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_LIBCPP_NORETURN _LIBCPP_FUNC_VIS void terminate() _NOEXCEPT;
116
117_LIBCPP_FUNC_VIS bool uncaught_exception() _NOEXCEPT;
118
119class _LIBCPP_TYPE_VIS exception_ptr;
120
121_LIBCPP_FUNC_VIS exception_ptr current_exception() _NOEXCEPT;
122_LIBCPP_NORETURN _LIBCPP_FUNC_VIS void rethrow_exception(exception_ptr);
123
124class _LIBCPP_TYPE_VIS exception_ptr
125{
126    void* __ptr_;
127public:
128    _LIBCPP_INLINE_VISIBILITY exception_ptr() _NOEXCEPT : __ptr_() {}
129    _LIBCPP_INLINE_VISIBILITY exception_ptr(nullptr_t) _NOEXCEPT : __ptr_() {}
130    exception_ptr(const exception_ptr&) _NOEXCEPT;
131    exception_ptr& operator=(const exception_ptr&) _NOEXCEPT;
132    ~exception_ptr() _NOEXCEPT;
133
134    _LIBCPP_INLINE_VISIBILITY
135    _LIBCPP_EXPLICIT
136        operator bool() const _NOEXCEPT {return __ptr_ != nullptr;}
137
138    friend _LIBCPP_INLINE_VISIBILITY
139    bool operator==(const exception_ptr& __x, const exception_ptr& __y) _NOEXCEPT
140        {return __x.__ptr_ == __y.__ptr_;}
141    friend _LIBCPP_INLINE_VISIBILITY
142    bool operator!=(const exception_ptr& __x, const exception_ptr& __y) _NOEXCEPT
143        {return !(__x == __y);}
144
145    friend _LIBCPP_FUNC_VIS exception_ptr current_exception() _NOEXCEPT;
146    friend _LIBCPP_FUNC_VIS void rethrow_exception(exception_ptr);
147};
148
149template<class _Ep>
150exception_ptr
151make_exception_ptr(_Ep __e) _NOEXCEPT
152{
153#ifndef _LIBCPP_NO_EXCEPTIONS
154    try
155    {
156        throw __e;
157    }
158    catch (...)
159    {
160        return current_exception();
161    }
162#endif  // _LIBCPP_NO_EXCEPTIONS
163}
164
165// nested_exception
166
167class _LIBCPP_EXCEPTION_ABI nested_exception
168{
169    exception_ptr __ptr_;
170public:
171    nested_exception() _NOEXCEPT;
172//     nested_exception(const nested_exception&) noexcept = default;
173//     nested_exception& operator=(const nested_exception&) noexcept = default;
174    virtual ~nested_exception() _NOEXCEPT;
175
176    // access functions
177    _LIBCPP_NORETURN void rethrow_nested() const;
178    _LIBCPP_INLINE_VISIBILITY exception_ptr nested_ptr() const _NOEXCEPT {return __ptr_;}
179};
180
181template <class _Tp>
182struct __nested
183    : public _Tp,
184      public nested_exception
185{
186    _LIBCPP_INLINE_VISIBILITY explicit __nested(const _Tp& __t) : _Tp(__t) {}
187};
188
189template <class _Tp>
190_LIBCPP_NORETURN
191void
192#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
193throw_with_nested(_Tp&& __t, typename enable_if<
194                  is_class<typename remove_reference<_Tp>::type>::value &&
195                  !is_base_of<nested_exception, typename remove_reference<_Tp>::type>::value
196                                    >::type* = 0)
197#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
198throw_with_nested (_Tp& __t, typename enable_if<
199                  is_class<_Tp>::value && !is_base_of<nested_exception, _Tp>::value
200                                    >::type* = 0)
201#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
202{
203#ifndef _LIBCPP_NO_EXCEPTIONS
204    throw __nested<typename remove_reference<_Tp>::type>(_VSTD::forward<_Tp>(__t));
205#endif
206}
207
208template <class _Tp>
209_LIBCPP_NORETURN
210void
211#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
212throw_with_nested(_Tp&& __t, typename enable_if<
213                  !is_class<typename remove_reference<_Tp>::type>::value ||
214                  is_base_of<nested_exception, typename remove_reference<_Tp>::type>::value
215                                    >::type* = 0)
216#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
217throw_with_nested (_Tp& __t, typename enable_if<
218                  !is_class<_Tp>::value || is_base_of<nested_exception, _Tp>::value
219                                    >::type* = 0)
220#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
221{
222#ifndef _LIBCPP_NO_EXCEPTIONS
223    throw _VSTD::forward<_Tp>(__t);
224#endif
225}
226
227template <class _Ep>
228inline _LIBCPP_INLINE_VISIBILITY
229void
230rethrow_if_nested(const _Ep& __e, typename enable_if<
231                                   is_polymorphic<_Ep>::value
232                                                   >::type* = 0)
233{
234    const nested_exception* __nep = dynamic_cast<const nested_exception*>(&__e);
235    if (__nep)
236        __nep->rethrow_nested();
237}
238
239template <class _Ep>
240inline _LIBCPP_INLINE_VISIBILITY
241void
242rethrow_if_nested(const _Ep&, typename enable_if<
243                                   !is_polymorphic<_Ep>::value
244                                                   >::type* = 0)
245{
246}
247
248}  // std
249
250#endif  // _LIBCPP_EXCEPTION
251