLINE_VISIBILITY exception_ptr(nullptr_t) _NOEXCEPT : __ptr_() {}
134    exception_ptr(const exception_ptr&) _NOEXCEPT;
135    exception_ptr& operator=(const exception_ptr&) _NOEXCEPT;
136    ~exception_ptr() _NOEXCEPT;
137
138    _LIBCPP_INLINE_VISIBILITY
139    _LIBCPP_EXPLICIT
140        operator bool() const _NOEXCEPT {return __ptr_ != nullptr;}
141
142    friend _LIBCPP_INLINE_VISIBILITY
143    bool operator==(const exception_ptr& __x, const exception_ptr& __y) _NOEXCEPT
144        {return __x.__ptr_ == __y.__ptr_;}
145    friend _LIBCPP_INLINE_VISIBILITY
146    bool operator!=(const exception_ptr& __x, const exception_ptr& __y) _NOEXCEPT
147        {return !(__x == __y);}
148
149    friend _LIBCPP_FUNC_VIS exception_ptr current_exception() _NOEXCEPT;
150    friend _LIBCPP_FUNC_VIS void rethrow_exception(exception_ptr);
151};
152
153template<class _Ep>
154exception_ptr
155make_exception_ptr(_Ep __e) _NOEXCEPT
156{
157#ifndef _LIBCPP_NO_EXCEPTIONS
158    try
159    {
160        throw __e;
161    }
162    catch (...)
163    {
164        return current_exception();
165    }
166#endif  // _LIBCPP_NO_EXCEPTIONS
167}
168
169// nested_exception
170
171class _LIBCPP_EXCEPTION_ABI nested_exception
172{
173    exception_ptr __ptr_;
174public:
175    nested_exception() _NOEXCEPT;
176//     nested_exception(const nested_exception&) noexcept = default;
177//     nested_exception& operator=(const nested_exception&) noexcept = default;
178    virtual ~nested_exception() _NOEXCEPT;
179
180    // access functions
181    _LIBCPP_NORETURN void rethrow_nested() const;
182    _LIBCPP_INLINE_VISIBILITY exception_ptr nested_ptr() const _NOEXCEPT {return __ptr_;}
183};
184
185template <class _Tp>
186struct __nested
187    : public _Tp,
188      public nested_exception
189{
190    _LIBCPP_INLINE_VISIBILITY explicit __nested(const _Tp& __t) : _Tp(__t) {}
191};
192
193template <class _Tp>
194_LIBCPP_NORETURN
195void
196#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
197throw_with_nested(_Tp&& __t, typename enable_if<
198                  is_class<typename remove_reference<_Tp>::type>::value &&
199                  !is_base_of<nested_exception, typename remove_reference<_Tp>::type>::value
200                                    >::type* = 0)
201#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
202throw_with_nested (_Tp& __t, typename enable_if<
203                  is_class<_Tp>::value && !is_base_of<nested_exception, _Tp>::value
204                                    >::type* = 0)
205#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
206{
207#ifndef _LIBCPP_NO_EXCEPTIONS
208    throw __nested<typename remove_reference<_Tp>::type>(_VSTD::forward<_Tp>(__t));
209#endif
210}
211
212template <class _Tp>
213_LIBCPP_NORETURN
214void
215#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
216throw_with_nested(_Tp&& __t, typename enable_if<
217                  !is_class<typename remove_reference<_Tp>::type>::value ||
218                  is_base_of<nested_exception, 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*>(&__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